Chip mounting structure based on zirconium tungstate-metal composite material

Abstract

The utility model relates to a zirconium tungstate-metal composite material-based chip mounting structure, which comprises a composite connecting part used for connecting a chip body and a substrate, and a limiting clamping edge arranged on the chip body and used for being matched with the edge of the composite connecting part for limiting, the composite connecting part comprises a plurality of zirconium tungstate-metal composite layers, and the zirconium tungstate-metal composite layers are arranged on the substrate. The thermal expansion coefficient of the zirconium tungstate-metal composite layer is between the thermal expansion coefficient of the chip body and the thermal expansion coefficient of the substrate, and the thermal expansion coefficient gradually decreases in the direction away from the substrate. According to the utility model, the composite connecting part with the thermal expansion coefficient changing in a stepped manner is arranged between the substrate and the chip body, so that the mounting structure between the chip body and the substrate has adaptive capacity of gradual change of thermal expansion and cold contraction amplitude, and the thermal expansion coefficient of the composite connecting part is gradually increased in the direction from the chip body to the substrate; the stress of the chip body can be effectively eliminated under the condition of temperature change, and the problems of cracking, deformation and the like are effectively prevented.

Description

Technical Field

[0001] This utility model belongs to the field of chip packaging, specifically relating to a chip mounting structure based on zirconium tungstate-metal composite material. Background Technology

[0002] During the chip packaging process, bonding, welding, sintering and other methods are generally used to connect the chip body to the substrate, and then encapsulation is performed. Since the chip mainly consists of materials such as silicon or silicon carbide, the thermal expansion coefficient of the packaging substrate material is generally different from that of the chip body. Under the influence of thermal expansion and contraction, stress is easily generated, causing cracking, breakage and other problems.

[0003] Zirconium tungstate is a material with negative thermal expansion, meaning its volume shrinks as the temperature rises. By combining zirconium tungstate with metals (such as one or more of aluminum, copper, and silver) to form composite materials, the required coefficient of thermal expansion can be obtained through volume ratio. This material is commonly used in high-precision chip packaging. However, common composite materials only place a composite material with a coefficient of thermal expansion between the chip body and the substrate, lacking a gradient change. Therefore, there is still room for improvement in its stress relief effect. Utility Model Content

[0004] The purpose of this invention is to provide a chip mounting structure based on zirconium tungstate-metal composite material in order to solve the above problems.

[0005] This utility model achieves the above objectives through the following technical solutions:

[0006] A chip mounting structure based on zirconium tungstate-metal composite material includes a composite connection portion for connecting a chip body and a substrate, and a limiting edge disposed on the chip body for engaging and limiting the edge of the composite connection portion. The composite connection portion includes a plurality of zirconium tungstate-metal composite layers, wherein the coefficient of thermal expansion of the zirconium tungstate-metal composite layers is between that of the chip body and the substrate, and the coefficient of thermal expansion decreases in the direction away from the substrate.

[0007] As a further optimization of this utility model, the zirconium tungstate-metal composite layer on the side of the composite connection near the substrate is bonded together by an adhesive layer. This solution is the prior art, which uses an adhesive curing method to bond the composite connection to the substrate.

[0008] As a further optimization of this utility model, the zirconium tungstate-metal composite layer on the side of the composite connection near the substrate is provided with a first rough surface, and the surface of the substrate is provided with a second rough surface. The first rough surface and the second rough surface make the composite connection and the substrate firmly bonded and not easy to fall off.

[0009] As a further optimization of this utility model, the length and width dimensions of the zirconium tungstate-metal composite layer gradually decrease away from the substrate to form a stepped portion at the edge of the composite connection. The inner edge of the limiting edge is provided with a mating groove adapted to the stepped portion. The stepped portion and the limiting edge are used to improve the bonding stability.

[0010] As a further optimization of this utility model, the corner of the mating groove is chamfered, which facilitates the flow of colloid to fill the stepped part and the limiting edge when the composite connection part is bonded to the chip body.

