Probe, Assembly, and Test

 

Description: A survey of microchip packaging including various types of package, functions of packages, common parts of the package, and packaging process flow includes inspections and tests. Also includes topics on process yield.

Length of time: 6 hrs.

Prerequisites:

Module: Wafer Cleaning

Module: Metallization and Thin Film

Module: Photolithography

Module: Etch

Topics:

1. Wafer probe, test, and sort

2. Major assembly (packaging) processes

Backside preparation

Die separation

Die pick and plate

Die attach

Lead bonding

Encapsulation (sealing)

Lead plating, cutting, and bending

Marking

3. Packaging types and techniques

Types

Techniques

Materials

Functions

Designs

4. Assurance

Inspections during assembly operations

Final test

Burn-in

5. Process yields

 

Student objectives:

Student will be able to:

1. Discuss the four major functions of a chip package (Lead system, physical protection, environmental protection, and heat dissipation). Explain how the functions are achieved.

2. Explain what is meant in a chip package by "die-attachment area," "bonding wires," "inner and outer leads," and "enclosure." Use a sketch to clarify.

3. List some environmental factors to which chips are vulnerable.

4. Describe at least four type of package design and give benefits of each.

5. Explain what is involved in wafer probe, test, and sort. Explain procedures upon failure of test and passing of test.

6. Construct a process flow diagram to show major operations, including inspections, beginning with backside preparation and ending with final test.

7. Explain at least two methods for separating dies and for attaching dies to the package.

8. Explain at least three types of bonding from the bonding pads to the package inner leads.

9. List and describe at least four achieving a sealed enclosure for the chip.

10. Describe final tests and burn-in tests. Include electrical tests and environmental effects that the reliable package must withstand.

11. Discuss process yield, major yield points, yield sheets, and major influences on process yields.