Tony Smith LHCb Velo Hybrid Meeting CERN 29

Presentation Transcript

VELO HYBRID STATUS SUBSTRATES CONSTRUCTION of composite SUBSTRATE – best levelness acquired with TPG focal center 400um woven layer of CF prepreg each side situated +-45 degrees 125um ostensible woven layer of CF prepreg each side arranged 0,90 degrees 125um ostensible Total thickness ~900um Two Lamination techniques attempted: in vac pack and autoclave at Liverpool - a few voids and Flat to 200um Thickness 900um +-30um arbitrarily dispersed in PCB press at Stevenage Circuits – exceptionally flat*, still some little voids* Thickness 870um at focus – 40um at edges yet smooth decrease Obvious loss of epoxy at the edges – not considered an issue * little voids could be loaded with epoxy *flat to the degree that it glides on air when put on a level surface on either side. . Tony Smith LHCb Velo Hybrid Meeting CERN 29/07/04

VELO HYBRID STATUS SUBSTRATES 2 LAMINATION of circuits Two Adhesives attempted: STAYSTIK 672 75um 130 degs BONDPLY (polyimide utilized for PCB overlay) 35um 160degs Staystik test dished ~500um however great surface complete – great grip yet circuit peels effectively at the edges Thickness 1.38 – 1.47 It is not known whether substrate added to dishing. Bondply test great evenness yet surface complete shows voids in substrate -great grip Thickness 1.35 – 1.36 BUT the specimen indicated delamination of the TPG Tony Smith LHCb Velo Hybrid Meeting CERN 29/07/04

VELO HYBRID STATUS SUBSTRATES 3 DELAMINATION of TPG considered a major issue Note that the disappointments at the edges all seemed, by all accounts, to be because of laminar splits in the TPG as opposed to a disappointment of the security between the tpg and the CF facings New substrates made with a CF outline approx 4mm wide around TPG is sliced to a littler size and CF prepreg strips set around the edges This securities the CF facings at the edges and diminishes the outward weight on the TPG. Cover was done in vac sack and autoclave at Liverpool Circuits were fortified utilizing Bondply and there were no indications of delamination at the edges. Sadly the set patterns in the side were not machined out so the overlay weight would not have been even. There is a little zone on one side where the circuit has clearly been squeezed hard, as observed from its taking up the example of the gaps in the substrate however there is a disappointment of the glue now. Given this is a confined issue and every single other territory appear to be reinforced extremely well it is felt that it is conceivable that there was some tainting from the profiling procedure. Substrates will be altogether cleaned before cover in future Tony Smith LHCb Velo Hybrid Meeting CERN 29/07/04

VELO HYBRID STATUS Population The two substrates overlaid at Stevenage will be sent back to them and laser cut instead of utilizing CNC processing. One will have gaps loaded with BN stacked Epoxy to planarise it. Need to make CAD information for profiling –Monday 2 nd August These will be overlaid with great K04 circuits on one side and fizzled circuits on the opposite side. 4 more arranged for cover by marry 11 August INVENTORY of parts 2 overlaid substrates 4 TPG centers in stock, 100 On request for conveyance by end October Sufficient CF prepreg for some Substrates however will be past utilize date for principle fabricate 9 great K04 circuits and 3 fizzled ones at Stevenage Tony Smith LHCb Velo Hybrid Meeting CERN 29/07/04

VELO HYBRID STATUS Population of circuits Final pop will be done utilizing patch glue stenciled onto circuit and reflowed setup for this will take too long to utilize this technique for beamtest (Will require some emphasis with the organization to get jigging right they ordinarily silk screen full boards populate them and after that cut/break out individual sheets. ) For October beamtest parts will be bound in house. Standard patch glue and indium bind glue will be attempted. Parts accessible for populace of 4 + single sided modules (connector constrained – bunches of different comps) One more arrangement of short tails accessible. Tony Smith LHCb Velo Hybrid Meeting CERN 29/07/04

VELO HYBRID STATUS Fanouts Fanout outlines for Phi and R both finished All areas are distinctive, attracted sets of 4 One finish set of Phi and R on one sheet Will make 6 sheets by 20 th August Gold on copper on upilex 22um min T&G Rfanout identifier end Tony Smith LHCb Velo Hybrid Meeting CERN 29/07/04

VELO HYBRID STATUS HT TEST Hybrid + short link tried together in Vac Tank Hybrid populated with decoupling tops (2*500v 10nf to Gnd) Guard and HT shorted together All lines aside from HT and Guard on HT connector shorted to ground (incorporates Power) 1meg ohms in both HT and return lines 0-420 volts spillage current consistent at 0.2nA (brief 0.3 at 90V) Discharges saw at 430V (2.3nA normal – a few seconds time span) Baseline =0.2nA 440V – 500V releases of up to 15nA practically every perusing over 460V Back down to 430 then up onset of releases at 480V Regular releases at 520V and benchmark = 0.5nA Down to 510 no releases, pattern back to 0.2nA Up to 550 –discharges of 6nA down to 530 no releases Baseline 0.3nA Left at 500V and following 1 hour standard 4nA no releases Up to 510V (releases) and withdraw gauge comes back to 0.2nA SEEMS TO RESPOND TO TRAINING – NEED LONGER TESTS Tony Smith LHCb Velo Hybrid Meeting CERN 29/07/04