HK1142698A - System and method for including protective voltage switchable dielectric material in the design or simulation of substrate devices - Google Patents

Description

System and method for incorporating protective voltage switchable dielectric material in design or simulation of substrate devices

RELATED APPLICATIONS

The present application claims priority from U.S. provisional patent application No. 60/943,556 entitled "system and METHOD for programming ELECTRONIC DEVICES USING voltage switchable dielectric material (SYSTEM AND METHOD for programming ELECTRONIC DEVICES USING voltage switchable dielectric material DIELECTRIC MATERIAL)" filed on 13.6.2007; the foregoing prior application is incorporated by reference herein in its entirety.

Technical Field

Embodiments described in this specification relate to the design or simulation of electrical devices. In particular, embodiments described in this specification relate to systems and methods of incorporating protective voltage switchable dielectric materials in the design or simulation of substrates or other electrical devices.

Background

Electronic Design Automation (EDA) software and similar programming tools (programmctol) enable the design and/or simulation of components on an electronic device. Examples of such devices include Printed Circuit Boards (PCBs) and integrated circuit or semiconductor packages. Typical functions provided by such tools include principle input, behavioral modeling, circuit simulation, full custom layout, physical verification, extraction, and reverse annotation. It is used primarily for analog, mixed signal, radio frequency communications components ("RF"), and standard cell or memory designs. EDA software is also used to perform functions such as: (i) manufacturing integrated circuit devices, including testing and placement of wiring for such devices; (ii) and (5) verifying the simulation function.

Drawings

Embodiments described in this specification make reference to any one or more of the following drawings.

Figure 1 is a simplified diagram of a system for designing an integrated circuit device using voltage switchable dielectric material (VSD material), according to one embodiment of the present invention.

Figures 2A and 2B each illustrate a design or simulation method of applying VSD material to a target device, according to one embodiment of the present invention.

Figure 3A is a simplified block diagram illustrating a manner to incorporate or integrate VSD material into a substrate device in accordance with one or more embodiments of the present invention.

Figure 3B illustrates a data structure maintained by the VSD material library in one embodiment of the present invention.

Figure 4 illustrates a method of how to determine VSD material implementation layouts in one embodiment of the invention.

Figure 5A is a diagrammatic cross-sectional view depicting a coating of VSD material at a given point on a substrate 500 during a design or simulation phase in accordance with an embodiment of the present invention.

FIG. 5B shows a variation in one embodiment of the present invention in which the protective electrical path includes an anti-pad.

Figures 6A and 6B are top views of a substrate illustrating area considerations implemented for VSD material according to one embodiment of the present invention.

Figure 7 illustrates another spatial implementation detail when using shapes as VSD material integrated on a substrate or other device in a design or simulation phase, according to one embodiment of the present invention.

FIG. 8 illustrates an embodiment of the invention in which implementation details include determining some or all of the following locations: the VSD formations will provide locations for transient connections to the protective electrical paths.

Figure 9 illustrates a design or simulation for applying VSD material into a multilayer device in one or more embodiments of the present invention.

FIG. 10 shows a design or simulation of a backplane of a display device in one embodiment of the invention.

Fig. 11 illustrates the use of an optimization module 1100 in connection with the system as shown in fig. 3A and described with respect to the embodiment of fig. 3A in one embodiment of the invention.

FIG. 12 illustrates a system for use with one or more embodiments.

FIG. 13 is a graph illustrating a relationship between threshold voltage levels (Y-axis) and gap values (X-axis) according to one embodiment of the invention.

Figure 14 is a graph illustrating the off-state resistance of a first type of VSD material, as may be experimentally determined from the gap separation of increasing size, in accordance with an embodiment of the present invention.

Fig. 15 is a graph showing the off-state resistance of a first type of VSD material as it may be determined experimentally for different gap sizes subject to varying magnitudes of operating voltage.

Detailed Description

Embodiments described in this specification provide for the programming or simulation of a substrate carrying electrical elements to integrate voltage switchable dielectric ("VSD") material as a protective component. In particular, VSD material can be incorporated into the design of substrate devices to provide protection against transient electrical conditions, such as electrostatic discharge (ESD) conditions. In this regard, the embodiments described in this specification can be used as part of a computer system or programmed method for designing and/or simulating substrate devices. For example, one or more embodiments may be implemented as part of an Electronic Design Automation (EDA) program that is typically used to design and manufacture electronic devices and systems including Printed Circuit Boards (PCBs), display devices and backplanes, integrated circuit devices, semiconductor components and devices, and the like.

Generally, VSD material refers to material that exhibits the following characteristics: (i) which in the absence of a threshold voltage or threshold energy, behaves as a dielectric, which threshold voltage or threshold energy is very large for the application or environment in which the VSD material is provided, (ii) which becomes conductive when a voltage exceeding the threshold voltage level is applied. The threshold voltage level is different for different kinds of VSD material, but it typically exceeds the operating voltage of the environment surrounding the VSD material. Because of this switching characteristic, VSD material can be arranged to form some transient electrical connections that can protect against transient electrical events, most severe electrostatic discharge (ESD).

The embodiments described in this specification recognize that ESD events typically range from hundreds of volts to tens of thousands of volts with peak amps ranging from a few amps to tens of amps. Because an ESD event lasts only a few picoseconds to a few nanoseconds, an ESD event is both a high wattage event (the product of voltage and current) and a low energy event (because energy is the product of voltage, current, and duration). When VSD material is triggered to an "on" state by a high voltage pulse, current begins to flow through the thickness of the material.

Some devices or structures are capable of handling ESD events by incorporating a layer of VSD material within or over the thickness of the device. Conventional methods present the deposition of VSD material to occupy a layer within the thickness of the printed circuit board. Such a layer of VSD material may be connected to various wires or current carrying elements through vias as conductive elements. U.S. patent No. 6,797,145 (incorporated herein by reference in its entirety) describes a technique for implementing VSD material within a current-carrying structure in such a manner that: such that the VSD material can be used to plate on the conductive elements. Such electroplating techniques also enable the device to have some ability to handle ESD events.

There are a number of examples of VSD material, including those described in U.S. patent application No. 11/881,896 and U.S. patent application No. 11/829,951, both of which are each incorporated by reference in their entirety. VSD material also includes products manufactured by surgcorroposition, owned by LITTLEFUSE inc. VSD material can also be characterized as material having a non-linear resistance.

In addition, according to one or more embodiments, the VSD material exhibits the electrical characteristics described above while also having characteristics of uniform composition. In such embodiments, the VSD material includes a matrix (matrix) or binder containing a substantially uniform distribution of conductive and/or semiconductive material.

As used herein, the "design phase" or "simulation phase" of a substrate or other device indicates a representation of data for such substrate and device.

In the description and examples provided, the characteristic voltage levels and threshold values are assumed values determined by experimental conditions that are influenced by a number of variables. In this regard, the values described in this application should not be construed as physically distinct objects, as would be the case for the density characteristics.

Embodiments described in this specification provide systems or methods for designing or simulating substrate devices. In particular, the embodiments described in this specification reside in, or are otherwise implemented in, the design or simulation phase of a substrate device. During the design or simulation phase, no real substrate devices are required for implementing one or more of the embodiments described herein. Embodiments described in this specification, in the design or simulation phase, can use data representative of the substrate device, VSD material, the components or elements of the substrate device, and the operating performance of the components/elements/VSD material under different conditions.

In one embodiment, a substrate device is designed by identifying one or more criteria for handling transient electrical events on the substrate device. The one or more criteria are based at least in part on input provided by a designer. Based on the one or more criteria, one or more characteristics for integrating the VSD material as a layer within or over at least a portion of the substrate device may be determined. The layer of VSD material may be arranged to protect one or more components of the substrate from transient electrical conditions.

In another embodiment, a system for fabricating a substrate device (rather than a system for design or simulation other than fabrication) is provided. The system may include an interface, memory resources, and processing resources. The interface receives one or more criteria from a designer. The memory resources store information about the substrate and/or various VSD materials. The processing resource may be configured to use the input and the information stored in the memory to: (i) identifying one or more criteria for handling transient electrical events on the substrate device; and (ii) determining, based on the one or more criteria, one or more characteristics for integrating the VSD material as a layer within or over at least a portion of the substrate device. The layer of VSD material is arranged to protect one or more components of the substrate from transient electrical conditions.

Still further, one embodiment provides for the design of a substrate device during a design or simulation phase. In response to interaction with the designer, selecting a plurality of the following locations on the substrate device: the location of the protective electrical path will be provided upon the occurrence of a transient electrical event. At each of the plurality of locations, a dimension of the layer of VSD material at the selected location is determined. The dimensions of the layer of VSD material are selected based at least in part on a threshold measure of energy (threshold measure of energy) to switch the layer of VSD material from a dielectric state to a conductive state. The VSD material interconnects one or more components to the protective electrical path when the VSD material is in a conductive state.

Another embodiment provides for determining the spacing of one or more electrical components to be connectable on a substrate device. In one embodiment, one or more electrical tolerances (electrical tolerances) of electrical components that are to be protected from a transient electrical event by a protective electrical pathway are identified. A layer of VSD material can be identified that will provide a gap separation between the electrical components and the protective electrical path. The VSD material is capable of switching from a dielectric state to a conductive state when a measure of energy is applied that exceeds a threshold level, which may be dependent at least in part on a size of the VSD material. In one embodiment, the gap separation is sized or dimensioned such that a threshold level of an energy metric at which switching of the VSD material occurs is less than the one or more tolerances of the electrical components.

In accordance with another embodiment, a system for implementing a design or simulation of at least a portion of a substrate device is provided. The system includes a data store and a configuration module. The data memory stores data relating to a first entry (entry) representing a first type of Voltage Switchable Dielectric (VSD) material having one or more characteristics. The one or more characteristics of the first VSD material may include a value representing a characteristic voltage per specified length. The characteristic voltage per specified length corresponds to a known or specified voltage level value that causes a first VSD material to switch from a dielectric state to a conductive state when applied to the first VSD material for a specified length. The configuration module determines, through one or more interactions with a system designer, (i) one or more dimensional parameters based on spatial constraints of a substrate or a portion of a substrate; and (ii) an allowable voltage level of one or more electrical components to be protected in a portion of the substrate device. The configuration module can be configured to determine a gap separation that (i) will be provided by the first layer of VSD material on at least a portion of the substrate, and (ii) will separate at least one electrical component from the protective electrical path on the substrate for the transient event. In addition, the configuration module determines the gap separation based at least in part on determining (i) a threshold voltage level suitable for switching the first VSD material into a conductive state, and (ii) the characteristic voltage per specified length and a magnitude of the gap separation. The configuration module also ensures that the threshold voltage level is less than an allowable voltage level of the one or more electrical components.

