Copper bridge connection structure and power module

Abstract

The utility model relates to a copper bridge connection structure, which is used for a power module, and the power module comprises a substrate and a chip electrically connected to the surface of the substrate. The copper bridge connection structure comprises a bridge surface; the upper end of the first supporting leg is connected to the side surface of the bridge surface, and the lower end of the first supporting leg is in line contact with the corresponding chip surface and is electrically connected with the chip surface; the bridge floor is erected above the substrate and the chip through the first supporting feet. According to the utility model, the lower ends of the first supporting legs are electrically connected with the surfaces of the corresponding chips in a line contact manner, and the bridge surface is overhead above the substrate and the chips by the upper ends of the first supporting legs, so that the equivalent effective current transmission sectional area is ensured, the generation of larger thermal stress is avoided, the mechanical damage to the chips is avoided, and the service life of the chip is prolonged. And the service life of the power module is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of power modules, in particular to a copper bridge connection structure and a power module. Background Art

[0002] The power module usually includes a substrate, a chip and terminals arranged on the substrate, and the chip and the terminals are electrically connected through a copper bridge. The copper bridge usually adopts a copper sheet or copper plate, and is electrically connected to the chip surface electrode and the copper layer on the substrate surface through surface contact. Although this connection method has a large contact area, the effective current transmission surface is still the cross-section of the copper bridge, and the larger contact area will generate greater thermal stress, which is easy to cause mechanical damage to the chip surface. It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art known to ordinary technicians in this field. Utility Model Content

[0003] In view of the deficiencies of the prior art, the embodiments of the present invention disclose a copper bridge connection structure and a power module to solve the problem that the copper bridge and the chip surface contact connection cause high thermal stress and easy damage during use.

[0004] The technical solutions adopted in this utility model are as follows:

[0005] A copper bridge connection structure is used for a power module, wherein the power module includes a substrate and a chip electrically connected to the surface of the substrate; the copper bridge connection structure includes: a bridge deck; a first leg, which is a metal sheet, the upper end of which is connected to the side of the bridge deck, and the lower end of which is in line contact with the surface of the corresponding chip and electrically connected to the surface of the chip; wherein the first leg suspends the bridge deck above the substrate and the chip.

[0006] A further technical solution is that the bridge deck is a horizontally arranged rectangular metal sheet, and the first support leg is perpendicular to the bridge deck.

[0007] A further technical solution is that there are a plurality of chips and four first legs, which are symmetrically arranged on both sides of the bridge deck and correspond to different chips respectively.

[0008] A further technical solution is that the bridge deck includes: a first through hole, which is opened through the bridge deck.

[0009] A further technical solution is that the bridge deck and the first supporting leg are formed by cutting and bending metal sheets into one piece, and the thickness of the metal sheets is not more than 1 mm.

[0010] A further technical solution is that there are a plurality of bridge decks, and adjacent bridge decks are connected by connecting plates.

[0011] A further technical solution is that the connecting plate includes a second through hole, which is opened through the bridge deck.

[0012] A further technical solution is that the copper bridge connection structure includes: a second leg, the upper end of which is connected to the bridge surface, and the lower end of which is electrically connected to the surface of the substrate.

[0013] The utility model also discloses a power module, comprising: a substrate; a chip, electrically connected to the surface of the substrate; a terminal, electrically connected to the surface of the substrate; a copper bridge connection structure, as mentioned above, wherein the lower end of the first support foot is in line contact with the surface of the chip and electrically connected to the surface of the chip, and the lower end of the second support foot is electrically connected to the surface of the substrate, so that the chip is electrically connected to the terminal; a shell, which is a hollow structure, fixed on the substrate; a filling material, filled in the hollow structure, covering the substrate, the chip and the copper bridge connection structure.

[0014] The beneficial effects of the embodiments of the present utility model are as follows:

[0015] (1) The copper bridge connection structure of the present invention includes a bridge deck and a first leg, which is electrically connected to the corresponding chip surface through line contact at the lower end of the first leg. The upper end of the first leg suspends the bridge deck above the substrate and the chip, ensuring the same effective current transmission cross-sectional area while avoiding the generation of large thermal stress, avoiding mechanical damage to the chip, and improving the service life of the power module.

