A rotary pressurized power diode module packaging structure

Abstract

The present invention belongs to the field of semiconductor packaging technology, and specifically relates to a rotary pressurized power diode module packaging structure. The present invention includes a positive metal component, an insulating material sleeve with internal threads on both ends, a positive metal gasket, a power diode chip, a negative metal gasket, a negative metal disc with external threads, and a plastic-encapsulated shell; the insulating material sleeve is rotated and fixed on a base plate boss, and then the positive metal gasket, the power diode chip, the negative metal gasket, and the negative metal disc with external threads are sequentially assembled into the insulating material sleeve, and finally the plastic-encapsulated shell is installed and fixed on the base plate to complete the module assembly; pressure is applied by rotating the negative metal disc to maintain good contact between components; a groove is engraved in the center of the negative metal disc for radiator positioning and rotational pressurization by an external tool, and a protrusion is engraved in the center of the negative radiator that matches the groove for radiator positioning and preventing the pressurized structure from loosening.

Description

Technical Field

[0001] The present 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 fundamental core components of power conversion equipment. Compared to traditional solder-packaged power diodes, press-fit packaged power diodes are more widely used in high-power applications due to their advantages such as double-sided heat dissipation, high power density, low parasitic parameters, and failure short circuit resistance. As power electronic equipment develops towards miniaturization and sustainability, the large space required for the supporting fixtures used in press-fit packaged power diodes has become a major obstacle to their miniaturization. Furthermore, press-fit packaged power diodes use a sealed package, so even if only one submodule fails, the entire module is scrapped, becoming a key challenge to their sustainability development. Therefore, achieving miniaturization and sustainability in press-fit packaged power diode modules is of great significance.

[0003] Currently, there are two main types of press-fit packaging structures: rigid press-fit packaging and elastic press-fit packaging. Rigid press-fit packaging modules require large, custom-made fixtures for fixturing during use, and are therefore typically used in equipment with ample space, such as flexible DC transmission converter valves and circuit breakers. Furthermore, due to factors such as module layout and fixture design, rigid press-fit packaging modules often suffer from uneven pressure distribution within submodules, making some submodules susceptible to overstress and leading to premature failure of the entire module. The elastic press-fit packaging structure effectively addresses the problem of uneven pressure distribution within the submodules by employing a disc spring design within each submodule. However, the introduction of the disc spring structure also leads to poor heat dissipation on the disc spring side of the chip, and there is a risk of disc spring failure after long-term stress cycling. Furthermore, existing press-fit packaging modules generally use sealed packaging, making it difficult to open the end caps without damage during later maintenance. Even if only a submodule within the module fails, the entire module is scrapped due to the difficulty in repair, resulting in poor sustainable application capabilities.

[0004] In summary, existing rigid press-fit packaging structures suffer from large space requirements and poor internal pressure distribution uniformity, while existing elastic press-fit packaging structures suffer from poor heat dissipation and disc spring failure. Furthermore, both utilize sealed packaging, making subsequent maintenance difficult and resulting in limited sustainability. Therefore, the development of a packaging structure with uniform pressure distribution, strong heat dissipation, and the ability to easily replace failed submodules is crucial for the miniaturization and sustainability of press-fit power diode modules. Summary of the Invention

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

[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 and lower ends 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 tightly connected 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 tightly connected by rotation.

[0009] The middle portion of the inner wall of the insulating material sleeve 11 does not have 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 portion 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 this cavity in order from top to bottom, with the upper surface of the negative metal gasket 7 in contact with the lower surface of the negative metal disc 5, and the lower surface of the positive metal gasket 9 in contact with the upper surface of the positive metal component 13.

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

[0011] The upper surface of the negative metal disc 5 has a first groove 4, and the lower surface of the negative radiator 2 has a first protrusion 1. The first protrusion 1 and the first groove 4 match each other. After the first protrusion 1 is embedded in the first groove 4, the negative radiator 2 can lock the negative 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 protrusion structure 16. The second protrusion structure 16 and the second groove 15 match each other. After the second protrusion 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 that of the power diode chip 8 .

[0014] Furthermore, the size of the positive metal gasket 9 is smaller than that 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 stress concentration 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, which realizes a multi-chip module packaging structure by placing the negative metal discs of multiple single-chip module packaging structures in the same plastic package shell, and merging the negative radiator and the positive radiator into a common negative radiator and positive radiator.

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

[0020] 1) The packaging structure designed in the present invention does not require the special fixtures required for the existing rigid press-fit packaging modules in application, thereby effectively reducing the space occupied by the module and achieving 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 the 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 a failed diode chip by opening the negative metal disc, which can realize convenient replacement of failed chips and effectively achieve 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 for 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 housing; 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-multi-chip module negative electrode heat sink; 19-multi-chip module first protruding structure; 20-multi-chip module plastic housing 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 solution of the present invention is further described below with reference to 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 an insulating 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 sleeve to maintain the chip surface pressure in the range of 10MPa to 20MPa.

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

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

[0034] The rotary pressurized power diode module packaging structure provided by the present invention eliminates the need for customized fixtures and effectively achieves module miniaturization. In multi-chip module applications, 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, reducing the module junction thermal resistance and effectively improving the long-term reliability of the module. The negative metal disc can be opened by rotating to facilitate replacement of failed diode chips, effectively achieving sustainable application of the module. Compared with existing pressurized packaging structures, the space required for the module and the uniformity of internal pressure distribution are comprehensively optimized, while also having advantages such as sustainable application.

[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 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 and square;

[0037] In the packaging structure, the submodule insulating material sleeve 30 is rotatably fixed to the multi-chip module positive metal component 34 via 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 metal disc 23 is engraved with a submodule first external thread 24 that matches the submodule first internal thread 28. The submodule negative metal disc 23 is opened with a submodule first groove 21, and the negative metal disc 23 is pressed and tightened by rotating it.

[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 that match the first grooves 21 of each sub-module and the second grooves 31 of the multi-chip module. The grooves and their 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 rotary pressurization structure is tightened and not loose.

[0041] In the packaging structure, the submodule positive metal gasket 27, the power diode chip 26, and the submodule negative metal gasket 25 are designed to match the size and have the same rounded corner design as 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 solutions of the present invention and are not limiting. 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 can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions, which should all 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 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 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 metal disc (5) is provided with a first external thread (6); 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 tightly connected 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 tightly connected by rotation; The middle portion of the inner wall of the insulating material sleeve (11) does not have 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 portion 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). 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 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) locks the negative electrode metal disc (5). The lower surface of the positive metal component (13) has a second groove (15), and the upper surface of the positive radiator (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 radiator (17) locks the positive 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: The invention comprises a plurality of single-chip module packaging structures as described in claim 1, wherein the negative metal discs of the plurality of single-chip module packaging structures are enclosed in the same plastic package shell, and the positive metal component, the negative heat sink and the positive heat sink are combined into a common positive metal component, the negative heat sink and the positive heat sink, thereby realizing a multi-chip module packaging structure.

Images