IC (IC)

IC stands for integrated circuit, a miniaturised electronic circuit fabricated by photolithography on a thin slice of semiconductor (almost always silicon). A modern IC packs anywhere from a few hundred transistors (a simple voltage regulator) to several billion (a smartphone application processor) onto a die typically 1-300 mm2 in area, then encapsulates the die inside a plastic or ceramic package with metallic leads or solder balls for board mounting.

Why ICs matter for precious-metal recovery: Inside every IC, the silicon die is electrically connected to the package leads by ultra-fine gold wire bonds — typically 18-25 micrometre diameter, with several hundred wires per high-pin-count chip. These gold wires are the single richest concentration of precious metals in the e-waste stream. Stripped wire-bond gold can reach 5,000-15,000 grams per tonne of pure IC scrap — roughly 1,000-2,000 times the gold concentration of the richest mineable ore. Add the gold-plated leadframes, palladium-bearing solder balls in BGA packages, and silver-loaded die-attach paste, and a single tonne of clean IC scrap yields Rs 20-40 lakh INR in recoverable precious-metal value at recent prices.

Segregation in the recycling line: Mature e-waste plants depopulate (mechanically remove) ICs from motherboards using infrared or hot-air depopulation tables before bulk shredding. This concentrates the precious-metal-rich fraction into a few percent of input weight by mass while leaving 95%+ as low-grade FR-4 fibreglass for separate handling. The IC fraction is then either sold to specialist precious-metal refiners at a premium of Rs 800-1,500 per kg over standard PCB scrap, or processed in-house via hydrometallurgical leaching using cyanide, thiourea, or chloride chemistries.

Trade-offs: Depopulation captures more precious-metal value per kg but requires 3-5 minutes of skilled labour per board and a Rs 5-10 lakh depopulation table investment. Plants without this step shred whole motherboards and recover at lower yield — roughly 80-85% of contained gold versus 95%+ with depopulation. The economic crossover for Indian recyclers typically occurs around 200 kg per day of clean motherboard feed.