MG Chemicals has recently released a new line of 1-Part Epoxy Adhesives and Potting Compounds for electronics manufacturing that overcome some of the challenges traditional 1-part formulations have faced as the demands of electronics manufacturers evolve. 1-part epoxy systems have long been mainstays of electronics manufacturing because of their ease of use and strong physical and chemical characteristics, but their high cure temperatures, frozen storage requirements, and limited shelf lives have started to become issues to more and more OEM’s.
Lower Cure Temperatures
As electronic components become thinner and smaller, high cure temperatures are becoming more of an issue. Cure temperatures in traditional 1-part systems can reach cure temperatures as high as 170°C. This was acceptable in many applications in the past, but in modern electronics, high cure temperatures are likely to cause component damage. Ultra-thin copper wafers will warp, and many heat-sensitive components will simply fail. Frozen, pre-mixed, two-part systems in the past have sometimes been tried as a solution to the high cure temperature issue, since they cure at much lower temperatures, but their weaker physical properties make them unsuitable for many applications. Now, however, new 1-part systems with lower cure temperatures are coming to the rescue. 1-part systems can now cure commonly at 100°C, and sometimes even as low as 70°C. This is allowing 1-part systems to continue to play an important role in electronics assembly.
Room Temperature Storage
Another major issue that has limited the use of 1-part systems in the past has been their onerous frozen storage requirements, but this too has now been overcome. Older 1-part systems must be stored at negative 40°C. Freezers that can maintain this low temperature are not inexpensive investments for smaller operations. As well, these products must be shipped in dry ice, which is very expensive for small or mid-size purchases, and a tedious obstacle to redistributing product to distributed manufacturing sites and subcontractors. New 1-part systems can be stored at room temperature for anywhere from nine months to two years, depending on the formula. This greatly reduces up front costs, operating costs, and allows these products to be available in small quantities for prototyping through distribution, since most distributors have been unwilling to deal with frozen storage or shipping requirements.
Unlimited Working Times
The removal of the frozen storage requirements for new 1-part epoxy systems also provides another bonus, which is unlimited working times. Traditional 1-part systems would typically have a working time of less than a day once they were removed from frozen storage. This would mean that any adhesive not used by the end of the day must be discarded. The cost of this waste can add up quickly over time, especially in the case of silver-filled conductive epoxies. As well, all filling lines and syringes would have to be thoroughly cleaned before they could be used again. With modern 1-part systems, an unfinished syringe may be put down at the end of a workday and then picked up at the start of the next one and continue to be used.
Because this new 1-part epoxy technology overcomes the three big issues of traditional formulations, onerous storage conditions, high cure temperatures, and limited working times, MG Chemicals is very optimistic about the impact on electronics assembly it will make in the years to come.