What standards should the solder dots meet during the production and soldering process of lead-free tin wire?

Lead-free solder wireIts birth and rapid development are mainly due to a mandatory standard issued by the European Union.RoHSStandards, generally in the production process, if one wants to meet the standards, what requirements are needed and do they change? The following is an explanation from JJY solder Paste Manufacturer:

(1The tin dots form an inner arc shape;

(2The tin dots should be full, smooth, free of pinholes and rosin stains.

(3There should be moldings, and the length of the moldings should be1-1.2mmBetween;

(4The shape of the part feet shows that the fluidity of tin is good.

(5Tin surrounds the entire upper tin position and the foot of the part.

2. Solder joints are considered non-standard solder joints when the following situations occur:

(1False soldering: It seems to be soldered but actually doesn't. The main reasons are dirt on the solder pads and pins or insufficient flux and heating time.

(2Short circuit: Some foot parts are connected between feet by excess solder, causing a short circuit. Another phenomenon is that the feet come into contact with each other due to improper operation by the inspector using tweezers, bamboo sticks, etc., resulting in a short circuit. It also includes a short circuit between feet caused by residual tin slag.

(3Offset: Due to inaccurate positioning of the device before soldering or errors during soldering, the pins are not within the specified pad area.