Several common wave soldering fixtures and their respective characteristics have what

Several common wave soldering fixtures and their respective characteristics have what

Wave soldering jig is also known as over the tin furnace wave soldering jig, is for the PCB board over the wave soldering some parts need to be protected or through the jig to play a role in assisting the positioning of plug-ins designed by a jig, PCB surface mounted smt and then plug-ins, the mounting of the finished pcb on a tray, has been mounted on the tin position of the components and tin can not be tinned place should be protected, and need to be soldered component pin position must be dug out. Need to weld the component pin position must be dug out, at the same time the tray needs to be done on both sides of the track for the wave furnace track bracket. Wave soldering fixtures can be made of glass fiber board or synthetic stone, synthetic stone is relatively more resistant to high temperatures and more durable, while the price of glass fiber board is lower, the customer can decide which material to use according to the number of pcb over the furnace times.

Wave soldering jig, has the following functions;

1.Support thin substrate or flexible circuit boards

2, can be used for irregular shape of the substrate

3, can carry multiple boards to increase productivity

4, to prevent the substrate in the soldering back, the phenomenon of bending wave soldering has a gradually rising temperature in the environment, can continue to maintain its physical properties of the ability to make the synthetic stone can be in the wave soldering process, to achieve high standards of results and will not have deformation of the situation, to be placed in a short period of time in 384 ℃ and continue to 325 ℃ of the operating temperature of the harsh environment, but also will not cause the material grass-roots level of separation.

There are many materials used to make wave soldering jigs:

1) durostone

Durostone is the wave soldering fixture base plate synthetic materials, the current market of synthetic stone has domestic and imported, a variety of types, performance differences. Before choosing the material, you must know more about the customer's production process and parameters. Synthetic stone plate has high elasticity and impact resistance, and has good corrosion resistance. The low thermal conductivity of synthetic stone ensures even heat distribution on the PCB and maintains its intrinsic dimensions after a long period of use. Synthetic stone heat-resistant temperature is generally between 300-350 ° C, a short period of time can be as high as 385 ° C, has a very good ability to withstand high temperatures, to ensure that a long time without fading, often used to make high-temperature devices, the cost is higher.

2) bakelite

Bakelite has high mechanical strength, good insulation, and heat resistance, corrosion resistance, its synthesis process is simple, inexpensive, better overall performance, but poor machining performance.

3)Metal frame

Used to make wave soldering jig metal materials generally have titanium alloy and aluminum. Titanium alloy has good strength and toughness, fatigue strength and good resistance to crack expansion. The maximum working temperature of certain titanium alloys is 550 ℃, and the surface will form a dense oxide film at high temperatures and will not be further oxidized, which is more expensive. Aluminum plate has high strength and good toughness, its density is lighter than titanium alloy, and its machining performance is very good.

(4) Glass fiber plate

Glass fiber plate with good flatness, smooth surface, better mechanical properties and dielectric properties. At 150 ℃ still has good mechanical strength, can withstand 300 ℃ high temperature, and has good moisture resistance, suitable for application in high-performance electronic insulation requirements of the product. Its disadvantages are that delamination may occur after long-term use, it is not resistant to strong acids and alkalis, and it has a short life. Figure 1 gives an example of the various materials of the jig, in the process of selecting the wave soldering jig, according to the customer's product requirements, wave soldering temperature, flux corrosive, as well as the requirements of the components on the PCB, cost and other aspects of the comprehensive consideration of the jig material to be selected.

In general, the use of wave soldering fixtures can avoid contamination of gold fingers or contact holes due to artificial contact, with the standardization of production line width and increase production efficiency to ensure the quality of PCB advantages, so we should choose the appropriate materials according to the actual needs of the wave soldering fixtures to be made!