Glue curing studies (contd)

Intention (collaboration: Berlin - Birmingham)a)glue and cure at room temp and elevated temp (+35C approx) and then shear test the glue bonds in Berlin.

b) exercise our ex-SCT Dotmaster glue dispenser to see if it could be used to lay down appropriate dot patterns for UV curable glue.

Immediate problem with (a)As reported at last (petalet/stave) meeting, the hybrid panel in Bham was so uneven that the hybrids fell off after gluing.

Next stepMake a feature of the problem?

1WP3_Birmingham; 16 Jan2014; John Wilson

Current plan (a)

• Tony has procured for us another 250nm panel, similarly uneven.

• Our gluing jig, originally out of shape, has been machined flat.

• The heights of the ASIC pads on the panel have been measured. Knowing the pad and jig dimensions, we can set the jig spacing legs so that the gaps straddle values around 80 μm. (Sam)

• 2 hybrids have been at room temp and 2 at elevated temp (all with glue thicknesses around 80μm); 2 hybrids have been glued at room temp with a wide range of glue thicknesses (Simon).

• will send to Berlin for shear testing (Ingo and Luise) in next few days.

If all goes well, we shall be able check for a systematic difference between curing at room and elevated temps and also for a dependence of glue strength with spacing (jig to ASIC pad).

2WP3_Birmingham; 16 Jan2014; John Wilson

Current plan (b)

• Before Christmas, Simon has been exercising the Dotmaster with the 3 UV curable glues, sent by Luise and Ingo.

• Lots of results which were discussed with Ingo, Luise and Denis last Friday.

• Please see a selection of Simon’s slides next.

3WP3_Birmingham; 16 Jan2014; John Wilson

S Pyatt

UV glue dispensing studieson the Dima Dotmaster

4WP3_Birmingham; 16 Jan2014; John Wilson

S Pyatt

The study involves the testing of 3 UV cure glues, received from Berlin.The candidates are:

•Loctite 3525•Dymax 6-621•Dymax 3013

Two dot pattern types have been defined, a five dot pattern and a one dot pattern.Due to time constraints this study will focus on the five dot pattern only.

There are several steps to the testing procedure, they are:

•Dispensing feasibility. Can the glue be dispensed and what setup is required for theDima Dotmaster glue dispenser?•Dispensing timing step test. Stepping through different dispense times until a target dispense time duration is indentified which gives the correct mass of glue.•Dispensing consistency for the identified fixed dispense time.

5WP3_Birmingham; 16 Jan2014; John Wilson

S Pyatt

Glue dispense testing systemA specially designed glue testing system is used for qualifying glues. This consists of a jig designed to hold three glass slides, one slide for a pre-test glue purge and two glass slides for dispensing test dots.The method is as follows:•Weigh the glass slide.•Dispense test dots on to the test slides.•Weigh glass slide to determine mass of glue dispensed.

6WP3_Birmingham; 16 Jan2014; John Wilson

S PyattLoctite 3525

Dispense time step test, 5 dots per slide. Increments are in 0.05 and 0.1 seconds. Target mass is 2.0 mg. 1 bar pressure. 0.6mm distance. Blue 22 gauge needle.

Target dispense time is around 1.80 seconds.7

WP3_Birmingham; 16 Jan2014; John Wilson

S Pyatt

Average 1.90Std Dev 0.29

Average 2.32Std Dev 0.31

Average 2.27Std Dev 0.23

Loctite 3525Variation in weight for fixed dispense times

8WP3_Birmingham; 16 Jan2014; John Wilson

S Pyatt

Conclusions

•All three glues can be dispensed with the Dotmaster but the Dymax 3013 looks the least suitable.

•The trial demonstrates all three glues require differentparameters which is most likely caused by the differencesin viscosity.

•The trail also demonstrates the variations in accuracy of the Dima Dotmaster glue dispensing system. This variation couldbe used as a guide for buying an up to date dispensing system. Newer dispensing systems may be more accurate.

9WP3_Birmingham; 16 Jan2014; John Wilson

Next Steps

250nm With “end of line” panels, gratefully received from Tony , we have learned a lot: measuring, adjusting jigs to meet 80μm glue thickness, remeasuring etc. But shear tests of ASIC-hybrid glue bonds will not be conclusive due to inferior quality of panels.

130nmLook forward to receiving soon. • repeat tests to compare room temp and heated plate curing.

With 250nm, potential to glue/cure 8 hybrids per day with heated plate curing (cf 2 hybrids per day at room temp).

Can the same rate be achieved with 130nm?If so, is ASIC-hybrid glue bond strength with elevated temp cure sufficient?

10WP3_Birmingham; 16 Jan2014; John Wilson