WO2025086019A1

WO2025086019A1 - Instrumented heater and method for testing cooling devices

Info

Publication number: WO2025086019A1
Application number: PCT/CA2024/051419
Authority: WO
Inventors: Michael Hinton; Laurent MYDLARSKI
Original assignee: Hypertechnologie Ciara Inc
Current assignee: Hypertechnologie Ciara Inc
Priority date: 2023-10-26
Filing date: 2024-10-25
Publication date: 2025-05-01
Anticipated expiration: 2026-04-26

Abstract

An instrumented heater, a cooling device test apparatus and a processed substrate. The instrumented heater comprises at least two cells, each cell comprising: at least one heating element, at least one temperature sensor, and at least one external connector; wherein each one of the at least one heating element and each one of the at least one temperature sensor are connected to the at least one external connector; and wherein the at least one heating element, the at least one temperature sensor, and the at least one external connector are contained within a respective cell, and are independent of any other cell of the at least two cells.

Description

Instrumented Heater and Method for Testing Cooling Devices

RELATED APPLICATION

[0001] The present application claims priority to or benefit of United States provisional patent application No. 63/545,830, filed October 26, 2023, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

[0002] The present disclosure relates to the cooling of electronics. More specifically, it relates to apparatuses and methods for testing cooling devices.

BACKGROUND

[0003] Various electronic components generate heat during operation and need to be cooled by cooling devices. One example of such an electronic component is a processor. When developing cooling devices for electronic components, the operation and performance of the cooling devices need to be tested. To test the effectiveness of cooling devices for electronics, an actual electronic component or, preferably, a test device may be used. The test device needs to imitate the operation of the electronic component by providing similar heating characteristics.

[0004] The test devices that are currently available are designed for one type of electronic component (for example, for a processor or for a power transistor) or for one specific electronic component (for example, for processor “A” or for processor “B”). None of the currently available (conventional) test devices can imitate several heat-generating electronic components without physically changing the internal components of the test devices.

SUMMARY

[0005] According to one aspect of the disclosed technology, there is provided an instrumented heater, comprising: at least one cell, each cell comprising: at least one heating element, at least one temperature sensor, and at least one external electrical connector; wherein each one of at least one heating element and each one of the at least one temperature sensor are connected to the at least one external electrical connector; and wherein the at least one heating element, the at least one temperature sensor, and the at least one external electrical connector are contained within their respective cell, and are independent of any other cells of the at least one cell or any other cell of the instrumented heater. Each one of the at least one heating element may be a resistor. Each one of the at least one temperature sensor may be a resistor with resistivity that is sensitive to temperature variation. The functionality of the at least one heating element and the at least one temperature sensor may be combined into a single component having both heating and sensing functionality. The cell components may be surrounded by an electrically insulating material. The at least one cell may be supported by and fabricated on a substrate layer. The heating element and the temperature sensor may be separated into one or more layers. The instrumented heater may further comprise at least one internal electrical connection connecting the heating elements and the temperature sensors to the external electrical connectors, and wherein at least one internal electrical connection is contained within the respective cell, and is independent of other cells.

[0006] According to another aspect of the disclosed technology, there is provided a processed substrate, comprising a substrate layer; at least one cell, wherein the at least one cell are supported by and fabricated on the substrate layer; and wherein the at least one cell each comprises at least one or more heating elements, at least one temperature sensor, and at least one external electrical connector; wherein the at least one heating element and the at least one temperature sensors are connected to the at least one external electrical connector; wherein the at least one heating element, the at least one temperature sensor and the at least one external electrical connector are contained within their respective cell, and are independent of other cells of the processed substrate.

[0007] From the processed substrate as disclosed herein, groupings of cells may be cut out to form instrumented heaters. The functionality of the one or more heating elements and the one or more temperature sensors may be combined into a single component. The heating elements, the temperature sensors and external electrical connectors may be surrounded by an electrically insulating material. The heating element and the temperature sensor may be separated into one or more layers. The at least one heating element may be located in a heating layer, the at least one temperature sensor may be located in a temperature sensor layer, and the at least one external electrical connector may be located in an external connector layer, wherein the heating layer, the temperature sensor layer and the external connector layer may be positioned one over another in the processed substrate.

[0008] According to a further aspect of the disclosed technology, a cooling device test system for testing the performance of a cooling device is provided. The cooling device test system comprises: at least one instrumented heater for heating the cooling device and measuring the temperature; a thermal control system for powering the at least one instrumented heater and recording its temperatures; and an external circuit for electrically connecting the at least one instrumented heater to the thermal control system. Each one of the instrumented heaters may comprise: at least one cell; a test surface for contacting the cooling device; wherein each cell comprises at least one heating element, at least one temperature sensor, and at least one external electrical connectors; wherein the at least one heating element and the at least one temperature sensor are connected to the at least one external electrical connectors; and wherein the at least one heating element, at least one temperature sensor and at least one external electrical connector are contained within their respective cell, and are independent of other cells of the instrumented heater.

[0009] The cooling device test system may further comprise a cooling device attachment system to fasten the cooling device on top of the one or more instrumented heaters. The cooling device test system may further comprise a thermal interface material between the one or more instrumented heaters and the cooling device.

[0010] The cooling device test system may further comprise at least one internal electrical connection connecting the heating elements to the external electrical connectors and the temperature sensors to the external electrical connectors, and wherein at least one internal electrical connection is contained within the respective cell, and is independent of other cells. The heating layer having the heating elements, the temperature sensor layer having the temperature sensors and the external connector layer with the external electrical connectors may be positioned one over another.

[0011] According to aspects of the disclosed technology, there are provided an instrumented heater, a cooling device test apparatus and a processed substrate. In at least one embodiment, the instrumented heater comprises at least one cell, each cell comprising: at least one heating element, at least one temperature sensor, and at least one external electrical connector; wherein each one of at least one heating element and each one of at least one temperature sensor are connected to the at least one external electrical connector; and wherein the at least one heating element, the at least one temperature sensor, and the at least one external electrical connector are contained within their respective cell, and are independent of other cells of the at least one cell.

[0012] In at least one embodiment, the instrumented heater has at least one cell comprising at least one heating element, at least one temperature sensor, and at least one external connector; wherein each one of the at least one heating element and each one of the at least one temperature sensor are connected to the at least one external connector; and wherein the at least one heating element, the at least one temperature sensor, and the at least one external connector are contained within each respective cell, wherein the at least one heating element, the at least one temperature sensor, and the at least one external connector are contained within a respective cell, and are independent of any other cell of the instrumented heater.

[0013] According to one aspect of the disclosed technology, there is provided an instrumented heater comprising: at least two cells, each cell comprising: at least one heating element, at least one temperature sensor, and at least one external connector; wherein each one of the at least one heating element and each one of the at least one temperature sensor are connected to the at least one external connector; and wherein the at least one heating element, the at least one temperature sensor, and the at least one external connector are contained within a respective cell, and are independent of any other cell of the at least two cells. Each one of the at least one heating element may be a resistor. Each one of the at least one temperature sensor may be a resistor with resistivity that is sensitive to temperature variation. In at least one embodiment, at least one external connector is an electrical connector. In at least one embodiment, each one of the at least one external connector is an electrical connector. One of the at least one heating element and one of the at least one temperature sensor may be combined into a single component having both heating and sensing functionality. The at least one heating element, the at least one temperature sensor, and the at least one external connector of the respective cell may be surrounded by an electrically insulating material. The at least two cells may be supported by and fabricated on a substrate. Each cell may comprise a portion of a substrate.

[0014] The at least one heating element and the at least one temperature sensor may be located in one layer or in more than one layers. In at least one embodiment, in addition to the heating element and temperature sensor, the same layer of the cell may also have the external connectors, and, in some embodiments, interconnects and/or trace interconnects). In at least one embodiment, the components are all in the same plane and, in some embodiments, they have the same distance from the plane test surface, when the components are manufactured on the substrate.

[0015] The instrumented heater may further comprise at least one internal electrical connection connecting the at least one heating element and the at least one temperature sensor to the at least one external connector of the respective cell, and wherein the at least one internal electrical connection is contained within the respective cell, and is independent of any other cell of the at least two cells.

[0016] In at least one embodiment, the at least one heating element, the at least one temperature sensor, and the at least one external connector of one cell are located in one layer or in more than one layers. For example, the at least one heating element, at least one temperature sensor, and at least one external connector of one cell may be located in one layer. In at least one embodiment, the at least one heating element, at least one temperature sensor, and at least one external connector of one cell are located in one layer or more than one layers, and on a portion of the substrate.

[0017] In at least one embodiment, the at least one heating element is located in a heating layer, the at least one temperature sensor is located in a temperature sensor layer, and the at least one external connector is located in an external connector layer, wherein the heating layer, the temperature sensor layer and the external connector layer are positioned one over another. For example, the heating layer may be located between the temperature layer and the external connector layer.

[0018] Each cell may further comprise at least one internal electrical connection connecting the at least one heating element to the at least one external connector and connecting the at least one temperature sensor to the at least one external connector, and wherein the at least one internal electrical connection is contained within the respective cell and is independent of any other cell of the at least two cells of the instrumented heater. The instrumented heater may further comprise at least one additional cell having at least one temperature sensor or at least one heating element. The instrumented heater may further comprise a buffer cell made of one material. In at least one embodiment, the buffer cell is made without any temperature sensor and without any heating element. The buffer cell may be made of an insulating material and/or the substrate. In at least one embodiment, the buffer cell comprises at least one external connector.

[0019] Each cell of the at least two cells of the instrumented heater may be configured to connect separately to a combined thermal control system configured to measure and control a temperature of the respective cell. In at least one embodiment, the instrumented heater is configured to connect to the combined thermal control system via the at least one external connector.

[0020] According to another aspect of the disclosed technology, there is provided a processed substrate comprising at least one instrumented heater, having each instrumented heater as described herein, wherein the at least two cells of each one of the at least one instrumented heater are supported by and fabricated on one substrate. In at least one embodiment, a processed substrate comprises at least two instrumented heaters, having each instrumented heater as described herein, wherein the at least two cells of each one of the at least two instrumented heaters are supported by and fabricated on one substrate.

[0021] According to a further aspect of the disclosed technology, there is provided a processed substrate comprising: a substrate; and at least two cells supported by and fabricated on the substrate; wherein each cell of the at least two cells comprises at least one heating element, at least one temperature sensor, and at least one external connector; wherein each one of the at least one heating element and each one of the at least one temperature sensor are connected to the at least one external connector; and wherein the at least one heating element, the at least one temperature sensor and the at least one external connector are contained within a respective cell, and are independent of any other cell of the at least two cells. Each cell may further comprise at least one internal electrical connection connecting the at least one heating element to the at least one external connector and connecting the at least one temperature sensor to the at least one external connector, and wherein the at least one internal electrical connection is contained within the respective cell and is independent of any other cell of the at least two cells of the processed substrate. In at least one embodiment, the processed substrate comprises one instrumented heater or more than one instrumented heaters, where each instrumented heater is formed by one cell or by more than one cell as described herein.

[0022] In at least one embodiment, groupings of cells (a plurality of cells) may be cut out from the processed substrate to form at least one instrumented heater. In at least one embodiment, the processed substrate may have at least four cells which may form at least two instrumented heaters each having two or more cells. One of the at least one heating element and one of the at least one temperature sensor may be combined into a single component having both heating and sensing functionality. The at least one heating element, the at least one temperature sensor and the at least one external connector may be surrounded by an electrically insulating material. The at least one heating element and the at least one temperature sensor may be located in one or more layers. In at least one embodiment, the at least one heating element may be located in a heating layer, the at least one temperature sensor is located in a temperature sensor layer, and the at least one external connector is located in an external connector layer, wherein the heating layer, the temperature sensor layer and the external connector layer are positioned one over another.

[0023] According to another aspect of the disclosed technology, there is provided a cooling device test system for testing performance of a cooling device, comprising: at least one instrumented heater for heating the cooling device and measuring temperature; a thermal control system for powering the at least one instrumented heater and recording temperatures; and an external circuit for electrically connecting the at least one instrumented heater to the thermal control system.

[0024] Each instrumented heater of the at least one instrumented heater may comprise: at least two cells; a test surface for contacting the cooling device; wherein each one of the at least two cells comprises at least one heating element, at least one temperature sensor, and at least one external connector; wherein each one of the at least one heating element and each one of the at least one temperature sensor are connected to the at least one external connector; and wherein the at least one heating element, the at least one temperature sensor and the at least one external connector are contained within a respective cell, and are independent of any other cell of the at least two cells. The cooling device test system may further comprise a cooling device attachment system to fasten the cooling device on top of the at least one instrumented heater. The cooling device test system may further comprise a thermal interface material between the at least one instrumented heater and the cooling device.

[0025] The cooling device test system may further comprise at least one internal electrical connection connecting the at least one heating element to the at least one external connector and connecting the at least one temperature sensor to the at least one external connector, and wherein the at least one internal electrical connection is contained within the respective cell, and is independent of any other cell of the at least two cells.

[0026] In at least one embodiment, the at least one heating element is located in a heating layer, the at least one temperature sensor is located in a temperature sensor layer, and the at least one external connector is located in an external connector layer, wherein the heating layer, the temperature sensor layer and the external connector layer are positioned one over another. In at least one embodiment, the cooling device test system may be used for testing the cooling device.

