DE102007041926A1 - Method for electrical insulation of unpackaged electronic construction element, particularly high power element or semiconductor high power element, involves fastening or electrical contacting of connection surface on lower surface - Google Patents

Abstract

The method involves fastening or electrical contacting of connection surface (7) on a lower surface (5) with another connection surface, particularly electrical conductors pre-structured substrate (11), particularly Direct Copper Bonded ceramic substrate. A structured encapsulation of the construction element (1) is produced by forming an electrically isolating mass (13) between a side carrying the construction element of the substrate and a forming tool (15). A highly resistant isolating plastic, particularly polyetheretherketone, liquid crystal polymer is used. An independent claim is included for a device manufactured during a method of electrical insulation.

Description

The The present invention relates to a method according to the The preamble of the main claim, and a device according to the Generic term of the secondary claim.

at the electrical insulation of one or more unhoused ones Chips and / or passive components, in particular in power electronics, Conventionally, DCB ceramics ("direct Copper bonding ") used as a substrate DCB ceramics are placed on top and bottom of a ceramic copper sheets and connected at about 1040 ° C with this form-fitting. Subsequently, at least one of the two copper sides structured wet-chemically. A well-known manufacturer of such ceramics is called "Curamik".

The components are soldered with their back face flat on the DCB ceramic substrate plate. Contacting can be achieved by means of thick wire bonding and silicon casting or alternatively by means of the so-called planar contacting according to the WO 03030247 be executed. The content of this patent application expressly belongs to the disclosure of the present application. In contrast to the thick wire bonding, a planar contacting takes place by laminating an insulation film onto the electronic component, opening contact windows, in particular by means of laser ablation, and producing the planar connection by means of a, in particular galvanically deposited, metallization. In a structure according to the planar contacting substrates are isolated on the one hand and on the other hand, a further interconnect level is built on the insulation. In a conventional manner, films are laminated on and constructed by sequential processes such as sputtering, photographic technology and electroplating tracks

It The object of the present invention is a cost-effective electrical insulation or a simple electrical Contacting at least one unhoused electronic Component or passive electronic component, in particular a power device or semiconductor power device, especially larger for the high voltage range as 1000 volts, each with at least one pad for attachment and / or for electrical contact on one To provide top and / or bottom. Furthermore, should a high reliability in electrical and thermal Zykelbeanspruchung be created. Likewise, thermally and be used mechanically highly stable plastics that are not can be processed in film or paint form, as for example PEEK (polyether ether ketone), LCP (liquid crystal polymer) or molding compounds and are the like.

electrical Zykelbeanspruchung means the alternating exposure to a low electrical power and high electrical power with a certain number of load changes. Thermal Zykelbeanspruchung means alternating exposure to a low temperature, for example, -40 ° C, and a high temperature, for example + 125 ° C, with a certain number of temperature changes, for example, 100 to 1000 cycles.

The Task is by a method according to the main claim solved in a device according to the independent claim.

through The proposed solution can be a cost effective Applying as well as wiring unhoused electronic Components are carried out on substrates, in particular on DCB ceramics, as an insulating material, an easy-to-produce injection-molded Plastic can be used as insulation material.

According to the present invention is a cost-effective molding process provided for the isolation and structuring of electronic modules. Furthermore, large insulation thicknesses are special Weak points, such as edges, corners of electronic components and ditches available. It is also very advantageous possible during the molding process additional Circuit traces, such as leadframe structures, into the electrical integrate insulating material. During the molding process In particular, active and / or passive components to get integrated. Furthermore, during of the molding process Load connection contacts for contacting to the outside be integrated into the electrically insulating mass. It will Particularly advantageous structuring processes for structuring the electrically insulating mass, avoided for example by means of laser ablation. A structuring of the electrically insulating mass is particularly advantageously by means of the molding tool.

Further advantageous embodiments can be found in the subclaims.

