1. Glue curing studies (contd)
Intention (collaboration: Berlin - Birmingham)
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 step
Make a feature of the problem?
WP3_Birmingham; 16 Jan2014; John Wilson

2. WP3_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).
WP3_Birmingham; 16 Jan2014; John Wilson

3. WP3_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.
WP3_Birmingham; 16 Jan2014; John Wilson

4. UV glue dispensing studies on the Dima Dotmaster
S Pyatt
UV glue dispensing studies
on the Dima Dotmaster
WP3_Birmingham; 16 Jan2014; John Wilson

5. WP3_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 the
Dima 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.
WP3_Birmingham; 16 Jan2014; John Wilson

6. WP3_Birmingham; 16 Jan2014; John Wilson
S Pyatt
Glue dispense testing system
A 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.
WP3_Birmingham; 16 Jan2014; John Wilson

7. WP3_Birmingham; 16 Jan2014; John Wilson
S Pyatt
Loctite 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.
WP3_Birmingham; 16 Jan2014; John Wilson

8. WP3_Birmingham; 16 Jan2014; John Wilson
S Pyatt
Loctite 3525
Variation in weight for fixed dispense times
Average 1.90
Std Dev 0.29
Average 2.32
Std Dev 0.31
Average 2.27
Std Dev 0.23
WP3_Birmingham; 16 Jan2014; John Wilson

9. WP3_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 different
parameters which is most likely caused by the differences
in viscosity.
The trail also demonstrates the variations in accuracy of the
Dima Dotmaster glue dispensing system. This variation could
be used as a guide for buying an up to date dispensing system.
Newer dispensing systems may be more accurate.
WP3_Birmingham; 16 Jan2014; John Wilson

10. WP3_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.
130nm
Look 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?
WP3_Birmingham; 16 Jan2014; John Wilson