[0027] An instrumented heater, a cooling device test apparatus and a processed substrate are described. In at least one embodiment, the instrumented heater comprises at least two cells, each cell comprising: at least one heating element, at least one temperature sensor, and at least one external connector; wherein each one of the at least one heating element and each one of the at least one temperature sensor are connected to the at least one external connector; and wherein the at least one heating element, the at least one temperature sensor, and the at least one external connector are contained within a respective cell, and are independent of any other cell of the at least two cells.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Further features and advantages of the present disclosure will become apparent from the following detailed description, taken in combination with the appended drawings, in which:

[0029] Fig. 1 illustrates a top view of an instrumented heater, according to at least one embodiment of the present disclosure;

[0030] Fig. 2 is a top view of a temperature sensor layer of one cell of the instrumented heater of Fig. 1 , according to at least one embodiment of the present disclosure;

[0031] Fig. 3 is a top view of the cell of Fig. 2, illustrating a heater layer superimposed over the temperature sensor layer, according to at least one embodiment of the present disclosure;

[0032] Fig. 4 is a top view of the cell of Fig. 2, illustrating a via interconnect layer with vias etched through the other layers and filled with interconnect material, according to at least one embodiment of the present disclosure;

[0033] Fig. 5 is a top view of the cell of Fig. 2, illustrating an external connector layer superimposed over the via interconnect layer, the heater layer and the temperature sensor layer, according to at least one embodiment of the present disclosure; [0034] Fig. 6 is a side cross-section illustrating the cell of Fig. 2, and the layers of the cell, as well as a thermal control system (also referred to herein as a “thermal control unit”) and a cooling device, according to at least one embodiment of the present disclosure;

[0035] Fig. 7 is a cooling device test apparatus using the instrumented heater of Fig. 1 , in accordance with at least one embodiment of the disclosure;

[0036] Fig. 8 is a top view of a processed substrate, with cells of Fig. 2, from which instrumented heaters of Fig. 1 are cut, according to at least one embodiment of the present disclosure;

[0037] Fig. 9A illustrates a top view of a cell, illustrating a combined temperature sensor and heater layer, where cell components are located side by side, in accordance with at least one embodiment of the present disclosure; and

[0038] Fig. 9B illustrates a side cross-section of the cell of Fig. 9A, in accordance with at least one embodiment of the present disclosure.

[0039] It will be noted that throughout the appended drawings, like features are identified by like reference numerals.

DETAILED DESCRIPTION

[0040] Various aspects of the present disclosure generally address one or more of the problems of simulating the operation of an electronic device for testing cooling devices.

[0041] The present description provides an apparatus (device) fortesting cooling devices, which is referred to herein as an “instrumented heater”. The description also provides a processed (fabrication) substrate for manufacturing the instrumented heater and a cooling device test system for testing the performance of the cooling device.

[0042] When referred to herein, terms “cooling device under test”, "cooling DUT", “device under test”, “cooling device”, or "DUT" refer to a cooling device being tested by the instrumented heater.

[0043] When used herein, the expression “at least one of A or B” means at least one of A or at least one of B, ora combination of one or more A and a combination of one or more B. When used herein, the expression “A and/or B” means only A, or only B, or both A and B. When used herein, the expression “A, B and/or C” means only A, or only B, or only C, or both A and B, or both A and C, or both B and C, or A and B and C.

[0044] According to embodiments of the present description, the instrumented heater as described herein may be used to test performance of cooling devices (for processors, electronics and other heat-generating devices). The instrumented heater as described herein simulates (is configured to simulate) the heat generation, heat profile, thermal characteristics, and a form factor of a processor. In addition to these functionalities, the instrumented heater as described herein allows controlling the generated heat and has on-board temperature sensors. The heater is "instrumented" because it is equipped with temperature sensors. The instrumented heater as described herein may be also referred to as the “instrumented pseudo processor” or “IPP”, which alludes to the instrumented heater’s advanced capabilities and better describes its planar, processorlike form factor. The terms “instrumented heater”, “instrumented pseudo processor”, and “IPP” are used interchangeably in the present disclosure and have the same meaning.

[0045] When referred to herein, the term “processor” refers to a heat-generating device that the IPP as described herein simulates. However, the applications (use) of the IPP are not limited to simulating processors only. The IPP can be used to simulate other electronics or heat-generating devices. In a non-limiting example of the application and use of the IPP, the description below generally compares the operation of the IPP to a processor.

[0046] Fig. 1 schematically illustrates a top view of an instrumented heater 100 (also referred to herein as an “instrumented pseudo processor 100” and “IPP 100”) for testing cooling devices, according to at least one embodiment of the present disclosure. The instrumented heater 100 in Fig. 1 has several cells 101.

[0047] The instrumented heater 100 comprises one or more unit cells 101 (referred to herein as “cells 101” or “main cells 101”), each cell 101 having its own heater(s), temperature sensor(s), external connectors, and interconnects. Consequently, each cell 101 of the instrumented heater 100 is self-contained and may be operated independently of the other cells 101.

[0048] Each cell 101 is defined by a cell border 102, which is illustrated in Figs. 2-6 with a dotted line because it outlines a border of a portion of the instrumented heater 100. Referring to Figs. 2-6, each cell 101 comprises the following cell components: at least one temperature sensor 201 (Fig. 2), at least one heating element 301 (also referred to herein as a “heater 301” and a “cell heater 301”, Fig. 3), and at least one external connector 502 (Fig. 5). In at least one embodiment, the external connector 502 is electrical and may be also referred to as an “external electrical connector”. Each cell 101 may also have at least one internal electrical connection 401 (also referred to herein as an “interconnect 401”, Fig. 4). When referred to herein, the term “cell components 201 , 301 , 401 , 502” means one or more temperature sensors 201 , one or more heating elements 301 , one or more external connectors 502, and, optionally, one or more internal electrical connections 401 , and in some embodiments, optional trace interconnects 501. [0049] Each cell 101 is self-contained, meaning each cell 101 has all of the cell components 201 , 301 , 401 , 502 to work on its own, without needing connections to other cells of the instrumented heater 100 or, for example, to a non-cell interconnect area. This means that the instrumented heater 100 may be diced into its individual cells, and each individual cell still works properly on its own (in other words, is still capable to work properly on its own). This provides flexibility during cell layout design and fabrication. For example, the instrumented heater 100 may have its shape adapted to the cooling DUT 801 (also referred to herein as the “cooling device 801”).

[0050] By applying different power levels to the heating elements 301 of different cells 101 , a so-called “heat profile”, which is nonuniform (different levels of heat in different locations of the instrumented heater 100), may be generated similar to those generated by real processors and other electronics. In response to the provided heat profile, a cooling DUT 801 (illustrated, for example, in Fig. 7), which at least partially touches the instrumented heater 100, cools the instrumented heater 100. The cell temperature sensors 201 located in each cell 101 measure temperature of each cell 100 and therefore obtain a so-called “temperature profile” of the instrumented heater 100, which helps to evaluate performance of the cooling DUT 801. The “temperature profile” comprises a set of time-temperature data based on measurement of temperatures by the cell temperature sensors 201.

[0051] Referring to Fig. 6, cell components 201 , 301 , 401 , 502 are manufactured in layers 200, 300, 400, 500, in at least one embodiment illustrated in Fig. 6 on a portion of a substrate 601 (the substrate 601 is also referred to herein as an “initial substrate 601”), and connections between the layers 200, 300, 400, 500 of the same cell 101 are made by the interconnects 401. In some embodiments, the cell 101 with cell components 201 , 301 , 502 (and in some embodiments with interconnects 401 and/or trace interconnects 501) may be manufactured without a substrate.

[0052] The temperature sensor 201 is implemented in a temperature sensor layer 200 (Fig. 2). The heating element 301 is implemented in a heating layer 300 (Fig. 3). The trace interconnects 501 are implemented in an external connector layer 500 (Fig. 5). The interconnects 401 are implemented partially in a via interconnect layer 400 (Fig. 4), while a portion of the interconnects 401 is also present in the heater layer 300 as illustrated in Fig. 6.

