The Pin-in-Paste Method
The integration of THR components in reflow processes is based on the pin-in-paste method.
A printed circuit board with a plated-through drill hole (1) and an appropriately designed and positioned template (2) is required when integrating THR components. In modern screen printing systems, solder paste must be applied (3) and fill the drill hole (4). The desired amount of pushed-through solder paste is shown here. Next, the component is fitted (5). The pin pushes the solder paste through the hole, forming a shape that resembles the head of a match (6). It is then reflow soldered (7). The connection that is achieved is as mechanically and electrically robust as the one that is created by the conventional wave soldering method (8).
The "Pin-in-Paste" Method
When integrating THR components in SMT processes, changes in process conditions must be taken into consideration. The male connectors must therefore be optimized for the processes. This includes:
- High-temperature resistant housing
- Appropriate flat surfaces for the intake action in automated pick-and-place fitting processes.
- An optimal component height with regard to packaging and the free fitting height of pick-and-place machines.
- The component must have ribs or offsets.
- Component geometry below the component. This prevents contact with the solder paste and also provides sufficient space according to the solder pad design.
- Free-standing pins and easily accessible metal parts are required to provide good access for heat. Shadowing by large housings must be avoided.
- The pin length should be optimized and adjusted in the same way as the height of the component.