The flip chip allows for a large number of interconnects with shorter distances than wire, which greatly reduces inductance. In the wire bond method (top), the die faces up and is attached to the package via wires.
What is flip chip bump?
In a FlipChip package the dies are bumped and then “flipped” onto a substrate, hence the name “FlipChip”. The bumps are placed directly on the I/Os pads and thereby connect the die to the substrate. Following the bumping process, the wafer is diced and finally, the bumped die is “flipped” on the substrate.
What is a flip-chip BGA?
A flip chip BGA is a specific type of ball grid array that makes use of a controlled collapse chip connection, or flip-chip. It works though solder bumps on the top of the chip pads. The process starts with integrated circuits on the wafer. Pads are metallized on the chips and solder balls are placed on each pad.
What is BGA package?
B. G. (Ball Grid Array) A popular surface mount chip package that uses a grid of solder balls as its connectors. Available in plastic and ceramic varieties, BGA is noted for its compact size, high lead count and low inductance, which allows lower voltages to be used.
What is flip-chip technology?
Flip-chip is not a new technology. To provide links between bonding pads of the chips and the metallization on the substrate, flip-chip technology has been developed by IBM Corporation since 1960s. It is the first proposed method called the Controlled Collapse Chip Connection (C4) to displace wire bolding, expanded IO density, and cost reduction.
What is the difference between die and flip-chip?
The die is then connected to the carrier, and then a wire is bonded first to the die, then looped and bonded to the carrier. The length of wires is typically 1-5mm. On the other hand, in flip-chip technology, the interconnection between the die and the carrier is set up through a bump which is located on the die surface.
Why are flip-chips mass reflowed?
Most of the flip chip assemblies are mass reflowed. Recently, because of the requirements of higher functionalities of the chips and shrinking the chips’ area, the number of pin- outs of the processors, ASICs, and memories increases and their pitch (or the spacing between the pin-out pads) decreases.
Is thermocompression bonding necessary for flip-chip assemblies?
Higher pin counts, tighter pitches, thinner chips, and thinner package substrates lead to the necessity of the thermocompression bonding (TCB) method for flip- chip assemblies. In this study, besides mass reflow, various TCB techniques are mentioned.