[0053] Fig. 6 is a side cross-sectional schematic representation of the cell 101 connected to a thermal control unit 1002, and a portion of the cooling DUT 801 , in accordance with at least one embodiment of the present disclosure. Fig. 6 illustrates the temperature sensor layer 200, the heating layer 300, the interconnect layer 400, and the external connector layer 500 of the cell 101 of the instrumented heater 100 (collectively referred to herein as “layers 200, 300, 400, 500”), and how they are interconnected. In at least one embodiment, the heating layer 300, the temperature sensor layer 200 and the external connector layer 500 are positioned one over another. [0054] The layers 200, 300, 400, and 500 are electrically separated from each other with an electrically insulating material referred to herein as an insulating material 602 which is a dielectric insulating material. In at least one embodiment, the heating element 301 , the temperature sensor 201 , and the external connector 502 of the cell are surrounded by the electrically insulating material. Different layers of the cell 101 are made of different materials.

[0055] Fig. 6 illustrates also the portion of the substrate 601 of the cell 101. In some embodiments, the cell 101 does not have the portion of the substrate 601 illustrated in Fig. 6 when the cell 101 is manufactured without any substrate 601. The cell 101 has a test surface 603 (which, in some embodiments, is also the surface of the portion of the substrate 601) that, in operation, is connected to a cooling DllT’s surface 803. The test surface 603, where the cooling DUT 801 (illustrated in Figs. 6, 7) is attached, is the surface on the side of the substrate 601 opposite to the location of the major components 201 , 301 , 401 , 502 of the cell 101. The multi-layer design of the cell 101 of the instrumented heater 100 ensures that the temperature sensor 201 measures cell temperature directly between the heating element 301 and the test surface 603.

[0056] In at least one embodiment, each cell 101 of the instrumented heater 100 may have more than one temperature sensor 201 and/or more than one heating element 301. In some embodiments, one or more cells 101 of the instrumented heater 100 may lack the temperature sensor 201 and/or the heating element 301. For example, the instrumented heater 100 may comprise at least one additional cell having either at least one temperature sensor or at least one heating element. In at least one embodiment, the additional cell may also comprise at least one external connector. The instrumented heater 100 may comprise at least one buffer cell made of one material. The buffer cell is made without any temperature sensor 201 and without any heating element 301. For example, the material of the buffer cell may be an insulating material and/or the substrate. In at least one embodiment, the buffer cell may comprise at least one external connector 502. In at least one embodiment, the instrumented heater 100 has, in addition to two or more cells 101 (main cells), one or more additional cell and/or one or more buffer cells. In at least one embodiment, in addition to main cells 101 of the instrumented heater 100 as described herein, having both the at least one heating element 301 and at least one temperature sensor 201 , one or several additional cells of the instrumented heater 100 may have at least one heating element 301 or at least one temperature sensor 201 , and at least one external connector 502.

[0057] In at least one embodiment, the temperature sensor 201 and the heating element 301 may be combined into a single component. In some embodiments, a single component may have the functionality (combined functionality) of both the heating element 301 and the temperature sensor 201. In other words, the heating element 301 and the temperature sensor 201 may be combined into a single component having both heating and sensing functionality. For example, combining the heating element 301 and the temperature sensor 201 is possible, for example, with a resistancebased heater if one may simultaneously measure how its resistance changes with temperature while providing power for heating. In other words, combining the heating element 301 and the temperature sensor 201 may be possible, for example, for the resistance-based heater, if changes in temperature may be determined based on measured changes in resistance, when the resistance-based heater is heated.

[0058] In at least one alternative embodiment, the vertical order of the layers 200, 300, 400, 500 in Fig. 6 may be changed in many ways. In some embodiments, the location of the substrate 601 may be changed compared to the layers 200, 300, 400, 500 of Fig. 6. For example, in at least one embodiment, the heating element 301 and the temperature sensor 201 may be located on one side of the substrate 601 , while the external connectors 502 may be located on the other side of the substrate 601 , and thus the heating element 301 and the temperature sensor 201 may be connected to the external connectors 502 by the interconnects 401 going through (crossing, traversing) the substrate 601.

[0059] In at least one embodiment, the cell components 201 , 301 , 401 , 502 may be located side by side, such that the cell 101 may be designed not in layers (as illustrated in Figs. 2-6) but in a side- by-side construction. In other words, the cell 101 may be designed to have only one layer where all the components of that cell 101 are located. When referred to herein, the expressions “side by side” and “side-by-side” mean that several components, such as the temperature sensor 201 , the heating element 301 , and in some embodiments the external connectors 502, and in some embodiments interconnects 401 and/or trace interconnects 501 , are located in the same one layer and in/on the same plane with reference to the test surface 603 of the cell 101 that is to be attached to the DllT’s surface 803. For example, the temperature sensor 201 may be located centrally and the heating element 301 surrounding the temperature sensor 201 (for example, concentrically).

[0060] Figs. 9A, 9B illustrate a top view and a side cross-sectional view of a non-limiting example of a cell 101a (which may be referred to as the “side-by-side cell 101a”) where the cell components are located side by side, in accordance with at least one embodiment of the disclosure. The side-by-side cell 101a is an embodiment of the cell 101 described herein and used in the instrumented heater 100, processed substrate 820 and the cooling device test system as described herein. In Figs. 9A, 9B, the temperature sensor 201 and the heating element 301 are located (positioned) on the same plane (in the same layer) with respect to the test surface 603 of the cell 101a, while the external connectors 502 are located in another layer. Vias for the heating element 301 , which are present in the side-by-side cell 101a, are not depicted in Fig. 9B because they are not visible in this view.

[0061] In at least one embodiment, the cell 101 may have a combination of components 201 , 301 , 401 , 502 and layers positioned next to each other. For example, at least one heating element 301 and at least one temperature sensor 201 may be located in one layer or in more than one (two or more) layers. In at least one embodiment, the heating element 301 and the temperature sensor 201 may be located side by side in the same layer (in other words, next to each other in the same layer and not one over another as in layers) while the external connectors 502 are located in another layer. In another embodiment, all components 201 , 301 , 401 , 502 may be positioned side by side in the same layer. In at least one embodiment, all components of the same cell 101 may be located in the same one layer. In at least one embodiment, the components of the cell 101 may be located in more than two layers.

[0062] In at least one embodiment, the cell components 201 , 301 , 401 , 501 , 502 may be any other size (not necessarily having the dimensions depicted in Figs. 1-6). Moreover, dimensions (sizes) of the cell components 201 , 301 , 401 , 501 relative to one another may be different from the relative dimensions (sizing) depicted in Figs. 1-6.

[0063] Examples of the designs of the cell components 201 , 301 , 401 , 501 , 502 (e.g., the component shapes) illustrated in Figs. 1-8 are nonlimiting, and the designs of the cell components 201 , 301 , 401 , 501 may be different from the illustrated embodiments.

[0064] In at least one embodiment, the cell components 201 , 301 , 401 , 502 of several cells 101 of the instrumented heater 100 may have designs that are different from each other, and the designs of cell components 201 , 301 , 401 , 502 may be different for two different cells 101 of the instrumented heater 100. For example, the instrumented heater 100 may have cells 101 with different numbers of temperature sensors 201 , or the instrumented heater 100 may have cells 101 with heating elements 301 of different shapes.

