RUSH PCB Inc Pin-Through-Hole Reliability Demands


Long before Surface-Mount-Technology came along, Pin-Through-Hole (PTH) Printed Circuit Boards (PCB) ruled. The same issues, though, that were a concern then, with PTH printed circuit boards, are a concern now.

PTH Reliability


The reliability of PTH starts at the design. Because of the larger component size, which affects the overall size of the finished product, and component weight, requiring more strength in both the PCB and the finished product, extra design considerations are needed.


PTH Manufacturability

Not only does the circuit have to operate properly, as laid out and prototyped, but the manufacturability, or how the finished PCB functions in the finished product, is an essential part of the design.

A Pin-Through-Hole PCB, with its Plated-Through-Holes, is fabricated similar to a Surface-Mount-Technology PCB, but with a few more steps in the manufacturing process.

After most of the PCB is fabricated, copper foil is laminated to both sides of the PCB. Then, where the leads of the PTH components are to go through, holes are drilled through the circuit board. The insides of the holes are electro-plated, using the foil laminated to the board to help conduct electricity during the plating process. After that, to form traces and solder pads, the outside copper layers are etched.

When assembling the components to the board, after the leads are inserted into the holes, the circuit board is wave soldered. The wave soldering can only be done to the solder side of the circuit board because the components are often times too large to allow proper wave soldering from the component side.


Concerns


Care needs to be taken when reworking the PCB (repairing or modifying the PCB), after it is finished. Heating the solder for removal from the hole during the repair has potential to damage the joint connecting the annular rings around the hole-plating.

Wave soldering temperatures with lead free solder are critical. Tighter temperature settings are needed because the solder, being lead free, has a higher melting temperature; if the process temperature is set wrong, either the solder won’t bond properly, or the components and board may be damaged.


RUSH PCB Inc Plated-Through-Hole Technology


RUSH PCB Inc is familiar with all aspects of Plated-Through-Hole technology. Let the engineers at RUSH PCB Inc work with you on the engineering and design of your Plated-Through-Hole printed circuit boards.

For more information on Plated-Through-Hole printed circuit boards, contact us at sales@rushpcb.com, or call us at 408-496-6013.

call_back email skype