PC/104 is an embedded computer standard defined by its compact footprint and its stacking bus structure. In essence, PC/104 is a modular, ruggedized version of the PC. Instead of using a backplane, PC/104 modules mate together via stackable ISA, PCI, and PCIe bus connectors. The stackable connectors and asymmetric corner mounting holes create a compact and modular rugged system.
Since more powerful components are available, the PC/104 systems had to be supplemented with a faster bus system. The PC/104 system was supplemented with the PCI bus and thus it was further developed. This supplement is described in the PC/104-Plus specification.
While the PC/104 bus comprises two connectors with 40 and 64 pins which can be placed side-by-side and a grid size of 2.54 mm, the PC/104-Plus features 120 pins with a distance of 2.00 mm. By using connectors with long press-fit pins, several boards can be stacked on top of each other. The clearances specified by the PC/104 consortium are ensured by using spacers and shrouds. The additional use of spacing bolts is therefore not required.
Historically, all long tail PC/104 connectors required a through hole solder application. While many through hole components may be hand or wave soldered, this is extremely difficult and time-consuming for the 104 gold-plated connector pins. Solder pre-form donuts or solder and flux bearing clips allow for improvements in the soldering process by eliminating the hand soldering operation; they do, however, still require a high temperature IR or hand solder process and close visual inspection.
The superior option for applying a long tail stack-through connector is with compliant pin technology. Adopted by the telecom industry many years ago, press fit technology has proven itself to be a cost-effective alternative to soldering connectors to a board. The compliant pins on the connector are designed to deform during the "press-in" process, resulting in an extremely tight and reliable connection to the PCB. Extensive laboratory testing and years of field operation have proven press fit connector reliability in demanding environments. Pressfit connector technology using compliant press-in zones on every pin has revolutionized the way PCB manufacturers mate connectors to PCBs of all kinds. It is the simplicity of applying the connector to the board, and the superior mechanical holding ability, which makes pressfit connectors a cost effective replacement for soldering.
The pressfit advantage:
* Constant and defined impedance across all positions (excellent high frequency properties)
* Compensation for plated through hole irregularities
* No thermal stresses on the PCB
* No chance of fumes, gases, flux residue or solvents penetrating the solder joint
* No risk of cold solder joints
* No risk of shorts as a result of solder bridging
* No risk of solder interference on long tail connectors
* Fast and reliable application of the connector to the board with simple, flat rock insertion tools
* Serviceable and replaceable single contacts and whole connectors
PC/104 connectors are now available in pressfit versions in long and short tail. This allows for fast and simple insertion of the connectors into the finished boards, without any risk of uneven solder flow or contamination to the gold tails of the connectors.
Fast and simple insertion of the connector into the through hole is accomplished by means of a flat rock tool and a simple bottom support fixture mounted on a hand press. The entire press-in process takes less then five seconds, with all positions maintaining equal resistance across the hole. Another added benefit of pressfit connectors is the ability to rework the board by pressing the connector in a reverse process, allowing a replacement connector to be inserted. The innovative 'ept' PC 104+ pressfit-style connector is a revolutionary concept in the PC/104 market.
'ept' now offers the VarPol-PC/104 female connector in FlatRock press-fit construction. This connector was developed for the stacking of PCBs (Piggyback, Sandwich) and is particularly well suited for use in PC/104 modules. These connectors are available in the J1 and J2 variation with 2x32 and 2x20 pins. They can be obtained with short or long pins according to the PC/104 standard. VarPol connectors offer a wide range of possibilities for embedded PCB connection solutions.
In2Connect UK Ltd | Unit 5 Home Farm | Petersfield Rd | Ropley | Hampshire | SO24 0EF | UK | Tel:+44(0)1962 773004 | Fax:+44(0)1962 600034