two versions went for manufacture – test vehicle for tab and solder resist evaluation trying to...
TRANSCRIPT
•Two versions went for manufacture – test vehicle for tab and solder resist evaluation•Trying to improve planarity of circuits
•Circuit build is identical to the electrical version – when submitted•3 layers, 18µm Cu using 50µm dielectric (polyimide) with 150µm blind vias
•Circuits identical except for use of differing solder resists:•One batch made with ‘standard’ rigid resist (as presently used on ABCN-25 hybrids)•Second batch made with flexible resist
•Received 5 panels of each – 80 circuits total (40 of each flavour)
•Quality looks very good•Panels and hybrids are very flat and first pass with tooling shows nothing untoward•Anecdotal evidence to suggest that shrinkage control has further improved
•Comes from trying tooling – will confirm their geometry next week on SmartScope
•Hybrid thickness is ~265µm and weigh 1.30g •Present ABCN-25 hybrids come in at ~260µm and weigh 1.65g•Build thicknesses similar due to use of 18/50/18 Cu-Clad carriers on new circuits
•‘Old’ hybrids used thinner carrier for outer layers but 18/50/18 for inner layers•3 layer build contributes to weight reduction (less Cu)
1
ABC130 Thermo-mechanicals
ABC130 Thermo-mechanicals HCC heat loadDigital
ThermometerNTC
•On-hybrid temperature monitoring using either•1-wire digital thermometer (DS18B20, -55ºC to +125ºC range with 12 bit resolution)•NTC (1kΩ at 25ºC)•Both circuits accessible via bond field towards end of hybrid
•Resistive elements used to emulate asic heat loads•Embedded trace for ABC130 - leaves lands clear for dummy asic placement (tooling
evaluation)•Design specification was ~230mΩ /asic•Measured resistance is higher – see next slide
•SMD resistors for HCC
•One circuit evaluated using thermal imaging camera – looked very uniform•Tim Jones has data...
3
ABC130 Thermo-mechanicals
12/15/1900
12/20/1900
12/25/1900
12/30/1900
01/04/1901
01/09/1901
01/14/1901
01/19/1901
01/24/1901
01/29/1901
02/03/1901
02/08/1901
02/13/1901
02468
101214161820
Embedded Resistor for Standard and Flexible Resist ABC130TM Hybrids
Fre
qu
en
cy
Resistance mOhms
Flexible Resist
Standard Resist
01/02/1900
01/02/1900
01/02/1900
01/02/1900
01/02/1900
01/02/1900
01/02/1900
01/02/1900
01/02/1900
01/02/1900
01/02/1900
01/02/1900
0
1
2
3
4
5
6
Hybrid Resistance for Standard and Flex-ible Resist ABC130TM Hybrids
Fre
qu
en
cy
Resistance OhmsFlexible Resist
Standard Resist
Resistance measured for 8 hybrids (80 asics)
Resistance measured for all hybrids
•Clearly 2 families of resistance•Both batches processed at differing times•No evidence of over-etching, difference probably due to differing Cu weights
•Expected resistance ~280mΩ/asic, measured:•Standard resist: ~364mΩ/asic (σ ~ 3.67mΩ)•Flexible resist: ~400mΩ/asic (σ ~ 3.75mΩ)
•‘asics’ linked up serially (likewise hybrids...)•For ~5W dissipation/module will require ~6V/module and ~80V/Stave side•Within the “Extra Low Voltage” regime for safety (<120V DC)
~1% spread