图片名称

Comparison of contact Angle before and after plasma cleaning before plastic IC sealant

Keywords:

Published on:

12 Apr,2021

Comparison of contact Angle before and after plasma cleaning before plastic IC sealant:
Plasma cleaning is a pollution-free stripping cleaning. When plasma cleaning is used, different chip cleaning techniques vary greatly. For example, the surface of metal fragments cannot be cleaned with oxygen to prevent oxidation. The application of plasma cleaning technology in LED packaging can be roughly divided into the following categories.

CRF plasma cleaning
(1) dispensing and packaging before: if there are pollutants in the substrate dispensing silver glue, silver glue is easy to form a ball, reduce chip adhesion. Plasma cleaning can increase the surface roughness of the workpiece, which is conducive to the success of dispensing silver. At the same time, it can save the amount of silver glue and reduce the cost.


(2) Before lead bonding, the chip is pasted on the lead frame substrate, and should be cured at high temperature. If there are contaminants on the surface of the chip, it will affect the bonding effect between the lead and the chip and the substrate, resulting in incomplete bonding or poor adhesion and low strength. Plasma cleaning before bonding can significantly improve the surface activity, bonding strength and tensile uniformity of the wires.


(3) before curing: the existence of pollutants will also lead to the formation of bubbles in the process of epoxy resin injection, so that the chip is easy to damage in the temperature change, reduce the service life of the chip. Plasma cleaning enables the chip and substrate to bond more tightly to the gel, reducing the formation of bubbles, and significantly improves the characteristics of the components.


The contact Angle test of the chip shows that the contact Angle of the sample without plasma cleaning is about 39°~65°. After chemical plasma cleaning, the chip contact Angle is about 150°~20°. After the chip is cleaned by the physical reaction plasma, the contact Angle is 20°~27°. This shows that the plasma surface treatment of the encapsulated chip is effective.


The contact angles of copper lead frames before and after plasma cleaning were compared by means of contact Angle tester. The contact Angle before cleaning is 46°~50°, and the contact Angle after cleaning is 14°~24°, which meets the requirements of chip surface treatment.


Today, with the rapid development of integrated circuit technology in accordance with Moore's law, microelectronics manufacturing technology has become the frontier technology representing advanced manufacturing technology, and is also an important standard to measure the manufacturing level of a country.


With the improvement of IC chip integration, the number of pins increases and the pin spacing decreases. Particulate pollutants, oxides and epoxy resins on chips and substrates will restrict the rapid development of integrated circuit packaging industry to a large extent. The on-line plasma cleaning technology, which is beneficial to environmental protection, good cleaning uniformity, good repeatability, strong controllability, strong 3D processing ability and directional selective processing, is applied to the integrated circuit packaging technology, and will promote the faster development of the integrated circuit packaging industry.

Hot Products

Related articles