Copper-clad ceramic substrate and power module

Abstract

The utility model provides a copper-clad ceramic substrate and a power module, and relates to the technical field of semiconductor devices, and the copper-clad ceramic substrate comprises an upper copper layer, a middle ceramic layer and a lower copper layer which are stacked from top to bottom. A plurality of upper convex hulls are distributed on the surface of the upper copper layer, and a plurality of lower convex hulls are distributed on the surface of the lower copper layer; the surface of the copper substrate is in welded connection with the lower copper layer of the copper-clad ceramic substrate; each chip is correspondingly welded on one upper convex hull, and the adjacent chips are bonded through bonding wires; and the power terminal is welded on the surface of the upper copper layer of the copper-clad ceramic substrate. The copper-clad ceramic substrate has the beneficial effects that the upper convex hulls and the lower convex hulls have certain heights, so that a certain gap is formed between the surface of the copper substrate and the copper-clad ceramic substrate, and carbon dioxide gas generated by reaction of organic components and oxygen can completely escape with enough space; and no cavity is formed between the copper-clad ceramic substrate and the chip or the heat dissipation substrate in the escaping process.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor device technology, and in particular to a copper-clad ceramic substrate and a power module. Background Technology

[0002] Copper-clad ceramic substrates (CCLs) are widely used in semiconductor power module packaging due to their excellent thermal cycling performance, outstanding shape stability, superior rigidity, high thermal conductivity, and high reliability. Their copper-clad surfaces can be precisely etched with diverse patterns. During the packaging process, solder paste or silver paste is typically used as a bonding medium to tightly bond the CCL to the chip and heat sink.

[0003] However, traditional soldering processes have a significant problem: both solder paste and silver paste contain a considerable amount of organic components. Under the high temperatures of soldering, these organic components react with oxygen to generate large amounts of carbon dioxide gas. Some of this gas escapes, but during this process, it creates voids between the copper-clad ceramic substrate and the chip or heat sink; the remaining gas fails to escape and is trapped at the interface. This situation results in numerous voids between the copper-clad ceramic substrate and the chip / heat sink, severely weakening their electrical and thermal conductivity. Utility Model Content

[0004] To address the problems existing in the prior art, this utility model provides a copper-clad ceramic substrate, comprising an upper copper layer, an intermediate ceramic layer, and a lower copper layer stacked from top to bottom; the surface of the upper copper layer is distributed with multiple upper bumps, and the surface of the lower copper layer is distributed with multiple lower bumps.

[0005] Preferably, the height of the upper convex bulge is in the range of 100±50μm.

[0006] Preferably, the height of the lower convex hull is in the range of 150±100μm.

[0007] This utility model also provides a power module that uses the copper-clad ceramic substrate as described above, including:

[0008] A copper substrate, the surface of which is welded to the lower copper layer of the copper-clad ceramic substrate;

[0009] Multiple chips, each chip is soldered onto one of the upper bumps, and adjacent chips are bonded together by bonding wires;

[0010] Power terminals are soldered to the surface of the upper copper layer of the copper-clad ceramic substrate.

[0011] Preferably, the copper-clad ceramic substrate has multiple positioning holes, and the copper substrate has multiple positioning elements corresponding to each of the positioning holes.

[0012] Preferably, at least one copper-clad ceramic substrate is welded to the surface of the copper substrate, and adjacent copper-clad ceramic substrates are connected by connecting copper sheets.

[0013] Preferably, the chip includes an IGBT chip and a diode chip, and the surface of the IGBT chip and the surface of the adjacent diode chip are bonded together by bonding wires.

[0014] The above technical solution has the following advantages or beneficial effects:

[0015] Because the upper and lower bumps have a certain height, there is a certain gap between the surface of the copper substrate and the copper-clad ceramic substrate, allowing sufficient space for the carbon dioxide gas generated by the reaction of organic components with oxygen to escape completely, and preventing the formation of voids between the copper-clad ceramic substrate and the chip or heat dissipation substrate during the escape process. Attached Figure Description

[0016] Figure 1 A side view of the copper-clad ceramic substrate in a preferred embodiment of the present invention;

[0017] Figure 2 A top view of the copper-clad ceramic substrate in a preferred embodiment of the present invention;

[0018] Figure 3 A bottom view of the copper-clad ceramic substrate in a preferred embodiment of the present invention;

[0019] Figure 4 This is a structural diagram of the power module in a preferred embodiment of the present invention. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The present invention is not limited to this embodiment; other embodiments that conform to the spirit of the present invention may also fall within its scope.

[0021] In a preferred embodiment of the present invention, based on the above-mentioned problems existing in the prior art, a copper-clad ceramic substrate 1 is provided, comprising an upper copper layer 11, an intermediate ceramic layer 12 and a lower copper layer 13 stacked from top to bottom; the surface of the upper copper layer 11 is distributed with a plurality of upper bumps 111, and the surface of the lower copper layer 13 is distributed with a plurality of lower bumps 131.

[0022] In a preferred embodiment of this utility model, the height of the upper convex bulge 111 is in the range of 100±50μm.