One embodiment also includes an optimization system for implementing a design or simulation of at least a portion of a substrate device. The system includes a data store, a configuration module, and an optimization component. The data store holds information about a plurality of VSD materials. The information can include a characteristic voltage per specified length of each of the one or more VSD materials. The characteristic voltage per specified length corresponds to a voltage level value suitable for triggering switching of a particular type of VSD material from a dielectric state to a conductive state when applied to that type of VSD material for a specified length. The configuration module is configured to determine, by one or more interactions with a system designer, (i) one or more dimensional parameters based on spatial constraints of the substrate or a portion of the substrate; and (ii) a voltage level allowable for one or more electrical elements to be protected in a portion of the substrate device. The configuration module is configured to determine, for any of the VSD materials in the plurality of VSD materials, a gap separation that (i) will be occupied by this type of VSD material on at least a portion of the substrate, and (ii) will separate at least one electrical element from a protective electrical path for a transient event. The configuration module is further configured to determine, for any of the plurality of VSD material, a gap separation required to use a layer of the VSD material to separate the at least one electrical element from the protective electrical path. The optimization component is configured to make at least one of the following selections: (i) selecting a selected class of VSD material from the plurality of VSD materials; or (ii) selecting a size of gap separation for the selected species of VSD material. The optimization component is further configured to select based on one or more optimization criteria.

Still further, one or more embodiments include a system for optimizing the application of VSD material to a substrate device. The system includes an interface, a memory resource, and a processing resource. The interface may be configured to receive one or more criteria from a designer of the substrate device. The memory resource stores information of at least one of the substrate or the plurality of VSD materials. The processing resource is coupled to the interface and memory resources and is configured to use the input and information stored in the memory to: (i) identifying one or more criteria for handling transient electrical events on the substrate device; and (ii) determining, based on the one or more criteria, one or more characteristics for integrating the VSD material as a layer within or over at least a portion of the substrate device. The layer of VSD material is arranged to protect one or more components of the substrate from the transient electrical condition. One or more optimization criteria are identified for integrating VSD material onto a portion of the substrate or the entire substrate.

Further, one embodiment includes a data system. The data system may be used in applications including implementing a design or simulation of a substrate device. The data system includes a data storage accessible to a configuration module for integrating VSD material into the substrate device. The data store maintains a plurality of entries, each entry (i) identifying a type of VSD material, and (ii) including data identifying one or more electrical characteristics on such VSD material suitable for integrating such VSD material into a substrate device. The one or more electrical characteristics of such VSD material may include any one or more of the following: (1) a characteristic measure of energy suitable for causing such VSD material to switch from a dielectric state to a conductive state when applied to such specified measure of VSD material; (ii) leakage currents associated with such VSD materials; or (iii) the off-state resistance associated with such VSD material.

As provided below, numerous other embodiments are described. Additional embodiments may also combine features of multiple different embodiments, even if such a combination is not explicitly noted in the present application.

The embodiments described in this specification provide that methods, techniques and actions performed by a computing device are performed programmatically, or as computer-based implementations. Programmatic means through the use of code, or computer-executable instructions. The steps that are performed programmatically may or may not be automatic.

One or more embodiments described in this specification can be implemented using modules or components. A module or component may include a program, a subroutine, a part of a program, or a software component or hardware component capable of performing one or more of the described tasks or functions. As used herein, a module or component may exist on a hardware component independently of other modules/components, or a module or component may be a common element or process of other modules, programs, or machines.

Furthermore, one or more embodiments described in this specification can be implemented using instructions executable by one or more processors. The instructions may be embodied on a computer-readable medium. The machine illustrated in the figures that follow provide examples of processing resources and computer-readable media on which instructions for implementing embodiments of the present invention may be written and/or executed. In particular, many of the machines shown with embodiments of the invention include a processor and various forms of memory for storing data and instructions. Embodiments of the computer-readable medium include a persistent memory storage device, such as a hard drive on a personal computer or server. Other embodiments of computer storage media include portable storage devices such as CD or DVD machines, flash memory (such as that found in many cell phones and Personal Digital Assistants (PDAs)), and magnetic memory. Computers, terminals, network-enabled devices (e.g., mobile devices such as cell phones) are all embodiments of machines and devices that use processors, memory, and instructions stored in computer-readable media.

Application of VSD material to substrate devices

Figure 1 is a simplified diagram of a system for designing an integrated circuit device using voltage switchable dielectric material (VSD material), according to one embodiment of the present invention. The system 100 for designing an electronic device may be used in the manufacture of new electronic devices, such as integrated circuit devices or printed circuit boards, incorporating manufacturing or production methods, and/or in the simulation or testing operations of the device layout or configuration. Examples of devices that may be produced and/or simulated by the embodiments described herein include printed circuit boards, wafers and chips, semiconductor package substrates, display devices and backplanes, and other circuit devices or hardware (collectively "target devices"). In addition to the substrate of the internal device, etc., embodiments may also be used to design various electrical and protective properties on more integrated and finished devices, such as electronic hand-held devices (such as cell phones or electronic paper display devices). For example, one or more embodiments enable the design of a housing for a cell phone or a device carrying a trace element and/or integrated logic circuit. Thus, the term "device" is intended to include a substrate device comprising internal components that carry or provide hardware and logic circuitry; and fully or partially formed devices including designed electrical components in the active or near active phase. For example, the term device may include a product in which electrical elements and/or logic circuitry are integrated into a completed housing or structure.

Referring to the embodiment of FIG. 1, system 100 includes a design module 110 for creating a design layout for a target device 122. The designer 102 interacts with the design module 110 and operates the design module 110 to formulate or configure layout and/or design information for the target device 122. In one implementation, the design module 110 corresponds to a software design application that may be operated by a designer using a computer terminal. For example, the software design application may correspond to an Electronic Design Automation (EDA) package such as manufactured by Cadence System designs, Inc. or Mentor Graphics.

The designer 102 may apply various information in the design module 110 including circuit arrangements, components, design parameters, and/or performance criteria. These specifications enable the target device 122 to be designed, simulated, and optionally fabricated in the design medium 120. Accordingly, the design medium 120 may be virtual or simulated, or alternatively actual or real. The simulated or virtual design medium may correspond to a computer execution environment that enables, for example, simulation or testing of target device 122. As with the embodiments described for design or simulation, the device 122 may include a data representation of the actual physical device. An actual design medium may include the use of manufacturing, production, and/or other implementation equipment and processes to implement the design produced by module 110 on the target device 122 production.

In one embodiment, design module 110 includes logic 114 for determining and automatically applying VSD material to target device 122. The logic 114 may be responsive to design and/or performance parameters 104 specified by the designer 102 and/or obtained from other sources. The application of the VSD material may include an initial determination as to whether VSD material is to be used. In one embodiment, an initial determination is made as to whether a circuit board of the target device 122 or essential elements of the target device are to include VSD material. For example, a user may simply choose to design the substrate to have a layer of VSD material embedded within it. If VSD material is to be included, then various prompts and/or design ("VSD material configuration 116") instructions may be used by VSD material application logic 114 to determine how to apply the VSD material to target device 122.

In one embodiment, design module 110 may provide an initial prompt 111 or interface that enables designer 102 to select (either explicitly or implicitly) to include the VSD material in target device 122. The module 110 may also provide one or more subsequent hints 111 or interfaces for determining the specific details of the devices in the design, including the tolerance levels of the individual components on the substrate, the space constraints, and the device type. In one embodiment, all of the information used to determine the configuration of the VSD material is inferred. For example, user input relating to voltage tolerances of individual components or elements of a device under design may be used to programmatically determine at least some of the VSD configuration information, such as the type of VSD material used, and one or more spatial characteristics of the VSD material (e.g., gap separation or shape as described below). In another embodiment, some VSD configurations may be determined by user input directly related to the VSD material. The response to the prompt 111 may be provided by an input 113 of the designer 102. Additional VSD material configurations 116 can indicate, for example, the location of the VSD material, as well as the material composition of the VSD material or other factors that may affect the performance of the VSD material in the event of an ESD event. According to one embodiment, the presence and technical requirements of VSD material depend on the ESD characteristics desired for the target device 122.

Figures 2A and 2B each illustrate a design or simulation method for applying VSD material to a target device, according to one embodiment of the present invention. In describing the various methods, elements suitable for performing a step or sub-step are described with reference to elements of FIG. 1. The described method or methods may be performed programmatically, for example, by an EDA application installed and running on the terminal.

In step 210, design module 110 prompts the user to provide information relating to the application of VSD material to target device 122, either directly or indirectly. In one embodiment, the prompt includes an initial prompt as to whether the designer wishes to include VSD material and/or its protective functions on the substrate. As an alternative or variation, the designer may also be prompted to provide one or more of the following: (i) a desired ESD characteristic or type of electrical event to be protected, (ii) an optimization parameter, such as cost or prioritization of spatial constraints, (iii) a zone input that affects where VSD material is to be provided. The listed cues are not intended to be exhaustive, but may also comprise many others. In one embodiment, the prompt may be in the form of a question and answer that instructs the user to enter the desired characteristics. As another implementation, the prompt may be provided in the form of a graphical menu representation or other graphical feature or option that enables the user to specify design choices, such as those related to ESD processing capability.

Based on the information provided by the user, a determination is made at step 215 as to whether VSD material will be present on the target device 122. In one implementation, this determination is as simple as the user elects to use VSD material and/or material to protect against ESD and/or other transient events. In another implementation, the determination is programmatically inferred, such as by inputs from a designer specifying desired characteristics of the target device 122 and how the target device 122 handles ESD (e.g., allowable voltage levels).

If VSD material is not necessary, step 220 provides that the design of the target device 122 be performed without the use of VSD material. If VSD material is deemed necessary, step 230 provides for integrating the VSD material into the configuration or thickness of the device while continuing to perform the design of the target device 122. In one embodiment, for example, an application or program implementing the method selects a substrate having VSD material integrated therein as an inner or surface layer.

Figure 2B shows some additional steps, optionally as part of or subsequent to step 230, in which step 230 it has been determined to include VSD material in the design or simulation of the substrate. In step 235, some or all of the placement or routing of the current carrying element or device is automatically determined and/or implemented. Based on the determination that VSD material is to be present on device 122, step 235 may include automatically performing one or more of: (i) routing current carrying traces, components, and devices on the board, (ii) determining desired impedance and/or capacitance values of selected components on the target device 122 while component routing is performed, (iii) maintaining signal integrity and characteristics while routing is performed.