According to one advantageous embodiment is a generating the structured Encapsulation by Molden with a mold tool as a mold or by injection molding with an injection molding tool as a mold. This can be cost-effective Mold and casting processes are used.

According to a further advantageous embodiment, highly resistant insulating art materials, in particular PEEK (polyether ether ketone), LCP (liquid crystal polymer), molding compositions and the like can be used as an electrically insulating mass. Particularly advantageous thermomechanically advantageous adapted molding material can be used, wherein the coefficient of thermal expansion (CTE), is adapted to that of the electrically-suffering material.

According to one further advantageous embodiment can by means of Forming tool in the electrically isolated mass recesses for Provision of access to connection surfaces of the electronic component, to on the substrate and / or in and / or on the electrically insulating mass formed electrical Ladders and / or for separating modules are generated. At on the electrically insulating mass formed electrical conductors can use the mold trenches as recesses on top of the electrically insulating molding material mass be generated for receiving overhead electrical conductors. Such trenches are particularly advantageous. The on the electrically insulated mass generated conductors are only after generating the structured encapsulation having the acquired accesses educated. The generated in the electrically insulating mass Ladder become while creating structured Encapsulation formed. Conductors produced on the substrate become prominent formed generating the structured encapsulation. This means, both through the Mold process in a structured form Through holes of electronic components and on the Substrate lying conductor tracks, as well as in the mold material or the electrically insulating ground, embedded tracks provided. Furthermore, on top of the mold material or the electrically insulating mass, trenches for receiving be provided from overhead tracks.

According to one Another advantageous embodiment of the mold is exactly be formed and / or the electronic component on the substrate be accurately positioned with respect to the mold. To this Way, accurate access to the pads of the device are generated and also residues of electrically insulating Mass on the pads are avoided.

According to one Another advantageous embodiment of existing remains of electrically insulating mass on the contact surfaces and / or electrical conductors in the entrances by means of ablation, especially laser ablation, removed.

According to one further advantageous embodiment, the electrically insulating Mass adapted to the substrate thermal expansion coefficient and / or a high temperature resistant material. So it's special advantageous if the thermal expansion coefficient of substrate and electrically insulating mass are the same. By means of adaptation of expansion coefficient of substrate and insulator can be a created high thermomechanical and electrical reliability become.

According to one Further advantageous embodiment is in the electrically insulating Mass and / or on the substrate means for cooling, in particular a cooling channel, a heat sink and / or a heat pipe, cast and / or positioned on the substrate. In this way, particularly effective cooling options for example by means of cooling channels, heat sinks and / or heatpipes available.

According to a further advantageous embodiment, a planar electrical contacting of connection surfaces on the upper side is carried out, wherein the accesses having electrically insulating material of an opening having film according to the WO 03030247 equivalent. This document is the entire disclosure of this application, in particular with regard to planar electrical contacting. Finally, there is a surface contact of each / each access point having pad and / or electrical conductor, each with an electrically conductive material layer having. The planar electrical contacting may include, for example, the following steps: full surface sputtering of a base metallization; Applying, exposing and developing a photosensitive layer; Galvanizing the accesses; Removal of the photosensitive layer and etch back of the base metallization. In this way, a high current carrying capacity is provided by thick connec tions of electrically highly conductive material in planar contacting. Likewise, a low-inductance contacting of the electronic components is created.

According to one Further advantageous embodiment is a generating the electrical conductive material layer by means of planar, in particular ganzflächigem, sputtering and generating a planar galvanic reinforcement or alternatively by means of deposition methods such as plasma spraying or Cold spray method. The contacting of the components and conductor tracks takes place in particular over a whole area Sputtering step and a whole-area galvanic reinforcement or alternatively by means of deposition methods such as plasma spraying or Cold spray method.

