Chip Cooling Technology
In the development of semiconductor equipment, the innovation of equipment and the improvement of technology will always face different difficulties and problems. A small number of transistors may not have a great impact on reliability, but the heat generated by billions of transistors will affect reliability. High utilization will increase heat dissipation, but heat density will affect every advanced node chip and package, which are used in smart phones, server chips, ar/vr and many other high-performance devices. For all of these, DRAM layout and performance are now the primary design considerations.
In addition to DRAM, thermal management has become critical for more and more chips. It is one of more and more interrelated factors that must be considered in the whole development process. The packaging industry is also looking for ways to solve the heat dissipation problem. Choosing the best packaging method and integrating chips in it is very important for performance. Components, silicon, TSV, copper pillars, etc. all have different coefficient of thermal expansion (TCE), which will affect the assembly yield and long-term reliability.
The Choice of TIM:
In the chip package, more than 90% of the heat is emitted from the top of the chip to the radiator through the package, which is usually an anodized aluminum substrate with vertical fins. A thermal interface material (TIM) with high thermal conductivity is placed between the chip and the package to help transfer heat. The next generation Tim for CPU includes sheet metal alloy (such as indium and tin) and silver sintered tin, with conduction power of 60w/mk and 50w/mk respectively.
Micro Chip cooling channel：
Now, Swiss researchers have finally found a better way to invent a chip that does not need external cooling. The microtubules integrated in the semiconductor will bring the cooling liquid directly around the transistor, which not only greatly improves the heat dissipation effect of the chip, but also saves energy and makes future electronic products more environmentally friendly. The production of this integrated cooling is cheaper than the previous process.
The original idea behind advanced packaging is that it can work like Lego bricks - small chips developed at different process nodes can be assembled together and can reduce thermal problems. However, from the perspective of performance and power, the distance that the signal needs to be transmitted is very important, and the circuit that is always open or needs to be kept partially dark will affect the thermal characteristics. It is not as simple as it seems to be to divide the mold into multiple parts just to improve the output and flexibility. Every interconnection in the package must be optimized, and the hotspot is no longer limited to a single chip.
On the whole, in terms of the development trend, DRAM chips improve the storage density by miniaturizing the manufacturing process for the storage chip technology. For the storage products, they will develop in the direction of high speed and large capacity in the future, and the product performance will continue to improve; For the application field of storage products, PC, 5g mobile phone, wearable device and security are the main development trends in the traditional application fields, and data center, smart home and smart car are the main development trends in the emerging application fields. Therefore, the packaging industry will continue to promote the research and development of chip cooling technology.
