AMB substrate for packaging IGBT and SIC modules

Abstract

The utility model discloses an AMB substrate used for packaging an IGBT module and an SIC module. The circuit board comprises an upper covering layer, a substrate and a lower covering layer, the upper covering layer and the lower covering layer are fixedly arranged on the upper end face and the lower end face of the substrate respectively, the upper covering layer is provided with a plurality of first etching grooves used for forming circuit patterns, the lower covering layer is transversely provided with a second etching groove in a penetrating mode, and the second etching groove enables the lower covering layer to be divided into a first metal block and a second metal block; the lower coating layer is divided into a first metal block and a second metal block through a second etching groove so as to reduce stress extrusion when the lower coating layer is heated; when the substrate is heated, the temperature gradient can cause thermal stress to be generated in the material, the lower coating layer is divided into the first metal block and the second metal block, and the second etching groove is reserved between the first metal block and the second metal block, so that the temperature gradient of the whole area can be reduced, and generation of the thermal stress is reduced; in the heating process, more space can be provided for expansion of the copper material, and therefore thermal stress generated due to expansion limitation is avoided.

Description

Technical Field

[0001] This utility model relates to the field of power module technology, and in particular to an AMB substrate for packaging IGBT and SiC modules. Background Technology

[0002] AMB (Active Metal Brazing) technology is a further development of DBC technology. It utilizes the reaction of small amounts of active elements Ti and Zr in the solder with the ceramic to generate a reaction layer that can be wetted by the liquid solder, thus achieving bonding between ceramic and metal. The AMB substrate achieves bonding through a chemical reaction between the ceramic and active metal solder paste at high temperatures, resulting in higher bonding strength, better reliability, and making it more suitable for manufacturing ceramic copper-clad laminates for IGBT / SiC module packaging in electric vehicles and locomotives. IGBT modules are modular semiconductor products packaged by IGBT chips and FWD (freewheeling diode) chips through specific circuit bridging. SiC modules refer to power semiconductor modules made of silicon carbide (SiC) material. Especially in important fields such as wind power, solar power, heat pumps, hydropower, biomass energy, green buildings, new energy equipment, electric vehicles, and rail transportation, the rapid development of power electronics technology will create huge demand for ceramic copper-clad laminates, a key material for IGBT / SiC module packaging.

[0003] Currently, the copper thickness on the top and bottom surfaces of the AMB substrate is the same. This can lead to an imbalance of stress between the two surfaces when the etching ratio on the top surface is too high. This can cause excessive heat deformation and warping during the subsequent fabrication of IGBT / SiC modules, increasing the difficulty of the process. In addition, long-term high and low temperature conditions in the application can also cause cracks in some weak points due to stress issues, posing a risk of breakage. Utility Model Content

[0004] To address the problems existing in the prior art, this utility model provides an AMB substrate for IGBT and SiC module packaging, which can effectively solve the problems existing in the prior art.

[0005] The technical solution of this utility model is:

[0006] According to one aspect of the present invention, it includes: an upper cover layer, a substrate, and a lower cover layer, wherein the upper cover layer and the lower cover layer are respectively fixed on the upper and lower end faces of the substrate, and the upper cover layer is provided with a plurality of first etching grooves for forming circuit patterns, and the lower cover layer is provided with a second etching groove that extends laterally through it, the second etching groove dividing the lower cover layer into a first metal block and a second metal block.

[0007] Furthermore, the second etching groove is located at the center of the underlayer, and the first metal block is symmetrical to the second metal block.

[0008] Furthermore, the thickness of the upper covering layer is greater than the thickness of the lower covering layer.

[0009] Furthermore, the upper cover layer and the lower cover layer have the same volume.

[0010] Furthermore, both the upper and lower cladding layers are made of copper, and the substrate is a ceramic substrate.

[0011] Furthermore, it also includes a first metal brazing layer and a second metal brazing layer, wherein the first metal brazing layer is fixed between the upper cover layer and the substrate; and the second metal brazing layer is fixed between the lower cover layer and the substrate.

[0012] By adopting the above technical solution, the beneficial effects of this utility model compared with the prior art are as follows:

[0013] Firstly, dividing the underlayer into a first metal block and a second metal block via a second etching groove reduces stress compression during heating. When the substrate is heated, the temperature gradient causes thermal stress within the material. Dividing the underlayer into the first and second metal blocks, with a second etching groove in between, reduces the temperature gradient across the entire area, thus minimizing thermal stress. Secondly, copper expands during heating. Segmenting the underlayer provides more space for this expansion, preventing thermal stress caused by restricted expansion. It also disperses and mitigates thermal deformation caused by temperature changes, improving the overall stability of the substrate. The segmented design also enhances the structural strength of the substrate to some extent. When one block (the first or second metal block) is subjected to external force, the other block can provide support and distribute stress, preventing localized damage.

[0014] Secondly, the thickness of the upper cover layer is greater than that of the lower cover layer, and the upper and lower cover layers have the same volume, which makes the overall structure of the substrate symmetrical. This symmetry can reduce stress concentration caused by structural asymmetry, thereby reducing the risk of the substrate deforming or breaking when heated or stressed. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the planar structure of the present invention;

[0017] In the figure: upper cover layer-1, first etching tank-11, substrate-2, first metal brazing layer-3, second metal brazing layer-4, lower cover layer-5, second etching tank-51, first metal block-52, second metal block-53. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be particularly noted that the following embodiments are only for illustrating the present invention and do not limit the scope of the present invention. Similarly, the following embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0019] like Figure 1 As shown, this solution provides an AMB substrate for packaging IGBT and SiC modules.

[0020] Please see Figure 1 The substrate 2 comprises an upper cover layer 1, a substrate 2, and a lower cover layer 5. The upper cover layer 1 and the lower cover layer 5 are fixed to the upper and lower end faces of the substrate 2, respectively. The upper cover layer 1 has several first etching grooves 11 for forming circuit patterns. It also includes a first metal solder layer 3 and a second metal solder layer 4. The first metal solder layer 3 is fixed between the upper cover layer 1 and the substrate 2; the second metal solder layer 4 is fixed between the lower cover layer 5 and the substrate 2. Both the upper cover layer 1 and the lower cover layer 5 are made of copper, and the substrate 2 is a ceramic substrate. The thickness of the upper cover layer 1 is greater than the thickness of the lower cover layer 5. The upper cover layer 1 and the lower cover layer 5 have the same volume. The thickness of the upper cover layer 1 is calculated based on the actual etching area, and then the upper cover layer 1 is thickened to make its volume the same as the volume of the lower cover layer 5. The equal volume of the upper cover layer 1 and the lower cover layer 5 ensures the symmetry of the overall structure of the substrate 2. This symmetry can reduce stress concentration caused by structural asymmetry, thereby reducing the risk of the substrate deforming or breaking when heated or stressed.

[0021] Please see Figure 1A second etching groove 51 is transversely provided in the lower cover layer 5, dividing the lower cover layer 5 into a first metal block 52 and a second metal block 53. Preferably, the second etching groove 51 is located at the center of the lower cover layer 5, and the first metal block 52 and the second metal block 53 are symmetrical. Dividing the lower cover layer 5 into the first metal block 52 and the second metal block 53 through the second etching groove 51 is to reduce stress compression of the lower cover layer 5 when heated. When the substrate 2 is heated, the temperature gradient will cause thermal stress to be generated inside the material. By dividing the lower cover layer 5 into the first metal block 52 and the second metal block 53, and leaving the second etching groove 51 in the middle, the temperature gradient of the entire area can be reduced, thereby reducing the generation of thermal stress. During the heating process, the copper material will expand. Segmenting the lower cover layer 5 can provide more space for the expansion of the copper material, thereby avoiding thermal stress caused by limited expansion; it can also disperse and alleviate thermal deformation caused by temperature changes, thereby improving the overall stability of the substrate. The segmented design can also enhance the structural strength of the substrate 2 to a certain extent. When one of the blocks (the first metal block 52 or the second metal block 53) is subjected to external force, the other block can play a supporting and stress-dispersing role, thereby preventing local damage.

[0022] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. An AMB substrate for packaging IGBT and SiC modules, comprising: The substrate (2) comprises an upper cover layer (1), a substrate (2), and a lower cover layer (5). The upper cover layer (1) and the lower cover layer (5) are respectively fixed on the upper and lower end faces of the substrate (2). The upper cover layer (1) is provided with a plurality of first etching grooves (11) for forming circuit patterns. The lower cover layer (5) is characterized by having a second etching groove (51) that extends laterally through it. The second etching groove (51) divides the lower cover layer (5) into a first metal block (52) and a second metal block (53). The second etching groove (51) is located at the center of the underlayer (5), and the first metal block (52) and the second metal block (53) are symmetrical to each other; The thickness of the upper covering layer (1) is greater than the thickness of the lower covering layer (5); The upper cover layer (1) and the lower cover layer (5) have the same volume.

2. The AMB substrate for IGBT and SiC module packaging as described in claim 1, characterized in that, The upper cover layer (1) and the lower cover layer (5) are both made of copper, and the substrate (2) is a ceramic substrate.

3. The AMB substrate for IGBT and SiC module packaging as described in claim 2, characterized in that, It also includes a first metal brazing layer (3) and a second metal brazing layer (4), wherein the first metal brazing layer (3) is fixed between the upper cover layer (1) and the substrate (2); and the second metal brazing layer (4) is fixed between the lower cover layer (5) and the substrate (2).

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