Method for manufacturing an electronic module with a positioning frame as a positioning and connection aid in power electronic assembly processes

Abstract

Method for manufacturing an electronic module (10), comprising - Providing (S1) a positioning frame (2) which has at least one recess (23) for positioning a microchip (3, 4, 20, 21) - Positioning (S2) of the positioning frame (2) on a circuit carrier (11), wherein the circuit carrier (11) has conductor tracks (12, 13, 14, 17, 18, 19) which are applied to the circuit carrier (11), - Positioning (S3) the microchip (3, 4, 20, 21) in the recess (23) - Contact (S4) of the microchip (3, 4, 20, 21) with one of the conductor tracks (12, 13, 14, 17, 18, 19) - Embedding (S8) the positioning frame (2) and the microchip (3, 4, 20, 21) in an insulating material (15).

Description

[0001] The present invention relates to a method for manufacturing an electronic module, an assembly consisting of a positioning frame and microchips, and an electronic module.

[0002] In the manufacture of electronic modules, particularly power modules, soldering with or without metallic or graphite-based reusable soldering frames is known. The power module disclosed in US 2022 / 0131296 A features press-fit pins for the electrical and mechanical connection of the terminals, which can be inserted into sleeves on the substrate. The substrate rests on a base plate. An alignment frame ensures the accuracy of all components. The mechanical and electrical connection of the power and signal terminals is achieved via multiple (high-current) or single press-fit connections. When the pins are inserted, they are pushed firmly into these sleeves by overcoming a frictional force, and after proper alignment, an electrical contact is established for each individual pin across a surface.

[0003] The revealed alignment frame is structurally quite complex, as it consists of a high-temperature resistant plastic with incorporated copper sheets for the electrical substrate-substrate connection and several soft copper sleeves with a hardness <60 HV.

[0004] The object of the invention was to provide a solution for how several microchips and conductor connections for microchips can be positioned relative to each other on a substrate in a mechanically stable, simple and reproducible manner.

[0005] The invention discloses a method for manufacturing an electronic module, an assembly consisting of a positioning frame and microchips, and an electronic module according to the independent claims. Further embodiments are specified in the dependent claims and this description.

[0006] The invention specifies a method for manufacturing an electronic module, comprising - Providing a positioning frame that has at least one recess for positioning a microchip - Positioning the positioning frame on a circuit carrier, wherein the circuit carrier has conductor tracks that are applied to the circuit carrier, - Positioning the microchip in the recess - Contacting the microchip with one of the conductor tracks - Embedding the positioning frame and the microchip in an insulating material.

[0007] The invention, in its general or specific embodiments, achieves one or more of the following advantages: • Improved positioning of components, such as microchips, relative to each other. A placement aid is provided. After placement, components can be connected in various ways, for example by soldering, welding (such as laser welding), or friction welding. • Allows for smaller and more unstable components, as these are fixed and possibly also supported in the positioning frame. • Fewer soldering steps, if soldering is desired. • Closely spaced structures are possible. The positioning frame allows for smaller distances between components and better tolerances. • The positioning frame can remain in the electronic module and be embedded in an insulating compound. The positioning frame can therefore be a disposable frame that remains permanently in the electronic module. • Electrical parasitic effects are reduced. The real electrical quantities (R, C, L) that exist in a desired ideal conductor and reduce, hinder, slow down, or cause losses in its function. In the case of inductance, a more compact / smaller conductor loop, as possible in the present invention (smaller distances), directly leads to the possibility of faster switching. • The frame positions and maintains distances and prevents solder from blurring in the case of a soldered connection.

[0008] The invention describes features in the singular, such as a recess, a microchip, and a conductor connection. The invention also includes the presence of multiple elements described in the singular. In particular, the positioning frame can have multiple recesses, each for a microchip, and the method can be formulated accordingly.

[0009] The invention uses a positioning frame, or more specifically a binding frame, or in a particular variant, a soldering or welding frame, which can be used as a disposable frame. After use for aligning and reinforcing structurally weak components, such as microchips and conductor connections, the positioning frame can remain in an electronic module, particularly a power module. The positioning frame is encased or encapsulated within the module.

[0010] The positioning frame can be designed as a grid with at least one recess for positioning a microchip or as a film with at least one such recess.

[0011] The positioning frame can have at least one recess for positioning another component, such as a load connection or signal connection.

[0012] The positioning frame may have an adhesive for fixing it to the circuit board and / or conductor tracks. In the case of a film, the film may be self-adhesive.

[0013] In one embodiment of the assembly, the positioning frame is made of an electrically insulating plastic. This saves costs and weight and also reduces the risk of unintentional short circuits.