In addition to or in lieu of routing the board, components of the target device 122 may be selected. In one embodiment, step 235 may thus provide for full or partial automatic routing, or performing a design of target device 122 based on the determination that the device is to inherently include a layer of VSD material (such as in the form of a layer of VSD material in the substrate thickness of target device 122).

Further, as another alternative or addition to step 235, step 240 enables designer 102 to input information regarding desired performance parameters, material strengths, and/or components to be used on the target device. Based on this information, step 240 configures or constructs VSD material elements within target device 122. In one implementation, the material composition of the VSD material may be determined by the material characteristics of the target device 122. For example, the flexibility or strength of the plates, or parts thereof, can determine the composition, thickness, and location of the VSD material. Likewise, performance parameters such as switching voltage (as dictated by the characteristic voltage per specified length) can affect the type and/or thickness of VSD material used, or the manner in which VSD material is used to plate vias or other conductive regions of target device 122. In this manner, the application of VSD material is based on information provided by the user regarding the characteristics desired in: (i) how the target device 122 and/or (ii) the target device handles ESD events.

VSD material configuration in a design phase

In addition to or in lieu of the embodiments described above, one or more embodiments described herein are provided for design or simulation of a substrate that includes a programmed selection or design of specified characteristics (during design or simulation) of VSD material, including local characteristics and substrate-level characteristics. Figure 3A is a simplified block diagram illustrating a manner to incorporate or integrate VSD material into a substrate device in accordance with one or more embodiments of the present invention. In one embodiment, configuration components for implementing VSD material during design or simulation of a substrate are provided as VSD configuration module 310. The VSD configuration module 310 may form a program or a portion of a program. Alternatively, the VSD configuration module 310 may be provided by multiple programs or program portions, whether independent of each other or integrated with each other. More specifically, the VSD configuration module 310 may correspond to or include the logic circuit 114 of the design module described with respect to one or more embodiments of FIG. 1. As will be described, the VSD configuration module 310 may be used in conjunction with a library of designs 350 and/or a library of VSD material 360. In one implementation, each library is presented in the form of a data store that holds data and information corresponding to a set of instructions or data distributed at multiple sources or held in one location (e.g., in one folder).

In general, the embodiments described in this specification recognize that VSD material can be of various types, where the material can have a variety of compositions. The composition of the VSD material affects the electrical and physical properties of the VSD material. Some relevant electrical characteristics of the VSD material include a characteristic voltage level or energy level that enables a specified type or composition of VSD material to be switched into an on state (i.e., switched from dielectric to conductive).

The characteristic energy level indicates a measure of energy required to switch a given amount of a particular type of VSD material on. Because the ability of VSD material to switch on typically lasts for a short period of time, the amount of energy required to switch VSD material to a conductive state can be represented by a characteristic energy level. The characteristic energy level for a given type of VSD material generally corresponds to some form of energy (such as a voltage) that may be applied to a specified measure of VSD material to switch the VSD material into a conductive state. The specified measure of VSD material can correspond to a linear dimension of the VSD that corresponds to a gap or separation distance between two conductive elements that are to be connected when the VSD material is switched on. Although the energy form may be expressed as a current, power, or electric field, the embodiments described in this specification primarily refer to a characteristic energy level in the form of an applied voltage. Clearly, however, the applied voltage used can be readily replaced with other forms of energy, such as current or power. Using the applied voltage as a form of energy for a defined specific level of performance and performance of the VSD material under transient and operating conditions is only an option, as the voltage can also be replaced with other forms of energy according to a simple cross-correlation. The characteristic current can be determined from the characteristic voltage, for example, applying ohm's law (which applies strictly only within a limited range of voltage values in view of the non-linear resistance characteristics of the VSD material).

In the description given in this specification, the "characteristic energy level" is characterized by a voltage (i.e., a "characteristic voltage level"). The "characteristic voltage level" (i) is for a particular type of VSD material, and (ii) is known to be somewhat switchable from dielectric to conductive for a specified measure of the particular type of VSD material. Unless otherwise noted, a characteristic voltage level is a voltage that is applied over a specified length of VSD material and is known to cause the amount of VSD material having that length to switch into a conductive state. As previously mentioned, the voltage used as a form of energy may be replaced by other forms of energy, such as current, power or electric fields.

The "threshold energy level" represents the amount of energy applied to switch the VSD material to the on state. When the applied energy is represented as a voltage, a "threshold voltage level" or "on voltage" refers to the voltage level required to switch a particular amount of VSD material into a conductive state. In many cases, the threshold voltage level may be assumed to be the product of the characteristic voltage level per specified length multiplied by the length that the VSD material exhibits.

More specifically, the characteristic energy level includes a trigger and clamp (clamp) portion. The trigger energy level is the initial energy level that causes the material to switch from dielectric to conductive. The clamped energy level is the energy level that needs to be maintained to maintain the VSD material in the "on state". When denoted as voltages, both the trigger voltage and the clamp voltage provide a measure of energy that can be applied over a given duration to effect switching of the electrical properties of the material. Even if the length of time that the VSD material can remain on is brief, in some cases, compensation can be made in time when applying energy measured from the trigger voltage. In at least some cases, the trigger voltage may be reduced or compensated for with a lower voltage that exceeds the clamp voltage for a sufficient period of time. In most cases, it is necessary to generate a voltage that exceeds the clamp voltage to switch the VSD material on. However, to switch the VSD material on, the trigger voltage does not always have to be matched. Likewise, unless otherwise specified, embodiments described in this specification with reference to the characteristic voltage level of VSD material (per specified length) should be assumed to indicate a clamp voltage.

Another electrical characteristic of the VSD material to be considered is a measure of leakage current, or alternatively, off-state resistivity. In general, leakage currents are undesirable, but can be tolerated. Different types of VSD material have different leakage flow rates. Also, the leakage current characteristics (or alternatively, the off-state resistance) of VSD material may fluctuate with other factors, including operating voltage. Thus, for environments in which VSD material is used, and more particularly, when VSD material is analyzed or considered for design, the operating voltage is also a factor to consider.

For any given type of VSD material, both the threshold voltage (needed to switch the material "on") and the leakage current are affected by the effective amount of material present at the relevant location (i.e., between the two conductive paths). The effective amount of material can be measured linearly by area or volume. In general, the greater the linear length of VSD material used (alternatively referred to as gap separation or gap value), (i) the greater the threshold voltage level required to switch the material on, and (ii) the less leakage current present (or conversely, the greater the off-state resistance). For reference, the characteristic voltage level and leakage current value of VSD material may be determined from a specified length.

The amount of area or volume of VSD material at a relevant location between two conductive points can also be related to the electrical characteristic to be exhibited between the two conductive points. For example, in some cases, the volume occupied by VSD material in providing transient connections may increase leakage current.

Embodiments described herein recognize that VSD material can be selectively arranged to form a transient connection between a conductive path and a protective electrical path (e.g., ground) during design or simulation of a substrate device or other electrical component. A designer of a substrate or electrical device may specify design criteria for transient connections that explicitly or implicitly result in one or more of the following determinations: (i) determining at which voltage level the connection should be switched on (i.e., the threshold voltage level); (ii) determining how much leakage current at the connection is acceptable, taking into account the tolerance level of the surrounding components; (iii) it is determined how much space is available for the transient connection.

In applying VSD material to meet a given design criteria, the following determination can be made: (i) determining the type of VSD material to be used, as that type can affect the desired electrical characteristics; and/or (ii) determining a gap separation distance that the VSD material is to occupy to form the transient connection. One or more embodiments also contemplate that the VSD material will occupy area and volume (i.e., thickness and area) to provide separation and transient connection between two conductive elements.

In one embodiment, the VSD configuration module 310 implements the various considerations and principles described for integrating VSD material onto a substrate as part of a transient protection connection. As described, various considerations and principles of implementing VSD material may require determining parameters regarding the spatial constraints of the device or area on which the VSD material is to be present, the tolerance levels of the components and elements surrounding or using the VSD material, and the transient level requirements (e.g., desired levels of ESD protection) of the device or element to be protected. Referring to the embodiment of fig. 3A, the parameters are collectively referred to as design parameters 312. The VSD configuration module 310 uses the design parameters 312 to determine the details of how the VSD material is integrated or contained on the design device. These determinations may correspond to, for example: (i) determining a gap or separation formed by the VSD material between the element to be protected and the protective electrical path; and (ii) determining the type of VSD material to be used. In one embodiment, the additional determinations include: (iii) determining an area to be occupied by the VSD material when separating the element to be protected from the protective electrical path; and (iv) shape considerations that will affect the area. Still further, other determinations that may be made include determining the volume to be occupied by the VSD material when providing the separation. Referring to FIG. 3A, these determinations may collectively be referred to as VSD implementation determinations 332. As described below, the VSD implementation determination 332 may be based on user input or design rules for a particular substrate device application.

In one embodiment of fig. 3A, the VSD configuration module 310 encapsulates information, data and/or rules or conditions relating to the inclusion of VSD material by using one or more libraries. In one embodiment of FIG. 3A, the VSD configuration module 310 accesses and uses a design library 350 that includes some design rules and information related or unrelated to the manner in which VSD material is implemented into the device. The rules and information may include, for example, information for determining various design parameters 312 from limited user input. For example, the design library 350 may carry information such as: the information identifies the allowable levels of leakage current and breakdown voltage for the different components that are selected for a particular device. As another example, the design library 350 may carry information identifying space constraints to determine how much space on the device can provide for a particular connection of VSD material overlays. In one embodiment, some substrates may carry a prefabricated layer of VSD material having a particular type of configuration. The design library 350 may carry information regarding the location, type, and electrical characteristics of such VSD material, among other kinds of information.

In addition to the design library 350, the VSD configuration module 310 may also access a library of VSD material 360. The VSD material library 360 may be incorporated or integrated into, for example, a design library 360. The library of VSD material 360 may carry data relating to various VSD material related characteristics, including various electrical characteristics of the VSD material. For example, the library of VSD material 360 may carry the following information relating to one type of VSD material: a characteristic voltage level, a reference measure of leakage current (or off-state resistance), and a gap distance required for a given threshold voltage to cause the material to switch on. This threshold voltage can be used to confirm the level of ESD protection that can be provided by the particular type of VSD material applied over the gap distance.

