SMT solder paste printing machine operation process and precautions

Abstract: The masters who are engaged in the SMT chip processing industry are of course very familiar with the operation process of the automatic solder paste printing machine, but they are very at a loss for newcomers who are new to SMT. We should know that in SMT chip processing, the accuracy of solder paste printing plays a key role in the quality of SMT chip soldering. At present, SMT solder paste printing machines are mainly divided into semi-automatic printing machines and fully automatic printing machines. To ensure the accuracy of printing solder paste on the printing machine, the operator must clearly understand the operation process and precautions of the equipment. Today SZTech-SMT will introduce to you the operation process and precautions of the automatic printing machine.

SMT solder paste printing machine operation process

1. Before printing solder paste on the PCB board, confirm whether the opening of the stencil coincides with the corresponding PCB pad, to avoid missing printing and causing spattering of materials or empty soldering.

2. For the stencil that has been used or reused, confirm whether there is any tin slag and foreign matter left over from the previous batch of use at the opening. The newly opened steel mesh checks whether the opening wall is smooth.

3. According to the different process requirements of customers, confirm that the product uses the brand of solder paste.

4. Confirm that the solder paste has returned to temperature and stirred. The return time is 4 hours and the stirring time is 5 minutes. Fill in the number of uses on the surface label of the solder paste bottle.

5. Position the stencil and PCB on the corresponding position of the printing machine, adjust the equipment parameters until the opening of the stencil completely coincides with the PCB pad, save the program name must be the same as the name of the project issued file, to ensure that it is easy to find for the next use.

6. Take SZTech-SMT printing machine as an example: conventional scraper angle is 45-60 degrees, printing speed is 30-120mm/s, scraper pressure is 2.5-4.5kg/, peeling speed: 0.2-1.8mm/sec, set automatic cleaning Stencil frequency: 3-5PCS/time.

7. Check the PCB for deformation, damage, pad oxidation, etc. before loading the board, and wipe the surface dust with a dust-free cloth to ensure the quality of the patch soldering.

8. After the printing is completed, judge whether the printing is good through manual visual inspection or SPI (3D solder paste inspection instrument). If there are defective products such as printing less tin, short circuits, offset, missing printing, etc., clean the PCB in time. First, use a manual stirring scraper to scrape off the solder paste on the board, store it in a solder paste bottle with a red label, and then wash it with board washing water. Clean the solder paste remaining on the pad, and then blow it with an air gun until it is clean! After the process engineer confirms, put it into the oven again for secondary baking.

9. After the whole batch is produced, remove the steel mesh from the equipment, and blow off the residual solder paste in the holes of the steel mesh with an air gun. Place them on the steel mesh frame according to the number of the steel mesh, and handle them with care.

Precautions:

1. When there is no patch on the printed PCB board, the online storage time should not exceed 1 hour. When adding solder paste in the middle, the rolling amount of the scraper shall prevail, neither more nor less.

2. The safety door of the equipment cannot be opened when the printing machine is running, which may easily cause personal injury.

3. In the process of equipment maintenance, the power supply must be cut off first.

4. During the operation of the equipment, do not put other parts into the internal working surface of the equipment (such as a scraper, solder paste bottle, and dust-free cloth).

The above content is the operation process and precautions of the SMT printing machine shared by SZTech-SMT for you. I hope it will be helpful to you. To learn more about SMT chip processing, welcome to visit www.sztech-smt.com

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