[0014] A conductor connection creates a link between a microchip and a conductive trace, in addition to the contact between the microchip and another conductive trace on the underside of the microchip. The conductor connection can be, for example, without limitation: a top-side chip contact, a clip connection, a stamped grid, a sheet, or a leadframe.

[0015] In one embodiment of the method, the positioning frame has at least one support by which a conductor connection for contacting the microchip with a conductor track in a Z-direction of a Cartesian coordinate system can be supported in order to prevent bending of the conductor connection in the Z-direction, in the direction of the microchip, and wherein the method further comprises - Contacting the conductor connection with the microchip, - Positioning the ladder connection on the support, - Contacting the conductor connection with at least one other conductor track, whereby when embedding the positioning frame and the microchip in the insulating material, the conductor connection is also embedded in the insulating material.

[0016] In this embodiment, the positioning frame has a support that braces the conductor connection in a Z-direction of the Cartesian coordinate system to prevent bending of the conductor connection in the Z-direction towards the microchip, i.e., towards the top of the microchip. The conductor connection can rest on the support, preferably in a central section located between the ends of the conductor connection.

[0017] In a further development of this embodiment, the support is designed such that the support - the conductor connection is supported in a first Z-direction of the Cartesian coordinate system to prevent bending of the conductor connection in the Z-direction towards the microchip, i.e. towards the top of the microchip and - the conductor connection is supported in a second Z-direction of the Cartesian coordinate system, opposite to the first Z-direction, to prevent bending of the conductor connection in a direction away from the microchip.

[0018] The support prevents short circuits, changes in inductance, or mechanical damage, especially when the conductor connection is embedded in an insulating compound and a mechanical load is applied to the conductor connection by the insulating compound.

[0019] The support can be mounted on a circuit carrier or a conductor track in the electronic module described below.

[0020] The support can be designed as a bridge or pin on the positioning frame.

[0021] The support can expand in the Z-direction.

[0022] The support may have an opening through which the ladder connection can be or is guided.

[0023] The support can protrude from surrounding parts of the positioning frame in the Z-direction. The support can thus be a raised section within the positioning frame.

[0024] In one embodiment, the positioning frame is made of an electrically insulating material.

[0025] In one embodiment, the positioning frame has an alignment aid for aligning the positioning frame relative to a circuit carrier.

[0026] Possible alignment aids include studs, holes or locating marks (fiduschel).

[0027] In another aspect, the invention specifies an assembly consisting of a positioning frame and microchips, wherein several structurally separate microchips are fixed relative to each other in an XY direction of a Cartesian coordinate system within the positioning frame, and at least one of the microchips has a conductor connection on a top side of the microchip for contacting the microchip with a conductor track.

[0028] The conductor track mentioned is not part of the assembly, but is present in an electronic module according to the invention.

[0029] In this aspect of the invention, several structurally separate microchips are already connected to the positioning frame for the aforementioned assembly. The microchips are placed in the aforementioned recesses and connected to the positioning frame there. The assembly can be used to manufacture the electronic module. In the aforementioned method, a - Positioning the positioning frame on a circuit carrier, wherein the circuit carrier has conductor tracks that are applied to the circuit carrier, - Positioning the microchip in the recess

[0030] The assembly process makes the latter step unnecessary because the microchips are already connected to the positioning frame.

[0031] Full reference is made to the above disclosure regarding the positioning framework.

[0032] For attaching the microchips to the positioning frame, material-bonded, force-fit, or form-fit connections are conceivable. Examples of such connections include click or clamp connections or injection-molded bridges.

[0033] In one embodiment, the assembly further comprises at least one load connection and / or at least one signal connection, which is / are fixed in an XY direction of a Cartesian coordinate system relative to the microchips in the positioning frame. The advantage here is the connection of other components important for electronic modules and their relative fixation to the microchips.

[0034] In another aspect, the invention relates to an electronic module comprising - a circuit carrier - Conductive traces that are applied to the circuit board, - a positioning frame having at least one recess in which a microchip is positioned, the microchip being contacted with one of the conductor tracks, - an insulating material in which the positioning frame and the microchip are embedded.

[0035] All preceding descriptions of features are fully referenced.

[0036] Embedding can be achieved by casting and hardening the insulating material, which is, for example, a synthetic resin.

[0037] In one embodiment, the electronic module features: - a conductor connection that contacts the microchip with one of the other conductor tracks where the positioning frame has at least one support by which the ladder connection is supported in a Z-direction of a Cartesian coordinate system, the conductor connection is also embedded in the insulating material.

