Void-Free/Flux-Free Die Attachment for Multichip Modules Using Solder Alloys

The pressure variation method uses external gas pressure to achieve voidness results in electronic packaging, improving device reliability.

The increasing demand for advanced integrated circuits has placed an important focus on electronic packaging, materials and process. Any variations will have an effect on temperature uniformity, reliability and integrity of the multichip modules. The presence of voids reduces the reliability of the device when subjected to mechanical and thermal stresses. Improvements were developed where fluxless and voidless results were achieved using a technique referred to as the “pressure variation” method. The principle of the pressure variation method is to use external gas pressure to compress the air trapped in the joint.