Practical knowledge in smt pnp processing

In smt patch processing, there are some small knowledge that cannot be ignored.
This also belongs to the knowledge of smt patch processing, which is easily overlooked by people.
Next, the technicians of Qihe smt pick and place machine sorted out some knowledge about smt patch processing for us.

1. Generally speaking, the regular temperature of the SMT patch processing workshop is 25±3°C;
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2. When printing solder paste, the required materials and items are: solder paste, scraper, steel plate, wiping paper, cleaning agent, dust-free paper, mixing knife;
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3. The solder paste alloy composition is generally Sn/Pb alloy, and Sn accounts for 63%, Pb accounts for 37%;
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4. The main ingredients in solder paste are divided into two categories: tin powder and flux;
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5. The primary role of flux in soldering is to remove oxides, damage the surface tension of molten tin, and prevent re-oxidation.
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6. The volume ratio of flux and tin powder particles in solder paste is 1:1, and the weight ratio is about 9:1;
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7. The principle of taking solder paste is first in first out;
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8. When the solder paste is unpacked and used, it must go through two important processes: warming up and mixing;
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9. The common production methods of steel plates are: etching, laser, electroforming;
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10. The full name of SMT chip processing is Surface mount (or mounting) technology, which means surface adhesion (or mounting) technology in Chinese;
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11. ESD is the English abbreviation of “Electrostatic discharge”, which means “electrostatic discharge” in Chinese;
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12. When writing an SMT placement machine program, the program contains five types of data, namely: PCB data; Mark data; Feeder data; Nozzle data; Part data;
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13. The melting point of lead-free solder Sn/Ag/Cu (96.5/3.0/0.5) is 217°C;
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14. The relative temperature and humidity of the parts drying box should be less than 10%;
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15. Commonly used passive components (Passive Devices) include: resistors, capacitors, point senses (or diodes), etc.; active components (Active Devices) include: transistors, ICs, etc.;
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16. The common material of SMT stencil is stainless steel;
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17. The thickness of SMT steel mesh is 0.15mm;
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18. The types of electrostatic charge generation are different, conflict, induction, electrostatic conduction, etc.; the impact of electrostatic charge on the smt chip processing industry is: ESD failure, electrostatic pollution; the three principles of static electricity elimination are electrostatic neutralization, grounding, shielding .
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19. Inch standard 0603 means lengthwidth is 0.06inch0.03inch, metric standard 3216 means lengthwidth is 3.2mm1.6mm;
20. QHSMT is an enterprise specializing in the production of SMT equipment, like pick and place machine ，reflow oven，stencil printer ，welcome to send inquiry.

smt pick and place machine