Enhanced X-Ray Shielding Device Package

Raymond Kuang

Randy Sampan

September 7 - 9, 2005

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Limitation of Conventional CQFP Packages

Current X-ray shielding package limitation:Most of the X-Ray enhanced packages, particularly the

Ceramic Quad Flat Pack(CQFP) packages only provide top and bottom X-ray shielding

Actel's solution:Special CQFP package construction to provide 360

deg. X-ray protection. Use the existing methods of substrate manufacturing and

assembly technologies

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Enhanced X-Ray Radiation Shielding Package from Actel

Advantages: Designed for use on environment where intense

radiation is a concern the heavy metal on top, bottom, and internal tab of the

package provides 360° radiation shielding

It is easy to implement for CQFP packages with existing assembly technology

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Enhanced Radiation Shield Package

Features for single tier internal bonding Shields the device from radiation from any direction

An internal tab protects the die from horizontal direction The top lid and die paddle blocks radiation from top and

bottom directions

die

CuW for X-ray shielding

CuW lid

Ceramic body

CuW tab – intended to block radiation comingfrom this direction, CuW tapis higher than bond finger tier

Better Thermal performance. The CuW at the bottom provides better heat dissipation.

die

CuW for X-ray shielding

CuW lid

Ceramic body

CuW tab – intended to block radiation comingfrom this direction, CuW tapis higher than bond finger tier

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Features… con’t

CuW tab

A delidded unit showing the CuW tab between die and package’ lead finger.

Enhanced Radiation Shield Package

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Picture of current CQ84 X-Ray enhanced package

Enhanced Radiation Shield Package

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Enhanced Radiation Shield Package

Features for two-tier internal bonding Shields the device from radiation from any direction

An internal tab protects the die from horizontal direction

The top lid and die paddle block radiation from top and bottom directions

Allow more I/Os routing out to package

die

Ceramic bodyCuW for X-ray shielding

CuW tab – intended to block radiation comingfrom this direction, CuW tapis higher than the second tierof bond finger

CuW Lid

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Manufacturing Concerns and solution

Major concern is package’s lead fingers and seal ring are of the same plane. If lid is dropped incorrectly, it can damage the wires This is addressed by using a lid aligner tool to ensure an

lid placement accuracy

The rest of the assembly and test handling are very similar with conventional CQFP package

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Reliability

Reliability is comparable with the regular CQFP packages.

The X-ray shielding packages are heavierAssembly of the parts to end users’ system boards need

special attention in order to prevent leads breaking during vibration testing

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Summary

The Actel’s enhanced X-ray Shielding package is an alternative solution for application that requires extreme protection from X- ray radiation.

Currently CQ84 is available, but bigger CQ could be tooled up.

There are no reliability issues from manufacturing of substrate and assembly standpoint

Packages are heavier, therefore, special attention for mounting to the system to pass vibration requirement is needed.

Thanks!