Types of BGAs - Ceramic 1

The Ceramic Ball Grid Array usually has Non-Collapsible balls.
• The BGA balls are made of a higher temperature material. Either a greater
Lead content or a greater Tin content means the balls will not melt under
normal reflow conditions.
• The BGA balls retain their nearly spherical shape after reflow.
• The x-ray diameter of the ball can have certain assumptions made:
− The largest diameter of the ball is at the ball's radius above the panel
(TOP + radius) as specified in a data sheet.
− The x-ray image of the solder joint at the panel (TOP) is about 1/2 the
diameter of the ball.
− The x-ray image of the solder joint at the device (TOP + diameter) is
about 1/2 the diameter of the ball also.
• Set the slice heights
− The first slice is at TOP + radius. This is at the maximum diameter.
− The device slice is set at TOP + (1.5 x radius). This places it slightly
below the device, but close enough to see any faults with the joint at the
device.
− An optional third slice is at TOP. This is used by the Short Test
algorithm only.