Heat dissipation cover with silicon substrate replacing metal for heat conduction
By using silicon-based materials to replace metals and using contact heat dissipation methods, the problems of low thermal conductivity and non-contact heat dissipation in the prior art are solved, and a more efficient heat dissipation effect is achieved.
Patent Information
- Application Number
- CN202510652205.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-20
- Publication Date
- 2025-08-08
AI Technical Summary
In the prior art, the thermal conductivity of the metal heat dissipation cover is low, resulting in poor heat dissipation effect, and due to non-contact heat dissipation, it is difficult to effectively dissipate heat.
Silicon-based materials are used to replace metals, and contact heat dissipate with flip chips through a high-thermal conductive material layer and a silicon-based high-thermal conductive cover plate, changing the packaging process to FC—UF—HSLA—OPEN MOLD.
It improves thermal conductivity, thins the package thickness, realizes effective contact heat dissipation, and improves heat dissipation efficiency.
Smart Images
Figure CN120453246A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of chip packaging, in particular to a silicon-based heat dissipation cover that replaces metal heat conduction. Background Art
[0002] FC (Flip Chip) is an advanced integrated circuit packaging technology. In this technology, the chip is flipped over and directly connected to the substrate via solder balls. UF (Under Fill) is a material used to fill the gap between the chip and the substrate.
[0003] like Figure 2 As shown, the existing technology is to do underfill (UF) after FC, directly plastic encapsulate, and then apply heatsink high thermal conductivity material to dissipate heat. However, the heat source is inside the plastic encapsulation, and the metal cover and the heat source are non-contact heat dissipation. The thermal conductivity of the plastic encapsulation material is too low, only 0.8, so the thermal resistance is the plastic encapsulation material. The heat cannot be effectively dissipated and can only be dissipated through the metal material and holes of the substrate.
[0004] Currently, the material used in heat dissipation covers is metal, which is too thick, has low thermal conductivity, and has poor heat dissipation. Summary of the Invention
[0005] The object of the present invention is to provide a silicon-based heat dissipation cover that replaces metal heat conduction to solve the problems raised in the above background technology.
[0006] To achieve the above objectives, the present invention provides the following technical solution: a silicon-based heat dissipation cover that replaces metal heat conduction, comprising: A high thermal conductivity material layer and a silicon-based high thermal conductivity cover plate covering the flip chip; Among them, the high thermal conductivity material layer is located between the flip chip and the silicon-based high thermal conductivity cover plate, and the periphery of the flip chip, the high thermal conductivity material layer and the silicon-based high thermal conductivity cover plate are surrounded by plastic packaging material, and the upper surface of the silicon-based high thermal conductivity cover plate is flush with the upper surface of the plastic packaging material.
[0007] Preferably, the specific steps of packaging the heat dissipation cover when in use are as follows: S1: flip chip mounting; S2: bottom filling; S3: Cover with high thermal conductivity material; S4: Plastic sealing. Preferably, in step S1, the temperature of the flip-chip core is between 180° C. and 260° C., and the relative humidity is maintained at 30% to 60% RH.
[0008] Preferably, in step S2, the bottom filling temperature is between 100° C. and 150° C., and the relative humidity is maintained at 30% to 60% RH.
[0009] Preferably, in step S3, the temperature range of applying the high thermal conductivity material to the cover is between 150° C. and 200° C., and the relative humidity is controlled between 45% and 65%.
[0010] Preferably, in step S4, the molding temperature is between 150° C. and 200° C., and the relative humidity is maintained at 30% to 60% RH.
[0011] Compared with the prior art, the present invention has the following beneficial effects: Use silicon-based heat sinks instead of metal heat sinks to improve thermal conductivity and reduce thickness. Attach the silicon-based material (high thermal conductivity material) directly to the (chip) heat source for contact heat dissipation. Change the workflow from FC-UF-MOLD-LA to FC-UF-HSLA-OPEN MOLD. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 This is a schematic diagram of the structure of the heat dissipation cover of the present invention when in use; Figure 2 The figure is a schematic diagram of the structure of the existing flip chip package.
[0013] In the figure: 1. Substrate; 2. Bottom filler; 3. Flip chip; 4. High thermal conductivity material layer; 5. Silicon-based high thermal conductivity cover; 6. Plastic encapsulation material. DETAILED DESCRIPTION
[0014] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0015] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.
[0016] Example 1: See also Figure 1-2 , the present invention provides a technical solution: a silicon-based heat dissipation cover that replaces metal heat conduction, comprising: a high thermal conductivity material layer 4 covering a flip chip 3 and a silicon-based high thermal conductivity cover plate 5; Among them, the high thermal conductivity material layer 4 is located between the flip chip 3 and the silicon-based high thermal conductivity cover plate 5. The periphery of the flip chip 3, the high thermal conductivity material layer 4 and the silicon-based high thermal conductivity cover plate 5 are surrounded by the plastic packaging material 6, and the upper surface of the silicon-based high thermal conductivity cover plate 5 is flush with the upper surface of the plastic packaging material 6.
