Introduction to various technical knowledge of welding and assembly of electronic components

Date：2022-05-09 16:11:25Views：955

Components in electronic circuits are usually installed horizontally. Lead wires of electronic components shall be formed during installation. The forming of electronic component leads is mainly to meet the requirements of installation size and circuit board coordination. When forming the lead, it should be noted that the lead should not be bent at the root, and the fillet radius r at the bend should be greater than twice the lead diameter. The two bent leads shall be perpendicular to the component body and located in the same plane as the center of the component. The components are welded to the corresponding position on the PCB board. The welding steps adopt five steps. The standard of solder joint is: the solder joint is conical, the amount of solder should be appropriate, and the surface is shiny, smooth and clean. This paper collects and arranges various technical knowledge of welding and assembly of electronic components, which is expected to be of great reference value to all readers.

Ordinary arc welding: use the high temperature of up to 3000 to 6000 generated by the arc to weld. An arc is generated between the coated electrode and the base metal, and the welding method of melting the electrode and the base metal by arc heat. The outer layer of the electrode is covered with flux, which melts in case of heat, and has the functions of stabilizing the arc, forming slag dissolution, deoxidation and refining. It is mainly used for ferrous metals with a thickness of more than 3mm.

Argon arc welding: a kind of electric arc welding, which can weld all kinds of black and non-ferrous metals and thin workpieces with a thickness of 1mm.

Gas welding (without electricity, the flame temperature is about 2500, and thin workpieces can be welded).

Resistance spot welding (no solder is required, the welding place is flat, and only thinner parts can be welded).

Brazing: welding that only melts the solder but does not melt the base metal is called brazing. Soldering temperature above 500 is called brazing, and soldering temperature below 500 is called soldering. Soldering belongs to soldering.

Welding electrode welding temperature: welding temperature: more than 13001300 ((other shielding gases can also be used)) (argon arc welding is a kind of electric arc welding, which can weld thinner and more active workpieces) (argon arc welding is a kind of electric arc welding, which can weld thinner and more active workpieces) ((welding wire is used as electrode and melted in welding, welding wire is used as electrode and melted in welding)) (tungsten material is used as electrode) (tungsten material is used as electrode)（ (gas used: acetylene gas; gas used: acetylene gas + oxygen gas)) temperature of welding position of oxygen valve oxygen valve acetylene valve acetylene valve: temperature of welding position: more than 13001300 resistance spot welding (only one point can be welded at a time, so it is referred to as spot welding for short) Upper copper electrode upper copper electrode pressurization energization pressurization energization lower copper electrode lower copper electrode pressurization energization pressurization energization welding temperature: welding temperature: spot welding above 13001300 without solder spot welding without solder manual soldering schematic diagram manual soldering schematic diagram printed circuit board solder joint components ordinary internal thermal electric soldering iron with 1.2mm solder wire with flux. Melting point 183 welding temperature: welding temperature: 210 ~ 230210 ~ 230 gold plated parts: patch PCB pads with high requirements. Chemical gold deposition: chemical gold deposition: PCB pad with high requirements.

Red copper: copper foil on a circuit board Copper foil on a circuit board. Copper alloy copper alloy (brass, tin bronze, etc.):: ICIC pin, reed. Pin, reed. Tinned iron parts: separate element pins (resistance capacitance, diode, etc.). Ideal solder joint shape and soldering mechanism 2.1 requirements for solder joint of plug-in components: the solder joint is isosceles triangle, the two waists are slightly concave moon, and the contact angle is 25 ~ 45 (the height h of solder joint is about 0.6 times of the diameter D of solder joint, h0.6d). The surface of the solder joint shall be smooth, and the pin outcrop shall be about 1 ~ 1.5mm. The solder joint should basically cover the pad. The shape of the actual solder joint of the solder joint component of the circuit board

Ideal solder joint for mounting components

Ideal solder joint for mounting components: the solder joint of wing lead IC mostly follows the installation position and solder joint requirements for chip components. For chip components, the installation position and solder joint requirements mostly follow the 1 / 21 / 2 tolerance principle. In addition, the coplanarity of wing pins allows one pin to be thick. Poor principle. In addition, the coplanarity of wing pins allows one pin to be thick. Soldering is a method of joining metals. Through the mutual diffusion of atoms or molecules between the welding material and the workpiece, an alloy layer (0.5 ~ 2.2m) is formed to form a permanent and firm bond between the two metals.

The above contents are related to various technical knowledge of welding and assembly of electronic components compiled by Chuangxin testing team. I hope it will be helpful to you. Chuangxin testing is a professional testing organization for electronic components. At present, it mainly provides integrated circuit testing services such as capacitance, resistance, connector, MCU, CPLD, FPGA, DSP and so on. Specializing in functional testing of electronic components, incoming appearance testing of electronic components, anatomical testing of electronic components, acetone testing, X-ray scanning testing of electronic components and RoHS component analysis testing. Welcome to call, we will serve you wholeheartedly!