[0065] The present description provides a constant heat-flux use case in which a predetermined, constant power is sent to the heating elements 301 , and the temperature is measured. In other words, the instrumented heater 100 as described herein uses a constant heat flux such that a predetermined, constant power is transmitted to the heating elements 301 while the sensor temperature is measured by the temperature sensor(s) 201. In another embodiment, the cell 101 may be configured to operate in a constant temperature mode in which a predetermined constant temperature value is set for the cell 101 , and a thermal control unit 1002 (schematically illustrated in Figs. 6, 7, and also referred to herein as a “thermal control system 1002”) adjusts and records the power supplied to the heating element(s) 301 of the cell 101 actively to achieve that predetermined constant temperature (for example, by a proportional-integral-derivative (PID) control). In at least one embodiment, the thermal control unit 1002 is configured to record the sensor temperature received from the temperature sensor(s) 201.

[0066] Fig. 2 illustrates a top view of a single cell 101 of the instrumented heater 100, and its temperature sensor layer 200, according to at least one embodiment of the present disclosure. The temperature sensor 201 is implemented and is visible in the temperature sensor layer 200 of the cell 101.

[0067] In at least one embodiment, as illustrated in Fig. 2, the temperature sensor 201 is a resistance temperature detector (RTD) (for example, having four wires 204), which is a resistor that changes resistance depending on the temperature. In other words, the resistor may have resistivity that is sensitive to temperature variation. The resistance is measured externally, via sensor connections 210 running between the four wires 204 and the thermal control unit 1002 (illustrated schematically in Fig. 6), and converted to an equivalent temperature by the thermal control unit 1002. For example, the temperature may be determined by converting the measured analog electrical resistance to a digital resistance (number) using an analog-to-digital converter (ADC), and then converting the digital resistance (number) to an equivalent digital temperature (number) taking into account characteristics of the temperature sensor.

[0068] The resistor 201 as illustrated in Fig. 2 is made using a thin sensor material patterned into a serpentine shape to increase the resistance and thus the sensitivity of the temperature sensor 201. The sensor material of the temperature sensor 201 may be, for example, and preferably, a metal (for example, platinum or copper) that has a linear resistance-temperature relationship, which may provide accurate temperature measurement, which may be used to determine a test surface temperature which corresponds to the temperature at the test surface 603 of the cell 101 and evaluate the performance of the cooling DUT 801 .

[0069] In some embodiments, a 2-wire RTD or a 3-wire RTD may be used as the temperature sensor 201. Other types of temperature sensors, such as, for example, thermistors or thermocouples, may be used as the temperature sensor 201. Multiple temperature sensor layers 200, each temperature sensor layer 200 having its own temperature sensor(s) 201 , may be used, which may enable the estimation of heat flux across the layers of the cell 101 (for example, along the z-axis in Fig. 6).

[0070] The cell 101 may have other electronics related to the temperature sensor 201 and built into the cell 101. For example, the cell 101 may have a transmitter or an analog-to-digital converter (ADC). The ADC may provide as an output the measured temperature (temperature measurement) digitally, rather than by the analog voltage, resistance, or current.

[0071] The cells 101 may also have additional sensors, such as, for example, dedicated heat flux sensors or strain sensors.

[0072] Fig. 3 is a top view of the cell 101 of Fig. 1 illustrating a heater layer 300 superimposed over the temperature sensor layer 200, according to at least one embodiment of the present disclosure. The heating element 301 is a resistor that generates heat by applying a voltage and a current across it. The heating element 301 may have a serpentine shape that creates (generates) a more uniform heat flux across the cell 101. Furthermore, it is designed for maximum coverage area to also ensure that the cell heat flux profile is uniform.

[0073] Preferably, the heating element 301 may be made from a material that does not change resistance with changes in temperature (for example, a metal such as nickel-chromium). If the resistance does change with temperature, then the voltage levels and current levels need to be actively controlled to maintain the desired power level. In at least one embodiment, any other types of heating elements (heaters) may be used, such as, for example, a silicon diode.

[0074] In some embodiments, other electronics, such as voltage amplifiers, may be built into the cell 101. For another example, a digital-to-analog converter (DAC) may be built into the cell 101. The DAC may allow the heat to be digitally controlled rather than voltage- or current-controlled.

[0075] Fig. 4 illustrates a top view of the cell 101 illustrating a via interconnect layer 400 with vias etched through the other layers, the heater layer 300 and the temperature sensor layer 200, and filled with interconnect material, according to at least one embodiment of the present disclosure.

[0076] An interconnect 401 is a connection (for example, an electrical connection) made between two or more components, other than the interconnect(s) 401 , of the same cell 101. In the embodiment illustrated in Figs. 2-6, the interconnects 401 are provided between the temperature sensor 201 and the external connectors 502 (see Figs. 5, 6), and between the heating element 301 and the external connectors 502. In the context of a layered embodiment of the instrumented heater 100 depicted in Figs. 1-7, there may be via interconnects 401 (which may be also referred to as “vias”) and trace interconnects 501 (which may be also referred to as “traces”), better illustrated in Fig. 6. The via interconnects 401 are connections, which traverse between two or more layers, that are manufactured by etching through the insulation between those layers and subsequently filling the etched holes with an interconnect material. The trace interconnects 501 are connections within a given layer. The material of the interconnects 401 , 501 may be, for example, a low-resistance metal such as copper or aluminum. [0077] Fig. 4 illustrates six via interconnects 401 , four of which connect to the temperature sensor 201 , and two of which connect to the heating element 301 .

[0078] Fig. 5 is a top view illustrating an external connector layer 500 superimposed over its via interconnect layer 400, the heater layer 300 and the temperature sensor layer 200 of the instrumented heater 100, according to an embodiment of the present disclosure. Fig. 5 illustrates trace interconnects 501 and external connectors 502. The trace interconnects 501 connect the via interconnects 401 (which are connected to the heating element 301 and temperature sensor 201) to the external connectors 502.

[0079] The external connector 502 may be a circular pad, as illustrated in Fig. 5. In at least one embodiment, the external connectors 502 and their corresponding trace interconnects 501 are made of a single, continuous material, and thus nearly indistinguishable. Therefore, a dotted line has been used in Fig. 5 to show the separation between the cell component 501 and the external connector 502, though there is no separation in reality. The external connectors 502 may be solder pads, which as the name implies, are connected externally using solder. To minimize the length of the trace interconnects 501 , the solder pads are placed near their corresponding via interconnects 401. In this case, as illustrated in Fig. 5, the trace interconnects 501 are so short that they are nearly indistinguishable from the pads (external connectors 502) themselves.

[0080] In Fig. 5, there are several additional solder pads 503 that are not connected to any component. These additional solder pads 503 are added to conform to a standard layout (in this case, an evenly spaced grid), as well as to provide a more robust mechanical connection.

[0081] The external connectors 502 may have various forms, such as, for example, solder pads, spring-loaded pins, pin sockets, etc. The layout of the external connectors 502 may also vary, whether it is a standard, uniform grid or a custom, nonuniform layout.

