Browse Prior Art Database

WAFER POSITIONING STAGE WITH LOW PROFILE THETA ACTUATOR

IP.com Disclosure Number: IPCOM000009421D
Original Publication Date: 1999-Sep-01
Included in the Prior Art Database: 2002-Aug-22
Document File: 3 page(s) / 113K

Publishing Venue

Motorola

Related People

Brian T. Albrecht: AUTHOR [+2]

Abstract

Eutectic die attach of RF super high tech devices is often a complex and tedious semi-manual operation. At the die attach stage of the final assem- bly process of RF devices, there can be as many as eight separate components attached to the same header or substrate. This causes low throughput and increased chances for non-conforming product. The current process uses a Multi Chip Die Bonder that relies on an operator to perform both the die and header alignment. First, the operator aligns a die into a reference box displayed on a monitor and then presses a button to initiate the pickup process. After the die has been picked, the operator aligns the next die for pickup. This is repeated until all of the dies have been picked. The operator will then manually align the header or substrate to the reticule lines dis- played on a second monitor and then press a button to initiate the bonding sequence. While the bonding sequence is in process, the operator can only locate one die.

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MOTOROLA Technical Developmen&

8

WAFER POSITIONING STAGE WITH LOW PROFILE THETA ACTUATOR

by Brian T. Albrecht and Mike Eleff

BACKGROUND

  Eutectic die attach of RF super high tech devices is often a complex and tedious semi-manual operation. At the die attach stage of the final assem- bly process of RF devices, there can be as many as eight separate components attached to the same header or substrate. This causes low throughput and increased chances for non-conforming product. The current process uses a Multi Chip Die Bonder that relies on an operator to perform both the die and header alignment. First, the operator aligns a die into a reference box displayed on a monitor and then presses a button to initiate the pickup process. After the die has been picked, the operator aligns the next die for pickup. This is repeated until all of the dies have been picked. The operator will then manually align the header or substrate to the reticule lines dis- played on a second monitor and then press a button to initiate the bonding sequence. While the bonding sequence is in process, the operator can only locate one die.

PROBLEM

  To improve the process throughput and product quality, an automated wafer positioning stage was proposed to locate all dies prior to bonding. The wafer positioning stage had to be designed to fit within the existing Multi Chip Die Bonder con- straints. Due to the limited travel of the existing ejector assembly, an off-the-shelf theta actuator could not be purchased. In addition, the overall height of the Wafer Positioning Stage had to be the

same height as the currently used Bearing Plate assembly. The stage had to locate and align up to four wafers independently, and not interfere with the existing bond head and workholder. The Wafer Positioning Stage must also be robust enough...