Field decoupling type elastic crimping power module

Abstract

The invention discloses a field decoupling type elastic crimping power module, and relates to the technical field of power semiconductor packaging, the field decoupling type elastic crimping power module comprises a substrate and a notch groove arranged on the substrate, and the notch groove blocks heat transverse transmission and disperses stress distribution; the chips are arranged on the substrate; and the elastic crimping assembly is used for realizing electrical interconnection among the plurality of chips. According to the invention, transverse heat conduction among different independent areas on the substrate is blocked through the notch grooves, heat accumulation is prevented from forming a heat concentration point, and the heat dissipation efficiency is improved; the notch grooves disperse the internal stress distribution of the substrate, reduce the stress coupling between different independent areas, and reduce the deformation or cracking risk of the substrate caused by stress concentration.

Description

Technical Field

[0001] The present invention relates to the technical field of power semiconductor packaging, in particular to a field decoupling elastic compression power module. Background Art

[0002] Power modules are core components for modern power conversion and transmission, serving as the "CPU" of power electronics devices. In the power industry, high-voltage, high-power modules are core components of various high-voltage, high-capacity power conversion and control equipment. They are widely used in the entire process of renewable energy power collection and grid connection, AC / DC power transmission and networking, and flexible power applications.

[0003] Depending on the packaging form, power modules can be divided into welded and press-fit types. Press-fit power modules have advantages such as double-sided heat dissipation, high power density, low stray inductance, and ease of series connection, making them the preferred devices for flexible high-voltage direct current transmission. Existing press-fit power modules are divided into rigid press-fit and elastic press-fit types. Elastic press-fit power modules have the advantages of high reliability, flexible current level changes, and low manufacturing process difficulty. They are the main devices used in the current ultra-high voltage flexible direct current transmission converter valves of the power grid. Therefore, research on elastic press-fit power modules is very necessary to enhance the independent control of power grid technology.

[0004] Existing elastic compression-bond power modules solder multiple power chips together onto a single substrate, using an elastic compression assembly to electrically interconnect the chips. During module operation, the chips generate heat collectively. This heat is not only dissipated vertically through the substrate but also transferred laterally. This causes the heat dissipated by different chips to be superimposed and coupled, leading to heat concentration points and reducing module performance. Furthermore, the multiple chips on the substrate are simultaneously subjected to pressure from the elastic compression assembly during operation, generating internal stress in the compressed areas. This coupled effect creates stress concentration points, shortening the module's lifespan. Summary of the Invention

[0005] In view of the above problems or problems existing in the prior art, the present invention is proposed.

[0006] Therefore, the purpose of the present invention is to provide a field-decoupled elastic compression-bonded power module, which aims to solve the problem in existing elastic compression-bonded power modules that the lateral heat transfer of multiple power chips leads to heat superposition, forming a heat concentration point, reducing the heat dissipation efficiency and module performance, and the problem that the stress superposition between chips leads to stress concentration, shortening the module life and affecting reliability.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: a field-decoupled elastic compression-bonding power module, comprising a substrate, a groove arranged on the substrate, the groove blocking the lateral heat transfer and dispersing the stress distribution; a substrate, a groove arranged on the substrate, the groove blocking the lateral heat transfer and dispersing the stress distribution; a chip arranged on the substrate and an elastic compression-bonding assembly for realizing electrical interconnection between multiple chips.

[0008] As a preferred solution of the field decoupling elastic compression power module of the present invention, the grooves include transverse grooves and longitudinal grooves perpendicular to the transverse grooves, and the transverse grooves and longitudinal grooves separate the substrate into multiple independent areas.

[0009] The grid-like isolation structure formed by transverse and longitudinal grooves can block the cross-transmission of heat and stress and improve the thermal field decoupling efficiency; the independent areas can flexibly match the layout requirements of different power chips and optimize the module layout design.