[0082] In at least one embodiment, the heating element(s) 301 , the temperature sensor(s) 201 , and the external connector(s) 502 of the same cell 101 are contained within their respective cell 101 , and are independent of at least one other cell of the instrumented heater 100. For example, when the instrumented heater 100 has two or more cells 101 , each one of these cells 101 is independent of the other cell 101 of the instrumented heater 100 and is connected on its own to the thermal control unit 1002. In at least one embodiment, the internal electrical connections 401 , 501 are contained within a respective cell 101 of the instrumented heater 100, and are independent of other cells (in other words, independent of any other cell) of the at least two cells. In other words, the components of the respective cell 101 (main cell 101) are not connected to any components such as a temperature sensor 201 , or a heating element 301 , or an interconnect 401 , or a trace interconnect 501 , or an external connector 502 of any other cell, such as for example any of cells that share borders (which may be referred to as “neighboring cells”) with the respective cell 101 , of the processed substrate 820 or of the instrumented heater 100. When the cell 101 in the processed substrate 820 or in the instrumented heater 100 is independent from any other cell, there is no connection of the component 201 , 301 , 401 , 501 , 502 of that cell 101 to any component 201 , 301 , 401 , 501 , 502 of any other cell (similar main cell and/or an additional cell and/or a buffer cell) of the processed substrate 820 or in the instrumented heater 100. The cell 101 is connected to or is configured to be connected directly to the thermal control unit 1002 via the external connector(s) 502.

[0083] The cell 101 may have an additional insulation layer made of an additional insulation material and located on top of the pads 501 , 502, 503 (the trace interconnects 501 , the external connectors 502, and the additional solder pads 503) with etched openings. The etched openings may have the shapes and sizes of the external connectors 502 to mark out pads of consistent shape and size for the external connection. For example, a consistent circular pad opening may be used with the illustrated embodiment. For simplicity, the consistent circular pad has been omitted in Fig. 5. In another embodiment, the external connectors 502 may be a part of or directly attached to the temperature sensors 201 or heating elements 301 , and thus not require the trace interconnects 501 and via interconnects 401 .

[0084] In at least one embodiment, the cell 101 may have additional interconnect layers of additional interconnects, which may contain vias or traces, in order to redistribute connections before reaching the external connector layer 500. These additional interconnect layers may also be referred to as “redistribution layers” or “RDL”.

[0085] It should be understood that Fig. 6, which is a side cross-sectional schematic representation of the cell 101 , is not to scale and does not line up with any possible cross-sections through the instrumented heater’s cell 101 , therefore no cross-section line has been added to the other drawings of the cell 101. This representation has been chosen to illustrate all relevant components in a single cross-sectional view.

[0086] The substrate 601 represents the frame upon which the layers 200, 300, 400, 500 of one or more instrumented heaters 100 are fabricated. Preferably, the substrate 601 is a flat, planar piece of a substrate material or composite. Preferably, the substrate 601 is made of a silicon wafer, which is the preferred substrate for processors as well.

[0087] Preferably, the substrate material has a high thermal conductivity, so that the generated heat is more likely to flow toward the test surface 603 and cooling DUT 801 , rather than toward the external connectors 502 (representing a heat loss). In at least one embodiment, the substrate 601 is relatively large, so that many cells (and more than one instrumented heater) may be supported by and fabricated on a single substrate 601 .

[0088] The substrate material and the substrate shape may vary. In at least one embodiment, the substrate 601 may be a printed circuit board (PCB). In such an embodiment, the external connectors 502 may not be needed if they are provided by the PCB substrate itself.

[0089] In the embodiment described above, in which the external connectors 502 are on the opposite side of the substrate 601 compared to the temperature sensor 201 and the heating element 301 , it is instead preferable for the substrate material to have low thermal conductivity so that there is less heat loss toward the external connectors 502.

[0090] As illustrated in Fig. 6, the insulating material 602 is applied in between the layers 200, 300, 400, and 500. Furthermore, it is applied in between components of the same layer, as well as in the spaces within the components themselves. The insulating material 602 is dielectric, which prevents unintended electrical connections between the components of the cell 101. The insulating material 602 surrounds the temperature sensor 201 and the heating element 301. The insulating material 602 has the additional benefit of securing the components 201 , 301 , 401 , 502 in place. The insulating material 602 may be composed of a single material or multiple materials. The thickness and material choice of the insulating material 602 may be optimized to minimize stress or heat loss, for example.

[0091] The test surface 603 is the surface of the instrumented heater 100 to which the cooling DUT 801 contacts and connects and which the cooling DUT 801 cools. The test surface 603 of the instrumented heater 100 contacts the cooling DUT 801. The instrumented heater 100 determines the heat going to the test surface 603, and measures the temperature of the test surface 603, which allows the user to analyze the performance of the cooling DUT 801 .

[0092] In the embodiment illustrated in Figs. 1-8, the test surface 603 is the back surface of the substrate 601. In at least one other embodiment, the test surface 603 does not necessarily need to be a surface of the substrate 601 . The test surface may be, for example, any surface the cooling DUT 801 cools, typically the surface of the instrumented heater 100 that is opposite of the external connectors 502.

[0093] Fig. 8 is a top view of the processed substrate 820 with fabricated cells 101 of Fig. 2 from which instrumented heaters 100 of Fig. 1 are cut, according to at least one embodiment of the present disclosure. Fig. 8 illustrates an example of the processed substrate 820 (in the illustrated embodiment, a silicon wafer) which was patterned with fabricated cells 101 of the instrumented heater 100.

[0094] In at least one embodiment, the cells 101 have a square shape, as illustrated in Figs. 1 and 8. Cells 101 may have any shape or size. In at least one embodiment, all cells are the same shape and size. Typically, the cell 101 is made small enough so that the instrumented heater 100 may be comprised of many cells, which allows for more control over the heat profile and more data on the temperature profile. In some embodiments, the instrumented heater 100 may have cells 101 of various sizes and/or shapes.

[0095] Referring again to Fig. 1 , the illustrated embodiment of the instrumented heater 100 has a 5 by 5 array of cells 101 , all of which have the same design. This is a non-limiting example of the potential layout of the cells 101 of the instrumented heater 100.

[0096] The array of cells 101 of one instrumented heater 100 has an array of heating elements 301 that may all be controlled individually by the thermal control unit 1002, if desired. That means that the instrumented heater 100 can (is configured to) generate various nonuniform heat profiles to test the cooling DUT 801. For example, the same heat profile of a specific processor may be simulated. The array of cells 101 of one instrumented heater 100 also has an array of temperature sensors 201 , which measures the temperature profile across the entire test surface 603 of the instrumented heater 100, thus providing a more complete data set for analyzing the performance of the cooling DUT 801.

[0097] The shape of the instrumented heater 100 may be rectangular or any other shape, and the size may vary. The number of cells and their layout in the instrumented heater 100 may vary. One instrumented heater 100 may have cells having different designs, shapes and sizes in its layout. The instrumented heater 100 may or may not be a single cohesive unit. In at least one embodiment, several instrumented heaters 100 are connected to the same cooling DUT to form a larger instrumented heater.