[0016] (2) Furthermore, the bridge decks are provided with a plurality of adjacent bridge decks connected by connecting plates, which can accommodate a large number of chips. A first through-hole is provided through the bridge deck, and a second through-hole is provided through the connecting plate. The first through-hole and the second through-hole facilitate the flow of the filling material and the exhaust of the gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is an axonometric drawing of the copper bridge connection structure of the present invention.

[0018] Figure 2 This is an axonometric diagram of multiple copper bridge connection structures of the utility model.

[0019] Figure 3 It is a cross-sectional view of the power module of the present utility model.

[0020] In the figure: 11, bridge deck; 111, first through hole; 12, first leg; 13, second leg; 14, connecting plate; 141, second through hole; 2, substrate; 3, chip; 4, terminal; 5, filling material; 6, shell. DETAILED DESCRIPTION

[0021] The specific implementation of the present utility model will be described below with reference to the accompanying drawings.

[0022] In order to make the purpose, technical solution and advantages of the present invention clearer, the device proposed in the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the accompanying drawings adopt a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the implementation method of the present invention. In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, please refer to the accompanying drawings. It should be noted that the structure, proportion, size, etc. illustrated in the drawings of this specification are only used to match the content disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no technical substantive significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in the present invention without affecting the efficacy and purpose that can be achieved by the present invention.

[0023] First embodiment:

[0024] This embodiment discloses a copper bridge connection structure.

[0025] Figure 1 This is an axonometric drawing of the copper bridge connection structure of the present invention. Figure 2 This is an axonometric diagram of multiple copper bridge connection structures of the utility model. Figure 3 This is a cross-sectional view of the power module of the present utility model. Figures 1 to 3 As shown, the copper bridge connection structure is used in a power module, which includes a substrate 2 and a chip 3 electrically connected to a surface of the substrate 2 .

[0026] like Figure 1 As shown, the copper bridge connection structure includes a bridge deck 11 and a first leg 12. The first leg 12 is a metal sheet, the upper end of which is connected to the side of the bridge deck 11, and the lower end is in line contact with the surface of the corresponding chip 3 and electrically connected to the surface of the chip 3. Among them, the first leg 12 suspends the bridge deck 11 above the substrate 2 and the chip 3. Exemplarily, the bridge deck 11 is a horizontally arranged rectangular metal sheet, and the first leg 12 is perpendicular to the bridge deck 11. The bridge deck 11 and the first leg 12 are formed by cutting and bending the metal sheet into one piece, and the thickness of the metal sheet is not more than 1 mm. Preferably, the thickness of the metal sheet is 0.4 mm. Specifically, there are several chips 3 and four first legs 12, which are symmetrically arranged on both sides of the bridge deck 11, corresponding to different chips 3 respectively.

[0027] like Figure 2As shown, further, the bridge deck 11 includes a first through hole 111 . The first through hole 111 is opened through the bridge deck 11 . The first through hole 111 facilitates the flow and exhaust of the filling material 5 .

[0028] like Figure 2 As shown, further, there are a plurality of bridge decks 11, and adjacent bridge decks 11 are connected by connecting plates 14. For example, the chips 3 are arranged in an array, and the bridge decks 11 are arranged parallel and spaced along the arrangement direction of the chips 3, and the connecting plates 14 are connected to the places without support legs on both sides of the bridge decks 11.

[0029] like Figure 2 As shown, further, the connecting plate 14 includes a second through hole 141 . The second through hole 141 is opened through the bridge deck 11 . The second through hole 141 facilitates the flow and exhaust of the filling material 5 .

[0030] like Figure 1 and Figure 3 As shown, the copper bridge connection structure further includes a second leg 13, the upper end of which is connected to the end of the bridge deck 11, and the lower end of which is electrically connected to the surface of the substrate 2. The lower end of the second leg 13 and the surface copper layer of the substrate 2 can be in line contact or surface contact, as long as the second leg 13 can be fixedly connected to the surface copper layer of the substrate 2.

[0031] In this embodiment, the lower end of the first leg 12 is electrically connected to the surface of the corresponding chip 3 through line contact, and the upper end of the first leg 12 suspends the bridge deck 11 above the substrate 2 and the chip 3, ensuring the same effective current transmission cross-sectional area while avoiding the generation of large thermal stress, avoiding mechanical damage to the chip 3, and improving the service life of the power module.

