MATERIALS AND PROCESSES FOR MICROELECTRONIC PACKAGING

THE CHALLENGE OF ELECTRONIC PACKAGING

Though the primary function of an electronic package is to provide power and signal input and output to the chip it must also provide mechanical integrity and several other critical functions as well. Among these are dissipating excess heat from the chip and protecting it from corrosive environments and rough handling and vibration. All of these functions are further compounded in the newer generation of multichip modules where in addition to all the previously mentioned requirements the package must further provide efficient wiring channels among an array of single chip devices. The staff of MST Technologies have worked extensively on the materials and processing aspects of both single and multichip modules. MST assists clients in making critical materials/process decisions in the following areas of packaging design for both single and multichip modules:

Materials Selection

When considering a new thin film wiring design the choice of which insulator material to use will be critically important to achieving practical success. For a given application there are dozens of candidate resins just within the class of polyimide materials alone. MST can help clients select the best material on the basis of product functionality, reliability, process constraints and manufacturability.

Materials Characterization

A fundamental aspect of materials selection is the careful characterization of a set of candidate materials. MST can assist clients in screening materials on the basis of mechanical strength, adhesion at critical interfaces and manufacturing processability.

Process Development

MST assists clients in developing methods for robust process development and manufacturing so that process specifications are:

• Forgiving and implementable in a manufacturing environment.
• Repeatable.
• Allow for cost reduction.
• Extendable.
• Based on an Understanding of the chemistry and physics of interfacial zones.
• Accounting for effects of contaminants (sources/levels) on process and product reliability.
• Employing the latest techniques in robust design of experiments and statistical process control.

Reliability Testing

MST will assist clients in the development and implementation of test procedures to ensure product reliability.

Engineering Design

In certain demanding applications situations arise where a number of conflicting requirements of a manufacturing process must be simultaneously satisfied. The problem eventually comes down to making a series of tradeoffs among desired functional requirements and manufacturing constraints. Many times one of the major constraints in using high temperature insulators such as polyimides is the buildup of coating stresses subsequent to various processing steps. MST has developed a powerful engineering design tool known as stability map analysis in dealing with this type of problem. By this method a map of all of the process parameters which affect stress buildup is created which delineates a region of acceptable stress as a function of parameter settings. With this map a set of process parameters can be determined which will not give rise to stress related problems thereby greatly simplifying to overall product design process. For an example see our case study concerning the controll of stress in diamond coatings.

Case study: Fracture delamination in advanced ceramic packaging application.

Copyright © 2004, MSTCONFERENCES, LLC.
Revised -- 10/6/2004
URL: http://ourworld.compuserve.com/homepages/rhlacombe/micropac.htm