[0010] The beneficial effects of this solution are as follows: the present invention blocks the lateral heat conduction between different independent areas on the substrate by cutting grooves, avoids the accumulation of heat to form heat concentration points, and improves the heat dissipation efficiency; the cutting grooves disperse the internal stress distribution of the substrate, avoids stress coupling between different independent areas, and reduces the risk of substrate deformation or cracking caused by stress concentration.

[0011] As a preferred solution of the field decoupling elastic compression power module described in the present invention, the chip is arranged on an independent area; the elastic compression assembly includes an emitter elastic compression assembly for realizing electrical interconnection between multiple chips and a gate elastic compression assembly for transmitting signals.

[0012] As a preferred solution of the field decoupling elastic pressing power module, wherein: the emitter elastic pressing assembly includes a molybdenum sheet arranged on the chip, a first sleeve arranged on the molybdenum sheet, a first guide rod embedded in the first sleeve, a first elastic member sleeved on the first guide rod, a first conductive sheet sleeved on the first guide rod and located on both sides of the first elastic member, and an emitter plate arranged on the first guide rod.

[0013] Dynamic current connection is achieved through the emitter elastic crimping assembly; the molybdenum sheet and the first elastic member ensure that the crimping force can be evenly transmitted to the emitter plate, avoiding damage caused by local overvoltage.

[0014] As a preferred solution of the field decoupling elastic compression-bonded power module of the present invention, the first guide rod is provided with a protrusion for facilitating the installation of the emitter plate.

[0015] The protrusion simplifies the installation process of the emitter plate and the first guide rod, thereby improving efficiency. In addition, the protrusion can limit the displacement of the emitter plate and ensure the stability of the connection.

[0016] As a preferred solution of the field decoupling elastic pressing power module described in the present invention, wherein: the gate elastic pressing assembly includes a lining plate arranged on the independent area, a guide rod base arranged on the lining plate, a second guide rod embedded in the guide rod base, a second elastic member sleeved on the second guide rod, a second conductive sheet sleeved on the second guide rod and located on both sides of the second elastic member, and a second sleeve arranged on the second guide rod.

[0017] The integrity of the signal is guaranteed by the gate elastic pressing assembly; the second elastic member and the second conductive sheet ensure the stability of the gate contact pressure and reduce signal fluctuations; the second sleeve and the guide rod base can provide mechanical limit to prevent poor contact caused by vibration.

[0018] As a preferred solution of the field decoupling elastic pressing power module described in the present invention, it further includes an auxiliary protective component, which includes a support plate, a first through hole for the emitter elastic pressing component to pass through, and a first blocking block is arranged on the support plate and located around the first through hole; a second through hole for the gate elastic pressing component to pass through is opened on the support plate, and second blocking blocks are arranged on the support plate and located on both sides of the second through hole.

[0019] Airflow can pass through the first through hole and the second through hole to enhance the overall heat dissipation capacity of the module; the first and second blocking blocks can isolate and separate the emitter elastic pressing components and the gate elastic pressing components to prevent coupling.

[0020] As a preferred solution of the field decoupling elastic compression power module of the present invention, the auxiliary protection component further includes a support block arranged on one side of the support plate and a side plate arranged around the support plate.

[0021] The support blocks and side panels form a frame-like support, which improves the module's resistance to mechanical deformation. The side panels cover the edges of the module to prevent dust or moisture from invading, thereby extending the module's service life.

[0022] Beneficial effects of this program:

[0023] The elastic pressing assembly of the present invention can achieve compact electrical interconnection, support parallel or series connection of multiple chips, and improve the power density of the module; the present invention combines the substrate and the elastic pressing assembly together, solving the problem of thermal field and force field coupling while also significantly improving the reliability and service life of the module. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 Schematic diagram of the overall structure of the substrate.

[0026] Figure 2 Schematic diagram of the thickness of the groove on the substrate.

[0027] Figure 3 Schematic diagram of the chip position of the field-decoupled elastic press-fit power module.

