High-temperature solder based on Ag@In core-shell structure and preparation method thereof

Abstract

The invention provides high-temperature solder based on an Ag@In core-shell structure and a preparation method thereof. The high-temperature solder based on the Ag@In core-shell structure comprises Ag balls, the surface of each Ag ball is coated with an In layer, and the Ag@In core-shell structure is formed. The solder of the technical scheme has the characteristics of low-temperature bonding and high-temperature service and has very good electricity and heat conducting performance, and a multi-stage-packaging temperature process window can be greatly broadened; and in addition, quite thick weld seams can be formed, and accordingly, the problem that the deform resistance is low due to the fact that weld seams in a TLP method are too thin is effectively solved. Meanwhile, the bonding reaction time depends on the thickness of the In layer outside one Ag ball, so that the thickness of the weld seam is increased without prolonging the bonding time, and the production efficiency is ensured; and the defects that in the prior art, bonding is high in temperature and long in time, and the weld seams are thin are effectively overcome.

Description

technical field [0001] The invention belongs to the technical field of materials, and relates to a solder, in particular to a high-temperature solder based on an Ag@In core-shell structure and a preparation method thereof. Background technique [0002] Power devices are widely used in almost all electronic manufacturing industries. From notebooks, servers, monitors and various peripherals in the computer field to mobile phones, telephones and other various terminals and central office equipment in the field of network communications, from traditional black and white home appliances and various digital products in the field of consumer electronics to industrial fields All kinds of instrumentation and control equipment, power devices are important components. [0003] At present, power devices are developing in the direction of high power, high frequency and integration. This trend will definitely pose a severe test to the high temperature resistance of devices and their con...

AI Technical Summary

Problems solved by technology

The advantage of this welding method is that the source of raw materials is wide, the cost is low, and it has high processing compatibility with the machines of the current enterprise production line; the disadvantage is that due to the limited diffusion rate of elements in the entire process, the compound forms and grows The speed is relatively slow, so it takes a long time to get the structure of the whole compound solder joint

Therefore, the TLP process is currently only suitable for the welding of narrow welds. Due to the difference in thermal expansion coefficient, stress concentration problems will occur at the welds, and this problem is more prominent for narrower welds. The external compound is usually a hard and brittle phase. It greatly increases the possibility of solder joint cracking and failure during compound service

Although increasing the thickness of the weld seam can solve the problem of stress concentration, the reflow time or reflow temperature will also be increased. A longer reflow time or a higher reflow temperature will have an adverse effect on other devices on the substrate.

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