By using the design library 350 or the VSD materials library 360, the design parameters 312 can be confirmed (explicitly) by explicit designer input, or programmatically inferred or determined from other inputs. According to one embodiment, design parameters 312 may include spatial constraint parameters 322 that include data that may infer or confirm a preferred size of an inter-element interconnection or spacing. Additionally or alternatively, the spatial constraint parameters 322 clearly define the spacing of the VSD material, and/or the availability of protective grounding elements and/or other components. As described above, the spatial constraint parameters 322 may be inferred based on spatial information explicitly given by the designer, or from other information, including the use of the design library 350. For example, a designer may specify a circuit board and the space constraint parameters may be identified by cross-referencing the type or circuit board to the design library 350. Thus, for example, a circuit board for a particular kind of application may be associated with a default size range, such as by a value (e.g., "small").

Another one of the design parameters 312 may correspond to the tolerance parameter 324. The tolerance parameters 324 may include voltage and/or current values that define limits including one or more of: (i) the operating voltage range of some or all of the devices, (ii) the breakdown voltage of such devices, and/or (iii) the tolerable leakage current. In one embodiment, the VSD configuration module 310 uses the design library 350 to access information associated with particular components contained on the board or device having respective tolerance parameters 324. In this manner, the tolerance parameters of the device under design or simulation may be determined by user-provided inputs, including inputs corresponding to component selection. The components used on the device may also be determined by default or in association with other components or by user input. For example, a designer (or design library 350) may include information in the form of government regulations or industry standards that require an allowable amount that exceeds that of a particular device. Likewise, the designer (or design library 350) may incorporate information relating to security factors, or include other conditions by which one or more tolerance levels may be inferred. The tolerance parameter 324 may also be analyzed or subjected to various determinations. For example, the tolerance 324 may be localized on the substrate device (e.g., the voltage tolerance in one region of the substrate may be different from the tolerance in another region), or processed to determine a minimum or threshold value (e.g., the value of the voltage at which one component will break down).

The VSD configuration module 310 may take into account various other design rules or implementation characteristics when it determines implementation details of VSD material. For example, design rules, regulations, or other factors may determine ESD parameters that may limit the allowable amount of voltage that a device may experience in general, or alternatively, limit the allowable amount of voltage that a particular component or portion of the device may experience.

The VSD configuration module 310 uses the various design parameters 312, along with the VSD materials library 360 (and the design library 350), to determine implementation details 332 including one or more of: (i) a gap value 343, (ii) an area determination 344, (iii) a shape determination 346, and/or (iv) a type determination 348. Other determining factors may also be determined, such as volume determination, location determination, or cost ranges or limits. In accordance with one or more embodiments, each of these determinations may be made based on any one or more of the design parameters 312. For example, the spatial parameters 312 may determine constraints on the gap values 342.

However, calculations need to be made to ensure that the gap value 342 does not cause the threshold voltage level for switching the VSD material on to be too high. This calculation may be determined by: the characteristic voltage level of the particular VSD material identified by the type determination 348 is identified and then the product of the characteristic voltage level (per specified length) and the gap value (in terms of the specified length) is determined. The threshold voltage across the gap identified by the gap value determined for deposition of VSD material (as identified by type determination 348) must also be such that the threshold voltage level is less than the breakdown voltage of the component to be protected. A safety factor is also applied to the breakdown voltage to ensure that the threshold voltage level is switched on before a destructive event.

Likewise, the type determination 348 can be used to identify the leakage or off-state resistance value of the selected VSD material, and the gap value 342 can be used to calculate the leakage current resulting from the use of the VSD material (leakage current decreases and off-state resistance increases as the gap value 342 increases). The induced leakage current may be compared to an allowable leakage current level to ensure that the leakage current is less than the allowable level. In some cases (such as when performing optimizations), some implementation details 332 may depend on determinations of other implementation details.

The gap value 342 can correspond to the separation distance provided by the VSD material that extends between the conductive element to be protected and the protective electrical path. The gap value 342 is shown by one embodiment of fig. 5A. As described below, the gap value 342 determines a trigger threshold voltage level by which a given type of VSD material is switched "on". In this regard, the gap value 342 and VSD type determination 348 can provide a primary implementation determination 332 for confirming a threshold voltage level (i.e., an "on voltage" level) at which VSD material is deposited between two conductors.

The area determination 344 may correspond to a planar measure of the VSD material that provides the gap value 342. While the gap value 342 is a major factor in determining the overall voltage level for a given type of VSD material, the total area occupied by the VSD material may increase leakage current and may affect the on-voltage level. The embodiment of fig. 6A and 6B shows how area determination 344 is implemented when the general shape of the VSD material is formed as concentric circles around the protected conductive path (or element to be protected). As discussed above, the larger the area for a particular gap value, the more leakage current is present for a given type of VSD material. Significantly different areas may be obtained without affecting the gap value 342. At the same time, however, the greater the value of area determination 344, the greater the tolerance on the substrate that can interconnect the electrical component with the protective electrical via. Thus, when manufacturing is actually performed, one of the considerations in generating area determination 344 is the range of acceptable amounts available to interconnect the components (or alternatively, to the protective electrical paths) on the substrate when manufacturing is actually performed. This consideration is quantified by the design library 350, user input, or assumptions by other conditions. Still further, the area determination 344 is subject to overall size constraints, such as specified by the spatial constraints 312.

The shape designation 346 may designate a default shape (e.g., concentric rings) from which the area determination 344 provides the area determination 344, or alternatively change the default shape. In one embodiment, for example, the VSD material may be assumed to form a concentric ring or ellipse around the protective electrical path. The shape designation 346 can modify the profile of the default shape to reduce the overall area while maintaining the gap value 342 and the overall diameter or size of the surrounded conductive element (e.g., ground via). By reducing the area, the shape designation 346 can provide such benefits as reducing leakage current from the VSD material cladding. The shape specification 346 may be determined, for example, by using the spatial constraint parameter 322 and may be motivated by one or more tolerance parameters 324 that indicate a desire to reduce or ensure leakage current.

The type determination 348 specifies the composition of the VSD material to be used. There are many different compositions for VSD material having different electrical and mechanical properties. In particular, the characteristic voltage levels and leakage currents vary significantly between different types of VSD material. The library of VSD material 360 can be referenced for desired electrical characteristics, which can be determined from the design parameters 312, to identify one or more compositions. Other inputs or considerations, such as desired mechanical properties (e.g., strong adhesion when adhering copper) or cost, may also influence the selection.

FIG. 3B illustrates a data structure maintained by the VSD materials library 360 (FIG. 3A) in one embodiment of the invention. The table 372 or other data structure may include a plurality of entries 382. Each entry 382 may identify a particular composition of VSD material. The composition of each VSD material may be associated with known (approximate or measured) characteristics including a characteristic voltage level value 384 and a leakage current value 386. Other electrical characteristics may also be preserved. The entry 282 may also include a cost value 388, or other value related to the cost value 388. The library of VSD material 360 may be accessed by the VSD configuration module 310 to identify the necessary gap values for the various VSD materials being considered. Based on various criteria, the selection may include using data from the VSD materials library 360.

Figure 4 illustrates a method of how VSD material implementation layouts are determined for a substrate during a design phase in one embodiment of the invention. The methods as described herein may be integrated or incorporated into one or more other embodiments. For example, referring to the embodiment of fig. 2A, the embodiment as described in fig. 4 may be integrated in steps 210 and 230 of fig. 2B, in which steps 210 and 230 a design/simulation of the substrate is performed. For purposes of illustration, reference may be further made to elements of the embodiment of fig. 3A.

At step 410, one or more user input parameters are received. Depending on implementation details, the user input parameters may vary from simple to detailed or complex. According to one or more embodiments, the user input parameters may correspond to one or more of: (i) the selection of VSD material to include as an integrated component on the substrate, a designer selection for protection against transient electrical events such as electrostatic discharge, and/or (ii) the selection of a particular type of substrate that includes, for example, a pre-deposited layer of VSD material. Alternatively or additionally, the designer input may correspond to an explicit input in the form of design parameters 312 for the embodiment of FIG. 3A.

Step 420 provides for the validation and implementation of design rules for a particular simulation or design. The design rules may be selected based on, for example, the particular application, substrate, or other parameters. Design rules may specify various conditions and criteria, including individual component or device overall protection requirements, and/or specific component specifications or types of components to be included on a substrate. For example, a design rule may specify for a circuit board (such as for a wireless device) in a particular application: (i) specific components on the board, (ii) ESD protection requirements for individual components, areas, or the entire board, (iii) space constraints or parameters on the board, (iv) thickness and other dimensions of the board. In one embodiment, design library 350 holds different sets of design rules for various applications that may be designed or simulated by a program that performs the method of FIG. 4.

At step 430, one or more design parameters may be programmatically determined based on the inputs and confirmations made in either or both of step 410 or step 420. The determination of such design parameters may be generated by designer input, as well as other logic circuitry connected to the design library 350 and/or the VSD materials library 360 to determine any one or more of the design parameters 312. Thus, for example, the design library 350 may set the requirement for breakdown voltage based on industry or legal standards, as well as based on the presence of one or more sensitive components selected for use by the designer. Likewise, the spatial parameters 322 may be inferred by reference to the type of device being manufactured by the designer.

At step 440, implementation details of the VSD material are determined. The implementation details may include any of the implementation details 332 as described in the embodiment of fig. 3A, including (i) a gap value 342, (ii) an area determination 344, (iii) a shape determination 346, and/or (iv) a type determination 348. In determining implementation details 332, an embodiment provides for calculating the on-voltage from the product of gap value 342 and the identified VSD material characteristic voltage. Additional or alternative calculations include determining the leakage current for a quantity of VSD material to be used, and an area determination 344 (which may be referenced to the spatial constraint 322). Upon completion of the VSD implementation, different types and configurations of VSD material are processed and analyzed. The selected VSD material satisfies many of the conditions specified by the design parameters 312 and design rules. Additionally, VSD material may be selected based on cost and/or optimization procedures that, for example, are directed to prioritizing particular implementation details 332 (e.g., minimizing the total area of the VSD material).

According to one embodiment, once implementation details are determined, the remainder of the design and/or simulation may be performed by a program that encompasses or includes the desired properties and characteristics (as implemented) of the VSD material. Thus, for example, a designer may construct the remainder of the circuit board. Alternatively or additionally, the simulator may anticipate ESD events and determine the impact of such unexpected events on the operation of the device.