[0028] Figure 4 This is a schematic diagram of the overall structure of the field-decoupled elastic press-fit power module.

[0029] Figure 5 This is a schematic diagram of the overall side cross-sectional structure of the field decoupling elastic press-fit power module.

[0030] Figure 6 This is an overall schematic diagram of the auxiliary protection components of the field-decoupled elastic press-fit power module.

[0031] Figure 7 Schematic diagram of the bottom of the auxiliary protection component of the field-decoupled elastic press-fit power module.

[0032] Figure 8 A comparison diagram of chip heat dissipation paths between an existing substrate without grooves and a substrate of the present invention.

[0033] 1. Substrate; 11. Grooves; 111. Horizontal grooves; 112. Longitudinal grooves; 12. Independent areas; 2. Chip; 3. Elastic pressing assembly; 31. Emitter elastic pressing assembly; 311. Molybdenum sheet; 312. First sleeve; 313. First guide rod; 3131. Protrusion; 314. First elastic member; 315. First conductive sheet; 316. Emitter plate; 32. Gate elastic pressing assembly; 321. Lining plate; 322. Guide rod base; 323. Second guide rod; 324. Second elastic member; 325. Second conductive sheet; 326. Second sleeve; 4. Auxiliary protective assembly; 41. Support plate; 411. First through hole; 412. First blocking block; 413. Second through hole; 414. Second blocking block; 42. Support block; 43. Side plate. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0035] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0036] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it constitute a separate or selective embodiment that is mutually exclusive with other embodiments.

[0037] Example 1

[0038] Reference Figure 1-Figure 2 , which is the first embodiment of the present invention, provides a field-decoupled elastic compression power module, which includes a substrate 1, a groove 11 arranged on the substrate 1, and the groove 11 blocks the lateral heat transfer and disperses the stress distribution; a chip 2 arranged on the substrate 1 and an elastic compression assembly 3 for realizing electrical interconnection between multiple chips 2.

[0039] Furthermore, the groove 11 includes a transverse groove 111 and a longitudinal groove 112 perpendicular to the transverse groove 111 . The transverse groove 111 and the longitudinal groove 112 separate the substrate 1 into a plurality of independent areas 12 .

[0040] It should be noted that in order to ensure that the groove 11 can effectively block heat conduction and stress transfer while ensuring the strength of the substrate 1, certain restrictions are placed on the depth of the groove 11. The thickness of the substrate 1 is t (set according to actual conditions), the width of the groove 11 is d (set according to actual conditions), the heat diffusion angle is α (set according to actual conditions), and the depth of the groove 11 is h. h needs to satisfy 2(th)tanα≤d, that is, h≥td / 2tanα.

[0041] The present invention blocks the lateral heat conduction between different independent areas 12 on the substrate 1 through the grooves 11, avoids heat accumulation to form heat concentration points, and improves the heat dissipation efficiency; the grooves 11 disperse the internal stress distribution of the substrate 1, reduces the stress coupling between different independent areas 12, and reduces the risk of deformation or cracking of the substrate 1 caused by stress concentration.

[0042] Example 2

[0043] Reference Figure 3-Figure 7, which is the second embodiment of the present invention. This embodiment is different from the previous embodiment in that the chip 2 is arranged on an independent area 12; the elastic pressing component 3 includes an emitter elastic pressing component 31 for realizing electrical interconnection between multiple chips 2 and a gate elastic pressing component 32 for transmitting signals.

[0044] Furthermore, the emitter elastic pressing assembly 31 includes a molybdenum sheet 311 arranged on the chip 2, a first sleeve 312 arranged on the molybdenum sheet 311, a first guide rod 313 embedded in the first sleeve 312, a first elastic member 314 sleeved on the first guide rod 313, a first conductive sheet 315 sleeved on the first guide rod 313 and located on both sides of the first elastic member 314, and an emitter plate 316 arranged on the first guide rod 313.

[0045] It should be noted that the molybdenum sheet 311 in this embodiment is a ceramic molybdenum sheet 311 .

[0046] Furthermore, a protrusion 3131 is provided on the first guide rod 313 to facilitate the installation of the emitter plate 316 .

[0047] Furthermore, the gate elastic crimping assembly 32 includes a lining plate 321 arranged on the independent area 12, a guide rod base 322 arranged on the lining plate 321, a second guide rod 323 embedded in the guide rod base 322, a second elastic member 324 sleeved on the second guide rod 323, a second conductive sheet 325 sleeved on the second guide rod 323 and located on both sides of the second elastic member 324, and a second sleeve 326 arranged on the second guide rod 323.

[0048] It should be noted that this embodiment uses 12 chips 2, and the field decoupling substrate 1 is divided into 15 independent areas 12 by grooves 11, wherein the first row and the third row are both welded with chips 2, and only the second and fourth columns of the second row are welded with chips 2. The emitter elastic pressing assembly 31 is arranged on the independent area 12 welded with the chip 2 to realize electrical interconnection between the chips 2; the first column and the fifth column of the second row are provided with the gate elastic pressing assembly 32 for signal transmission; no components are set in the second row and the third column.

[0049] In this embodiment, the first elastic member 314 and the second elastic member 324 are both disc springs, but may also be coil springs.

[0050] Example 3

[0051] Reference Figure 6-Figure 7, which is the third embodiment of the present invention. Different from the previous two embodiments, this embodiment further includes an auxiliary protective assembly 4, which includes a support plate 41. The support plate 41 is provided with a first through hole 411 for the emitter elastic pressing assembly 31 to pass through, and a first blocking block 412 is provided on the support plate 41 and located around the first through hole 411; the support plate 41 is provided with a second through hole 413 for the gate elastic pressing assembly 32 to pass through, and a second blocking block 414 is provided on the support plate 41 and located on both sides of the second through hole 413.

[0052] Furthermore, the auxiliary protection assembly 4 also includes a support block 42 arranged on one side of the support plate 41 and a side plate 43 arranged around the support plate 41 .

[0053] It should be noted that the first barrier block 412 and the second barrier block 414 can isolate and separate the emitter elastic pressing assembly 31 and the gate elastic pressing assembly 32 to prevent interference and coupling.

[0054] The support block 42 is located at the bottom of the support plate 41 and is connected to the side plates 43 on all sides. The support block 42 and the side plates 43 form a frame-like support, which improves the module's resistance to mechanical deformation. The side plates 43 cover the edges of the module to prevent dust or moisture from invading, thereby extending the service life of the module.

[0055] The elastic pressing assembly 3 of the present invention can achieve compact electrical interconnection, support parallel or series connection of multiple chips 2, and improve the power density of the module; the present invention combines the field decoupling substrate 1 and the elastic pressing assembly 3 together, solving the problem of thermal field and force field coupling while also significantly improving the reliability and service life of the module.

[0056] Reference Figure 8 The lower figure is a substrate 1 without a groove 11, and the upper figure is a substrate 1 with a groove 11; the chip 2 is connected to the substrate 1, and the chip 2 will generate power consumption as a heat source when working, and the generated heat will be transferred through the substrate 1.

[0057] In a substrate 1 without grooves 11, the heat dissipation path of the chip 2 is downward, and there is also a lateral heat dissipation path, resulting in a heat diffusion angle α. α is related to the heat generation power of the chip 2, the heat capacity of the substrate 1 material, and the thermal conductivity. The greater the heat generation power, the smaller the heat capacity, and the smaller the thermal conductivity, the larger the heat diffusion angle α. The existence of the heat diffusion angle α causes the heat transfer paths between the chips 2 to overlap, resulting in a thermal accumulation effect. If the chips 2 are spaced at the same distance and are thermally coupled, the more adjacent chips 2 are in the middle of the substrate 1, the more severe the heat accumulation, and the junction temperature of the chip 2 will be higher than that of the peripheral chips 2. In addition, thermal expansion can cause the substrate 1 to warp. The more severe the heat accumulation, the greater the thermal stress generated at that location.

