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Does any one know what kind of material of the black goop on the IC or what it call and where to buy it? Answered


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iceng (author)2011-05-17
There are some very specific properties epoxy / resin formulators strive for
in that "black goop" as you call it;
  • Mechanical goop expansion / contraction on setting must not dislodge the itsy-bitsy wires attached to the silicon, germanium or other delicate semiconductor so glooped.
  • Passivation of the raw semiconductor chip edge, protects the vulnerable perimeter of the thin edge from chemical contaminants outside and curative byproducts.
  • Electrical voltage with standing abilities as high as 400 volts per mil.
  • Adhesion, the goop needs to latch on to whatever surface the silicone chip is mounted on keeping moisture and gases from invading the protected semiconductor chip.
  • Light exclusion, the black goop must block photons from introducing unwanted electron / hole pairs from changing the characteristic conduction bands within the semiconductor.
No wonder, there are obscuring goop formulations being touted and secrets being kept.

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AndyGadget (author)2011-05-17

 
 As Steve says, it's epoxy and something very similar is available as potting compound which is used for encapsulating electronic assemblies for protection against vibration failure, corrosion etc.  Many electronic suppliers will stock this.  A cheaper alternative would be standard 2-part epoxy resin.

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Vyger (author)2011-05-17

Its also very tough stuff. The only thing that will affect it besides very high heat is concentrated hot Hydrochloric acid.

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steveastrouk (author)2011-05-17

Its an epoxy resin, I don't know the exact mix, but there are plenty of epoxy makers out there.

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