[0011] As a further optimization of this utility model, a hot-melt edge is provided on the surface of the zirconium tungstate-metal composite layer near the chip body. The hot-melt edge and the zirconium tungstate-metal composite layer form a glue storage tank. By setting the glue storage tank, adhesive can be stored. During the hot-melting process of the glue storage tank, adhesive is evenly released to the surrounding area so that the adhesive can be evenly filled into the gap between the limiting edge and the stepped part.

[0012] The beneficial effects of this utility model are as follows:

[0013] This invention provides a composite connection with a stepped coefficient of thermal expansion between the substrate and the chip body. The composite connection is bonded to both the substrate and the chip body, giving the mounting structure between the chip body and the substrate the ability to adapt to gradual changes in thermal expansion and contraction. The coefficient of thermal expansion of the composite connection increases progressively from the chip body to the substrate, effectively eliminating stress on the chip body under temperature changes and preventing cracking and deformation. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0015] Figure 2 This is the utility model Figure 1 Schematic diagram of part A in the middle.

[0016] Figure 3 This is a schematic diagram of the composite connection part of this utility model.

[0017] In the figure: 1. Composite connection part; 101. Zirconium tungstate-metal composite layer; 102. First rough surface; 103. Stepped part; 2. Hot melt edge; 3. Glue reservoir; 4. Limiting edge; 5. Chip body; 6. Substrate; 601. Second rough surface; 602. Adhesive layer. Detailed Implementation

[0018] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0019] Example 1

[0020] like Figure 1-3 As shown, a chip mounting structure based on zirconium tungstate-metal composite material includes a composite connection part 1 for connecting a chip body 5 and a substrate 6, and a limiting edge 4 disposed on the chip body 5 for engaging and limiting the edge of the composite connection part 1. The composite connection part 1 includes a plurality of zirconium tungstate-metal composite layers 101, the coefficient of thermal expansion of the zirconium tungstate-metal composite layers 101 being between that of the chip body 5 and the substrate 6, and the coefficient of thermal expansion gradually decreases in the direction away from the substrate 6.

[0021] This solution provides a composite connection part 1 with a stepped change in the coefficient of thermal expansion between the substrate 6 and the chip body 5. The composite connection part 1 is bonded to both the substrate 6 and the chip body 5, which enables the mounting structure between the chip body 1 and the substrate 6 to adapt to the gradual change in the magnitude of thermal expansion and contraction. From the chip body 1 to the substrate 6, the coefficient of thermal expansion of the composite connection part increases step by step. Under temperature changes, it can effectively eliminate the stress on the chip body 1 and effectively prevent cracking and deformation.

[0022] It should be noted that the composite sintering of zirconium tungstate with metals such as copper, aluminum, and silver, and the orientation selection of the thermal expansion coefficient of the zirconium tungstate-metal composite layer 101 based on different proportions are existing technologies. Specifically, the composite connection part 1 is formed by hot pressing or discharge plasma sintering, and the volume fraction of zirconium tungstate is between 10% and 50%. In this embodiment, there are four zirconium tungstate-metal composite layers 101, from the substrate 6 to the chip body 1. The volume fraction of zirconium tungstate in each zirconium tungstate-metal composite layer 101 is 10%, 25%, 40%, and 50%, respectively. The zirconium tungstate-metal composite layers 101 with different volume fractions are all existing technologies.

[0023] The zirconium tungstate-metal composite layer 101 on the side of the composite connector 1 closest to the substrate 6 is bonded together by an adhesive layer 602. This solution is existing technology, which uses an adhesive curing method to bond the composite connector 1 to the substrate 6. Furthermore, the zirconium tungstate-metal composite layer 101 on the side of the composite connector 1 closest to the substrate 6 is provided with a first rough surface 102, and the surface of the substrate 6 is provided with a second rough surface 601, which makes the composite connector 1 and the substrate 6 firmly bonded and not easy to fall off.

[0024] The length and width of the zirconium tungstate-metal composite layer 101 gradually decrease in the direction away from the substrate 6, so as to form a stepped portion 103 at the edge of the composite connection portion 1. The inner edge of the limiting edge 4 is provided with a mating groove adapted to the stepped portion 103. The corner of the mating groove is chamfered. The stepped portion and the limiting edge are provided to improve the bonding stability. When the composite connection portion 1 is bonded to the chip body 5, it is convenient for the adhesive to flow and fill the stepped portion 103 and the limiting edge 4.

[0025] A hot-melt edge 2 is provided on the surface of the zirconium tungstate-metal composite layer 101 near the chip body 5. The hot-melt edge 2 and the zirconium tungstate-metal composite layer 101 form a glue storage tank 3. By setting the glue storage tank 3, adhesive can be stored. During the hot-melting process of the glue storage tank 3, adhesive is evenly released to the surrounding area so that the adhesive can be evenly filled into the gap between the limiting edge 4 and the stepped part 103. The hot-melt edge 2 can be made of a material with a melting temperature of 80-100 degrees Celsius, such as partially modified silicone or EVA-based hot melt adhesive. The adhesive in the glue storage tank is a thermosetting adhesive with a curing temperature higher than the melting temperature of the hot-melt edge 2.

[0026] The specific implementation method is as follows: When the chip body 5 and the substrate 6 are installed, the composite connection part 1 and the substrate 6 are first bonded and fixed by the adhesive layer 602. Then, adhesive is filled into the glue storage tank 3. After pressing the chip body 5, it is heated and pressure is applied to the chip body 5 so that the hot melt edge 2 gradually melts and releases the thermosetting adhesive in the glue storage tank 3. The adhesive gradually flows to the surrounding area due to the hot melt edge 2 and fills the gap between the limiting edge 4 and the stepped part 103. When the adhesive reaches the curing temperature, it is cured, so that the chip body 5 and the substrate 6, as well as the stepped part 103 and the limiting edge 4 are bonded together.

[0027] The embodiments described above are merely examples of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.

Claims

1. A chip mounting structure based on zirconium tungstate-metal composite material, characterized in that: The device includes a composite connection portion (1) for connecting the chip body (5) and the substrate (6), and a limiting edge (4) disposed on the chip body (5) for engaging and limiting the edge of the composite connection portion (1). The composite connection portion (1) includes a plurality of zirconium tungstate-metal composite layers (101). The coefficient of thermal expansion of the zirconium tungstate-metal composite layer (101) is between that of the chip body (5) and the substrate (6), and the coefficient of thermal expansion decreases in the direction away from the substrate (6).

2. The chip mounting structure based on zirconium tungstate-metal composite material according to claim 1, characterized in that: The zirconium tungstate-metal composite layer (101) of the composite connection part (1) near the substrate (6) is bonded together by an adhesive layer (602).

3. The chip mounting structure based on zirconium tungstate-metal composite material according to claim 2, characterized in that: The composite connection part (1) has a first rough surface (102) on the zirconium tungstate-metal composite layer (101) near the substrate (6) and a second rough surface (601) on the surface of the substrate (6).

4. The chip mounting structure based on zirconium tungstate-metal composite material according to claim 1, characterized in that: The length and width of the zirconium tungstate-metal composite layer (101) gradually decrease in the direction away from the substrate (6) to form a stepped portion (103) at the edge of the composite connection portion (1), and the inner edge of the limiting edge (4) is provided with a mating groove adapted to the stepped portion (103).

5. A chip mounting structure based on zirconium tungstate-metal composite material according to claim 4, characterized in that: The corners of the mating groove are chamfered.

6. The chip mounting structure based on zirconium tungstate-metal composite material according to claim 4, characterized in that: A hot-melt edge (2) is provided on the surface of the zirconium tungstate-metal composite layer (101) near the chip body (5), and the hot-melt edge (2) and the zirconium tungstate-metal composite layer (101) form a glue storage tank (3).

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