VSD material implementation at protective vias

Figure 5A illustrates a diagram representing the deposition of VSD material at a given point on a substrate 500 during a design or simulation phase, according to one embodiment of the present invention. The gap value 515 may define a separation 525 between the conductive element 510 to be protected (from the transient electrical event) and the protective electrical path 520. The conductive elements 510 may correspond to traces or electrical components, for example. The protective electrical path 520 may be a ground or connected electrical path for removing transient voltages in the operating environment. A coating of VSD material 540 may span or fill the separation 525. As illustrated by the other embodiments, the VSD material used (which is identified by type determination 348) includes characteristics that are dielectric at the normal operating voltage of the substrate. Thus, the normal or typical operating voltage of conductive element 510 should not change the dielectric properties of VSD material 540 deposited at separation 525. Thus, the design may assume that under normal operating conditions, the protected conductive element 510 is separated from the protective electrical path 520.

However, the VSD material 540 switches to a conductive state in the presence of a surge or other high voltage. In the conductive state, charge from the event is transferred to the protective conductive path 520, which may be ground. In the implementation shown, for example, the guard conductive path 520 is a through-hole extending to an integrated ground plane disposed within the thickness of the substrate device. As an inherent characteristic of VSD material, the transition from dielectric to conductive occurs almost instantaneously, such that even within a short time scale of an ESD event, VSD material 540 can become conductive before electrical components connected to conductive element 510 are damaged by the ESD event. Thus, the VSD material 540 can protect the substrate from ESD events by connecting the conductive elements 510 to the protective electrical path 520. But this connection is only made when a sufficiently large transient electrical event occurs. Thus, the connection formed across the gap is referred to as a transient electrical path 508.

Specifically, the transient electrical event must have a magnitude that exceeds the threshold (or "on") voltage of the VSD material 540. The threshold voltage refers to the minimum voltage suitable for switching a given VSD material coating from dielectric to conductive. If the voltage is at the low end of the threshold at which switching should occur, the switching may not necessarily occur depending on the composition and duration (i.e., power) of the event and potentially other factors. Thus, one embodiment may include a safety factor, placing the "on voltage" of the material well below the breakdown or tolerance voltage of the element to be protected.

The determination or estimation of the threshold voltage required for a given cladding may be determined in part by the characteristic voltage per specified length or by a given amount of material. For the gap value 515, the threshold voltage corresponds to the product of the gap value 515 and the known or estimated characteristic voltage of the VSD material being used. Specifically, a characteristic voltage may be provided for a given specified length, and the gap value 515 may be defined (e.g., mils) for the same specified length. When the voltage tolerance is considered or included as one of the design parameters 312 (fig. 3A) of the gap value 151, the product of the gap value and the characteristic voltage should be less than the voltage tolerance of the design parameter 312 (without considering safety factors). A simple equation expressing this relationship is:

gap value (voltage allowance safety factor)/(characteristic voltage) (1)

The safety factor is assumed to be less than 1.0.

This relationship ensures that a transient conductive path 508 occurs when an electrical event is at a potentially damaging voltage level. This ensures, for example, that the conductive element 510 will be grounded, but only when voltage levels are present that would otherwise be harmful.

Various types of VSD material can be distinguished by their composition, as well as their electrical and/or mechanical properties. As previously mentioned, the electrical characteristics include a trigger voltage or a clamping voltage that makes the material conductive. The mechanical properties include physical properties of the material based on the composition of the material. One or more embodiments provide programmatically determining a gap value 515 from a selected or preselected type of VSD material 518. For example, according to one embodiment, a designer may prefer a particular type of VSD material in view of the characteristics of the material (e.g., strong adhesion to copper, non-brittleness) or aesthetics. The gap value 515 may be calculated taking into account the characteristic voltage level of the VSD material selected, as well as the necessary threshold or "on voltage" for protecting the necessary components or elements of the device.

According to another embodiment, a program can be configured to select the least costly VSD material that provides the desired electrical characteristics. The desired electrical characteristics may be determined, for example, by designer input and/or designer library 350 (FIG. 3A). The desired electrical characteristics include, for example, a threshold or "on voltage" that defines a level of ESD protection, as well as other factors such as leakage current. Spatial constraints may also be considered. For example, the spacing requirements can indicate a relatively crowded environment, giving preference or a need for opportunity to give VSD material that can provide desired electrical characteristics within a small gap value. From the desired electrical characteristics, the desired type of VSD material may be selected and confirmed by type determination 348 (fig. 3A). One or more embodiments provide for the selection to be made using other criteria, such as cost, when multiple types of VSD material meet the requirements.

Various other parameters or inputs can be used to enable the validation of particular VSD material 518. Each VSD material may have a different known or estimated characteristic voltage per specified length. Thus, some types of VSD material may require a smaller or larger gap value 515 to provide a desired result or threshold trigger voltage value for an electrical event.

While the embodiments described above provide for determining the gap value 515 from the electrical characteristics of the VSD material, other embodiments provide that the gap value 515 is the criteria for selecting VSD material. For example, one of the design parameters 312 (FIG. 3A) may provide a specified range of gap values 515 as a requirement. A program or module configured in accordance with one embodiment of the present invention may then specify the type 518 of VSD material 540 based in part on identifying which VSD material has a characteristic voltage per linear length that provides a gap value within the desired range. Thus, either the gap value 515 or the type value 518 is considered critical, or one takes precedence over the other, whether a global indication or condition exists as a condition or parameter.

FIG. 5B shows a variation in one embodiment of the present invention in which the protective electrical path includes an anti-pad. According to one embodiment, anti-pad 582 may be incorporated onto substrate 500 as part of a protective electrical pathway. In one embodiment as shown, the protective electrical path further includes a via 580 extending inwardly into the substrate 500. Rather than requiring VSD material 590 to form a direct connection with via 580 to establish a transient electrical connection, one or more embodiments enable anti-pad 582 to form an extensive layer or component over via 580. Because anti-pad 582 is larger in size than via 580, the use of an anti-pad reduces the manufacturing tolerances required for the separation occupied by VSD formation 590 as described.

The separation 585 between the conductive element to be protected and the anti-pad 582 may be defined by a gap value 575. The gap value 575 can be determined in a manner such as described for the embodiment of fig. 5A. As described below, the use of anti-pad 582 may also facilitate VSD material shaping and/or facilitate determining the total area thereof while maintaining a specified gap value.

Figures 6A and 6B are top views of a substrate illustrating area considerations implemented for VSD material according to one embodiment of the present invention. In one embodiment, the protective transient path is provided by anti-pad 622, which corresponds to a pad or other conductive layer that is covered over a through hole 620 that extends in the Z-direction (into the paper). The anti-pad 622 may be circular or circular in shape, providing a lip or field formation over the via 624. One purpose of using anti-pad 622 is that it increases manufacturing or forming tolerances. In the absence of the anti-pad 622, precise manufacturing techniques are required to extend the conductive element or trace element to the via 620. Such accuracy is not always possible or even desirable (such as when it is not cost-effective).

As with other embodiments, the conductive vias 610 required for protection may be separated from the anti-pad 622 by an area defined in part by a gap separation 625. The gap value (such as determined for the embodiment of fig. 5A) characterizes the gap separation 625 and may be determined in the manner described for other embodiments herein. In addition to the parameters of gap value 615, another dimensional characteristic for implementation details is the area occupied by the VSD material. Specifically, one or more embodiments determine a total area 615 of VSD material 640 separating anti-pad 622 from conductive pad 610. The total area 615 of VSD material 640 may depend, for example, on the size of anti-pad 622, as well as the gap value of separation 625.

In particular, embodiments contemplate that the size of anti-pad 622 may be increased or decreased while not affecting the gap value characterizing the size of separation 625. Figure 6B shows a variation of the embodiment of figure 6A with changes that increase the size of the formation of VSD material 640. This increase is shown as the height H2 of VSD material in the formation of figure 6B is greater compared to the height H1 of the formation of figure 6A. Even with the additional dimensions, the gap value characterizing the separation 625 does not change.

Thus, as shown in the embodiment of fig. 6A and 6B, the area of VSD material can also be considered as one of the implementation details 332 (see fig. 3A). Specifically, selecting the area (as provided by area determination 344) can lead to results that include (i) a potential increase in leakage current, and (ii) a reduction in allowable tolerances for aligning and interconnecting components with the VSD material and/or anti-pad 622 (or other components of the protective via). Other considerations include the cost of additional VSD material, the space occupied by the VSD material, and potential secondary electrical effects, such as electric fields.

Figure 7 illustrates another spatial implementation detail when using shapes as VSD material integrated on a substrate or other device in a design or simulation phase, according to one embodiment of the present invention. On the substrate 700, one or more embodiments provide that the shape designation 735 defines the general shape of the VSD material 740, and in particular its concentric separation relative to the anti-pad 722 and the shape of the conductive element 710. The final shape of the VSD formation provided between the conductive element 710 and the anti-pad 722 (or other element of the protective electrical path) can be formed by designing the shape of one or both of the anti-pad 722 and the VSD material 740.

In one embodiment, the default shape may be assumed to be an annular ring or ellipse, such as shown and described in the embodiment of fig. 6A or 6B. The shape designation 735 parameter may define or designate the shape of the VSD material formation or a portion thereof, modifying the overall shape to change the size of the area. Among other benefits, the effective area remains at the separation 725 point, the separation 725 being determined by the gap value. The active area 738 corresponds to the area surrounding the anti-pad 722 that is closest to the conductive element 710 (i.e., the area where the separation or gap distance is provided). However, the total area may be reduced, potentially reducing leakage current. Further, the VSD formation 740 can be shaped to be accurate over a mark point (spot point) rather than over the entire perimeter. To this end, the shape designation 735 may designate a contact point or contact area, wherein the effective area is taken into account by the gap value and the separation 725 is determined. At these designated points or designated areas, one or more embodiments provide for considerations including maintaining the overall radius of curvature of the shape of the conductive material 710 substantially matching the periphery of the VSD material 740.

FIG. 8 illustrates an embodiment of the invention in which implementation details include determining some or all of the following locations: the VSD formations will provide locations for transient connections to the protective electrical paths. On substrate 800, one embodiment provides a programmed determination of the location 812 where the formation of VSD material is to be used ("location determination 812"). In one embodiment, the substrate includes an interior layer of VSD material that spans the entire substrate or at least the following portions: i.e. those parts of the electrical components that need to be protected from ESD. Those locations for VSD formations can be provided by exposing the underlying VSD material at selected locations, or by extending anti-pads, vias, or other connecting elements to the VSD material.

