SMT assembly of PCB are wildly used in electronic industries, it can be said as the corner stone of finished products PCBA used in medical, industry, military, auto etc. There are manual welding and machine welding. In this article we will introduce you the operation methods for manual welding which are the cherished experience in long production history of Sayfu group.
Firstly: Manual welding’s requirements and conditions for SMT assembly of PCB
The so-called welding is to use solder as a medium, that is, heating and making the two metals connected and achieve the purpose of conducting electricity.The following are the necessary conditions and requirements for SMT assembly of PCB.
- Welding parts must have good weldability.
- Operators must keep the surface of the welding parts clean.
- Suitable flux is necessary.
- Operators should heat the welding parts to an appropriate temperature.
- Correct hand welding techniques.
- The mechanical strength of the solder joints must meet the needs.
- Reliable welding to ensure good electrical conductivity.
- The surface of the solder joints should be smooth and clean.
Secondly:Welding Method and Steps
1. Preparation before welding:there will be an oxide film on the surface of the component leads, which affects the welding. An operator must remove the oxide layer first and then tin the surface.Except for a few leads with silver and gold plating, an operator must tin most of the components before soldering.
2.Five-step method of welding operation:Preparation, heating, wire feeding, wire removal, and soldering iron removal.
Finally:Precautions for Welding Operation
When soldering, the soldering iron tip is in a high temperature state for a long time, and it is exposed to weak acid substances such as flux, and its surface is easily oxidized, stained with black impurities. Pay attention to rubbing away impurities on the soldering iron stand at any time. Wiping it with a damp cloth or sponge at any time is also one of the common methods.The main points to note of SMT assembly of PCB are as follows
(1)Use the correct heating method.
(2)Heating depends on solder bridge.
(3)Use the correct method to evacuate the soldering iron and remove it in a timely manner.
(4)Tin dosage for solder should be moderate.
(5)The amount of flux should be moderate.
(6)Do not use the soldering iron tip as a tool for carrying solder.
(7)Solder joint quality requirements
The concept of the sayfu group is to understand the real-time needs of customers, to accurately analyze the market, to seek and develop feasible and complete project development plans.The pursuit of efficiency and high quality in SMT Assembly of PCB is a never-ending step, we are committed to delivering high quality products to our customers in a tight timeframe and flexible to meet individual demands. To be top class PCBA supplier, we still need to work hard continually both on machines and technology parts.