With the rapid development of electronic technology, the integration of applied electronics is getting higher and higher, resulting in a large number of highly integrated chips being widely used. The chip with high integration, especially as the core business processing unit, needs to perform multiple tasks at the same time, and the data processing speed is fast, which is bound to produce relatively high power consumption and heat. This heat must be transferred in time, otherwise the heat accumulates, resulting in a sharp rise in the temperature of the internal environment of the device, resulting in excessive junction temperature inside the chip, resulting in failure. It can cause the device to restart or crash, or the chip to burn out. This leads to the damage of equipment, causing unnecessary losses to users, so chip cooling is very important. For this purpose, the industry usually installs a chip heat sink on the top of the chip which generates more heat, and then provides the thermal design processing system of the device to discharge the heat. For light and small heat sink, usually use silica gel or thermal conductive silica pad directly glued to the top of the chip, but this way is not suitable for large heat sink. Because the weight of the large heat sink itself is heavier, if the chip heatsink is directly glued to the chip, it may bring hidden trouble to the stability and reliability of the chip, or even direct damage to the chip due to transport or external vibration. The way that installs large heat sink on circuit board basically has a few kinds as follow.
1. Heat sinks with welded feet are used to weld the circuit board.This method is usually in the heat sink diagonal position processing a small platform; One metal welding foot shall be embedded in the platform, and tin shall be attached to the welding foot. Usually, tin shall be coated or pressed on the surface of the welding foot, or tin coated wire shall be directly used, and thermal conductive silicon grease or silica gel shall be coated on the top surface of the chip.
2. Adopt the way of wire fastening installation.The steel wire buckle passes through the middle groove of the profile heat sink, pressing, coating the top surface of the chip with thermal conductive silicon grease or silica gel, the chip heat sink with steel wire buckle placed on the top surface of the chip, flat, the wire buckle at both ends of the hook down, hanging in the ring of the fixed hook welded on the circuit board. In this way, the chip heatsink is fixed.
3. The installation method of plastic elastic retaining claw is adopted. The method is fixed by means of locking device. The cylindrical plastic retaining column is mounted on the chip heat sink through the springs and round holes in the chip heatsink ears. When installing the chip heat sink, place the chip heatsink on the chip and press it square and flat. Finally, press down hard so that the jaw of the fixing column passes through the circuit board and clips to the bottom of the circuit board.