For each location determination 812, considerations such as those described for the embodiments of fig. 5A-7 may be determined. For example, implementation details in the form of a gap value defining the separation of two elements to be connected by VSD material under transient conditions may be determined. Further, the type of VSD material may be determined for the entire substrate, or alternatively, different VSD material may be used at different locations. Area and shape determinations may also be made on a partial or bulk substrate basis.

Multilayer device

Figure 9 illustrates a design or simulation for applying VSD material into a multilayer device in one or more embodiments of the present invention. According to one embodiment, the substrate device 900 may include a plurality of layers 902, 904, 906, each carrying various electrical elements and components. One or more vias may be used to electrically connect the layers.

Any of the implementations of VSD material described by figures 5A through 8 can be implemented on a single layer of a multilayer device according to embodiments described in this specification. Additionally or alternatively, one or more embodiments provide a device 900 that includes multiple layers 920, 922 of VSD material. In one embodiment, the layers of VSD material 920, 922 separate one or more layers having conductive elements disposed thereon. As described in the embodiment of fig. 5A, one of the factors to be considered in integrating or incorporating protection of VSD material is determining the gap values for the points to be placed in transient electrical connection with the protective electrical path. In devices such as the described multilayer devices, the gap value may be provided by the shortest distance to the protective electrical path in the presence of a transient electrical condition.

The individual layers 902, 904, 906 may include elements (in the form of traces or components) that are protected from transient electrical conditions. Vias 930 may interconnect the layers and provide a ground or other protective electrical path. According to one embodiment, a plurality of gap values may be determined to define the separation of the different conductive elements and the protective electrical path under this described embodiment. The first gap value 915 may define a separation between the first conductive element 910 (on the layer 902) and the via 930. As described in the embodiments of fig. 5A and 5B, separation 925 may correspond to the linear dimension of VSD material separating first conductive element from via 930.

The second gap value 917 can define a separation between the second conductive element 912 (on the layer 904) and a protective electrical path that includes the first electrical element 910. The actual metrics of the first separation and the second separation may be different and affected by the first gap value 915 and the second gap value 917. In one embodiment shown in fig. 9, the first layer of VSD material occupies the separation between the second conductive element 912 and the first location of the protective electrical path, which corresponds to the via 930. The second layer of VSD material occupies the separation between the second conductive element 912 and the second location of the protective electrical path, which corresponds to the first electrical element. For the second conductive element, the relevant formation of VSD material for connection to the protective electrical path is the formation that provides the shortest separation. In the provided embodiment, a second gap value 917 determination may thus be provided for obtaining separation between the first conductive element and the second conductive element. Gap values corresponding to other transient electrical connections formed by the VSD material may be similarly calculated.

Display device backplane and device

The embodiments described in this specification can be implemented in various applications, such as printed circuit boards. In addition, as described in the embodiment of fig. 10, one or more embodiments may be applied to a chassis for a display device 1000. In general, the display device 1000 includes a transparent conductor 1010 disposed outside the device. The transparent conductors 1010 may be separated from the ground pads 1012, 1014 (or other points connected to the protective electrical path) by respective formations 1022, 1024 of VSD material. As illustrated by other embodiments, the linear dimensions of the VSD formations 1022, 1024 can define the threshold or "on voltage" by which the formations are made conductive. When switched to a conductive state, VSD material formations 1022, 1024 provide grounding of conductors 1010. To prevent shadowing of transparent conductor 1010, formations of VSD material may be disposed on the periphery of the device. The linear dimensions of the VSD material, as well as other determinations such as type, etc., can be determined in accordance with other embodiments described above.

Optimization

In general, the process of selecting VSD material and designing it for integration into a device is a multivariable consideration process in which selecting one desired result may adversely affect another. For this reason, one embodiment provides a prioritization or selection scheme by which a designer may specify a desired characteristic, variable, or result (as desired over another characteristic, variable, or result). In more detail, in determining to implement the determination 332 (see fig. 3A), one or more embodiments provide for making the determination by using one or more optimization processes. According to one embodiment, the optimization process may affect which materials are selected, as well as the spatial characteristics of the selected materials.

Fig. 11 illustrates the use of an optimization module 1100 in connection with the system as shown in fig. 3A and described with respect to the embodiment of fig. 3A in one embodiment of the invention. The optimization module 1100 may perform one or more processes to select or influence the selection of one or more implementation determinations 332 (see fig. 3A). In one embodiment, the optimization module 1100 performs a process to select VSD material for use on a substrate during a design or simulation mode. The selection may be made based on one or more optimization criteria. Examples of optimization criteria include (i) a cost parameter 1112, (ii) a quantity parameter 1114, and/or (iii) a performance parameter 1116. The optimization module 1100 can interact or communicate with the VSD configuration module 310 to affect the selection or use of one of the implementation determinations.

Cost parameter 1112 may reflect a process by which the cost of integrating VSD material into a substrate device may be minimized. Factors that affect overall cost include the cost of a particular VSD composition, and the amount of VSD material required according to the composition. Some VSD compositions, for example, require less material — for example, by using small gap distances and areas to obtain desired performance characteristics. Furthermore, some VSD material is easier to integrate into a device than other VSD material. For example, some substrates may include pre-fabricated VSD material as a layer within or near the surface of the substrate, and adding other layers after pre-fabrication is more expensive than using the pre-fabricated VSD material. Thus, more than one factor may affect cost parameter 1112. The cost parameter 1112 may be provided as a composite value, or as a multi-dimensional parameter having a plurality of variables that affect the cost of using a particular type of VSD material.

In one embodiment, cost parameter 1112 may be used to select VSD material (and thereby affect VSD indication 348). Alternatively or additionally, the cost parameter 1112 may affect the location determination 812 (see FIG. 8), the area determination 344, and/or the shape designation 346. For example, area and shape designations may be selected to reduce cost, even at the expense of performance. Cost parameter 1112 may be considered a composite value, or in combination with a plurality of independent variables that are combined together to enable determination or estimation of the total cost of integrating a particular type of VSD material into a particular substrate device.

Quantity parameter 1114 may correspond to a prioritized amount of VSD material used on the board to be reduced. For example, when the environment in which VSD material is to be deposited is crowded, it may be desirable to use a smaller amount of VSD material at this time. In crowded environments, the small separation gaps for VSD material are also expensive in practice. To perform optimization based on quantity parameter 1114, one embodiment, for example, provides that optimization module 1100 use the output of VSD configuration module 310 (fig. 3A) to determine which types of VSD material require less area to satisfy various criteria and design parameters 312. The smallest area may correspond, for example, to VSD material having the lowest characteristic voltage, as such material requires the smallest gap separation and area size.

Other characteristics of the VSD material, such as leakage current, may affect the selection of the type of VSD material, in part, as described in the embodiments provided in figures 13-15. In particular, for a given type of VSD material, the leakage current can vary with the magnitude of the gap distance (the leakage current is greater when the gap size is smaller) and/or with the presence and magnitude of the operating voltage of the substrate device. To this end, simply confirming that the material with the minimum gap separation size requirement does not achieve optimization or even produce usable results. Thus, the optimization module 1100 is operable to implement the optimization process using the tolerance level and the necessary gap separation dimension, which may be balanced against each other. The optimization module 1100 can prioritize these factors under selection conditions. For example, the optimization module 1100 may find the minimum separation distance size without having any components receive more than an allowable amount of leakage current.

Still further, the optimization module 1100 may be optimized to enhance specific performance characteristics 1116. For example, for sensitive devices, VSD material may be selected that may be configured to provide a minimum amount of threshold voltage. The material can, for example, provide desirable characteristics with small gap separations while having leakage currents within device tolerances. Thus, even when performance is considered, the optimization module 1100 can require the output of various VSD implementations to select or influence the selection of a particular type of VSD material. Examples of performance characteristics include (i) the presence of negative capacitance, (ii) impedance, and (iii) heat loss. Any optimization process may be optimized for one of these characteristics.

Description of the System

Fig. 12 illustrates a system for use with one or more embodiments. The system 1200 includes processing resources 1210, memory resources 1220, a designer interface 1230, and a display device 1240. The processing resource 1200 may perform modules and functions such as those shown and described in fig. 1 or 3A, including, for example, the logic circuitry 114 (fig. 1). Memory resources 1220 may store instructions corresponding to the modules and functions performed, as well as information and data provided in design library 350 (FIG. 3A) and VSD materials library 360 (FIG. 3A). The design interface may correspond to, for example, a keyboard or a mouse or a pointing device, although various tools are contemplated that enable a user to provide input and receive output. Display 1240 may be provided as part of interface 1230, for example, may display prompts to which the designer responds.

Optionally, system 1200 may be coupled to a manufacturing interface 1250. Processing resources 1210 may communicate the implementation configuration 332 (fig. 3A) for a particular design with a manufacturing interface 1250 that may then send instructions to the manufacturing/fabrication site (ex-situ) or tool (in-situ). The manufacturing interface 1250 may generate substrate design data 1252 for the manufacturing site. The manufacturing interface 1250 may be configured to format the substrate design data 1252 and/or to communicate the data directly for use in a manufacturing process.

Examples of the embodiments

The following section sets forth examples of implementations including one or more of the embodiments described in the specification.

Example (c): a Printed Circuit Board (PCB) is designed using software configured according to embodiments described in this specification, such as EDA applications. The design of the printed circuit board may require integration of VSD material to provide protection against potentially adverse transient electrical events, such as ESD. PCB designs may require the use of three chips, each with a different tolerance setting for ESD, leakage current, or other electrical characteristics. Table 1 shows the recommended or manufacturing-specified tolerances for each chip. The identified tolerances are for ESD and off-state resistance. As noted elsewhere, the off-state resistance may also infer the tolerance for leakage current. In one embodiment, the information provided in Table 1 may be listed in a design library 350 (see FIG. 3). As an initial step, a design for configuring a PCB makes the data corresponding to table 1 accessible to modules including VSD material.

Table 1: printed circuit board ESD

One embodiment provides for programmatic identification of candidate types of VSD material. As a candidate, VSD material need not be fully processed to determine whether all of the tolerances and criteria for integrating the VSD material are met. In analyzing VSD material as a candidate, the electrical characteristics can be confirmed with reference to a given linear dimension, which in the given embodiment is a 1 mil (mil) gap. To analyze the voltage level at which the VSD material goes on, the characteristic voltage level is normalized to the voltage required to switch the VSD material on when applied over a 1 mil gap. Next, the threshold voltage level (the total voltage required to switch a quantity of VSD material on) is calculated from the product of the characteristic voltage level (per mil) and the gap size (also measured in mils).

