Rotary pressurization type power diode module packaging structure

Abstract

The invention belongs to the technical field of semiconductor packaging, and particularly relates to a rotary pressurization type power diode module packaging structure. The power diode comprises a positive electrode metal component, an insulating material sleeve with internal threads at two ends, a positive electrode metal gasket, a power diode chip, a negative electrode metal gasket, a negative electrode metal disc with external threads and a plastic package shell, the insulating material sleeve is rotationally fixed on a boss of the substrate, then the positive electrode metal gasket, the power diode chip, the negative electrode metal gasket and the negative electrode metal disc with the external threads are assembled in the insulating material sleeve in sequence, and finally the plastic package shell is installed and fixed on the substrate, so that module assembling is completed; by rotating the negative electrode metal disc to load pressure, good contact between the assemblies is kept; a groove is engraved in the center of the negative metal disc and used for radiator positioning and external tool rotating pressurization, and a protrusion matched with the groove is engraved in the center of the negative radiator and used for radiator positioning and preventing a pressurization structure from loosening.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor packaging, and in particular relates to a rotary pressurized power diode module packaging structure. Background Art

[0002] Power diode modules are the basic core components of electric energy conversion equipment. Compared with traditional welded packaged power diodes, press-fit packaged power diodes are more widely used in high-power occasions due to their advantages such as double-sided heat dissipation, high power density, low parasitic parameters, and failure short circuit. As power electronic equipment develops towards miniaturization and sustainability, the large space occupied by the supporting fixtures required for the use of press-fit packaged power diodes has become the main difficulty restricting its development towards miniaturization. In addition, press-fit packaged power diodes use a closed package. Even if only one sub-module inside fails, the entire module will be scrapped, which has become a key problem in its development towards sustainability. Therefore, it is of great significance to achieve miniaturization and sustainability of press-fit packaged power diode modules.

[0003] At present, there are two mainstream structures of crimping packaging structure: rigid crimping packaging and elastic crimping packaging. Among them, the rigid crimping packaging module needs to be fixed by a large special clamp during use, so it is usually used in equipment with sufficient space such as flexible DC transmission converter valves and circuit breakers. In addition, due to factors such as module layout and fixture design, there is a common problem of uneven pressure distribution of submodules in rigid crimping packaging modules, and some submodules are prone to overstress, resulting in premature failure of the entire module. The elastic crimping packaging structure effectively solves the problem of uneven pressure distribution inside the submodule by adopting a disc spring design inside each submodule, but the introduction of the disc spring structure also leads to worse heat dissipation on the disc spring side of the chip, and there is a risk of disc spring failure after long-term stress cycles. In addition, the existing crimping packaging modules generally adopt closed packaging, and the end cover is difficult to open without loss in later maintenance. Even if only a submodule inside the module fails, the entire module will be scrapped due to the difficulty in maintenance, and the sustainable application capability is poor.

[0004] In summary, the existing rigid crimping packaging structure has problems such as large space occupation and poor uniformity of internal pressure distribution, and the existing elastic crimping packaging structure has shortcomings such as poor heat dissipation capacity and disc spring failure. In addition, the two adopt closed packaging, which makes it difficult to carry out later maintenance operations and has poor sustainable application capabilities. Therefore, inventing a packaging structure with uniform pressure distribution, strong heat dissipation capacity, and convenient replacement of failed sub-modules is of great significance to the development of crimping packaging power diode modules in the direction of miniaturization and sustainability. Summary of the invention

[0005] The purpose of the present invention is to promote the miniaturization of the press-fit packaged power diode module and effectively improve the sustainable application of the module, so as to solve the problems of the existing packaging structure such as the difficulty in balancing the space utilization and heat dissipation capacity and the poor sustainable application capacity.