[0098] Referring back to Fig. 8, the cells 101 are fabricated onto the substrate 601 , preferably the silicon wafer, and patterned across its surface with the layers 200, 300, 400, 500 to manufacture a processed substrate 820. This allows multiple instrumented heaters 100 to be cut from a much larger piece of the processed substrate 820, similar to the fabrication of processors. This also gives the flexibility of being able to cut instrumented heaters 100 of a variety of sizes from the same processed substrate 820. For example, to simulate two or more differently sized processors, the instrumented heater 100 that can (is configured to) simulate these two or more differently sized processors, may be cut out of the same processed substrate 820 without having to do multiple fabrication runs. Furthermore, this type of design of the processed substrate 820 with many instrumented heaters 100 permits reducing the amount of and avoid using any defective cells when cutting and planning how to cut the processed substrate 820 into the instrumented heaters 100. In some embodiments, groupings of cells 101 may be cut out from the processed substrate 820 to form one or more instrumented heaters 100.

[0099] If a non-heated, non-measured perimeter area is desired around the active cells 101 of an instrumented heater 100, one can cut into adjacent sacrificial cells 101 and/or use the unpatterned portions of the processed substrate 820 as well.

[0100] In at least one embodiment, cells of multiple shapes, sizes and designs may be fabricated on a single substrate. The substrate 601 used for the fabrication of the processed substrate 820 may be any shape or size, and does not need to be a wafer.

[0101] To achieve the same thermal characteristics as a processor, the instrumented heater 100 as described herein may be fabricated using processes and materials similar to those of processors. The instrumented heater 100 may be fabricated in a series of layers 200, 300, 400, 500 on top of a flat, planar substrate 601 using microfabrication and nanofabrication processes. In some embodiments, standard PCB fabrication processes may be used to make the instrumented heaters 100, though the capabilities and thus design may be more limited.

[0102] Fig. 7 is a side view of a cooling device test apparatus 800 (which may be also referred to as “test apparatus for a cooling device" or a “cooling device test system”) having the instrumented heater 100 connected by solder 802 to an external circuit 805 (illustrated in Fig. 7 not in scale, to depict the thermal control unit 1002), and with a cooling DUT 801 attached to it, according to at least one embodiment of the present disclosure. In at least one embodiment, the cooling device test system 800 for testing the performance of the cooling device 801 comprises one or more instrumented heaters 100 for heating the cooling device 801 and measuring the temperature, a thermal control system for powering the instrumented heaters 100 and recording its temperatures, and an external circuit for electrically connecting the instrumented heaters 100 to the thermal control system.

[0103] Each one of the one or more instrumented heaters of the cooling device test system 800 may comprise one or more cells; a test surface for contacting the cooling device; wherein the one or more cells comprise one or more heating elements, one or more temperature sensors, and one or more external connectors; wherein the one or more heating elements and the one or more temperature sensors are each connected to one of the one or more external connectors; and wherein the one or more heating elements, the one or more temperature sensors and the one or more external connectors are contained within their respective cell, and are independent of other cells of the one or more cells. The at least one internal electrical connection may connect the one or more heating elements to the one or more external connectors and connecting the temperature sensors to the external connectors, and at least one internal electrical connection in the cell 101 of the instrumented heater 100 is contained within a respective cell, and is independent of other cells.

[0104] The cooling device test system 800 may also have a cooling device attachment system to fasten the cooling device 801 on top of the one or more instrumented heaters 100. For example, the cooling device attachment system may be designed to match a cooling device attachment system for a common processor platform such that it will be compatible with the cooling devices designed for that processor platform. The cooling device test system 800 may also have a thermal interface material between the one or more instrumented heaters 100 and the cooling device 801.

[0105] The cooling DUT 801 is illustrated in Fig. 7 as an air-cooled finned heat sink that is a common cooling device for processors. The thermal interface material (for example, a thermal paste), which is omitted from the drawing for simplicity, may be applied between the cooling DllT’s surface 803 and the instrumented heater’s test surface 603 to improve the heat transfer. The mechanical connection to properly secure the cooling DUT 801 to the instrumented heater 100 and external circuit 805 is also omitted for simplicity.

[0106] In the embodiments illustrated in Figs. 1-8, the instrumented heater 100 may be attached directly (for example, by solder) to an external circuit 805, which, in this case, may be a PCB. Connections to the heater control system 1005 and the temperature sensor data acquisition system 1006 (which is also referred to herein collectively as the thermal control system 1002 for short or the combined thermal control system 1002) are thus made through the PCB (these systems and connections are illustrated schematically in the drawings). In at least one embodiment, each cell 101 of the instrumented heater 100 is configured to connect separately from other cells, for example via the external connector 502, to the combined thermal control system 1002 which is configured to measure and control the temperature of the cell 101 and other cells 101 of the instrumented heater 100.

[0107] Any connections between cells 101 may be done within this external circuit board 805. For example, a common ground may be made within the PCB 805 to limit the total number of off- board connections required. Certain cell heaters 301 (heating elements 301) may be permanently connected together if, for example, that grouping of cells will only ever generate matching heat fluxes. [0108] Connections to the heater control system 1005 and the temperature sensor data acquisition system 1006 may be made directly from the instrumented heater 100 without any intermediate board or package. External connection may be made to another type of circuit, or to a combination or series of circuits (e.g., another substrate, or an interposer, then the PCB). The instrumented heater 100 as described herein may be packaged with an integrated heat spreader and spring-loaded pins. A common ground may be included within the cells 101 of the instrumented heater 100 and/or between them. The external circuit 805 may include fastening mechanisms for the instrumented heater 100 and/or the cooling DUT 801 . For example, a fastening mechanism that matches those used for processor cooling devices may be provided.

[0109] Various types of cooling devices 801 may be tested with the instrumented heater 100 as described herein.

[0110] The IPP 100 as described herein is configured to (may) simulate the operation of a real processor in terms of heat generation, heat profile, and thermal characteristics, and offer more control compared to using the real processor. In a real processor, the heat generated and the heat profile, etc. cannot be controlled precisely. The IPP 100 as described herein may be configured to control the heat generated and the heat profile with precision. Furthermore, a real processor may have built-in temperature sensors, but they are rarely accurate, are usually inconveniently located, and/or don’t give a full temperature profile, whereas the IPP 100 as described herein does not suffer from these drawbacks. The IPP 100 (instrumented heater 100) as described herein is configured to simulate nonuniform heat flux profiles, which are common in processors due to cores and hotspots. The instrumented heater as described herein provides more accurate temperature measurement than the on-board sensors present in most processors. The instrumented heater 100 measures the full surface temperature profile.

[0111] The instrumented heater 100 may be easily configured and designed to match the heat profile and the form factor of the processor die and/or the processor package (including the integrated heat spreader) that the instrumented heater 100 is simulating. The instrumented heater 100 may simulate a processor before it has been released if the heat profile and the form factor are known.

[0112] The instrumented heater 100 as described herein permits the testing of cooling devices at temperatures and powers beyond the range that is considered safe for processors, which allows one to fully characterize the performance of a cooling device to its maximum capabilities. The instrumented heater 100 is designed for rapid and efficient testing because it can quickly reach a steady state and has low heat losses. [0113] To limit the number of voltage levels required in the heater control system 1005, it is possible to ensure that the same amount of power or power per unit area is sent to all cells connected to a particular voltage level by designing the cell heating elements 301 strategically. For example, the same amount of power or power per unit area is sent to all cells connected to a particular voltage level if all cells have the same heating element 301 design, as is the case for the shown embodiment of the instrumented heater 100.

[0114] The instrumented heater as described herein allows for flexibility in fabrication by using one (or a few) repeated cell designs that can be cut out into instrumented heaters of a variety of shapes and sizes. Therefore, to test new DllTs 801 , the instrumented heater does not need to be redesigned.

[0115] In at least one embodiment of the instrumented heater, as described herein, the heater layer 300 and the temperature sensor layer 200 are separate, which allows for improved temperature readings. As described above, in at least one embodiment, the instrumented heater 100 has several cells 101. Instrumented heaters 100 of a variety of shapes and sizes may be cut from the same processed substrate 820. As described herein, one or many cells 101 are cut out of the processed substrate 820 to form an instrumented heater 100. As each cell 101 of the instrumented heater 100 is self-contained, each cell 101 may operate independently of other cells of the same instrumented heater 100, and therefore the cells 101 as described herein do not need to rely on interconnections between them.

[0116] In other words, the processed substrate 820 having cells thereon may be split (for example, by cutting) into several instrumented heaters 100, each instrumented heater 100 having one or more cells 101 , and these cells 101 are completely independent from each other. The processed substrate 820 may be split into independently functioning instrumented heaters 100 with independently functioning cells 101 , and these independently functioning instrumented heaters 100 may have any shape or size (dimensions), dependent only on the shape and size (dimensions) of the cells 101 on the processed substrate 820. Similarly, one larger instrumented heater 100 may be split into smaller instrumented heaters 100, where the dimensions of the smaller instrumented heaters 100 are only limited by the dimensions of the cells 101 and the number of the cells 101 in the larger instrumented heater 100.

[0117] While preferred embodiments have been described above and illustrated in the accompanying drawings, it will be evident to those skilled in the art that modifications may be made without departing from this disclosure. Such modifications are considered as possible variants comprised in the scope of the disclosure.

Claims

CLAIMS:

1. An instrumented heater comprising: at least two cells, each cell comprising: at least one heating element, at least one temperature sensor, and at least one external connector; wherein each one of the at least one heating element and each one of the at least one temperature sensor are connected to the at least one external connector; and wherein the at least one heating element, the at least one temperature sensor, and the at least one external connector are contained within a respective cell, and are independent of any other cell of the at least two cells.

2. The instrumented heater of claim 1 , wherein each one of the at least one heating element is a resistor.

3. The instrumented heater of claim 1 or 2, wherein each one of the at least one temperature sensor is a resistor with resistivity that is sensitive to temperature variation.

4. The instrumented heater of any one of claims 1 to 3, wherein one of the at least one heating element and one of the at least one temperature sensor are combined into a single component having both heating and sensing functionality.

5. The instrumented heater of any one of claims 1 to 4, wherein the at least one heating element, the at least one temperature sensor, and the at least one external connector of the respective cell are surrounded by an electrically insulating material.

6. The instrumented heater of any one of claims 1 to 5, wherein the at least two cells are supported by and fabricated on a substrate.

7. The instrumented heater of any one of claims 1 to 6, wherein the at least one heating element and the at least one temperature sensor are located in one layer or in more than one layers.

8. The instrumented heater of any one of claims 1 to 7, wherein each cell comprises at least one internal electrical connection connecting the at least one heating element to the at least one external connector and connecting the at least one temperature sensor to the at least one external connector, and wherein the at least one internal electrical connection is contained within the respective cell and is independent of any other cell of the at least two cells.

9. The instrumented heater of any one of claims 1 to 8 further comprising at least one additional cell having at least one temperature sensor or at least one heating element.

10. The instrumented heater of any one of claims 1 to 9 further comprising a buffer cell made of one material without any temperature sensor or heating element.

11. The instrumented heater of any one of claims 1 to 10, wherein each cell of the at least two cells of the instrumented heater is configured to connect separately to a combined thermal control system configured to measure and control a temperature of the respective cell.

12. A processed substrate comprising: a substrate; and at least two cells supported by and fabricated on the substrate; wherein each cell of the at least two cells comprises at least one heating element, at least one temperature sensor, and at least one external connector; wherein each one of the at least one heating element and each one of the at least one temperature sensor are connected to the at least one external connector; and wherein the at least one heating element, the at least one temperature sensor and the at least one external connector are contained within a respective cell, and are independent of any other cell of the at least two cells.

13. The processed substrate of claim 12, from which groupings of cells are cut out to form at least one instrumented heater.

14. The processed substrate of any one of claims 13 or 13, wherein one of the at least one heating element and one of the at least one temperature sensor are combined into a single component having both heating and sensing functionality.

15. The processed substrate of any one of claims 13 to 14, wherein the at least one heating element, the at least one temperature sensor and the at least one external connector are surrounded by an electrically insulating material.

16. The processed substrate of any one of claims 13 to 15, wherein the at least one heating element and the at least one temperature sensor are located in one or more layers.

17. The processed substrate of claim 16, wherein the at least one heating element is located in a heating layer, the at least one temperature sensor is located in a temperature sensor layer, and the at least one external connector is located in an external connector layer, wherein the heating layer, the temperature sensor layer and the external connector layer are positioned one over another.

18. A cooling device test system for testing performance of a cooling device, comprising: at least one instrumented heater for heating the cooling device and measuring temperature; a thermal control system for powering the at least one instrumented heater and recording temperatures; and an external circuit for electrically connecting the at least one instrumented heater to the thermal control system.

19. The cooling device test system of claim 18, wherein each instrumented heater of the at least one instrumented heater comprises: at least two cells; a test surface for contacting the cooling device; wherein each one of the at least two cells comprises at least one heating element, at least one temperature sensor, and at least one external connector; wherein each one of the at least one heating element and each one of the at least one temperature sensor are connected to the at least one external connector; and wherein the at least one heating element, the at least one temperature sensor and the at least one external connector are contained within a respective cell, and are independent of any other cell of the at least two cells.

20. The cooling device test system of claim 18 or 19, further comprising a cooling device attachment system to fasten the cooling device on top of the at least one instrumented heater.

21. The cooling device test system of any one of claims 19 to 20, further comprising a thermal interface material between the at least one instrumented heater and the cooling device.

22. The cooling device test system of any one of claims 19 to 21 , further comprising at least one internal electrical connection connecting the at least one heating element to the at least one external connector and connecting the at least one temperature sensor to the at least one external connector, and wherein the at least one internal electrical connection is contained within the respective cell, and is independent of any other cell of the at least two cells.

23. The cooling device test system of claim 22, wherein the at least one heating element is located in a heating layer, the at least one temperature sensor is located in a temperature sensor layer, and the at least one external connector is located in an external connector layer, wherein the heating layer, the temperature sensor layer and the external connector layer are positioned one over another.

24. Using the cooling device test system of any one of claims 19 to 23 for testing the cooling device.