Fig. 13 is a graph showing a relationship between a threshold voltage level (Y-axis) and a gap value (X-axis). The larger the size of the gap separation, the larger the threshold voltage level for a given type of VSD material. In the given embodiment, the relationship may be expressed (e.g., linearly) by an equation, although other curve fitting techniques (e.g., parabolic) may also be used to fit the experimental results. The information and/or data may be stored, for example, in a data store corresponding to the VSD materials library 360 (see figure 3). The VSD library 360 may hold values or alternatively use predetermined equations (e.g., linear relationships) that enable the configuration module 310 to separate the values of the assumed threshold voltage levels for a given gap.

For analysis of leakage current/off-state resistance, the following relationship is generally applicable to VSD material: (i) larger gap sizes have larger off-state resistance and smaller leakage current; and (ii) higher operating voltages have lower off-state resistance and greater leakage current. Fig. 14 is a graph showing the off-state resistance of the first type of VSD material, as may be experimentally determined from the gap separation of increasing size. The graph compares the off-state resistance value (Y-axis) to the gap separation dimension (X-axis), where the off-state resistance increases as the gap value increases.

Fig. 15 is a graph showing the off-state resistance of a first type of VSD material as it may be determined experimentally for different gap sizes subject to varying magnitudes of operating voltage. More specifically, the relationship indicates that the off-state resistance (Y-axis) decreases with increasing applied voltage.

Using the test results, the relationships of both fig. 14 and 15 can be linearly expressed. Information corresponding to this relationship can be stored, for example, in a data store corresponding to the VSD library 360 (FIG. 3). The VSD library 360 may hold values or alternatively use a predetermined equation (e.g., a linear relationship) that enables the configuration module 310 to assume values of leakage current and off-state resistance for a given type of VSD material, size of gap separation, and/or operating voltage.

With these relationships in mind, one embodiment provides that the first type of VSD material can be analyzed as a candidate for integration into a substrate device by first determining the size of the gap separation, the size of the gap separation between each chip and its ground required to provide protection against ESD events. The necessary voltage protection requires that the threshold voltage level of the VSD material be turned on at a voltage below the breakdown voltage, as modified by safety considerations. In one embodiment, once the size of the gap separation is determined, the size of the gap separation may be used to determine the off-state resistance and/or the leakage current.

According to a given embodiment, type I VSD material may have a characteristic voltage level of 113 volts/mil. The off-state resistance can also be expressed by the following equation:

(off state) resistance (Gohm) 490.91 (gap/mil) -1132.3

(2)

In the given embodiment, equation (2) applies to components having operating voltages in the 12 volt range. As shown in fig. 15, the equation is different for any particular component if the operating voltages are different.

Table 2 shows the results of integrating VSD material on a PCB where the electrical characteristics of the clamping voltage and its off-state resistance are known or assumed. As noted, one embodiment provides for sizing the gap separation to meet ESD requirements, and then referencing the size of the gap separation to determine the off-state resistance and/or leakage current. Table 2 summarizes these results:

TABLE 2

Calculated gap (mil) for protection chip

Calculated off-state resistance at operating voltage (G-ohm)

Pass/fail design parameters

Chip 1	1.42	-437.55	Fail to work
				Chip 2	3.54	604.57	By passing
Chip 3	7.09	2341.43	By passing

Table 2 shows that to obtain the desired ESD protection for chip 1 on the PCB, the gap separation formed by introducing VSD material between (i) chip 1 and ground or other protection elements requires 1.42 mils: (ii) the gap formed by directing VSD material between chip 2 and ground is divided into about 3.54 mils; and (iii) the gap formed by the VSD material contained between chip 3 and ground is separated by 7.09 mils. However, VSD material type I cannot meet the off-state requirements for passing through chip 1 according to equation 2.

In one embodiment, when one component fails, the configuration module 310 (see fig. 3) or other programmatic component selects another candidate VSD material (or alternatively selects some other design parameter). The selection of another candidate VSD material may be for a particular chip or component, or for the entire substrate device. For example, one embodiment provides that the configuration module 310 seeks to use the same type of VSD material across the entire substrate. However, the given embodiment determines VSD material type II only for failed chips 1. VSD material type II can have a characteristic voltage of 50 volts/mil while assuming, for simplicity, an off-state resistance represented by equation 2.

Table 3 provides some results of using VSD material type II to provide transient connections to ground for the chip.

TABLE 3

	Calculated gap (mil) for protection chip	Calculated off-state resistance at operating voltage (G-ohm)	Pass/fail design parameters
				Chip 1	3.2	436.02	By passing
Chip 2	8.00	2788.50	By passing
				Chip 3	16.00	6709.30	By passing

Alternatives

While the embodiments described in this specification provide for determining VSD material, or characteristics thereof, in a design or simulation medium in order to handle ESD or overvoltage conditions, other embodiments may provide for a logic circuit or software program to make the determination as to whether VSD material is to be used. For example, a user may specify conditions and parameters under which ESD protection is not desired, in which case the logic circuit may make a determination that VSD material is not included in the device design.

Summary of the invention

Although illustrative embodiments of the present invention have been described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments. As such, many modifications and variations will be apparent to practitioners skilled in the art. Accordingly, it is intended that the scope of the invention be defined by the following claims or their equivalents. Furthermore, it should be noted that a particular feature described either individually or as part of an embodiment may be combined with other separately described features or parts of other embodiments even if the other features or embodiments do not mention the particular feature. Accordingly, a combination not described does not exclude the rights the inventors have for such a combination claim.

Claims (46)

1. A computer-implemented method for designing a device in a design or simulation phase, the method comprising:

identifying one or more criteria for handling a transient electrical event on a device, wherein identifying the one or more criteria is based at least in part on input provided by a designer; and

in accordance with the one or more criteria, one or more characteristics are determined for integrating Voltage Switchable Dielectric (VSD) material as a layer within or on at least a portion of a device, the layer of VSD material being arranged to protect one or more electrical components of the device from transient electrical conditions.

2. The method of claim 1, wherein determining one or more characteristics for integrating VSD material includes selecting one or more types of VSD material based on at least one of the criteria.

3. The method of claim 2, wherein identifying the one or more criteria includes identifying a threshold measure of energy that causes the VSD material to switch from a dielectric state to a conductive state in order to protect the one or more components from the transient electrical event, and wherein selecting one or more types of VSD material includes identifying a type of VSD material having a known characteristic measure of energy for causing a specified amount of that type of VSD material to switch from a dielectric state to be conductive.

4. The method of claim 3, wherein determining the one or more characteristics comprises determining a linear dimension of the layer that will separate the one or more components from the protective electrical path, wherein determining the one or more characteristics is based on: in determining a threshold measure of energy for switching the VSD material to the conductive state, a known characteristic measure of energy is applied to the linear dimension, the threshold measure of energy being less than an allowable level of the one or more components.

5. The method of claim 3, wherein determining one or more characteristics for integrating VSD material includes determining a plurality of locations on at least one layer of the device: at the plurality of locations, the layer of VSD material will protect one or more components from transient electrical events.

6. The method of claim 1, wherein the first step is carried out in a single step,

wherein identifying the one or more criteria comprises identifying, as one of the criteria, a threshold measure of energy that, when exceeded by the transient electrical event, causes the VSD material to switch from a dielectric state to a conductive state, thereby protecting the one or more components from the transient electrical event; and

wherein determining the one or more characteristics includes selecting a linear dimension of the VSD material that will define a gap separation between a component to be protected and a protective electrical path of a device,

wherein the threshold measure of energy at which the VSD material is switched from a dielectric state to a conductive state is dependent upon a linear dimension of the VSD material, an

Wherein selecting the linear dimension is based at least in part on making the threshold energy metric less than a tolerable energy metric processable by the one or more components.

7. The method of claim 6, wherein selecting the linear dimension includes identifying a characteristic voltage level for a specified measure of the VSD material, and wherein selecting the linear dimension includes using the characteristic voltage level to determine the linear dimension that provides a threshold voltage level for switching the VSD material into the conductive state that is less than an allowable voltage level of the one or more components or the device.

8. The method of claim 1, wherein identifying one or more criteria comprises identifying one or more voltage or current tolerances of one or more components to be protected on the device.

9. The method of claim 8, wherein the one or more tolerances include a breakdown voltage corresponding to a voltage level at which one or more components or other elements of the device may fail.

10. The method of claim 8, wherein identifying one or more criteria comprises identifying a tolerance of the one or more components for leakage current.

11. The method of claim 5, wherein identifying one or more criteria includes identifying a tolerance of the one or more components for leakage current, wherein the leakage current is dependent on a linear dimension, wherein selecting a linear dimension is based at least in part on the leakage current of the VSD material that determines the linear dimension.

12. The method of claim 11, wherein determining the one or more characteristics includes identifying a type of VSD material based at least in part on a leakage current produced by the VSD material for providing the threshold measure of energy across the linear dimension of gap separation.

13. The method of claim 12, wherein determining the one or more characteristics comprises identifying at least one of: (i) a threshold measure of energy provided by the VSD material based on a linear dimension of the gap separation, or (ii) a linear dimension of the gap separation required to provide a threshold energy level.

14. The method of claim 1, wherein identifying one or more criteria includes identifying a spatial constraint at the at least a portion of the location of the device where the layer of VSD material is to be provided.

15. The method of claim 14, wherein determining the one or more characteristics includes selecting a type of VSD material based in part on the identified spatial constraint.

16. The method of claim 15, wherein selecting the type of VSD material is based at least in part on the steps of:

identifying a threshold measure of energy that causes a selected type of VSD material to switch from a dielectric state to a conductive state, thereby protecting the one or more components from the transient electrical event, wherein the selected type of VSD material has a known characteristic measure of energy that causes a specified amount of the type of VSD material to switch from a dielectric state to conductivity, and

determining a linear dimension of the layer that will separate the one or more components from the protective electrical path by applying a known characteristic measure of energy to the linear dimension when determining a threshold measure of energy for switching the VSD material into the conductive state, the threshold measure of energy being less than an allowable level of the one or more components,

wherein the linear dimension satisfies the spatial constraint.

17. The method of claim 14, wherein determining the one or more characteristics includes determining an area to be occupied by the VSD material when separating one of the one or more components to be protected from the protective electrical path, wherein the area satisfies the spatial constraint.

18. The method of claim 17, wherein determining the one or more characteristics includes determining a linear dimension of VSD material separating one of the one or more components from the protective electrical path.

