Bump config

1
Precision Bump Formation Mushroom type bump
Fabrication process
X-Sec laser ablate plated up bump
2
Precision Bump Formation Mushroom type bump
Design considerations (dot to dot spacings)

• Simultaneous Laser Operation
• Define dot location
• Define alignment hole location
• Position tolerance /- .002

h
b
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.
w
3
Precision Bump Formation Mushroom type bump
Examples of mushroom type bump parts For military
and commercial applications
4
Photolithography Bump Formation Photoresist
defined bump
Fabrication process
.004
.008
Bump heights are 0.003-0.005 in. Bump Widths are
0.004 in. smaller than the trace widths
The shape of the bump is controlled by the
photoresist image, so various shapes can be
defined. Typically used with larger or gross
opening in the coverlay.
5
Photolithography Bump Formation Photoresist
defined bump
Examples of mushroom type bump parts For military
and commercial applications
.004
.008
6
Precision Bump Formation Etch-a-dot type bump
Fabrication process
The bump is plated within and above The coverlay
surface.
7
Precision Bump Formation Etch-a-dot type bump
Examples of mushroom type bump parts For military
and commercial applications
Typical bump dimensions
8
Typical Gold dot circuit layout
Circuit Trace Capabilities .0025/. 00250.0635/0.0635 Width/ Space
Bump Height Bump Base Diameter Bump Base Pad Diameter
.00450.114 .0080.216 .01450.368
Calculating Contact Pitch For Column
Pitch Pcolumn(No rows-1) x (Trace width) Base
Pad Dia (No Rows) x Conductor Spacing
9
Precision Bump Formation Typical Performance
Characteristics

• Rated current per dot 1 amp Max _at_ room temp
• Contact Resistance lt10mOhms
• 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