[0023] In a preferred embodiment of this utility model, the height of the lower convex bulge 131 is in the range of 150±100μm.

[0024] This utility model also provides a power module that uses the copper-clad ceramic substrate as described above, including:

[0025] A copper substrate 2, the surface of which is welded to the lower copper layer 13 of the copper-clad ceramic substrate 1;

[0026] Multiple chips 3 are respectively soldered onto one of the upper protrusions 111, and adjacent chips 3 are bonded together by bonding lines 4;

[0027] Power terminal 5, which is soldered to the surface of the upper copper layer 111 of the copper-clad ceramic substrate 1.

[0028] Specifically, such as Figure 1-4 As shown, multiple upper bumps 111 are distributed on the surface of the upper copper layer 11, and multiple lower bumps 131 are distributed on the surface of the lower copper layer 13. When the copper-clad ceramic substrate is used in a power module, the chip 3 is soldered onto the upper bumps 111, and the surface of the copper substrate 2 is soldered to the lower bumps 131 of the lower copper layer 13 of the copper-clad ceramic substrate 1. Since the upper bumps 111 and the lower bumps 131 have a certain height, there is a certain gap between the surface of the copper substrate 2 and the copper-clad ceramic substrate, so that the carbon dioxide gas generated by the reaction of organic components with oxygen can have enough space to escape completely, and no voids will be formed between the copper-clad ceramic substrate and the chip or heat dissipation substrate during the escape process.

[0029] In a preferred embodiment of the present invention, the copper-clad ceramic substrate 1 is provided with a plurality of positioning holes 14, and the copper substrate 2 is provided with a plurality of positioning elements corresponding to each of the positioning holes 14.

[0030] Specifically, in this embodiment, the positioning hole 14 is used for auxiliary positioning during the installation process to ensure accurate installation position.

[0031] In a preferred embodiment of the present invention, at least one copper-clad ceramic substrate 1 is welded to the surface of the copper substrate 2, and adjacent copper-clad ceramic substrates 1 are connected by connecting copper sheets 6.

[0032] In a preferred embodiment of the present invention, the chip 3 includes an IGBT chip 31 and a diode chip 32, wherein the surface of the IGBT chip 31 and the surface of the adjacent diode chip 32 are bonded together by a bonding wire.

[0033] Specifically, in this embodiment, multiple copper-clad ceramic substrates 1 on the copper substrate 2 are welded together by connecting copper sheets 6, so that the chips 3 on the multiple copper-clad ceramic substrates 1 can be electrically connected, thereby improving efficiency.

[0034] Furthermore, the aforementioned power module can be obtained using the following fabrication process, including:

[0035] S1: Add solder paste to the surface of the upper copper layer of the copper-clad ceramic substrate;

[0036] S2: Solder the chip to the upper copper layer bump of the copper-clad ceramic substrate and clean it;

[0037] S3: Bond the chip to the copper-clad ceramic substrate using metal bonding wires;

[0038] S4; Add solder to the copper-clad ceramic substrate to solder the power terminals and connecting copper sheets to the copper-clad ceramic substrate, and clean it;

[0039] S5: Place solder pads on the surface of the heat dissipation copper substrate, solder the lower copper layer of the copper-clad ceramic substrate to the heat dissipation copper substrate, and clean it;

[0040] S6: Package.

[0041] The above are merely preferred embodiments of the present utility model and are not intended to limit the implementation methods and protection scope of the present utility model. Those skilled in the art should realize that any equivalent substitutions and obvious changes made using the content of this specification and illustrations should be included within the protection scope of the present utility model.

Claims

1. A copper-clad ceramic substrate, characterized in that, It includes an upper copper layer, an intermediate ceramic layer, and a lower copper layer stacked from top to bottom; the surface of the upper copper layer is distributed with multiple upper bumps, and the surface of the lower copper layer is distributed with multiple lower bumps.

2. The copper-clad ceramic substrate according to claim 1, characterized in that, The height range of the upper convex hull is 100±50μm.

3. The copper-clad ceramic substrate according to claim 1, characterized in that, The height range of the lower convex hull is 150±100μm.

4. A power module, characterized in that, The application of the copper-clad ceramic substrate as described in any one of claims 1-3 includes: A copper substrate, the surface of which is welded to the lower copper layer of the copper-clad ceramic substrate; Multiple chips, each chip is soldered onto one of the upper bumps, and adjacent chips are bonded together by bonding wires; Power terminals are soldered to the surface of the upper copper layer of the copper-clad ceramic substrate.

5. The power module according to claim 4, characterized in that, The copper-clad ceramic substrate has multiple positioning holes, and the copper substrate has multiple positioning elements corresponding to each of the positioning holes.

6. The power module according to claim 4, characterized in that, At least one copper-clad ceramic substrate is welded to the surface of the copper substrate, and adjacent copper-clad ceramic substrates are connected by connecting copper sheets.

7. The power module according to claim 4, characterized in that, The chip includes an IGBT chip and a diode chip, and the surface of the IGBT chip and the surface of the adjacent diode chip are bonded together by bonding wires.

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