[0006] The technical solution of the present invention is:

[0007] A rotary pressurized power diode single chip module packaging structure, comprising a negative electrode heat sink 2, a plastic package shell 3, a negative electrode metal disc 5, a negative electrode metal gasket 7, a power diode chip 8, a positive electrode metal gasket 9, an insulating material sleeve 11, a positive electrode metal component 13 and a positive electrode heat sink 17;

[0008] The upper end and the lower end of the inner wall of the insulating material sleeve 11 are respectively provided with a first internal thread 10 and a second internal thread 12, the outer wall of the negative metal disc 5 is provided with a first external thread 6, and the outer wall of the positive metal component 13 is provided with a second external thread 14; the first internal thread 10 and the first external thread 6 match each other so that the negative metal disc 5 and the insulating material sleeve 11 are fastened together by rotation; the second internal thread 12 and the second external thread 14 match each other so that the positive metal component 13 and the insulating material sleeve 11 are fastened together by rotation;

[0009] The middle part of the inner wall of the insulating material sleeve 11 does not have a part with an internal thread structure. After the negative metal disc 5 and the positive metal component 13 are fastened to the insulating material sleeve 11, a cavity is formed in the middle part of the insulating material sleeve 11. The negative metal gasket 7, the power diode chip 8 and the positive metal gasket 9 are stacked in the cavity in order from top to bottom, and the upper surface of the negative metal gasket 7 contacts the lower surface of the negative metal disc 5, and the lower surface of the positive metal gasket 9 contacts the upper surface of the positive metal component 13;

[0010] The plastic-sealed shell 3 is sleeved on the outer wall of the negative electrode metal disc 5;

[0011] The upper surface of the negative electrode metal disc 5 has a first groove 4, and the lower surface of the negative electrode radiator 2 has a first protruding structure 1. The first protruding structure 1 and the first groove 4 match each other. After the first protruding structure 1 is embedded in the first groove 4, the negative electrode radiator 2 can lock the negative electrode metal disc 5.

[0012] The lower surface of the positive metal component 13 has a second groove 15, and the upper surface of the positive heat sink 17 has a second protruding structure 16. The second protruding structure 16 and the second groove 15 match each other. After the second protruding structure 16 is embedded in the second groove 15, the positive heat sink 17 can lock the positive metal component 13.

[0013] Furthermore, the size of the negative electrode metal gasket 7 is the same as the size of the power diode chip 8 .

[0014] Furthermore, the size of the positive electrode metal gasket 9 is smaller than the size of the power diode chip 8 .

[0015] Furthermore, the four corners of the negative electrode metal gasket 7, the power diode chip 8 and the positive electrode metal gasket 9 are designed with rounded corners.

[0016] The purpose of the above solution is to ensure that the negative electrode of the power diode chip 8 is evenly stressed after pressurization, and to effectively avoid the stress concentration problem in the corner contact area between the power diode chip 8 and the metal gasket 9.

[0017] Furthermore, the cross-sectional top view of the first groove 4 and the second groove 15 is one of a straight line shape, a cross shape, a star shape and a polygon shape.

[0018] Based on the above-mentioned single-chip module packaging structure, the present invention proposes a rotary pressurized power diode multi-chip module packaging structure, by arranging the negative metal discs of multiple single-chip module packaging structures in the same plastic packaging shell, and merging the negative heat sink and the positive heat sink into a common negative heat sink and positive heat sink, thereby realizing a multi-chip module packaging structure.

[0019] The beneficial effects of the present invention are:

[0020] 1) The packaging structure designed in the present invention does not need to be equipped with special fixtures required by existing rigid compression packaging modules in applications, thereby effectively reducing the space occupied by the module and realizing module miniaturization.

[0021] 2) The packaging structure designed in the present invention can ensure consistent pressure loading of each submodule by designing the number of rotations and cooperating with an anti-loosening structure, thereby achieving uniform pressure distribution of each submodule.

[0022] 3) The packaging structure designed in the present invention can achieve double-sided heat dissipation, reduce the module shell thermal resistance, and effectively improve the long-term reliability of the packaging structure.

[0023] 4) The packaging structure designed in the present invention can replace the failed diode chip by opening the negative metal disc, which can realize convenient replacement of the failed chip and effectively realize the sustainable application of the module. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the packaging structure of a single chip module of a rotary pressurized power diode;

[0025] Figure 2 This is a schematic diagram of the packaging structure of a rotary pressurized power diode multi-chip module.