[0038] In a more specialized version, the electronic module features, - a circuit carrier - Conductive traces that are applied to the circuit board, - an assembly as described above, wherein the microchips are each contacted with at least one of the conductor tracks and the conductor connection is contacted with at least one further conductor track, - an insulating compound in which the positioning frame, the microchips and the conductor connection are embedded.

[0039] The circuit carrier can be made of ceramic or plastic. The conductive traces can be made of a conductive metal, such as copper.

[0040] The insulating material can be a hardened synthetic resin.

[0041] If one of the aforementioned assembly methods is used, a method for manufacturing an electronic module may be designed as follows, comprising: - Providing an assembly as previously described, - Assembling the assembly with a circuit carrier which has conductor tracks applied to the circuit carrier, wherein the microchips are each contacted with at least one of the conductor tracks and the conductor connection is contacted with at least one further of the conductor tracks, - Embedding the positioning frame, microchips and conductor connection in an insulating compound.

[0042] The invention is described below with reference to exemplary embodiments. The figures shown are: Fig. 1 an electronic module according to the state of the art in a side section; Fig. 2 an electronic module according to the state of the art in a top view; Fig. 3 an electronic module according to the invention in a prior art in a top view; Fig. 4 an electronic module according to the invention according to the prior art in a side section; Fig. 5 a sequence of a method according to the invention; Fig. 6. A further process according to the invention when using an assembly.

[0043] Fig. Figure 1 shows a side section of the electronic module 100 according to the state of the art. The circuit carrier 11, made of ceramic or plastic, has conductor tracks 12, 13, and 14. The microchip 3 is attached to conductor track 12 via connection 16 and is connected to it. One end of the microchip 3 is connected to conductor track 5. The other end of conductor track 5 is connected to conductor track 14. Two load connections 7, also called load contacts, are also shown, connected to conductor track 12 and conductor track 13. The electronic module 100 is embedded in the insulating compound 15, except for a portion of conductor track 14 on the underside of the circuit carrier 11 and the ends of the load connections 7.

[0044] Fig. Figure 2 shows a top view of another prior art electronic module 101, which is similar to, but not entirely identical with, electronic module 100. Identical reference numerals have the same meaning as in Fig. 1. The electronic module 101 has a total of four microchips 3, 4, 20, 21. Four conductor connections 5 are also shown. In addition, further conductor tracks 17, 18, 19 are present alongside conductor tracks 12 and 13. A signal connection 8 is contacted on conductor tracks 17 and 18.

[0045] Fig. Figure 3 shows a top view of an electronic module 10 according to the invention. The reference numerals have the same meaning as in Fig. 2. Unlike Fig. Figure 3 shows that the electronic module 10 according to the invention has a positioning frame 2, here in a grid structure. The four microchips 3, 4, 20, 21, the two load connections 7 and the two signal connections 8 are positioned in recesses 23 on the positioning frame 2.

[0046] The recesses 23 are designed here as interruptions in the struts of the grid-shaped positioning frame 2. The recesses 23 can generally be designed so that the microchips 3, 4, 20, 21, the two load connections 7 and the two signal connections 8 fit precisely into them, or they can be designed to be slightly larger so that the aforementioned components have some play in their respective recesses 23.

[0047] If an assembly 1 is used, the aforementioned components are also attached in the recesses 23 on the positioning frame 2, in this case in a very slightly undersized recess to clamp the components.

[0048] Instead of a grid-shaped positioning frame 2, the positioning frame 2 can be designed as a film. The cutouts 23 are then openings in the film, rectangular openings for the microchips 3, 4, 20, 21, which can be slightly larger than the base area of ​​the microchips 3, 4, 20, 21. A film-shaped positioning frame also has further necessary openings to contact components with conductor tracks, for example, the conductor connections 5 with conductor tracks 12, 13.

[0049] The positioning frame 2 fixes the positions of the microchips 3, 4, 20, 21, the conductor connections 5, the two load connections 7 and the two signal connections 8 relative to each other, whereby a certain tolerance may exist.

[0050] The four conductor connections 5 are also contacted at one end on the top side of the microchips 3, 4, 20, 21. The aforementioned assembly 1 can serve as a precursor for the production of the electronic module 10. The positioning frame 2, together with the components attached to it, can be placed on the conductor tracks 12, 13, 17, 18, 19 such that the respective components contact the corresponding conductor tracks, e.g., microchips 3 and 20 contact conductor track 12, two of the four conductor connections 5 contact conductor track 13, etc.

[0051] If no assembly is used, the positioning frame 2 is first placed on the conductor tracks 12, 13, 17, 18, 19 and then the components microchips 3, 4, 20, 21, load connections 7 and signal connections 8 are positioned in the recesses 23.

