1 hour after applying glue to the HDI and gluing it to the sensor + ROCs, we took a look to see if the glue distribution was good. Unfortunately, the very edges on the long side didn't get glue so they are "bending" away from the sensor. This is bad since the wire bond pads are on these edges and if they're not properly glued, wire bonding will not be possible.
This happened because the glue stamp is narrower than the glue and we used a pretty viscose glue (Araldite). To remedy this, either a wider glue stamp needs to be used or a more liquid glue.
The module was put back on the jig with a weight on top of it to let it cure. Perhaps it will still be properly glued after more time passes. |