[0017] Example 2: See also Figure 1-2 The present invention provides a technical solution: the specific steps of packaging the heat dissipation cover when in use are as follows: Flip Chip -- Underfill -- Heatsink Lid Attach -- Molding; S1: Flip-chip die (1) The temperature is usually between 180°C and 260°C; (2) When operating in a clean room environment, the humidity needs to be strictly controlled, usually maintained at 30% to 60% RH (relative humidity); (3) Depending on the specific process type and equipment performance, it can range from a few seconds to tens of seconds.
[0018] S2: Bottom filling, filling bottom filler 2, (1) the temperature is usually between 100°C and 150°C; (2) when operating in a clean room environment, the humidity needs to be strictly controlled, usually maintained at 30% to 60% RH (relative humidity); (3) depending on the specific process type and equipment performance, it ranges from a few minutes to tens of minutes.
[0019] Bottom filler 2 is bottom filler (Underfill), which is an important electronic adhesive for integrated circuit packaging. In advanced packaging such as 2.5D and 3D packaging, it is used to alleviate the stress concentration problem caused by the mismatch of thermal expansion coefficients between different materials in chip packaging, thereby improving the reliability of device packaging.
[0020] Underfill, a key material in advanced packaging, can improve product reliability. Primary underfill material is primarily used to connect the chip to the substrate, dissipating stress on the chip surface and alleviating internal stress caused by thermal expansion coefficient mismatches among the chip, solder, and substrate. It also protects solder balls and improves chip drop resistance and thermal cycling reliability. The product must exhibit excellent flowability, high reliability, and a low thermal expansion coefficient, placing extremely high demands on its formulation and process. The underfill process involves applying epoxy resin glue to the edge of the flip-chip chip, completing the underfill process through a capillary effect. The glue is then cured by heating.
[0021] S3: For high thermal conductivity material covers, (1) Temperature: Generally, the recommended operating temperature range is between 150°C and 200°C; (2) Humidity: Usually, the humidity is controlled between 45% and 65% to prevent excessive humidity from affecting the glue curing effect or device performance; (3) Time: Generally, the curing time can vary from a few seconds to several minutes. For example, some fast-curing adhesives may only take 10 to 30 seconds to complete the curing process.
[0022] S4: Plastic encapsulation, (1) the temperature is usually between 150°C and 200°C; (2) the humidity needs to be strictly controlled when operating in a clean room environment, usually maintained at 30% to 60% RH (relative humidity); (3) the time depends on the specific process type and equipment performance, ranging from tens of seconds to several minutes.
[0023] Eliminating the metal cover after plastic sealing makes the overall package size thinner; It changes from non-contact heat dissipation to contact heat dissipation, and the thermal conductivity of silicon-based materials is much higher than that of plastic packaging materials and metals, so it can effectively dissipate heat.
[0024] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention; therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the appended claims rather than the above description. Therefore, it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any figure signs in the claims should not be regarded as limiting the claims involved.
[0025] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.
Claims
1. A silicon-based heat dissipation cover that replaces metal heat conduction, characterized in that: include: A high thermal conductivity material layer (4) and a silicon-based high thermal conductivity cover plate (5) covering the flip chip (3); The high thermal conductivity material layer (4) is located between the flip chip (3) and the silicon-based high thermal conductivity cover plate (5); the flip chip (3), the high thermal conductivity material layer (4) and the silicon-based high thermal conductivity cover plate (5) are surrounded by a plastic packaging material (6); and the upper surface of the silicon-based high thermal conductivity cover plate (5) is flush with the upper surface of the plastic packaging material (6).
2. The silicon-based heat dissipation cover as claimed in claim 1, characterized in that: The specific steps for packaging when using the heat dissipation cover are as follows: S1: flip chip mounting; S2: bottom filling; S3: Cover with high thermal conductivity material; S4: Plastic sealing.
3. The silicon-based heat dissipation cover as claimed in claim 2, characterized in that: In step S1 , the temperature of the flip-chip die is between 180° C. and 260° C., and the relative humidity is maintained at 30% to 60% RH.
4. The silicon-based heat dissipation cover as claimed in claim 2, characterized in that: In step S2 , the bottom filling temperature is between 100° C. and 150° C., and the relative humidity is maintained at 30% to 60% RH.
5. The silicon-based heat dissipation cover as claimed in claim 2, characterized in that: In step S3, the temperature range of applying the high thermal conductivity material to the cover is between 150° C. and 200° C., and the relative humidity is controlled between 45% and 65%.
6. The silicon-based heat dissipation cover as claimed in claim 2, characterized in that: In step S4, the molding temperature is between 150° C. and 200° C., and the relative humidity is maintained at 30% to 60% RH.