Search results
Results from the WOW.Com Content Network
The solder balls can be placed manually or by automated equipment, and are held in place with a tacky flux. [2] A coined solder ball is a solder ball subject to coining, i.e., flattening to a shape resembling that of a coin, to increase contact reliability. [3] Ball grid array, chip-scale package, and flip chip packages generally use solder balls.
A grid array of solder balls on a printed circuit board after removal of an integrated circuit chip. Cross-cut section of BGA mounted circuit. A ball grid array (BGA) is a type of surface-mount packaging (a chip carrier) used for integrated circuits. BGA packages are used to permanently mount devices such as microprocessors.
A solder ball is deposited on each of the pads, in a process called wafer bumping; Chips are cut. Chips are flipped and positioned so that the solder balls are facing the connectors on the external circuitry. Solder balls are then remelted (typically using hot air reflow).
Micro ball grid array : Ball spacing less than 1 mm; Thin fine-pitch ball grid array : A square or rectangular array of solder balls on one surface, ball spacing typically 0.5 mm; Land grid array (LGA): An array of bare lands only. Similar to in appearance to QFN, but mating is by spring pins within a socket rather than solder.
After soldering, the boards may be washed to remove flux residues and any stray solder balls that could short out closely spaced component leads. Rosin flux is removed with fluorocarbon solvents, high flash point hydrocarbon solvents, or low flash solvents e.g. limonene (derived from orange peels) which require extra rinsing or drying cycles.
Reballing involves dismantling, heating the chip until it can be removed from the board, typically with a hot-air gun and vacuum pickup tool, removing the device, removing solder remaining on the device and board, putting new solder balls in place, replacing the original device if there was a poor connection, or using a new one, and heating the ...
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Flexible placer, chip shooter, and other specialized machines. PWB with solder print. Components supplied by feeders. Computer files: computer program controls location of each component on the PWB (X, Y and angular theta), feeder inventory levels, placement machine vacuum holder capability, automatic component realignment, placement accuracy, vision systems, and transportation of PCBs through ...