A Guide to the Operation of Solder Pastes

I. Storing solder pastes

A. The solder pastes should be kept under the temperature of 5-10℃ at the shelf life of 6 months (calculated from the date of manufacture).

B. Before operation, first take the solder pastes out of refrigerators and let them stay at a room temperature for at least 4 hours to enable the solder pastes to recover to the operating temperature and also to prevent moisture from surface condensation on solder pastes.

II. Solder paste mixing

A.In order for solder pastes to be completely mixed in a well distributed manner, after the return of temperature, please adequately mix the solder pastes.

B. The mechanical mixing usually last 1 to 3 minutes, while manual mixing usually lasts 3 to 6 minutes (The longer time the solder pastes are kept, the longer time the mixing requires).

III. Operating Environment

Optimal operating environment of solder pastes: temperature at 20~25℃, and humidity 35~60%。

IV. Printing

Cautions in the operation of solder pastes during printing:

A、 Add 1/3 solder pastes on a steel screen by supplementing enough solder pastes in a manner of a small amount in several times to maintain the quality of solder pastes.

B、 For the solder pastes that have not run out, do not place them together with those unused solder pastes. They should be put in other containers. After being unsealed, the solder pastes should be completely used under a room temperature within 24 hours.

C、 For the solder pastes that have not run out the same day, it is recommended that the unused solder pastes on the other day will be mixed with new solder pastes in the ratio of 1:2 for mixing and using, and they will be used in a manner of adding in a small amount in several times.

D、 After solder pastes are printed on substrates, it is recommended that components should be placed into the return solder pots within 4 to 6 hours.

E、 When wire exchange exceeds one hour or more, please scrape the solder pastes up from the steel screen and put it into the solder paste container for sealing.

F、 Try not to make it contact skin. In the case of any such contact, please use isopropanol for rinsing, and try to avoid inhalation of the volatile gases.s

V. Backflow

Example: Curve of SnAgCu Pb-free Solder Pastes

Activating time

Heating zone

Preheating zone

Time

Backflow zone

Cooling zone

※ For the curve of temperature of other products, please refer to the specifications of solder paste products.