Basic knowledge of solder paste technology

- Aug 09, 2019-

1. Refrigeration, preservation and precautions

   A. Do not freeze, store a dry environment below 10 ° C, solder paste should be refrigerated at 5-10 ° C to extend the shelf life.

   B. Before use, remove the solder paste from the refrigerator for at least 2-4 hours at room temperature. This is to restore the solder paste to the working temperature, and also to condense the water-repellent portion on the surface of the solder paste.

   C. The printed circuit board is reflowed as soon as possible after printing.

   D. Do not touch the skin as much as possible. For contact, wash with isopropyl alcohol and avoid direct inhalation of volatile gases.

2. Solder paste mixing

   A. In order to completely temperature the solder paste, stir it well for about 1-4 minutes after warming up.

   B. To maintain the canned solder paste characteristics to a large extent, the unused solder paste must be sealed at all times.


3. The use of the environment

   The solder paste* is preferably used at a temperature of 20 to 24 ° C and a humidity of 65% or less.


4. Printing


    Angle: 60 degrees is the standard.

   Hardness: When the pitch is less than 0.1mm, the blade angle is 45 degrees. It is ideal to use a rubber scraper with a hardness of 80 to 100 degrees Shore and a stainless steel scraper*.

    Leave contact distance: 0mm

   Printing pressure: The set value is based on the length and speed of the scraper. The scraper should be scraped after the scraper is scraped. The pressure is usually 200gm/cm2.

    Printing speed: according to the structure of the board, the thickness of the steel plate and the printing ability of the printing machine.

    Stencil material: stainless steel, brass or nickel plated.

5. Quality inspection report

   According to the customer's request, we will provide inspection reports for each batch of solder paste. The contents of the report are as follows:

   a) Solder paste type b) Solder paste lot number c) Alloy

   d) Flux composition (Wt%) e) Solder paste viscosity f) Tin bead test


6. packaging method

   The standard package is 500g in a can, 5kg per carton.


7. The label

  a) solder paste type b) alloy c) batch number

  d) Particle size (mesh) e) Competition weight f) Production batch number g) Shelf life


8. The shelf life

   We recommend refrigerating at 5~10 °C. This spare part will have a life of six months (from the date of production) and a shelf life of three months at 20 °C.