According to another advantageous embodiment staltung takes place structuring the sheet-like electrically conductive material having layer by means of the side facing away from the substrate ablation of the surface to the plane of the electrically insulating material. A structuring of the entire surface generated metallization or electrically conductive material having layer by means of phototechnical processes can be avoided, since by catching up the Abschleifens or ablation of the surface to the molar plane or to the plane of the electrically insulating material, an automatic separation of the tracks takes place, that is , Phototechnical processes for structuring the electrically conductive material layer are avoided in this way.

According to one Further advantageous embodiment, an electrical contact the pads on the top by means of thick wire bonding using silicone potting.

To the The scope of the present application also includes Devices according to the inventive method have been produced.

According to a further advantageous embodiment, a device according to the invention has recesses produced in the electrically insulating mass for providing access to connecting surfaces of the electronic component, to the substrate ( 11 ) and / or in and / or on the electrically insulating mass ( 13 ) trained electrical conductors ( 23 . 21 . 27 ) and / or for separation into modules.

According to a further advantageous embodiment, the device according to the WO03030247 contacted electrically planar.

According to one further advantageous embodiment has at least one electrical Ladder on a thermo-mechanical profile such that occurring mechanical stresses and deformations influenced advantageous become. In this case, the thermal expansion coefficient of a conductor be adapted to an electrically insulating mass. conductor tracks already have a thermomechanically favorable profile, which particular occurring stresses and deformations advantageous affected.

The The present invention will be described with reference to exemplary embodiments described in more detail in connection with the figures. Show it:

1 an embodiment of a device according to the invention;

2 an embodiment of a method according to the invention

3a . 3b Embodiments of inventive devices according to certain process steps.

1 shows an embodiment of a device according to the invention. 1 shows as unhoused electronic components 1 , two Insulated Gate Bipolar Transistors (IGBTs) with at least one on each side 3 and / or a bottom 5 arranged connection surface 7 for attachment and / or for electrical contact. The connection surface 7 on the bottom 5 is with one, the connection surface 7 opposite connection surface 9 on a pre-structured with electrical conductors DCB ceramic substrate 11a attached and contacted electrically. As a substrate 11 can basically any substrates 11 be used. These have particularly advantageous pre-structured conductor tracks.

reference numeral 13 denotes the electrically insulating mass 13 that between the the electronic components 1 supporting side of the substrate 11 and a mold 15 was generated and forms the structured encapsulation after a compression molding. In the electrically insulating mass 13 are recesses 17 to provide access 17a to connection surfaces 7 of the electrical component 1 and / or singulated into modules. The mold 15 is created at the left and right ends with projections such that at these points the electrically insulating mass 13 is removed. In this way, limits are created for a module having both IGBTs. The connection surface 7 on the top 3 The IGBTs are electrically contactable planar, with the accesses 17a having electrically insulating mass 13 an opening film according to the WO 03030247 corresponds and finally a surface contact of each access 17a having pad 7 can be performed with a layer of electrically conductive material. The mold 15 according to 1 For example, it may be a molding tool.

2 shows an embodiment of a method according to the invention for producing a device according to the first embodiment. With a step S1, a locking takes place and electrically contacting the pad 7 on the bottom 5 with one, the connection surface 7 opposite connection surface 9 on a pre-structured on electrical conductors DCB ceramic substrate 11a ,

With a subsequent step S2, a structured encapsulation is produced by means of an electrically insulating mass 13 between the component 1 supporting side of the DCB substrate 11 and a mold 15 has been created by injection molding. At the same time, recesses are generated by means of step S2 17 to provide access 17a to connection surfaces 7 of the electronic component 1 and / or for separating components 1 or groups of components 1 to modules. Such recesses 17 be by means of the mold 15 in the electrically insulating mass 13 generated. The creation of the recesses 17 as well as the generation of the structured encapsulation takes place in a step S2. In step S2, it is particularly advantageous if accurate accesses 17a to the connection surfaces 7 of the component 1 created and remains of electrically insulating mass 13 on the connection surfaces 7 can be avoided. For this it is particularly advantageous if the mold 15 exactly generated and / or the electronic components 1 on the substrate 11 with respect to the mold 15 are accurately positioned.

