PCBA Tech - Do you know the SMT detection method and precautions?

The patch processed by SMT is to be inspected, and the commonly used inspection methods are manual visual inspection and optical inspection. Only in this way can the quality of SMT processing be ensured. SMT processing must strictly abide by the operating rules, and the operating steps cannot be changed arbitrarily.

The patch processed by SMT is to be inspected, and the commonly used inspection methods are manual visual inspection and optical inspection. Only in this way can the quality of SMT processing be ensured. SMT processing must strictly abide by the operating rules, and the operating steps cannot be changed arbitrarily. Then let us take a look at the detection methods and precautions for SMT processing.

1. Detection method of SMT processing

1. Manual visual inspection method. This method requires little investment and does not require test program development, but it is slow and subjective, and needs to visually observe the tested area. Due to the lack of visual inspection, it is rarely used as the main welding quality inspection method on the current SMT processing production line, and most of it is used for repair and rework.

2. Optical detection method. With the reduction of PCBA chip component package size and the increase of circuit board chip density, SMA inspection becomes more and more difficult, and manual visual inspection becomes insufficient, and its stability and reliability are difficult to meet the requirements of production and quality control.

Therefore, the use of motion detection is becoming more and more important.

3. Use automatic optical inspection (AO1) as a tool to reduce defects, which can be used to find and eliminate errors in the early stage of the placement process to achieve good process control. AOI adopts a vision system, a new light-giving method, a high magnification and a complex processing method, which can obtain a high defect capture rate at a high test speed.

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2. Precautions for SMT processing

1. The SMT patch technician wears an OK electrostatic ring, and checks that the electronic components of each order are free of errors/mixing, damage, deformation, scratches, etc. before plug-in.

2. The plug-in board of the circuit board needs to prepare the electronic materials in advance, and pay attention to the correct polarity of the capacitor.

3. After the SMT printing operation is completed, check for defective products such as no missing insertion, reverse insertion, misalignment, etc., and flow the good tin finished products into the next process.

4. Please wear an electrostatic ring before assembling the SMT patch. The metal patch should be close to the skin of your wrist and be well grounded. Work with your hands alternately.

5. Metal components such as USB/IF socket/shielding cover/tuner/network port terminal must wear finger cots when plugging in.

6. The position and direction of the inserted components must be correct, and the components must be flat against the board surface, and the elevated components must be inserted at the K foot position.

7. If any material is found to be inconsistent with the specifications on the SOP and BOM, it must be reported to the shift/group leader in time.

8. The materials should be handled with care. Do not drop the PCB board that has passed the SMT pre-process and cause damage to the components. The crystal oscillator cannot be used if it is dropped.

9. Please tidy up and keep the work surface clean before going to get off work.

10. Strictly abide by the operating rules of the work area. Products in the first inspection area, to-be-inspected area, defective area, maintenance area, and low-material area are strictly prohibited to be placed at will.

The above is the detailed content of "SMT processing detection methods and precautions", if you have any questions, you can consult the SMT processing factory.