Home /News /New /Industry News /What are the steps for soldering and inspecting the first PCB assembly board? /
What are the steps for soldering and inspecting the first PCB assembly board?
2026-02-02
The first piece refers to the first PCBA processing assembly board that meets the quality requirements of SMD processing and welding. The first batch of the first finished board of each new model is named "first article" in the SMT processing plant. Compared with the subsequent products, the first article is not only a physical test of product performance, but also a quality test of the engineering process. So what are the contents of the first PCB assembly board soldering and inspection?
1. The first PCBA assembly board is welded
The surface assembly board that has been mounted and inspected is placed flat on the mesh conveyor belt or chain guide rail, and the surface assembly board slowly enters the furnace with the conveyor belt at its set speed, and passes through the heating zone, insulation zone, reflow zone and cooling zone to complete reflow welding. Pick up the surface assembly plate at the exit in a timely manner. An anti-static wrist strap should be worn during operation.
2. Check the welding quality of the first PCB assembly board
(1) Inspection method of PCB board
The welding quality of the first PCB assembly board is generally visually inspected, and 2-5x magnifying glass or 3-20x microscope is selected according to the assembly density for inspection
The welding quality of the first PCB assembly board is generally visually inspected, and 2-5x magnifying glass or 3-20x microscope is selected according to the assembly density for inspection
(2) Inspection content
① Check whether the welding is sufficient, and whether there are traces of insufficient melting of solder paste.
② Check whether the surface of the solder joint is smooth, whether there are hole defects, and the size of the hole.
③ Check whether the amount of solder is moderate and whether the shape of the solder joint is half-moon-shaped.
④ Check the amount of solder balls and residue.
⑤ Check the defect rate of monument, virtual welding, bridging, component displacement, etc.
⑥ Also check the color change of the PCB surface, and allow the PCB to have a little but uniform discoloration after reflow soldering.
① Check whether the welding is sufficient, and whether there are traces of insufficient melting of solder paste.
② Check whether the surface of the solder joint is smooth, whether there are hole defects, and the size of the hole.
③ Check whether the amount of solder is moderate and whether the shape of the solder joint is half-moon-shaped.
④ Check the amount of solder balls and residue.
⑤ Check the defect rate of monument, virtual welding, bridging, component displacement, etc.
⑥ Also check the color change of the PCB surface, and allow the PCB to have a little but uniform discoloration after reflow soldering.
(3) Inspection standards
In accordance with the enterprise standards formulated by the unit or refer to other standards. At present, most of the implementations are carried out using IPC-A-610E.
In accordance with the enterprise standards formulated by the unit or refer to other standards. At present, most of the implementations are carried out using IPC-A-610E.
3. Adjust the parameters according to the welding quality inspection results of the first PCB assembly board
(1) When adjusting the parameters, the parameters should be carried out one by one, so as to facilitate analysis and summary.
(2) First, adjust (fine-tune) the speed of the conveyor belt, retest the temperature curve, and test welding.
(3) If the welding quality cannot meet the requirements, adjust the temperature of each temperature zone until the welding quality meets the requirements.
(2) First, adjust (fine-tune) the speed of the conveyor belt, retest the temperature curve, and test welding.
(3) If the welding quality cannot meet the requirements, adjust the temperature of each temperature zone until the welding quality meets the requirements.
How is a PCBA circuit board composed?
What is SMT Machining? What preparations do I need to do before SMT machining?
SEND MESSAGE