Difference between solid crystal solder pasteand normal solder paste

There are significant differences between solid crystal solder paste and regular solder paste in several ways.The following is a detailed comparison of the two:

1. Composition and particle size

Solid crystal solder paste:

Tin powder selection: solid crystal solder paste usually choose No. 6 powder, No. 7 powder or even No. 8 powder, these powder particles are very small.

Alloy composition:

solid crystal solder paste is mainly tin silver copper and other metal alloys as a substrate, high thermal conductivity, to meet environmental requirements (such as RoHS and halogen-free, etc.).

Ordinary solder paste:

Tin Powder Selection: Ordinary SMT solder paste generally uses No. 3, No. 4 powder or No. 5 powder, with relatively large particles.

Alloy composition: The alloy composition and application range of ordinary solder paste is wide, may contain a variety of metal elements.

2.  packaging and storage

Solid crystal solder paste:

Packaging: solid crystal solder paste is usually packaged in syringes, single-use quantity is easy to control, mostly 10g or 30g.

Storage requirements: due to small particles, easy to oxidise, solid crystal solder paste storage has certain technical barriers, need to be refrigerated in the environment of 5 ~ 10 ℃, and avoid contact with the skin.

Ordinary solder paste:

Packaging: Ordinary SMT solder paste is usually packed in jars, with a large amount of material per feeding, suitable for mass use.

Storage Requirements: Ordinary solder paste also needs to be kept refrigerated, but the storage conditions may be more relaxed compared to solid crystal solder paste.

Usage and process

Solid crystal solder paste:

Main uses: solid crystal solder paste is mainly used for pasting, connecting circuits to form a pathway, especially in the LED chip package and diodes and other power devices package is widely used.It can replace the silver welding high-power LED flip chip.

Process: solid crystal solder paste using needle transfer, dispensing, spray printing and other solid crystal process for welding, reflow mode requires nitrogen atmosphere for protection.

Ordinary solder paste:

The main purpose: ordinary solder paste is more widely used, can be used for a variety of electronic components welding.

Process mode: most of the ordinary solder paste using stencil printing process for welding, reflow mode does not require nitrogen protection.

Fourth, the performance requirements

Solid crystal solder paste:

As the components are nanoscale, solid crystal solder paste has high requirements for viscosity, viscosity, fluidity, oxidation resistance, slump resistance, wettability and so on.

Mostly choose high temperature solder paste to ensure the stability of the solder joints during the second reflow.

Ordinary solder paste:

Ordinary SMT solder paste has lower requirements for solder beads, wettability, voids and so on.

There are low-temperature, medium-temperature and high-temperature options to meet different soldering needs.

In summary

there are significant differences between solid crystal solder paste and ordinary solder paste in terms of composition and particle size, packaging and storage, use and process, and performance requirements.When choosing to use, you need to choose according to the specific application scenarios and soldering requirements.