[0032] Second embodiment:

[0033] This embodiment discloses a power module.

[0034] like Figure 3 As shown, the power module includes a substrate 2, a chip 3, terminals 4, a copper bridge connection structure, and a housing 6. Chip 3 is electrically connected to the surface of substrate 2. Terminal 4 is also electrically connected to the surface of substrate 2. As previously mentioned, the copper bridge connection structure has a first leg 12 whose lower end makes line contact with and electrically connects the surface of chip 3. The second leg 13 whose lower end is electrically connected to the surface of substrate 2 electrically connects chip 3 to terminal 4. Housing 6 is a hollow structure fixed to substrate 2. Filling material 5 is filled within the hollow structure, covering the substrate 2, chip 3, and copper bridge connection structure.

[0035] For example, the lower surface electrode of chip 3 is connected to the first copper layer on the surface of substrate 2 via metal sintering. The lower end of first leg 12 is soldered to the upper surface electrode of chip 3 via reflow soldering. Terminal 4 is laser welded to the second copper layer on the surface of substrate 2, and the lower end of second leg 13 is laser welded to the second copper layer on the surface of substrate 2. Housing 6 is fixed to substrate 2 via glue dispensing. Filler 5 is an insulating and heat-resistant epoxy resin.

[0036] In this embodiment, the surface electrode of the chip 3 and the copper layer of the substrate 2 are connected respectively by the first leg 12 and the second leg 13. The bridge surface 11 is responsible for transmitting most of the current of the circuit. The copper bridge connection structure realizes the electrical connection between the electrode of the chip 3 and the terminal 4. It has a simple structure, reliable connection, and a long service life of the power module.

[0037] At the same time, due to the use of line contact, the amount of solder used is reduced, reducing the possibility of solder overflowing to adjacent areas and causing short circuits, thereby improving the yield of power modules.

[0038] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0039] The above-described embodiments merely represent several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present utility model patent shall be determined by the appended claims.

Claims

1. Copper bridge connection structure, characterized in that, Used in a power module, the power module includes a substrate and a chip electrically connected to the surface of the substrate; the copper bridge connection structure includes: bridge deck; The first leg is a metal sheet, the upper end of which is connected to the side of the bridge deck, and the lower end of which is in line contact with the surface of the corresponding chip and electrically connected to the surface of the chip; The first legs raise the bridge deck above the substrate and the chip.

2. The copper bridge connection structure according to claim 1, characterized in that: The bridge deck is a horizontally arranged rectangular metal sheet, and the first supporting leg is perpendicular to the bridge deck.

3. The copper bridge connection structure according to claim 2, characterized in that: There are a plurality of chips, and there are four first legs, which are symmetrically arranged on both sides of the bridge deck and correspond to different chips respectively.

4. The copper bridge connection structure according to claim 2, characterized in that: The bridge deck comprises: The first through hole is opened through the bridge deck.

5. The copper bridge connection structure according to claim 1, characterized in that: The bridge deck and the first supporting leg are formed by cutting and bending metal sheets into one piece, and the thickness of the metal sheets is not greater than 1 mm.

6. The copper bridge connection structure according to claim 2, characterized in that: There are a plurality of bridge decks, and adjacent bridge decks are connected by connecting plates.

7. The copper bridge connection structure according to claim 6, characterized in that: The connecting plate comprises: The second through hole is opened through the bridge deck.

8. The copper bridge connection structure according to claim 1, characterized in that: The copper bridge connection structure comprises: The second leg has an upper end connected to the bridge deck and a lower end electrically connected to the surface of the substrate.

9. Power module, including: substrate; a chip electrically connected to the surface of the substrate; a terminal electrically connected to the surface of the substrate; The copper bridge connection structure according to claim 8, wherein the lower end of the first foot is in line contact with the surface of the chip and electrically connected to the surface of the chip, and the lower end of the second foot is electrically connected to the surface of the substrate, so that the chip is electrically connected to the terminal; The shell is a hollow structure and is fixed on the substrate; the filling material is filled in the hollow structure and covers the substrate, the chip and the copper bridge connection structure.

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