mhoulroyd
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One of the biggest challenges facing assembly of SMT interconnects is maintaining lead coplanarity over a distance.
The greater the distance, the more likely the PCB surface may display the effects of warp, twist, and thickness tolerances.
If the device lead is seated too high above the solder paste, then this will be either a poor solderjoint, cold solderjoint or
worse an open circuit due to no solderjoint. For a gull-winged interconnect, the device leads are visible, making them
somewhat accessible for emergency repair, but if the device leads are part of an inline array, and an inaccessible pin
location does not have a solderjoint. This may make the entire assembly unusable and require external white wiring to
physically jump the dead pin location.
There is a technique for screw machine socket receptacles that will allow the shell to achieve vertical travel inside the molded cavity.
This is referred to as "Floating Pin" technology. It is an ideal solution for attaching interconnects on uneven surface PCBs
Below are examples of inline interconnects (SMT pin base concentric to body) and Gull-Wing termination (leads flank package outline)
**broken link removed** **broken link removed**
Below is an animation (I hope video works on this board. If not, copy and paste url into browser)
[video=youtube_share;Buv-9jCX7C4]http://youtu.be/Buv-9jCX7C4[/video]
Please let me know if you need more help or explanation regarding this topic. Regards, Marty
The greater the distance, the more likely the PCB surface may display the effects of warp, twist, and thickness tolerances.
If the device lead is seated too high above the solder paste, then this will be either a poor solderjoint, cold solderjoint or
worse an open circuit due to no solderjoint. For a gull-winged interconnect, the device leads are visible, making them
somewhat accessible for emergency repair, but if the device leads are part of an inline array, and an inaccessible pin
location does not have a solderjoint. This may make the entire assembly unusable and require external white wiring to
physically jump the dead pin location.
There is a technique for screw machine socket receptacles that will allow the shell to achieve vertical travel inside the molded cavity.
This is referred to as "Floating Pin" technology. It is an ideal solution for attaching interconnects on uneven surface PCBs
Below are examples of inline interconnects (SMT pin base concentric to body) and Gull-Wing termination (leads flank package outline)
**broken link removed** **broken link removed**
Below is an animation (I hope video works on this board. If not, copy and paste url into browser)
[video=youtube_share;Buv-9jCX7C4]http://youtu.be/Buv-9jCX7C4[/video]
Please let me know if you need more help or explanation regarding this topic. Regards, Marty
