A high-quality Interconnection Technique
ACF Bonding means Anisotropic Conductive Films Bonding which is used for soft to rigid assembly in electronics assembly industry.
ACF or ACF tape is an epoxy adhesive system used for electronics industry, which is used to bond Chip ic/COF ic/FPC to the LCD(Glass)/PCB/Film/FPC etc to make electrical and mechanical connections between them. Recently, flex-on-board interconnection has become more and more popular for mobile electronic applications.
In the current trend of electronics assembly, flexible on-board (FOB) assembly has attracted more and more attention due to its important role in replacing traditional physical contact based socket type interconnects. For the traditional socket type interconnection, there are three main disadvantages, including: physical contact, large package size, and low package density. But ACF bonding no need of any phisical connectors which can save much time for flex assembling to flex and flex assembling to rigid. In membrane switch industry, the tail exit position is usually located at the middle of the keypad and also no enough room to assemble phisical connector, then ACF bonding can solve this problem. It can laminate the flex PET or FPC cable to rigid PCB soldering pad directly and the lamination area is flat.

ACF Bonding Advantages:
* ACF interconnect offers cost savings by substituting conventional mechanical connectors or soldering interconnect.
* ACF interconnect allows low height and fine pitch which enables high density and miniaturizing of assembly.
* ACF special conductive particle is made from environmental friendly material (ROHs compliance). It provides good metalic bonding.

Soldering assembly is a very common and standard technology in PCBA industry. But for membrane switch assembly, it is not common and also not easy. As we know the circuit layer for membrane switch is usually a completed Polyester or FPC layer. The "completed" here means the circuit tail (also called cable) is a part of the circuit layer, which is not a separate one. But for some special applications, for example, the tail exit position is not designed at the keypad border but at the middle of the keypad for the end equipment's needs or the circuit layer of the membrane switch is the rigid PCB and no enough room to assemble phisical connector, then we have to produce the separate FPC or FFC or PET cables and also need assemble the separate cable to the membrane switch circuit.
How to make this assembly? Except for the ACF bonding technology mentioned above, there is another mathod which is just the soldering technology common used for PCBA industry. As we know the membrane switch is very thin and it also need a flat backsurface, otherwise it is hard to be assembled on customer's equipment. So it becomes very important to control the soldering surface finishing. It must be flat, and as short as to the circuit level. LuphiTouch has mastered this soldering technology and can guarentee the soldering quality of our manufactured interface switch products.

Advantage: More stronger at soldering PINs;
Disadvantage: Easy to broke at soldering area and also hard to control its flatness at the soldering area;