Both FormFlex and Grid-lok tooling systems are marketed as compliant tooling systems. Both are able to conform to the variations of the topography on the bottomside of a substrate to provide full support during printing of 2nd side assembly. The basic difference between the two systems is, after setting the tooling and using in production:
* FormFlex pins are mobile and able to conform to changes in board underside profile relative to the profile of the board used for setup.
* Grid-lok pins are independently, mechanically locked in place. They do not move once locked, unless lowered purposely.
The FormFlex system utilizes an oil chamber that is common to ALL the pins once the system is set. Pushing down one pin will cause the displaced oil to be shared by all the others pins in that module. With the cut off valve closed, this volume of fluid will not change. As a board is presented to the FormFlex modules, the pins assume the shape of the substrate landscape providing complete support. However, because the total volume of the fluid is unchanged the overall height of the board is maintained. It is this "common fluid bed" concept that makes the FormFlex system superior to the mechanically locking pin approach. This feature allows the tooling to conform to board profile variations during a production run, prevailing over warpage and compensating for board tolerance and component position deviations that may likely occur, in order to produce a consistently supported surface for printing.
FormFlex has been reported to work extremely well in the field for double sided board assembly. Some of the concerns that have been reported with FormFlex are air entrapment in the module, oil leaking, and sticking pins. These are all issues that have been addressed through improving the module design itself and by educating users about the proper operation of the system, to follow the correct setup procedure and conduct routing health checks.
-Jeff
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