[0052] The positioning frame 2 ensures that the components are correctly positioned on the corresponding conductor tracks when placed on conductor tracks 12, 13, 17, 18, and 19. During a contacting process on conductor tracks 12, 13, 17, 18, and 19, such as soldering, the positioning frame 2 prevents the components from moving relative to each other and potentially leaving the conductor track. The correct positioning of the positioning frame 2 on the circuit carrier 11 is achieved using the alignment aids 9, which are aligned with the alignment aids (not shown) on the circuit carrier 11.

[0053] Fig. Figure 4 shows a side section through the electronic module 10 according to the invention. Fig. 3, the representation being not exactly to scale. The positioning frame 2 and the microchips 3, 4, conductor connections 5 and the load connections 7, as well as further components, positioned in recesses 23 on the positioning frame 2. Fig. The three components shown are almost completely embedded in the insulating compound 15.

[0054] These are merely the ends of the load connections 7 and the ends of the in Fig. The 3 signal connections 8 shown are not embedded in the insulating material 15.

[0055] The supports 6 extending in the Z direction of the Cartesian coordinate system can be seen, on which a middle section of one of the ladder connections 5 is supported.

[0056] During the potting with the insulating compound 15, pressure is exerted from above on the relatively unstable conductor connections 5, and the supports 6 prevent the middle sections of the conductor connections 5 from deflecting downwards in the Z-direction (in Fig. 4 from top to bottom).

[0057] Fig. Figure 4 shows further supports 22, which support the positioning frame 2 on the circuit carrier 11 to prevent deflection. At one upper end, the supports 22 are flush with the insulating compound 15. The wire connection is guided through an opening in the support 2. This also provides support in the Z-direction upwards, away from the microchip 3 or 4.

[0058] If the positioning frame 2 is designed as a sheet (the horizontal part of the positioning frame 2 in Fig. 4 is then a film, the supports 6, 22 can be formed in the film, for example as thickenings, or attached to the film as separate elements.

[0059] Fig. Figure 5 shows the process sequence according to the invention when no assembly is used, with S1 Providing the positioning frame 2, which has at least one recess 23 for positioning a microchip 3, 4, 20, 21 S2 Positioning the positioning frame 2 on a circuit carrier 11, wherein the circuit carrier 11 has conductor tracks 12, 13, 14, 17, 18, 19 which are applied to the circuit carrier 11, S3 Positioning the microchip 3, 4, 20, 21 in the recess 23 S4 Contacting the microchip 3, 4, 20, 21 with one of the conductor tracks 12, 13, 14, 17, 18, 19 S5 Contacting the conductor connection 5 with the microchip 3, 4, 20, 21, S6 Positioning the ladder connection 5 on the support 6, S7 Contacting conductor connection 5 with at least one other conductor track 12, 13, 14, 17, 18, 19, S8 Embedding the positioning frame 2 and the microchip 3, 4, 20, 21 in an insulating compound 15.

[0060] The designations S1-S8 do not imply a strict chronological order. The numbering serves only for unambiguous differentiation.

[0061] Fig. Figure 6 shows the process sequence according to the invention when an assembly is used, with R1 Deploy assembly 1 as previously described, R2 Assembling the assembly 1 with a circuit carrier 11, which has the conductor tracks 12, 13, 14, 17, 18, 19 that are applied to the circuit carrier 11, wherein the microchips 3, 4, 20, 21 are each contacted with at least one of the conductor tracks 12, 13, 14, 17, 18, 19 and the conductor connection 5 is contacted with at least one further of the conductor tracks 12, 13, 14, 17, 18, 19 R3 Embedding the positioning frame 2, the microchips 3, 4, 20, 21 and the conductor connection 5 in the insulating compound 15.

[0062] The individual characteristics mentioned have already been examined using the Fig. 1-4 described. Reference symbol list 1 Assembly 2 positioning frames 3 microchip 4 microchip 5 conductor connection 6 support 7 Load connection 8 Signal connection 9. Alignment aid 10 Electronic module, according to the invention 11 circuit carriers 12 conductor tracks 13 conductor track 14 conductor track 15 Insulating compound 16 Connection for microchip 17 conductor track 18 conductor track 19 conductor track 20 microchips 21 microchip 22 support 23 recess 100 Electronic module, state of the art 101 Electronic module, state of the art S1 Providing a positioning frame S2 Positioning the positioning frame S3 Positioning the microchip S4 Contacting the microchip S5 Contacting the ladder connection S6 Positioning the conductor connection S7 Contacting the ladder connection S8 Embedding the positioning frame R1 Providing an assembly 1 R2 Assembling assembly 1 with a circuit carrier 11 R3 Embedding the positioning frame 2, the microchips 3, 4 and the conductor connection 5 in an insulating compound 15 QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 2022 / 0131296 A

