Browse Prior Art Database

Method and use of a less-contact ejector stage

IP.com Disclosure Number: IPCOM000006846D
Publication Date: 2002-Feb-06
Document File: 3 page(s) / 38K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method and the use of a less-contact ejector stage. Benefits include improved throughput, improved yield, improved equipment capability and design of stage.

This text was extracted from a Microsoft Word document.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 68% of the total text.

Method and use of a less-contact ejector stage

Disclosed is a method and the use of a less-contact ejector stage. Benefits include improved throughput, improved yield, improved equipment capability and design of stage.

Background

A major problem with thin dice, 5 mils or less, is die breakage.

Description

              The disclosed design of the stage has pointed needle-like objects positioned side by side proportionally spaced to increase the surface area being sucked by vacuum pressure.  Comparing with the conventional stage that has a circular cavity to serve as relief for the wafer tape during suction.

              The method of the machine performs the same as conventional ejection process but instead of simply protruding, during wafer suction needles draw away the tape much than the conventional to release it from die backside adhesion. While the wafer tape is down, the pick-up process proceeds with ease because less tape surface is attached to the silicon.

              The use of pointed needles as the contact area for wafer tape is similar to the needle ejecting principle. During ejection, tape is stretched to follow the shape of the needle, reducing the surface area of the tape adhering to the silicon die backside.

              Differences from the conventional stage design are:


•             Reduced surface area of the tape that adheres to the die backside during vacuum
•             Increased suction power because the area of hallowed surface is increased

              The process of ejecting a die from a wafer tape includes the following steps:

1.           A di...