Browse Prior Art Database

Automated Tooling for On-line Fixture Calibration Concurrent With Servicing

IP.com Disclosure Number: IPCOM000101758D
Original Publication Date: 1990-Aug-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 3 page(s) / 116K

Publishing Venue

IBM

Related People

Kelly, L: AUTHOR

Abstract

Disclosed is a technique and the associated hardware developed to allow automated, on-line calibration of production fixtures - a procedure which would have required an intensive labor effort in the prior art.

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Automated Tooling for On-line Fixture Calibration Concurrent With Servicing

       Disclosed is a technique and the associated hardware
developed to allow automated, on-line calibration of production
fixtures - a procedure which would have required an intensive labor
effort in the prior art.

      The 4-up capping fixtures [*] and other fixtures which are
commonly used in bonding of semiconductor packages require frequent
calibration of the springs used to provide clamping force.  The 4-up
fixtures are used to provide different forces (through different
spring depressions) for different products, and each force setting
must be checked against the governing specification prior to use.
Because the force ranges are tightly controlled, due to product and
process sensitivities, it is relatively easy to have "out of spec"
fixtures from normal handling.  Therefore, it would be desirable to
calibrate them as frequently as possible to ensure process integrity.
However, the previous calibration procedure of each fixture entails
the adjustment of 4 arms and springs per fixture.  Also, the old tool
must be manually converted before each different product/force range
is tested.  This calibration procedure is therefore fairly labor
intensive, and can be a significant detractor to line capacity.

      An additional problem arises when an automated encapsulation
tool is used.  Calibration is still required, but if the prior-art
technique were utilized, the labor necessary for calibration could be
nearly equal to that required for all the other line functions
combined.  This is particularly true as up to 150 fixtures are used
in a typical job.

      The solution to these problems is illustrated in the figure.
The technique allows the fixtures to be calibrated right on the
conveyor, all four arms at once, each time a fixture is to be used,
and in an automated fashion, i.e., no operator handling for any
product type.  Each fixture will be verified to be "in spec"
immediately prior to each use for maximum process safety.  Since the
calibrations are done at a time in the flow when the fixture would
otherwise be idle, there is no effect on tool output.

      The calibrations are perfor...