Dan Cheng 1/13/2015 LARP Copper Plated Trace Development Update

Outline 1/13/2015LARP Copper Plated Trace Development2 Coil Trace fabrication update Trace plating development status update since 10/2014 Selective plating as an option

CERN has produced traces for first 3 LARP Coils already CERN has two new traces, to be shipped to LBNL – LARP Coil 4, spare (LBNL) – LARP Coil 5, being wound this month 1/13/2015LARP Copper Plated Trace Development3 CERN Trace, LARP v2 trace design

LARP Plated Trace Development Status, 10/2014 1/13/2015LARP Copper Plated Trace Development4 Identified three vendors last year for trace production – Two for producing copper plating on long material – One for selective copper etching and drilling Provided plating vendors with GTS-produced laminate with 304 SS on Apical AV – Requested 10 microns (0.0004”) of copper plating

LARP Plated Trace Development Status, 10/2014 1/13/2015LARP Copper Plated Trace Development5 Plating Vendor 1 – Not limited by tank size (long lengths okay, manual process) – Samples were produced However, thickness of copper plating has not been thick enough (see additional slides material) Control of consistent plating thickness is also difficult in this process Plating Vendor 2 – Concerned about process chemistry effects on polyimide Not likely to not be an issue—however, vendor has not worked with this material before – Has reel to reel capabilities But has concerns about thin nature of material—may be damaged during processing Cross-sectional thickness of plating process may also vary (“dogbone”) from edges to center of material – This edge buildup also will affect the plated material’s ability to be rolled up on takeup spool w/o damage

1/13/2015LARP Copper Plated Trace Development6 Resistance and Estimated Cu Thickness Sample #U (mV) R (m  R cu (m  Cu thickness d (  m) 1 (Batch 1) (Batch 1) (Batch 1) (Batch 1) (CERN) (Batch 2, Mid) (Batch 2, edge) I=0.98 A *Assuming  Cu =  m M. Marchevsky Within spec

1/13/2015LARP Copper Plated Trace Development7 Options Presented 10/2014 LBNL still has the capability to produce SS-only traces in ~4 m lengths – Options 2 & 3 are compatible with this Other plating/processing vendors have indicated that size and roll processes may be a problem (Process 1 style) CERN is exploring long trace fabrication infrastructure (Process 1) Process 1: SubtractiveProcess 2: AdditiveOption 3: Cu only? Plate copper onto SS laminate Etch circuit elements into SS laminate only Material does not come thinner than 9 µm Etch selectivelyPlate selectivelySingle etch process Drill holes

Vendor has been developing their process – Was provided spare HQ traces for development tests – They developed a calibrated device for measuring plating thickness on thin materials using NDE method – Selectively plated these sample traces to a specified thickness Will be visiting LBNL tomorrow to show their results 1/13/2015LARP Copper Plated Trace Development8 Selective Trace Plating Development Process 1: SubtractiveProcess 2: AdditiveOption 3: Cu only? Plate copper onto SS laminate Etch circuit elements into SS laminate only Material does not come thinner than 9 µm Etch selectivelyPlate selectivelySingle etch process Drill holes LBNL still has this capability

Summary 1/13/2015LARP Copper Plated Trace Development9 LARP copper plated trace development is still in progress – Copper plating over long lengths of material have not been satisfactory to date – Selective plating process has been developed; results to be seen in a few days – Appears to be within our capabilities, if this works Work still to be developed with drilling of traces CERN has produced enough traces for 4-5 LARP coils – Copper plated, drilled, etc.

Additional Slides 1/13/2015LARP Copper Plated Trace Development10

1/13/2015LARP Copper Plated Trace Development11 1 st Copper Plating Sample Testing M. Marchevsky

1 st Plated Trace Thickness Measurements 1/13/2015LARP Copper Plated Trace Development12 Profilometer measure-ments performed by a laser vision machine – Copper thickness measures ~8 microns thick However, not consistent across surface Assumes constant thickness of SS laminate underneath Does not really match with electrical resistance measurements What is being measured is driven more by the material imperfections, not the plating thickness

Sample 1 Cross Section Measurements 1/13/2015LARP Copper Plated Trace Development13 Polished samples viewed with a Keyence VHX-1000 digital microscope – Measuring with 1000x Qualitative measurements can be observed, even if exact quantitative measurements cannot be confirmed – Referenced SS thickness (should be approximately 25 µm) – Appears that polyimide thickness is only approximately ~40 µm (should be 50 µm) – Copper thickness is thicker than calculated thickness from resistance measurements (perhaps not uniform?) Vendor sample 1 Copper, ~3 µm Stainless, ~25 µm Adhesive, ~15 µm Polyimide, ~50 µm

Sample 2 Cross Section Measurements 1/13/2015LARP Copper Plated Trace Development14 Polished samples viewed with a Keyence VHX-1000 digital microscope – Measuring with 1000x Qualitative measurements can be observed, even if exact quantitative measurements cannot be confirmed – Referenced SS thickness (should be approximately 25 µm) – Appears that polyimide thickness is only approximately ~40 µm (should be 50 µm) – Copper thickness is thicker than calculated thickness from resistance measurements (perhaps not uniform?) Vendor sample 2 Copper, <1 µm Stainless, ~25 µm Adhesive, ~15 µm Polyimide, ~50 µm

CERN Sample Cross Section Measurements 1/13/2015LARP Copper Plated Trace Development15 Polished samples viewed with a Keyence VHX-1000 digital microscope – Measuring with 1000x Qualitative measurements can be observed, even if exact quantitative measurements cannot be confirmed – Referenced SS thickness (should be approximately 25 µm) – Appears that polyimide thickness is only approximately ~40 µm (should be 50 µm) – Copper thickness roughly matches calculated thickness from resistance measurements CERN sample Copper, ~10 µm Stainless, ~25 µm Adhesive, ~15 µm Polyimide, ~50 µm

1/13/2015LARP Copper Plated Trace Development16 Long trace etching/drilling development A third vendor was identified for the etching and drilling processes – Stated that selective etching copper and stainless over very long lengths is well within their capabilities Drilling operations might be more involved; may require some development time for that. – Will send some sample copper-plated material for them to work with before our copper plating development is complete