delphi confidential precision bump formation mushroom type bump x-sec laser ablate plated up bump...
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Delphi Confidential
Precision Bump FormationMushroom type bump
X-Sec laser ablate plated up bump
Fabrication process
Delphi Confidential
– Simultaneous Laser Operation
» Define dot location
» Define alignment hole location
» Position tolerance +/- .002”
w
b
h
h = bump height 0.003-0.005 in.
b = bump base w + h
w = bump opening 6,8,10 mils
The bump is plated within and above the coverlay material.
Precision Bump FormationMushroom type bump
Design considerations (dot to dot spacings)
Delphi Confidential
Precision Bump FormationMushroom type bump
Examples of mushroom type bump partsFor military and commercial applications
Delphi Confidential
Photolithography Bump FormationPhotoresist defined bump
Laminate Photoresist
Photo / Develope
Plating
Strip Photoresist
Fabrication process
The shape of the bump is controlled by the photoresist image, so various shapes can be defined. Typicallyused with larger or gross opening in the coverlay.
.008”
.004”
Bump heights are 0.003-0.005 in.Bump Widths are 0.004 in. smallerthan the trace widths
Delphi Confidential
.008”
.004”
Photolithography Bump FormationPhotoresist defined bump
Examples of mushroom type bump partsFor military and commercial applications
Delphi Confidential
Precision Bump FormationEtch-a-dot type bump
Laminate coverlay
Laser coverlay openings
Plasma Clean openings
Plate mushroom bump
Etch smaller bump tipOn mushroom bump
Fabrication process
The bump is plated within and aboveThe coverlay surface.
Delphi Confidential
Precision Bump FormationEtch-a-dot type bump
Examples of mushroom type bump partsFor military and commercial applications
Typical bump dimensions
Delphi Confidential
Typical Gold dot circuit layout
Circuit Trace Capabilities: .0025/. 0025[0.0635/0.0635] Width/ Space
Calculating Contact Pitch:For Column Pitch:Pcolumn=(No rows-1) x (Trace width) + Base Pad Dia + (No Rows) x Conductor Spacing
Bump Height* Bump Base Diameter
Bump Base Pad Diameter
.0045[0.114] .008[0.216] .0145[0.368]
Column of Contacts
Rows of Contacts
Circuit Trace
Bump Base
Bump Base Pad
Delphi Confidential
Precision Bump FormationTypical Performance Characteristics
•Rated current per dot 1 amp Max @ room temp
•Contact Resistance <10mOhms
•Contact Force 0-150 gms per contact
•Vibration 10 G max. peak, 10-500 Hz
•Mechanical shock 30 G, 294 m/s peak Accel. 11 ms duration
•Operating temp. -40 to +125 C, continuous
•Bump contact Au Plated over Nickel and Copper
•Mating surface Immersion/hard gold & solder