When we are making small batches of PCB products without the SMT machine and wave soldering, If every electronic component is soldered by hand, there will be a heavy workload.
Fortunately, we have a small batch production artifact – PCB Stencil.
Before we introduce how to use stencil, we should prepare the following tools:
(1). Stainless steel tweezers, you could choose a pointed or elbow, which is mainly used for clamping components, as shown in Figure 1.
Figure 1 Stainless steel tweezers
(2). Solder paste, put it to the pad for pcb soldering components, as shown in Figure 2.
Figure 2 Solder paste
(3). Smart temperature controller, used to heat the PCB board, melt solder paste, as shown in Figure 3.
Figure 3 Smart temperature controller
(4). Shovel, mainly used to brush the solder paste, as shown in Figure 4.
Figure 4 Shovel
(5). Washing water and brush, mainly used to clean the PCB board, as shown in Figure 5.
Figure 5 Washing water and brush
Below we take the M-Board PCB as an example (as shown in Figure 6 and Figure 7) to explain how to use stencil.
Figure 6 M-Board PCB
Figure 7 Stencil
Turn on the Smart temperature controller and set the temperature to 250℃.
First, make the two MARK points on the M-Board and Stencil aligned, the purpose is to align the original pads on the PCB with the pad holes on the stencil.
Then press the stencil on the table with one hand, and adjust the position of the M-Board with the other hand, so that the pads on the M-Board completely overlap with the corresponding holes on the stencil, as shown in Figure 8.
Figure 8 MARK point
At this time, both hands press the stencil at the same time to make the stencil and M-Board no longer move, and the other person uses a shovel to evenly apply the solder paste on each pad, as shown in Figure 9.
Lifting one end of the stencil and tap the blank to disengage the M-Board from the stencil.
According to the M-Board BOM, use the tweezers to place the components on the corresponding position on the M-Board. The intelligent temperature controller reaches 250℃, as shown in Figure 10.
Waiting for about 2 minutes, the solder paste has melted, gently remove it and put it on the small iron block, as shown in Figure 11.
This process must be handled carefully, otherwise the components are easily dropped because the solder does not solidify.
After the M-Board cool down, solder the components with soldering iron, then clean the M-Board with the washing water and brush, as shown in Figure 12. You can see that the effect is almost the same as that of factory mass production.
Anyway, RayMing Technology could provide PCB stencil and prototype pcb assembly service.