19. The method of claim 1, wherein determining the one or more characteristics for integrating VSD material includes determining a thickness of the layer of VSD material at one or more locations on the integrated circuit device based on the one or more criteria.

20. The method of claim 17, wherein determining the area comprises determining a shape of the area.

21. The method of claim 20, wherein determining the shape includes determining a shape of VSD material having a plurality of radii of curvature.

22. A system for fabricating a substrate device, the system comprising:

an interface configured to receive one or more criteria from a substrate device designer;

a memory resource storing information of at least one of a substrate or various types of Voltage Switchable Dielectric (VSD) material;

a processing resource coupled to the interface and the memory resource, the processing resource configured to use the input and information stored in the memory to:

identifying one or more criteria for handling transient electrical events on the substrate device; and

in accordance with the one or more criteria, one or more layers for integrating VSD material into or over at least a portion of the substrate device are determined, the layer of VSD material being arranged to protect one or more components of the substrate from transient electrical conditions.

23. The system of claim 22, further comprising a manufacturing interface in communication with a manufacturing workflow, wherein the processing resource is configured to generate substrate design data based at least in part on the determined one or more criteria for integrating VSD material, the substrate design data defining a design of a substrate to be manufactured, wherein the processing resource is configured to communicate the substrate design data to the manufacturing workflow.

24. The system of claim 22, wherein the memory resource stores a plurality of entries, each entry relating to a type of VSD material having one or more known characteristics, including at least one of: (i) a characteristic voltage level for switching a specified measure of the type of VSD material into a conductive state; or (ii) leakage current generated by a given measure of this type of VSD material.

25. A computer-implemented method for designing a substrate device in a design or simulation phase, the method comprising:

selecting, in response to an interaction with a designer, a plurality of locations on the substrate device that will provide a protective electrical pathway upon occurrence of a transient electrical event; at each of the plurality of locations, determining a dimension of a layer of Voltage Switchable Dielectric (VSD) material at the selected location, wherein the dimension of the layer of VSD material is selected based at least in part on a threshold measure of energy required to switch the layer of VSD material from a dielectric state to a conductive state, wherein the VSD material interconnects one or more components to a protective electrical path when the VSD material is in the conductive state.

26. The method of claim 25, wherein at one or more of the plurality of locations, the size of the layer of VSD material corresponds to a gap distance separating one or more components at that location from the protective electrical path, wherein the threshold measure of energy depends at least in part on the gap distance.

27. The method of claim 25, wherein the measure of energy corresponds to a threshold voltage level known to be within a tolerance of one or more components located at one or more of the plurality of locations.

28. A computer-implemented method for determining a spacing of one or more electrical components to be connectable on a substrate device, the method comprising:

identifying one or more electrical tolerances of the electrical component to be protected from the transient electrical event by the protective electrical path;

identifying a layer of Voltage Switchable Dielectric (VSD) material that is to provide gap separation between the electrical component and the protective electrical path; and

wherein the VSD material is switchable from a dielectric state to a conductive state by applying a measure of energy that exceeds a threshold level, wherein the threshold level is dependent at least in part on a size of the VSD material; and

the gap separation is sized such that a threshold level of an energy metric that results in the switching of the VSD material is less than one or more tolerances of the electrical components.

29. The method of claim 28, wherein identifying one or more electrical tolerances includes identifying a breakdown voltage of the electrical component, and wherein the VSD material is switchable from a dielectric state to a conductive state by applying a voltage that exceeds a threshold voltage level, wherein the threshold voltage level is dependent on a size of the gap separation.

30. The method of claim 28, wherein identifying one or more electrical tolerances includes identifying a leakage current tolerance for the electrical component, wherein the VSD material is known to produce a certain amount of leakage current, and wherein identifying the layer of VSD material includes configuring the layer of VSD material to produce a leakage current that is less than the leakage current tolerance for the electrical component.

31. The method of claim 30, wherein the leakage current of the VSD material is at least partially dependent on a size of the gap separation, wherein configuring the layer of VSD material includes specifying the size of the gap separation such that the leakage current produced by the VSD material is less than the leakage current tolerance of the electrical component.

32. The method of claim 30, wherein configuring the layer of VSD material includes selecting a composition of VSD material known to produce a certain amount of leakage current across the gap separation that is less than a leakage current tolerance of the electrical component.

33. The method of claim 28, further comprising sizing an area occupied by the layer of VSD material when providing the gap separation, wherein the sizing of the area is in view of or based on the one or more tolerances.

34. The method of claim 33, wherein the area is sized in view of one or more of: (i) a spatial constraint identified for the substrate, or (ii) a leakage current tolerance of the one or more components.

35. A system for implementing a design or simulation of at least a portion of a substrate device, the system comprising:

a data store holding data representing a first entry relating to a first type of Voltage Switchable Dielectric (VSD) material having one or more characteristics including a value characterizing a characteristic voltage per specified length corresponding to a known or specified voltage value that causes the first VSD material to switch from a dielectric state to a conductive state when applied across the specified length of the first VSD material;

a configuration module that determines, based on one or more interactions with a system designer: (i) one or more dimensional parameters based on one or more spatial constraints of the substrate or a portion of the substrate; and (ii) a voltage level allowable for one or more electrical components to be protected during a portion of the substrate; and

wherein the configuration module determines a gap separation that (i) will be provided by the first layer of VSD material on at least a portion of the substrate, and (ii) separates at least one electrical component from a protective electrical path for a transient event on the substrate, wherein the configuration module determines the gap separation based at least in part on: (i) determine a threshold voltage level suitable for switching the first VSD material into a conductive state, (ii) determine a size based on the characteristic voltage per specified length and the gap separation, wherein the threshold voltage level is less than an allowable voltage level of the one or more electrical components.

36. The system of claim 35, wherein the first programmatic component relates to a plurality of entries, each entry associated with a respective one of the VSD material, the plurality of entries including a first input associated with the first VSD material, wherein the respective VSD material of each entry of the plurality of entries has a different composition.

37. An optimization system for implementing a design or simulation of at least a portion of a substrate device, the system comprising:

a data store holding information related to a plurality of types of Voltage Switchable Dielectric (VSD) material, the information including a characteristic voltage per specified length for each of one or more types of VSD material, the characteristic voltage per specified length corresponding to a voltage level applied across a specified length of a particular type of VSD material, the voltage level being suitable for triggering the type of VSD material to switch from a dielectric state to a conductive state;

a configuration module that determines from one or more interactions with a system designer: (i) one or more dimensional parameters based on a spatial constraint of the substrate or a portion of the substrate; and (ii) a voltage level allowable for one or more electrical elements to be protected in a portion of the substrate device;

wherein the configuration module is configured to determine, for any of the plurality of types of VSD material, a gap separation that (i) will be occupied by that type of VSD material on at least a portion of the substrate, and (ii) separates at least one electrical element from a protective electrical path for the transient event, wherein the configuration module is further configured to determine, for any of the plurality of types of VSD material, a gap separation required to use the layer of VSD material to separate at least one electrical element from the protective electrical path;

an optimization component configured to select at least one of: (i) select a selected type of VSD material from the plurality of types of VSD material, or (ii) a size of the gap separation to which the selected type of VSD material corresponds, wherein the optimization component is configured to select based on one or more optimization criteria.

38. The system of claim 37, wherein the optimization component is configured to select based at least in part on using a determination of a threshold voltage level required to switch either type of VSD material into a conductive state, the threshold voltage level determined according to: (i) a characteristic voltage per specified length of VSD material of the type, and (ii) a size of the gap separation; wherein said optimizing means makes said selection such that the threshold voltage level is less than the allowable voltage level of said one or more components.

39. The system of claim 37, wherein the one or more optimization criteria are equivalent to at least one of: (ii) the cost of using each type of VSD material, (ii) the performance of each type of VSD material, and (iii) the minimum value of gap separation size required to use each type of VSD material.

40. A system for application of a voltage switchable dielectric material on a substrate device, the system comprising:

an interface configured to receive one or more criteria from a designer of a substrate device;

a memory resource storing information about a substrate or at least one of a plurality of types of Voltage Switchable Dielectric (VSD) material;

a processing resource coupled to the interface and memory resource, the processing resource configured to use the input and information stored in memory for:

identifying one or more criteria for handling transient electrical events on the substrate device;

determining, based on the one or more criteria, one or more characteristics for integrating the VSD material as a layer within or over at least a portion of the substrate device, the layer of VSD material being arranged to protect one or more components of the substrate from the transient electrical condition;

identifying one or more optimization criteria for integrating VSD material onto at least a portion of a substrate; and

optimizing the layer of VSD material based on the one or more optimization criteria.

41. The system of claim 40, wherein the one or more optimization criteria include one or more of: (i) a cost of the layer of VSD material, (ii) one or more dimensions of the layer of VSD material, and (iii) performance characteristics of the layer of VSD material.

42. A data system for implementing a design or simulation of a substrate device, the data system comprising:

a data store accessible to a configuration module for integrating VSD material into a substrate device, wherein the data store holds a plurality of entries, wherein each entry (i) identifies a type of VSD material, and (ii) includes data identifying one or more electrical characteristics of this type of VSD material that are suitable for integrating the type of VSD material into a substrate device,

wherein the one or more electrical characteristics of the type of VSD material include any one or more of: (i) a characteristic measure of energy suitable to cause the type of VSD material to switch from a dielectric state to a conductive state when applied to a specified measure of the type of VSD material, (ii) a leakage current associated with the type of VSD material; or (iii) an off-state resistance associated with the type of VSD material.

43. The data system of claim 42, wherein each entry includes data identifying a leakage current for a specified amount of the type VSD material.

44. The data system of claim 42, wherein each entry includes data identifying a characteristic energy metric as the characteristic voltage level that causes the VSD material to switch into a conductive state when it is applied to a specified linear dimension of the VSD material.

45. The data system of claim 42, further comprising an interface coupling the data storage to one or more modules for configuring the substrate device with VSD material during a design or simulation phase.

46. A computer-implemented method for designing a display device in a design or simulation phase, the method comprising:

identifying one or more criteria for handling a transient electrical event on a display device, wherein identifying the one or more criteria is based at least in part on input provided by a designer; and

in accordance with the one or more criteria, one or more layers are determined at selected locations between one or more locations for integrating Voltage Switchable Dielectric (VSD) material as transparent conductors and protective electrical pathways of a display device, the layer of VSD material being provided at the selected locations to protect one or more components of the display device from transient electrical conditions.