Lid

The metal page has some general tips.

Cutting

A little less safe than metal cans because the cutting wheel will be very close to the bond wires. Additionally, some lids bend easily under pressure and so may press on the bond wires before they start cutting. The chip won't give way around the ceramic but it still ma get pressed down around the edges.

Thermal

Ceramic-metal lids can also be removed with a torch. However, it is easy to warp the ceramic package making it difficult to get a good image of the die.

Laser

[Ultratec] video shows a package being opened…not sure what type, but I'm assume metal as ceramic would be very hard to vaporize.

Die attach / removal

Attachment methods include:

  • Glass
  • Metal (usually silver) epoxies
  • Solders

Generally removing dies from ceramic packages has proven difficult, especially when affixed with glass. So the general advice is don't remove the die form the package unless you have to. For general imaging there should be no reason to remove it from the package and the die should be better protected too.

Solder

Example soldered die after removed by force:

Note the raised corners. This means that without completely melting the solder it is hard to get loose. Soak in nitric acid and it should quickly dissolve and come loose:

Of course, it might take a while to get under the entire die. Heating without will help to get it off but I have found that it can take a lot of force to move even with solder melted and so its best to chemically remove as much silver as possible first.

Glass

Surface tension sometimes makes it difficult to remove dies. Cutting a side of the package off so it can slide out can be much easier. However, ceramic is difficult to cut. Even a diamond bit will be slow to cut, don't bother with others. Only use for very valuable specimens that you are willing to spend the time to carefully remove.

References

 
decap/ceramic_metal.txt · Last modified: 2013/10/20 10:59 (external edit)
 
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