With a step S3, the electrical contacting of pads occurs 7 on the top 3 , Particularly advantageous is a planar electrical contacting according to the WO 03030247 , According to this document, the following steps are carried out, namely laminating a film of electrically insulating plastic material on the surfaces of a substrate and a component arranged thereon under vacuum so that the film covers the surfaces tightly with the contact surface (s) and adheres to this surface, and exposing each contact surface to be contacted on the surface by opening respective windows in the film. According to the present application, such Fo lie by the from an electrically insulating material 13 replaced existing structured encapsulation. According to the present application, the first two steps according to the WO 03030247 laminating and exposing each contact surface to be contacted on the surface by opening respective windows in the film, since recesses already exist through the injection molding process 17 to provide access 17a to connection surfaces 7 of the electronic component are generated. According to the WO 03030247 Also, according to this application, a surface contacting each exposed contact surface, namely the accesses 17a to the connection surfaces 7 according to the present application, with a layer of electrically conductive material which can be produced for example by means of electroplating.

The basis of the present invention is the structured encapsulation of, in particular, DCB substrates 11a soldered high-performance semiconductor chips as an alternative to that in the WO 03030247 used laminating technique with foils.

This is done on a with chips or electronic components 1 equipped DCB 11a in an injection molding process, a thick layer of electrically and thermally highly resistant insulating plastic 13 applied. In this process step, in particular places are recessed, which are later connected by a contact or should serve to singulate modules. For this casting process, it is necessary the components 1 in particular to be soldered very precisely at their intended positions in order to bring the recesses provided in the mold / casting tool in line with the surfaces to be contacted.

The insulating plastic 13 consists for example of a material with the substrate 11 adapted coefficient of thermal expansion and / or of a high temperature resistant material.

Any thinnest residual material that may be present between the recesses and the contacting openings is removed by means of ablation, for example by means of laser ablation, or by etching processes, for example by means of plasma etching. The more accurate the tools needed for this process 15 the more accurate the chip position, the less material is produced 13 must be removed after potting.

If required, functional components such as cooling tubes or stabilizers may be incorporated in the electrically insulating material 13 be poured with.

The further electrical contacting of the electronic components 1 for the construction of electronic modules is analogous to the already known method according to the WO 03030247 or by other conventional contacting methods.

Due to the cost-effective structured application of injection-molded plastic 13 as insulation material, in particular for the power electronics, with subsequent electrical contacting, for example, wiring, there are numerous advantages.

3a and 3b show embodiments of the invention devices or modules after the above-described step S2 or S3 step.

With step S2, a structured encapsulation is produced by means of an electrically insulating mass 13 between the component 1 supporting side of the DCB substrate 11 and a mold 15 has been created by injection molding. At the same time, recesses are generated by means of step S2 17 to provide access 17a to connection surfaces 7 of the electronic component 1 , to on the substrate 11 and in the electrically insulating mass 13 trained electrical conductors ( 21 . 23 ) and for separating the device 1 to a module. A recess 17 to a connection surface 7 of the electronic component 1 may also be provided as a trough for laser opening. recesses 17 be by means of the mold 15 in the electrically insulating mass 13 generated. The creation of the recesses 17 as well as the generation of the structured encapsulation takes place in the step S2. In step S2, it is particularly advantageous if accurate accesses 17a to the connection surfaces 7 of the component 1 , to on the substrate 11 and in the electrically insulating mass 13 trained electrical conductors ( 21 . 23 ) created and remains of electrically insulating mass 13 on the connection surfaces 7 and the electrical conductors ( 21 . 23 ) can be avoided. For this it is particularly advantageous if the mold 15 exactly generated and / or the electronic components 1 on the substrate 11 with respect to the mold 15 are accurately positioned. Tolerances may preferably be less than one percent.

