General information

In third quarter of 2012, Cynel Unipress company started regular production of solder powders. They are the main component of solder pastes used by manufacturers of electronic components.

The quality of powders produced by Cynel Unipress meets the requirements for solder powders used for production of solder pastes (standard IPC J-STD-006B and J-STD-005). The powders are manufactured from the purest commercially available raw materials, using the latest available today technology, providing the highest quality and repeatability of parameters and properties of the product.

Currently we offer solder powders:

SAC305

(= S-Sn96Ag3Cu1 acc. to ISO 9453,Sn96.5Ag3Cu0.5 acc. to PN-EN 29453, Sn96.5Ag3.0Cu0.5
acc. to J-STD-006B
)

SAC387

(= S-Sn95Ag4Cu1 acc. to ISO 9453, Sn95.5Ag3.8Cu0.7 acc. to PN-EN 29453 i J-STD-006B)

types 3 and 4 according to IPC J-STD-005 standard.

In the first half of 2013 we will start regular production of solder powders S-Sn63Pb37
and S-Sn62Pb36Ag2 type 3 and 4 in accordance with IPC J-STD-005 standard.

Quality and particle size of powders

The shape of the powder particles should be as close to the spherical as possible. This shape provides minimum ratio of surface area of the particle to its volume, and therefore - minimizes the oxidation level of the particle. The roundness of the powder particles affects the viscosity of the paste, the speed of the soldering process, and reduces the risk of clogging of the screen while applying the paste. It also has an impact on the appearance of lack of paste, smearing the paste, which can result in solder bridging and solder balling. Solder paste manufactured of the proper quality powder has stable physical and rheological properties. This affects directly stability and cost-efficiency of the production process.

According to the standard J-STD-005, solder powders have been divided into six types, depending on the particles sizes. The higher the number indicating the type indicates the finer the powder (smaller particles sizes). The particle size of the powder is also defined by determining the mesh size of the sieve used for powder sorting.

Weight % structure of powder particles sizes - Types 1 - 3
Type No larger than Less than 1%
larger than
Minimum 80%
between
Maximum 10%
less than
1 160 μm 150 μm 150-75 μm 20 μm
2 80 μm 75 μm 75-45 μm 20 μm
3 50 μm 45 μm 45-25 μm 20 μm

Weight % structure of powder particles sizes - Types 4 - 6
Type No larger than Less than 1%
larger than
Minimum 90%
between
Maximum 10%
less than
4 40 μm 38 μm 38-20 μm 20 μm
5 30 μm 25 μm 25-15 μm 15 μm
6 20 μm 15 μm 15-5 μm 5 μm

Table of sizes: mesh / μm
mesh 200 325 400 500 625 800 1250 2500
μm 75 45 38 25 20 15 10 5

Types of powders - markings, ranges of particles sizes
Type Particle size Mesh size Oxygen content
2 75 - 45 μm -200 / +325 < 100 ppm
3 45 - 25 μm -325 / +500 < 100 ppm
4 38 - 20 μm -400 / +625 < 120 ppm
5 25 - 15 μm -500 / +800 < 200 ppm
6 20 - 10 μm -625 / +1250 < 200 ppm
7 10 - 1 μm -1250 < 220 ppm