New Process Describes Solder- and PCB-Free Assembly
Published: 31 July 2007
by Staff
What’s more, says the inventor, the end-product is expected to be more reliable than previous solder-free strategies (e.g., using conductive adhesive as a solder substitute) or traditionally manufactured soldered assemblies.
The name Occam comes from the 14th century philosopher William of Occam, whose words “It is vanity to do with more that which can be done with less”) inspired the concepts, says Joseph Fjelstad, the inventor and founder of Verdant Electronics.
In a white paper released by Verdant today, Fjelstad, a prolific inventor with more than 100 patents to his name, describes a method for interconnecting components by means of copper plating after they are assembled into their final positions in an encapsulated module. Conventional circuit boards, he says, are thus not required. Prototype assemblies using this new technology are currently being characterized, Fjelstad says.
The process has demonstrated the conceptual potential for the manufacture of high-density, high-performance, high-reliability and environmentally (i.e., RoHS) compliant products ranging from consumer to military and aerospace applications. Inherent in the concept is elimination of high-temperature exposure, tin whisker risk, and vulnerability to mechanical shock and thermal cycle fatigue failure. Other anticipated benefits include simplified design (tightened geometries for higher-density form factors), fewer processes (including elimination of all solder processing and associated issues), and diminished material costs and supply infrastructure.
As described in the white paper, the technology addresses three challenges to producing electronics assemblies:
1. The regulatory imperatives (e.g., RoHS) to produce lead-free electronics requires subjecting them to very high temperatures associated with lead-free solder, and involves reliability risks associated with the extensive use of tin plating as a termination finish.
2. The relentless drive to reduce size and cost results in increasing challenges for reliable component placement and attachment.
3. Global sourcing, and supply-chain expansion means more-distant PWB suppliers, reducing the resources and support for domestic technology development.
