Method to remove through hole components from board

This idea is a modification of a wave soldering system to desolder stuff and knock it loose.

A PC board with through-hole parts to be removed is placed in a carrier assembly. This carrier assembly consists of side clamps, and an overhead stiffener. The overhead stiffener is attached to the side clamps by studs/threaded rods that pass through ears on the sides of the clamps and stiffener. The overhead stiffener also has threaded holes to provision use of support dowels or studs that touch the pcb board once the clamps and stiffener are fastened together. See Figures 1 and 2:
Figure 1: The side clamps

Figure 2: the carrier assembly fully assembled with board attached

The stiffener also has ears to allow attachment to a robotic arm that will manipulate the carrier assembly inside a wave soldering machine.


The whole assembly of stiffener/board/clamps is loaded into the desoldering machine. Here, the carrier is reciprocated across the surface a wave solder pool/pot several times so as to melt the solder on the underside and melt the solder in all the layers/topside via conduction. Once the solder has had sufficient time to melt (1-2 seconds), it is rapidly lifted up or rotated up, and is translated sideways, and then slammed into a platen. This impact impacts sufficient force and impulse to displace the components and free (most or all of them) from the board. See figure 3:
Figure 3: the robotic arm assembly which operates inside wave desoldering machine/cell

The atmosphere inside this "flapjack" desoldering machine is controlled to prevent excessive oxidation. Thus, it is purged with Ar or N2 to reduce oxygen content below about 10 ppm (standard for most wave soldering machines). The gas temperature is also controlled to avoid thermal shock of components, thus it is held at nominally 80C.

The freed parts are then conveyed or wipered away to one of several holding cells; the holding cell has an airlock to prevent excessive loss of purge gas. The holding cell also allows parts to cool down to 30 C at a moderate pace (1 C/sec or less).

The spent board is then taken out through the entry/exit port, which also has an airlock.