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The manufacturing process of smt steel mesh is mainly to make plates with photographs, and then through the use of chemical corrosion processing, laser cutting processing or electroforming processing to open the plates of smt steel mesh. In the process of continuously manufacturing smt mounting stencils, it is found that the above three processing methods have their own advantages and disadvantages. The following will compare the advantages and disadvantages of these three smt stencil processing methods:
1. The chemical corrosion method is the earliest used smt steel mesh processing and opening method.
Advantages of the chemical corrosion method: chemical corrosion is used to process the smt steel mesh, without expensive equipment investment,
and the processing cost is relatively low.
Disadvantages of the chemical corrosion method: the corrosion time is too short, the hole wall of the smt steel mesh may have sharp corners, if the time is too long, the hole wall size may be enlarged, and the side corrosion also makes the smoothness of the hole wall not high.
2. The laser processing method is currently the most commonly used means of opening smt steel mesh. It relies on laser energy to melt the metal and then cut an opening in the sheet.
Advantages of laser processing method: the processing speed is much faster than the chemical corrosion method, and the opening size of the steel mesh is also easy to control, especially the added hole wall is tapered (taper about 2 degrees), which is easier to remove mold.
Disadvantages of the laser processing method: when the smt steel mesh has dense openings, the local high temperature generated by the laser sometimes deforms the adjacent hole walls, and the roughness of the metal exchange hole walls formed by melting is not high, so if necessary The hole wall needs to be trimmed. In addition, laser processing methods increase processing costs due to the need for dedicated equipment.
3. The electroforming method is a process that relies on the continuous accumulation and accumulation of metal materials (mainly nickel) to form a metal smt steel mesh.
Advantages of the electroforming method: The smt steel mesh produced by the method not only has high opening size accuracy and smooth hole walls, which is conducive to the quantitative distribution of printed solder paste, but also the opening is not easy to be blocked by the solder paste, thereby reducing the number of times of cleaning the smt steel mesh.
Disadvantages of electroforming: the cost of manufacturing smt steel mesh by electroforming is high and the production cycle is long.
Through continuous research and practice, it is found that smt steel mesh processed by chemical etching method or laser cutting method will have different degrees of opening clogging during printing. SMT patch proofing manufacturers need to clean smt steel mesh frequently, so electroforming The method has become the main processing method for solder paste printing smt stencils for fine-pin-pitch components.
