Heated plate curing

Heated plate curing

1WP3; 20 Mar2014; John Wilson

•Gluing and Measuring (130nm hybrIds)

• Trying to adjust touchdown pins on ASIC placement jig for flatness.

• Check after gluing glass ASICS (room tempo cure).

Shear testing

• Use Dage 4000 to shear-test the glass ASICs glued above (though the glue thicknesses are awry)

Adjustment of placement jig

Mini heating element

ASIC Placement Jig

Aluminium tooling plate

Assembly DowelsFeeler gauges

• Feeler gauges, placed between the jig and plate: gauge thickness = glue thickness + ASIC thickness + height of hybrid from panel. ( 80μm + 310μm + - 50μm ) = 340μm

2WP3; 20 Mar2014; John Wilson

Touchdown pin

Measure the resistance of each touchdown pin, stopping when it becomes finite

But find that pins are adjusted ~40µm too long.

The metal plate had small dents in the surface under the touchdown pins.Placing shims (of the same thickness) under the vacuum pads and spacing shims, and under the touchdown pins, has removed these surface dents.Now we achieve the target height.

3WP3; 20 Mar2014; John Wilson

The ASIC height should be equal to the distance set when adjusting the jig (i.e. 340μm) .

In fact, the ASIC height is ~ 50 µm lower → a reduced glue thickness.

After gluing and room temp curing, measure the heights of the ASICs above the touchdown pads.

The Glue Thicknesses are ~50µm than expected. The shape stays consistent with what we expected but it looks as if the whole jig has somehow ‘sunk’ into the panel

5WP3; 20 Mar2014; John Wilson

Adjustment of placement jig

6WP3; 20 Mar2014; John Wilson

There is a small dent in the centre of each of the ‘touch down pads’

We estimate this dent, has lowered the whole jig by ~50µm.

We think this has occurred because of the tight fit of the jig to the panel. Quite a force is required on to the jig to get it to sit correctly → dent on surface?

We have reamed out the holes on the panel to make the jig fit better. Will glue another hybrid to see if the problem persists.

Dage 4000 : shear tests

Need to support the hybrid firmly during the shear test:

• Videos of shearing available!

7WP3; 20 Mar2014; John Wilson

Clamp

Shear tool

Plate with lip to stop hybrid sliding

During these two shear tests the jig holding the hybrid twisted which is why there is a lower value recorded.

8WP3; 20 Mar2014; John Wilson

Dage 4000 : shear tests (contd)

No conclusions since glue thickness is wrong but glue joints seem very strong!i.e. within spec (MIL-STD-883G): if die area exceeds 4.1 sq mm, shearing at ≤ 2.5kg ≡ FAILURE;shearing at ≥ 5.0kg and adhesion over > 75% of area ≡ SUCCESS.

Aim for ≥ 5.0kg

9WP3; 20 Mar2014; John Wilson

Dage 4000 : shear tests (contd)