[0026] Figure numerals: 1-first protruding structure; 2-negative electrode heat sink; 3-plastic shell; 4-first groove; 5-negative electrode metal disc; 6-first external thread; 7-negative electrode metal gasket; 8-power diode chip; 9-positive electrode metal gasket; 10-first internal thread; 11-insulating material sleeve; 12-second internal thread; 13-positive electrode metal component; 14-second external thread; 15-second groove; 16-second protruding structure; 17-positive electrode heat sink; 18-negative electrode heat sink of multi-chip module; 19-first protruding structure of multi-chip module; 20-plastic shell of multi-chip module Shell; 21-submodule first groove; 22-submodule; 23-submodule negative metal disc; 24-submodule first external thread; 25-submodule negative metal gasket; 26-submodule power diode chip; 27-submodule positive metal gasket; 28-submodule first internal thread; 29-submodule second internal thread; 30-submodule insulating material sleeve; 31-multi-chip module second groove; 32-multi-chip module second external thread; 33-multi-chip module second protruding structure; 34-multi-chip module positive metal component; 35-multi-chip module positive heat sink. DETAILED DESCRIPTION

[0027] The scheme of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0028] Example

[0029] like Figure 1 As shown, this embodiment provides a rotary pressurized power diode module packaging structure, including a negative electrode heat sink 2, a plastic package shell 3, a negative electrode metal disc 5, a negative electrode metal gasket 7, a power diode chip 8, a positive electrode metal gasket 9, an insulating material sleeve 11, a positive electrode metal component 13 and a positive electrode heat sink 17; the distance connection relationship of each component has been described in detail in the invention part and will not be repeated here.

[0030] In this example, the positive metal component is a boss structure, the protruding portion is designed with external threads, and the insulating material sleeve is fixed to the boss of the positive metal component by rotating the threads;

[0031] The positive metal gasket, power diode chip, and negative metal gasket are stacked in the insulating material sleeve in sequence to improve the air gap electric field distribution and increase the breakdown voltage. The negative metal disc is rotated and fixed on the insulating material sleeve to maintain the chip surface pressure in the range of 10MPa to 20MPa.

[0032] Install and fix the plastic-sealed shell on the positive electrode metal component;

[0033] Install the positive radiator and the negative radiator. The protrusions of the positive radiator and the negative radiator should be accurately matched with the grooves of the positive metal component and the negative metal disc respectively.

[0034] By utilizing the rotary pressurized power diode module packaging structure provided by the present invention, there is no need for a matching customized fixture application, and the module miniaturization can be effectively achieved. In the application scenario of a multi-chip module, uniform pressure distribution can be achieved by controlling the number of pressurized rotations of each submodule. At the same time, double-sided heat dissipation of the chip can be achieved, the thermal resistance of the module junction can be reduced, and the long-term reliability of the module can be effectively improved. The negative metal disc can be opened by rotating, and the failed diode chip can be conveniently replaced, effectively realizing the sustainable application of the module. Compared with the existing crimping packaging structure, the space required for the module and the uniformity of the internal pressure distribution are comprehensively optimized, and it has the advantages of sustainable application, etc.

[0035] Figure 2 Shown is based on Figure 1 The multi-chip module packaging structure extended by the single-chip module packaging structure includes a multi-chip module negative electrode heat sink 18, a multi-chip module plastic package shell 20, a plurality of single-chip sub-modules 22 (consistent with the single-chip structure, including a sub-module negative electrode metal disc 23, a sub-module negative electrode metal gasket 25, a power diode chip 26, a sub-module positive electrode metal gasket 27, and a sub-module insulating material sleeve 30), a multi-chip module positive electrode metal component 34, and a multi-chip module positive electrode heat sink 35;

[0036] In the packaging structure, multiple submodules are connected in parallel to improve the module power level, and the layout includes but is not limited to circular, square, etc.;

[0037] In the packaging structure, the submodule insulating material sleeve 30 is rotatably fixed on the multi-chip module positive metal component 34 through the submodule second internal thread 29 matching the multi-chip module second external thread 32;

[0038] In the packaging structure, the submodule positive metal gasket 27, the power diode chip 26, and the submodule negative metal gasket 25 are stacked in sequence from bottom to top in the submodule insulating material sleeve 30;

[0039] In the packaging structure, the side of the submodule negative electrode metal disc 23 is engraved with a submodule first external thread 24 matching the submodule first internal thread 28, and the submodule negative electrode metal disc 23 is provided with a submodule first groove 21, which is tightened by rotating the negative electrode metal disc 23;

[0040] In the packaging structure, the surfaces of the positive and negative heat sinks 18 and 35 of the multi-chip module are provided with protrusions matching the first grooves 21 of each sub-module and the second grooves 31 of the multi-chip module. The grooves and the matching protrusions include but are not limited to cross shapes, star shapes, polygonal shapes, etc., which are used to position the heat sink and ensure that the rotating pressurization structure is tightened and not loose.

