Henkel solder pastes GC – Temperature stability as a game changer

Solder paste, also known as solder paste, is a spreadable compound that is used for soldering surface-mounted components on printed circuit boards (PCBs). This is also referred to as SMD components, where SMD stands for “surface-mounted device”.

The SMDs do not have wire connections, but have direct contact with the PCB via corresponding connection surfaces.

This type of soldering is also known as reflow soldering in electronics production.

The solder paste mixture consists of solder metal powder and flux. The latter ensures better wetting of the parts to be soldered. Incidentally, the English term for solder paste is “solder paste”.

In 2015, Henkel presented “Loctite GC 10“, the world’s first temperature-stable solder paste. GC stands for Game Changer (best translated as turning point). Users from the industry also praise this new solder paste as a game changer, as unused “Loctite GC 10” paste dries out much more slowly than previous pastes.

According to the manufacturer, the solder paste “Loctite GC 10” remains stable in the closed can at a temperature of 26.5 °C for one year, so there is no loss of performance if it is stored at this temperature. The advantage of the long-lasting temperature stability at room temperature is that the costs of transportation and storage have been reduced, as refrigerated packaging, overnight deliveries by air freight and chilled storage in refrigerators at temperatures below 10 °C are no longer necessary.

At temperatures of up to 40 °C, the temperature stability still lasts for a month. Despite these exceptional stability properties, the print and reflow performance is unbeatable.

At up to 24 hours, the possible service life (pressure interruption time or abandonment time) of “Loctite GC 10” is also considerably longer than with conventional solder pastes, which have a service life of between one hour and four hours. The stencil life of the GC 10 solder paste is up to 72 hours.

In summary, the solder paste “Loctite GC 10” has the following properties and advantages in particular:

• Temperature stability at room temperature
• Energy cost savings, as storage at room temperature is possible
• No more short-term rotations required for storage
• Reduced transportation costs, as no refrigerated overnight deliveries by plane are necessary
• Reduction to 5 % waste quantity instead of 25 %, as more paste can be processed (also means cost reduction)

• No start-up time as no defrosting required
• Long service life (up to 24 hours)
• Long stencil life (up to 72 hours)
• halogen-free
• lead-free
• RoHS-compliant
• Soak temperature (reflow): 150 °C – 200 °C
• Evaporation performance (IPC-7095B): Class 3 (< 10 %)
• Slump performance (IPC-TM-650 2.4.35): 0.15 mm
• Low shrinkage
• Print distance: up to 0.3 mm

In addition to the GC 10 solder paste, there are other solder pastes in the GC line, including “Loctite GC 18“, which is also halogen-free and lead-free. The GC 18 paste was specially developed for bottom terminated components (BTCs – QFN, DPAK and LGA). Bottom Terminated Components are components where the electrical connections, which are led downwards, are covered by a housing. The GC 18 solder paste is characterized by its low void formation.

For small and large BTCs, the void formation is less than 25 %. The GC 18 solder paste also exhibits good resistance to graping in demanding reflow profiles. Other properties of Loctite GC 18 solder paste include the fact that it is compatible with approved encapsulation technologies.

One of the most important suppliers of solder pastes is Henkel. As there are different types of solder pastes, each with different properties, Henkel has developed a selection tool for solder pastes, the “SOLDER Paste Product Selector”, in order to find a suitable solder paste for the desired application. The solder paste selection tool “SOLDER Paste Product Selector” is a web application that can be accessed via an Internet browser. First, you can select the region in which you are located on a world map in this application.

You can then specify the desired solder paste in six steps by selecting the relevant options. If no standard product matches the individually selected criteria, you will be notified accordingly.

You can find more selection tools from Henkel (Selectors) in our overview article “Henkel Selectors: Simply find the right Henkel Electronic Material online“.