Diebonder Delvotec Pegasus 3600
The die bonder is used to dispense adhesive in a selected pattern before the die is placed on the substrate. The adhesive is then cured in an oven.
Flip chip
The die bonder also has flip-chip capabilities. Flip(chip technology provides high packaging density and performance and a low packaging profile. It is defined as mounting the chip, with the active side facing down, on a substrate with any kind of interconnect material. In most, if not all, flip-chip systems in production today, the chip is bumped, i.e., there is a quasi-spherical bump on each contact pad on the chip. The bump-array pattern is mirrored onto the substrate chip site. The bumps are usually metal and serve as the joint-forming material either together with solder or adhesive or by the melting of the bump itself.
The advantages of flip-chip technology are the short interconnects, which improves electrical performance and reduces the size and weight and reduces the cost as less silicon and circuit-board material are used. The total size can be reduced in all three dimensions because the naked chip takes less space than does the packaged chip. Each chip can have many connections since it is possible to have contact points on the entire surface instead of just at the periphery.
In optoelectronics the requirements for alignment accuracy are often very extreme. Flip-chip technology offers the benefit of self-alignment through the soldering process.
Ballbonder: Delvotec bonder 5610
Wire bonding
A gold or aluminum wire is bonded between each pad on the chip and the corresponding bonding surface on the carrier. After chip mounting and bonding, the chip and its wires are protected from mechanical and chemical impact by a local epoxy encapsulation called glob top or dam and fill. For additional protection, the entire module can be encapsulated, a method used when the electronics will be exposed to harsh environments. Today, about 95% of all chips are wire bonded, either inside a package or directly to a substrate.
Stud bumping
We have the option of making stud bumps for flip-chip assembly. Bumping flip chips can be achieved in many different ways. Today, the availability of bumped dies is considered to be a significant bottleneck for flip-chip production. One method of bumping is to use a ball bonder to make the stud bumps. A ball bonder is used to form a ball on the aluminum pad. The wire is then pulled to breakage. The high speed of today’s wire bonders makes ball bonding an attractive alternative to plating. This method is especially suitable for prototyping.
Deep access wedge-wedge bonder
Delvotec bonder 5632
The deep access-bonding head makes it possible to reach down into very narrow cavities. The machine uses both gold and aluminum wires.
Pulltester 5600
A pull tester is used to verify the bonding parameters.