[0058] When chip 2 is connected to substrate 1 with grooves 11, the heat dissipation path is as shown in the figure: with grooves 11, each chip 2 is effectively connected to an independent area 12. Grooves 11 avoid lateral heat dissipation paths, effectively preventing thermal coupling between chips 2. The heat dissipation path for chip 2 is essentially vertical and downward, with no diffusion angle. This prevents excessively high junction temperatures due to thermal coupling, resulting in more uniform temperatures between parallel chips 2.

[0059] At the same time, the grooves 11 are used to reduce the continuity of the substrate 1 material. The stress field is terminated by the grooves 11, and the stress fields between different independent areas 12 of the connecting chip 2 will not overlap, which can effectively reduce the stress field coupling between different areas, thereby improving the device life.

[0060] It is important to note that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A field decoupling elastic pressure-bonded power module, characterized by: include, A substrate (1), and a groove (11) provided on the substrate (1), wherein the groove (11) blocks lateral heat transmission and disperses stress distribution; A chip (2) arranged on the substrate (1) and an elastic pressing assembly (3) for realizing electrical interconnection between a plurality of the chips (2).

2. The field decoupling elastic pressure-bonded power module according to claim 1, wherein: The groove (11) comprises a transverse groove (111) and a longitudinal groove (112) perpendicular to the transverse groove (111); the transverse groove (111) and the longitudinal groove (112) separate the substrate (1) into a plurality of independent areas (12).

3. The field decoupling elastic pressure-bonded power module according to claim 2, wherein: The chip (2) is arranged on the independent area (12); The elastic pressing assembly (3) comprises an emitter elastic pressing assembly (31) for realizing electrical interconnection between a plurality of chips (2) and a gate elastic pressing assembly (32) for transmitting signals.

4. The field decoupling elastic compression-bonded power module according to claim 3, wherein: The emitter elastic pressing assembly (31) comprises a molybdenum sheet (311) arranged on the chip (2), a first sleeve (312) arranged on the molybdenum sheet (311), a first guide rod (313) embedded in the first sleeve (312), a first elastic member (314) sleeved on the first guide rod (313), a first conductive sheet (315) sleeved on the first guide rod (313) and located on both sides of the first elastic member (314), and an emitter plate (316) arranged on the first guide rod (313).

5. The field decoupling elastic compression-bonded power module according to claim 4, wherein: The first guide rod (313) is provided with a protrusion (3131) for facilitating the installation of the emitter plate (316).

6. The field decoupling elastic compression-bonded power module according to claim 3, wherein: The gate elastic crimping assembly (32) includes a lining plate (321) arranged on the independent area (12), a guide rod base (322) arranged on the lining plate (321), a second guide rod (323) embedded in the guide rod base (322), a second elastic member (324) sleeved on the second guide rod (323), a second conductive sheet (325) sleeved on the second guide rod (323) and located on both sides of the second elastic member (324), and a second sleeve (326) arranged on the second guide rod (323).

7. The field decoupling elastic compression-bonded power module according to any one of claims 1 to 6, characterized in that: The auxiliary protection assembly (4) further comprises a support plate (41), wherein the support plate (41) is provided with a first through hole (411) for the emitter elastic pressing assembly (31) to pass through, and a first blocking block (412) is provided on the support plate (41) and located around the first through hole (411); The support plate (41) is provided with a second through hole (413) for the gate elastic pressing assembly (32) to pass through, and second blocking blocks (414) are provided on the support plate (41) and located on both sides of the second through hole (413).

8. The field decoupling elastic compression-bonded power module according to claim 7, wherein: The auxiliary protection component (4) further comprises a support block (42) arranged on one side of the support plate (41) and a side plate (43) arranged around the support plate (41).

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