The step S3, the electrical contacting of pads occurs 7 on the top 3 and generating on a mold or the electrically insulating material 13 deposited conductor tracks 27 that are leveled. The generated recess 17 prepares the access 17a to the electronic component 1 before, taking the access 17a was completed by laser opening. reference numeral 25 denotes the laser aperture 25 , Particularly advantageous is a planar electrical contacting according to the WO 03030247 , According to this document, the following steps are carried out, namely laminating a film of electrically insulating plastic material on the surfaces of a substrate and a component arranged thereon under vacuum so that the film covers the surfaces tightly with the contact surface (s) and adheres to this surface, and exposing each contact surface to be contacted on the surface by opening respective windows in the film. According to the present application, such a film is formed by an electrically insulating material 13 replaced existing structured encapsulation. According to the present application, the first two steps according to the WO 03030247 laminating and exposing each contact surface to be contacted on the surface by opening respective windows in the film, since recesses already exist through the injection molding process 17 to provide access 17a to connection surfaces 7 of the electronic component 1 are generated. According to the WO 03030247 Also, according to this application, a surface contacting each exposed contact surface, namely the accesses 17a to the connection surfaces 7 according to the present application, with a, in particular full-surface, layer of electrically conductive material which can be produced for example by means of electroplating.

When on the electrically insulating ground 13 separated electrical conductors 27 can by means of the mold trenches on top of the electrically insulating mold material 13 for receiving overhead electrical conductors 27 be generated. Such trenches are particularly advantageous because the electrical conductors can be easily generated. The on the electrically insulating mass 13 generated ladder 27 are only after generating the, the receipts generated 17a having formed, structured, encapsulation. The in the electrically insulating mass 13 cast-in ladder 21 are formed during the formation of the structured encapsulation. On the substrate 11 generated ladder 23 are formed prior to generating the patterned encapsulant.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - WO 03030247 [0003, 0017, 0023, 0030, 0033, 0033, 0033, 0034, 0039, 0043, 0043, 0043]

Claims (16)

