Procedure for final-step gluing Si-MCM assembly to C-cage

Equipment Needed

• Grounding wrist strap
• Conductive gloves
• Double-stick tape

1. You should still be wearing the conductive gloves and grounding wrist strap from the previous step, and the glue bead should have already been applied to the C-cage.

2. Ensure that two short dowel pins are in place on the gluing jig, to receive the pickup fixture. Disassemble the MCM plenum so that the proper slot is open to receive the MCM.

3. When gluing on the inner middle and inner top assemblies, we want to place some double-stick adhesive so that the kapton cables are held well in place. For inner middle, this consists of a single piece of tape on the inner bottom kapton cable, located at the flat end part of the C-cage where the cable bends around. For inner top, there are two pieces of tape to be placed on the inner middle cable--one on the flat end just as on the inner bottom cable, and one of the inner bottom face, just above the bend.

4. Recall the logistics of how the assembly will be transferred from the alignment fixture to the gluing jig, determined earlier. Remove the long dowel pin from the vacuum pickup fixture, and lift the full assembly from the alignment fixture--one hand should grab the pickup fixture and the other should grab the MCM by the sides.

5. Transfer the assembly to the C-cage gluing jig. Make sure the orientation is correct (i.e. that the MCM ends up in the right place). Lower the vacuum fixture onto the locating pins and set the MCM loosely into its slot. Secure the vacuum pickup fixture to the gluing jig with the appropriate screws.

6. (For inner middle and inner top only) Check the routing of the kapton cable and make sure it looks good. If so, pull the MCM back from its slot and remove the protective layer from the double-stick adhesive.

7. Place the MCM firmly in the proper slot in the plenum. Attach the shorted ZIF connector to the braid on the gluing jig with a small alligator clip.

8. (For inner middle and inner top only) Gently attach the kapton cable to the cable underneath it by rubbing on the area above the double-stick adhesive. For inner top, the adhesive on the end should be done first, and then the adhesive on the inner bottom face.

9. Reassemble the plenum around the newly inserted MCM.

10. Now we will transfer the jig to the environmental chamber for curing. Taking care not to foul the vacuum cable, pick up the jig and set it on the floor in front of the environment chamber. Open the door to the chamber, and set the jig on the floor of the chamber. Choose the appropriate vacuum hose from the manifold inside the chamber and have it in readily reachable. Close the vacuum valve on the gluing jig's small vacuum reservoir, remove the cable from the large reservoir and replace it with the cable from the chamber manifold. Reopen the vacuum valve on the gluing fixure. The switching of the cables must be done quickly but gently--if the vacuum lets go because of leakage or jostling, the Si could move on the still liquid glue bead. If that happens, remove the assembly from the cage--the procedure to recover from this situation will be developed if necessary.

11. Close the environmental chamber and allow the glue to cure overnight (nominal curing time is ~7 hours).