Huawei announces latest patent for flip-chip packaging: improved heat dissipation, can be used on CPU, GPU, etc.

According to news on August 16, it was learned from the official website of the State Intellectual Property Office that Huawei Technologies Co., Ltd. recently disclosed a patent called "Flip-chip packaging with improved thermal performance", and the application publication number is CN116601748A.

It is understood that the patent embodiment provides a flip chip package, a device equipped with a circuit using a package structure, and a method of assembling the package. More intuitively, it is a method that provides a connection between the chip and the heat sink. The contact method can help improve the heat dissipation performance.

The patent can be applied to chip types such as CPU, GPU, FPGA (Field Programmable Gate Array), ASIC (Application Specific Integrated Circuit), and the device can be a smartphone, tablet, wearable mobile device, PC, workstation, server, etc.

The patent mentions that recent advances in processing performance of semiconductor packaging have placed higher demands on thermal performance to ensure stable operation.

In this regard, flip-chip packaging has an advantage in terms of thermal performance due to its structural feature where the chip is connected to the substrate via bumps underneath it, allowing the heat sink to be positioned on the top surface of the chip.

To improve cooling performance, a thermal interface material (TIM) such as thermal grease is applied to the top surface of the chip and sandwiched between the chip and at least part of the heat sink. From the perspective of reducing the thermal resistance in the TIM to improve the thermal performance of the package, it is preferable to make the thickness of the TIM smaller.

It is understood that compared with previous heat dissipation solutions where it was difficult to precisely control the thickness of TIM, the thickness of the thermal interface material in Huawei's patent is limited by the height of the wall-like structure in the molded component.

Because the height of the wall-like structure composed of the mold compound can be easily controlled during the molding process, the thickness of the thermal interface material can be adjusted to as small a thickness as desired, resulting in improved thermal performance.

The summary of Huawei’s “Flip-chip packaging patent with improved thermal performance” is as follows:

A flip chip package (200) is provided, wherein the flip chip package includes: at least one chip (202) for connecting with a substrate (201); a mold formed on the substrate (201) member (209) to wrap the side portion of the at least one chip (202) and expose the top surface of each chip (202), wherein the upper surface of the molding member (209) has a surface similar to that of each chip (202). a continuous first area on the top surface of each chip (202), a second area where adhesive (210) is applied, and a wall-like structure (209a) placed to surround the top surface of each chip (202), and the first area and the second Zones are separated by wall-like structures (209a); a heat sink (206), placed over the top surface of each chip (202) and bonded to the molded member by an adhesive (210) filled in the second zone (209); Thermal interface material (205), the thermal interface material (205) is filled in the first area, the top surface of each chip (202), and the bottom surface of the heat sink (206) in the spatial region formed by at least a portion of the wall-like structure (209a) and the first side of the wall-like structure (209a).

Schematic cross-sectional view of a flip chip package according to an embodiment of Huawei's invention

Example of traditional flip chip packaging