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Characteristics of Dry Film Permanent Bonding

Dry film permanent bonding is used to bond the 3D TSV, or Through-Silicon-Vias as well as two dimensional wafer bonding applications. The film comes in various thicknesses, with different applications for various thicknesses, depending, of course, on the electronic material application. There are various characteristics of these photoresist films, made for, or adjusted to use with 3-D TSV and two dimensional wafer bonding. Dry film permanent bonding photoresists feature low residual stress with an ultra low modulus. As a result, there is a rubbery consistency to the film which is particularly helpful in preventing wafer bow. This feature is of particular importance when it comes to wafers that are 300mm and must be flat to process correctly.

Temperature and Adhesion

When it comes to electronic materials, heat is a crucial factor to consider in any aspect of the manufacturing process. The best dry film photoresists should feature some low temperature cure as a temperature buffer. There are many device types in which the electronic materials will fail if they are processed at temperatures above 200 degrees Celsius, or 392 degrees Fahrenheit. Dry film photoresists should also exhibit excellent adhesion and the adhesion promoters that are built in should ensure good bonding. These films also need to have a low dielectric constant for superior electrical performance. The films are applied with either a roll laminator or by vacuum lamination. As with any adhesion application, there is the possible issue of creating voids in the dielectric fill. CMOS image sensors are an advanced TSV technology that is being used in bonding applications like wafer to wafer, chip to wafer, and wafer to glass.

3D Packaging and Adhesive Solutions

3D semiconductor packaging technology has become both basic and essential for electronics materials production. It is used to stack thinned semiconductor chips with, TSV. These thinned chips have the great advantage of being able to integrate heterogeneous semiconductor technologies into micro-electronic modules. Because of the efficient use of space within the 3D packaging modules, miniaturization is made possible for multiple electronic materials, and portable to microelectronics systems like those in smart-phones, bio-medical solutions. Of course, the modules can be applied to large scale computing systems, as well. The market for electronic materials is demanding more and more devices which require 3D packaging, and therefore more dry film permanent bonding solutions specified to meet market needs.