[0041] In the packaging structure, the size matching design and rounded corner design of the submodule positive metal gasket 27, the power diode chip 26, and the submodule negative metal gasket 25 are consistent with those in the single chip structure, ensuring that the power diode chip is evenly stressed.

[0042] In the packaging structure, the design of the submodule insulating material sleeve 30 is consistent with that in the single-chip module packaging structure, and is used to improve the air gap electric field distribution and increase the breakdown voltage.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. 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 solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A rotary pressurized power diode module packaging structure, wherein the diode module is a single-chip module, characterized in that: It comprises a negative electrode radiator (2), a plastic-sealed housing (3), a negative electrode metal disc (5), a negative electrode metal gasket (7), a power diode chip (8), a positive electrode metal gasket (9), an insulating material sleeve (11), a positive electrode metal component (13) and a positive electrode radiator (17); The upper end and the lower end of the inner wall of the insulating material sleeve (11) are respectively provided with a first internal thread (10) and a second internal thread (12); the outer wall of the negative electrode metal disc (5) is provided with a first external thread (6); and the outer wall of the positive electrode metal component (13) is provided with a second external thread (14); the first internal thread (10) and the first external thread (6) match each other so that the negative electrode metal disc (5) and the insulating material sleeve (11) are tightly connected by rotation; the second internal thread (12) and the second external thread (14) match each other so that the positive electrode metal component (13) and the insulating material sleeve (11) are tightly connected by rotation; The middle part of the inner wall of the insulating material sleeve (11) does not have a portion with an internal thread structure. After the negative electrode metal disc (5) and the positive electrode metal component (13) are fastened to the insulating material sleeve (11), a cavity is formed in the middle part of the insulating material sleeve (11). The negative electrode metal gasket (7), the power diode chip (8) and the positive electrode metal gasket (9) are stacked in sequence from top to bottom in the cavity, and the upper surface of the negative electrode metal gasket (7) contacts the lower surface of the negative electrode metal disc (5), and the lower surface of the positive electrode metal gasket (9) contacts the upper surface of the positive electrode metal component (13); The plastic-sealed shell (3) is sleeved on the outer wall of the negative electrode metal disc (5); The upper surface of the negative electrode metal disc (5) has a first groove (4), and the lower surface of the negative electrode heat sink (2) has a first protruding structure (1), the first protruding structure (1) and the first groove (4) match each other, and after the first protruding structure (1) is embedded in the first groove (4), the negative electrode heat sink (2) locks the negative electrode metal disc (5); The lower surface of the positive electrode metal component (13) has a second groove (15), and the upper surface of the positive electrode heat sink (17) has a second protruding structure (16). The second protruding structure (16) and the second groove (15) match each other. After the second protruding structure (16) is embedded in the second groove (15), the positive electrode heat sink (17) locks the positive electrode metal component (13).

2. The rotary pressurized power diode module packaging structure according to claim 1, characterized in that: The size of the negative electrode metal gasket (7) is the same as the size of the power diode chip (8).

3. The rotary pressurized power diode module packaging structure according to claim 1, characterized in that: The size of the positive electrode metal gasket (9) is smaller than the size of the power diode chip (8).

4. The rotary pressurized power diode module packaging structure according to claim 1, characterized in that: The four corners of the negative electrode metal gasket (7), the power diode chip (8) and the positive electrode metal gasket (9) are designed with rounded corners.

5. The rotary pressurized power diode module packaging structure according to claim 1, characterized in that: The cross-sectional top view of the first groove (4) and the second groove (15) is one of a straight line shape, a cross shape, a star shape and a polygon shape.

6. A rotary pressurized power diode module packaging structure, wherein the diode module is a multi-chip module, characterized in that: It comprises a plurality of single-chip module packaging structures as described in claim 1, by setting the negative metal discs of the plurality of single-chip module packaging structures in the same plastic packaging shell, and merging the positive metal component, the negative heat sink and the positive heat sink into a common positive metal component, the negative heat sink and the positive heat sink, thereby realizing a multi-chip module packaging structure.

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