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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
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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
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
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
S Pyatt UV glue dispensing studies on the Dima Dotmaster 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
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
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
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
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
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