S Pyatt

Dummy module with copper on glass sensor

An adhesive tape has been identified that is suitable for dummy module building.This tape can be stuck on to the glass sensor for wire bonding practice.

S Pyatt

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 590

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Pull test number

Pull

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ngth

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Pull test results of copper tape

Average g 9.65025

St Dev g 0.445028

This was initially done to demonstrate to Sam that wire bonding on copper doesn’t work.

But it does work!

S Pyatt

Contacted manufacturer of the tape

Jerry Young, Applications head at Chomerics,spoke to me on the phone.

Tape is high purity annealed and rolled copper.There is nothing on the surface to protect the copper!This tape has been sitting on a shelf in the clean roomfor a few years and belongs to Astro Space Research.

This self adhesive tape is stuck down on the glass dummy Sensor and the BJ820 is programmed for Hybrid to Sensorwire bonding.

S Pyatt

Wire bonding trials (ASIC to copper tape)

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Wire bonding trials

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Completed 4 layer loops

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Completed 4 layer loops

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Good quality bonds on the copper

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Good quality bonds on the PGA

S Pyatt

However there are intermittent bond failureson the PGA. Maybe around 3 percent.

S Pyatt

Copper tape wire bonds well.

Intermittent wire bond failures on Pattern Glass ASIC.BJ820 checked, nothing to raise any alarms.

Contacted Bart who suggests what I’m seeing onthe PGA is not unusual.

Copper tape appears to work. This is a cheap, easy method of making a dummy wirebondable sensor using the glass sensors. Useful forgaining module wire bonding experience.

S Pyatt

This tape is available from Farnell

This appears to be thesame tape.

S Pyatt

And the next material to try is: