PCB board assembly process

PCB board assembly process

 

1, all-sided single-sided substrate

 Is the most basic, the most common type, the process of its installation has a long plug and short plug points.

Long plug refers to the device pin without pre-processing and directly into the circuit board mounting hole; short plug refers to the components of the pin first with a special equipment for bending forming, cut off, and then insert the circuit board mounting holes Inside.

A. Long plug process:

Program

1. Small-scale, small-batch type:

 PCB preparation → plug-ins → dip soldering → cut feet → wave soldering finishing → solder joint testing

2. Large-scale, high-volume type:

 PCB preparation → plug-in → ultra-high-frequency welding → cut foot → wave soldering finishing → solder joint testing

B. Short plug process:

Circuit board preparation → plug-ins → wave soldering → pin-foot → solder joint detection

2, single-sided all-mount substrate:

 There are currently two methods of surface mount component soldering, one is the flow soldering method, which is to apply the adhesive on the circuit board first, and then

Affix the components on the circuit board with a towel patch device and cure the glue with an oven or tunnel oven so that the chip components are firmly

Stick on the circuit board, and then wave soldering method. The other is the reflow method, which first soldered on the circuit board pads

Paste, and then use the patch device components attached to the circuit board, and then use the reflow soldering paste heating, solder paste in the solder

Tin particles melt after the flow, infiltration of the circuit board and the mounting pad components of the electrode, forming a solder joint after cooling

Law, single-sided all-mount substrate assembly process has a flow of solder and reflow points.

A. Flow welding process:

Circuit board preparation → glue → patch → glue → wave soldering → testing

B. reflow process:

Circuit board preparation → paste → patch → reflow soldering → testing

 

3, single-sided mounting, the other side of the plug-type substrate:

This type of substrate is characterized by solder joints on the same side, and plug-in components to be used flow welding process. Therefore, the placement of components also use the flow of welding technology, at the same time, plug-type components to short plug process. The process is as follows:

Circuit board preparation → glue → patch → glue → circuit board flip → plug-in → wave soldering → cut foot → test

 

4, single-sided mounting, the same side of the cartridge type substrate:

 Solder joints of such substrates are on two sides respectively. In principle, the mounting order of hybrid substrates is line-mounting and post-mounting. The placement of components such as the use of flow welding process, you must first tape tape plug device mounted pad, or the hole will be blocked by molten tin, it is more complicated and generally not used. The commonly used process is as follows:

 Circuit board preparation → Paste → Paste → Reflow soldering → Plug-in → Wave soldering → Cut foot → Test