Method for electrically insulating at least one unhoused electronic component ( 1 ), in particular a high-performance component or semiconductor high-performance component, with at least one respectively on a top side ( 3 ) and / or an underside ( 5 ) arranged connecting surface ( 7 ) for fastening and / or for electrical contacting, with the step - fixing and / or electrically contacting the connection surface ( 7 ) on the bottom ( 5 ) with one, the connection surface ( 7 ) opposite, pad ( 9 ) on one, in particular with electrical conductors ( 23 ) prestructured substrate ( 11 ), in particular DCB ceramic substrate ( 11a ), characterized by - producing a structured encapsulation of the component ( 1 ) by forming an electrically insulating mass ( 13 ) between which the component ( 1 ) supporting side of the substrate ( 11 ) and a mold ( 15 ). A method according to claim 1, characterized by producing the structured encapsulation by means of injection molding with an injection molding tool as a molding tool ( 15 ). A method according to claim 1 or 2, characterized by using a highly resistant insulating plastic, in particular PEEK (polyetheretherketone), LCP (liquid crystal polymer), molding compounds and the like, as an electrically insulating mass ( 13 ). Method according to one or more of the preceding claims 1 to 3, characterized by the molding tool ( 15 ) in the electrically insulating mass ( 13 ) generating recesses ( 17 ) for the provision of access ( 17a ) to pads ( 7 ) of the electronic component ( 1 ), on to the substrate ( 11 ) and / or in and / or on the electrically insulating mass ( 13 ) trained electrical conductors ( 23 . 21 . 27 ) and / or for separation into modules. Method according to one or more of the preceding claims 1 to 4, characterized by accurate production of the molding tool ( 15 ) and / or precise positioning of the electronic component ( 1 ) on the substrate ( 11 ) with respect to the mold ( 15 ) for generating accurate accesses ( 17a ) to the pads ( 7 ) of the component ( 1 ), on to the substrate ( 11 ) and / or in and / or on the electrically insulating mass ( 13 ) trained electrical conductors ( 23 . 21 . 27 ) and to avoid residues of the electrically insulating mass ( 13 ) on the connection surfaces ( 7 ) and / or the electrical conductors ( 23 . 21 . 27 ). Method according to claim 5, characterized by removal of existing residues of the electrically insulating compound ( 13 ) on the connection surfaces ( 7 ) and / or electrical conductors ( 23 . 21 . 27 ) in the receipts ( 17a ) by ablation, in particular laser ablation or etching, in particular plasma etching. Method according to one or more of the preceding claims 1 to 6, characterized in that the electrically insulating mass ( 13 ) one to the substrate ( 11 ) has adapted thermal expansion coefficient and / or a high temperature resistant material. Method according to one or more of the preceding claims 1 to 7, characterized in that in the electrically insulating mass ( 13 ) and / or on the substrate ( 11 ) a device for cooling, in particular a cooling channel, a heat sink ( 19 ) and / or a heat pipe is poured. Method according to one or more of the preceding claims 1 to 8, characterized by planar electrical contacting of pads ( 7 ) on the top ( 3 ), whereby the receipts ( 17a ) having electrically insulating mass ( 13 ) corresponds to an apertured film and finally a surface contacting each / each access ( 17a ) ( 7 ) and / or electrical conductor ( 23 . 21 . 27 ) is carried out with each having an electrically conductive material layer. Method according to claim 9, characterized by Producing the electrically conductive material layer by surface sputtering and generating a flat galvanic reinforcement or alternatively by means of a deposition process such as plasma spraying or cold spray method A method according to claim 10, characterized by structuring the planar electrically conductive material layer by means of the substrate ( 11 ) on the opposite side ablation of the surface to the plane of the electrically insulating mass ( 13 ). Method according to one or more of the preceding claims 1 to 11, characterized by electrically contacting pads ( 7 ) on the top ( 3 ) by means of thick wire bonding and Silikonverguss. Device produced by a method according to one or more of claims 1 to 12, comprising - at least one unhoused electronic Component ( 1 ), in particular a high-performance component or high-performance semiconductor component, with at least one each on top ( 3 ) and / or an underside ( 5 ) arranged connecting surface ( 7 ) for fastening and / or for electrical contacting, wherein - the connection surface ( 7 ) on the bottom ( 5 ) with one, the connection surface ( 7 ) opposite, pad ( 9 ) on a substrate pre-structured with electrical conductors ( 11 ), in particular DCB ceramic substrate ( 11a ), fixed and / or electrically contacted, characterized by - a component ( 1 ) enclosing structured encapsulation, by means of a, between which the component ( 1 ) supporting side of the substrate ( 11 ) and a mold ( 15 ), formed electrically insulating mass ( 13 ) was generated. Device according to claim 13, characterized by in the electrically insulating mass ( 13 ) generated recesses ( 17 ) for the provision of receipts ( 17a ) to pads ( 7 ) of the electronic component ( 1 ), on to the substrate ( 11 ) and / or in and / or on the electrically insulating mass ( 13 ) trained electrical conductors ( 23 . 21 . 27 ) and / or for separation into modules. Apparatus according to claim 13 or 14, characterized in that the connection surfaces ( 7 ) on the top ( 3 ) are electrically contacted planar, wherein the accesses ( 17a ) having electrically insulating mass ( 13 ) corresponds to an apertured film and finally a surface contacting each / each access ( 17a ) ( 7 ) and / or electrical conductor ( 23 . 21 . 27 ) was performed with a layer of electrically conductive material. Apparatus according to claim 13, 14 or 15, characterized characterized in that at least one electrical conductor is a thermomechanical Profile has such that occurring mechanical stresses and deformations are favorably influenced.