[0002]

Claims

[1] Method for manufacturing an electronic module (10), comprising - Providing (S1) a positioning frame (2) which has at least one recess (23) for positioning a microchip (3, 4, 20, 21) - Positioning (S2) of the positioning frame (2) on a circuit carrier (11), wherein the circuit carrier (11) has conductor tracks (12, 13, 14, 17, 18, 19) which are applied to the circuit carrier (11), - Positioning (S3) the microchip (3, 4, 20, 21) in the recess (23) - Contact (S4) of the microchip (3, 4, 20, 21) with one of the conductor tracks (12, 13, 14, 17, 18, 19) - Embedding (S8) the positioning frame (2) and the microchip (3, 4, 20, 21) in an insulating material (15). [2] Method according to claim 1, wherein the positioning frame (2) has at least one support (6) by which a conductor connection (5) for contacting the microchip (3, 4, 20, 21) with a conductor track can be supported in a Z-direction of a Cartesian coordinate system in order to prevent bending of the conductor connection (5) in the Z-direction, in the direction of the microchip (3, 4, 20, 21), and wherein the method further comprises - Contact (S5) of the conductor connection (5) with the microchip (3, 4, 20, 21), - Positioning (S6) the ladder connection (5) on the support (6), - Contact (S7) of the conductor connection (5) with at least one other of the conductor tracks (12, 13, 14, 17, 18, 19), where, when embedding (S8) the positioning frame (2) and the microchip (3, 4, 20, 21) into the insulating material (15), the conductor connection (5) is also embedded in the insulating material (15). [3] Method according to any of the preceding claims, wherein the positioning frame (2) is made of an electrically insulating material. [4] Method according to one of the preceding claims, wherein the positioning frame (2) has an alignment aid (9) for aligning the positioning frame (2) relative to a circuit carrier. [5] Assembly (1) of a positioning frame (2) and microchips (3, 4, 20, 21), wherein in the positioning frame (2) several structurally separate microchips (3, 4, 20, 21) are fixed relative to each other in at least one X, Y and Z direction of a Cartesian coordinate system, and at least one of the microchips (3, 4, 20, 21) has a conductor connection (5) contacted on a top side of the microchip (3, 4, 20, 21) for contacting the microchip (3, 4, 20, 21) with a conductor track. [6] Assembly (1) according to claim 5, wherein the positioning frame (2) has at least one support (6) by which the conductor connection (5) is supported in a Z-direction of the Cartesian coordinate system in order to prevent bending of the conductor connection (5) in the Z-direction in the direction of the microchip (3, 4, 20, 21). [7] Assembly (1) according to one of claims 5-6, comprising an alignment aid (9) for aligning the positioning frame (2) relative to a circuit carrier. [8] Electronic module (10) comprising - a circuit carrier (11) - Conductive traces (12, 13, 14, 17, 18, 19) which are applied to the circuit carrier (11), - a positioning frame (2) having at least one recess (23) in which a microchip (3, 4, 20, 21) is positioned, wherein the microchip (3, 4, 20, 21) is contacted with one of the conductor tracks (12, 13, 14, 17, 18, 19), - an insulating material (15) in which the positioning frame (2) and the microchip (3, 4, 20, 21) are embedded. [9] Electronic module (10) according to claim 8, further comprising - a conductor connection (5) which contacts the microchip (3, 4, 20, 21) with another of the conductor tracks (12, 13, 14, 17, 18, 19) where the positioning frame (2) has at least one support (6) by which the ladder connection (5) is supported in a Z-direction of a Cartesian coordinate system, the conductor connection (5) is also embedded in the insulating mass (15). [10] Method for manufacturing an electronic module (10) comprising - Providing (R1) an assembly (1) according to any one of claims 5 to 7, - Assembling (R2) the assembly (1) with a circuit carrier (11) which has conductor tracks (12, 13, 14, 17, 18, 19) applied to the circuit carrier (11), wherein the microchips (3, 4, 20, 21) are each contacted with at least one of the conductor tracks (12, 13, 14, 17, 18, 19) and the conductor connection (5) is contacted with at least one further of the conductor tracks (12, 13, 14, 17, 18, 19), - Embedding (R3) the positioning frame (2), the microchips (3, 4, 20, 21) and the conductor connection (5) in an insulating compound (15).

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