Reference
Era decoder
Pre-1985The best material there is.
| Solder | Leaded, bright and mirror-shiny |
| Packages | DIP, gold-lid ceramic, purple/gold ceramic CPUs, all through-hole |
| MLCC | Precious-metal electrode — Pd or Ag/Pd |
| Bond wire | Gold |
| Connectors | Edge fingers, DB25, DIN |
| Board | FR-2 phenolic or FR-4, 1–2 layers, curved hand-taped traces, minimal soldermask |
Pull ceramic ICs and connectors by hand. Thick gold plating, heavy pins, gold lids.
1985–1995Excellent — peak palladium MLCC era.
| Solder | Leaded, shiny |
| Packages | DIP plus PLCC; SMD passives start appearing on the solder side |
| MLCC | Pd / Ag-Pd |
| Bond wire | Gold |
| Connectors | ISA, VLB, DB9/DB25, DIN keyboard |
| Board | FR-4 1.6 mm, 2–4 layers, green mask, CAD-straight traces |
Thick gold fingers, ceramic CPUs, and the richest MLCCs you'll find.
1995–2005Very good — the sweet spot for a modern scrapper.
| Solder | Still leaded, shiny |
| Packages | QFP, BGA arrives, SMD-dominant |
| MLCC | Transitioning Pd → Ni, roughly 1999–2003 |
| Bond wire | Gold |
| Connectors | PCI, AGP, IDE, PS/2, USB-A |
| Board | 4–8 layers, green mask |
Gold bond wire throughout, MLCCs a coin-flip on palladium, leaded solder. AGP + IDE + PS/2 with no SATA is the signature to look for.
2005–2014Middling.
| Solder | Lead-free from 1 July 2006 — dull, grainy, frosty |
| Packages | BGA and QFN dominant |
| MLCC | Nickel — base metal electrode |
| Bond wire | Gold → copper transition, roughly 2010–2014 |
| Connectors | PCIe, SATA, USB-A, DDR2/DDR3 |
| Board | 6–12 layers, thinner |
Gold still in bond wire early in the window. No palladium in the MLCCs. Look for the Pb-free mark.
2014 and laterWorst per pound.
| Solder | Lead-free, dull |
| Packages | BGA, package-on-package, 0201 passives, few discretes |
| MLCC | Nickel |
| Bond wire | Copper or silver |
| Connectors | USB-C, M.2, DDR4, 5-character FCC grantee code |
| Board | Thin, HDI, microvias |
Bond wire is copper and the only gold is the ENIG surface. The value is whole-unit resale, not smelting.
Full guide to dating a board →
Board grading
HIGH GRADE $5–20/lb
- Many gold-plated connectors and gold fingers — multiple edges, DIN 41612 backplane connectors, dense pin fields
- Ceramic CPUs, gold-lid ICs and flat packs still on the board
- High IC density — many small chips packed close together
- Thick, rigid, multilayer — count laminate lines at a cut edge
- Metal (not plastic) CPU sockets, edge-plated grounds, gold-plated shields, conformal coating
- Examples: telecom line cards and backplanes, mainframe and server boards, industrial and medical controllers, Apple logic boards, HDD SATA boards, cell phone boards
MID GRADE $2–8/lb
- Standard desktop motherboards: coloured soldermask, one CPU socket, several gold-fingered expansion slots, moderate IC count
- Laptop mainboards and graphics cards trend toward the upper end of mid
- Mix of SMD and through-hole, 4–8 layers
LOW GRADE $0.20–0.60/lb
- Brown or tan phenolic / paper-composite substrate visible on at least one side — the single most reliable low-grade tell
- Thin and flimsy, single- or double-sided, feels like it would snap if bent
- Dominated by large electrolytics, transformers, heatsinks and big through-hole resistors, with few or no ICs
- No gold anywhere; tin-plated edges and headers
- Sources: TVs, DVD players, microwaves, power supplies, LED drivers, appliance and automotive boards
Discard the "hold it up to a light" transparency test — it does not grade boards. Plenty of low-grade boards are opaque. Use substrate colour, thickness, IC density and visible gold together.
Surface finishes
| Finish | Thickness | Appearance | Worth recovering? |
|---|---|---|---|
| Hard gold (fingers) | 15–50 µin Au over ~100 µin Ni | Bright, saturated brass-yellow. Confined to edge fingers and contact pads, never the whole board. Look for plating tie-bar stubs at the board edge. | The highest-value thing on the board. One square inch of double-sided 30 µin fingers is about 0.019 g = $2.48. Shear it off. |
| ENIG | 2–5 µin Au over 118–236 µin Ni | Flat, dull-to-satin pale greyish gold, uniform, no doming. Never bright brassy — it's semi-transparent over the nickel. | About 0.025 g Au per pound of board. Real, but see the warning below — stripping it is a losing trade. |
| ENEPIG | 1.2–2.8 µin Au, 2–12 µin Pd, over Ni | Visually almost identical to ENIG, sometimes marginally whiter. | Adds palladium — 12 µin over a square decimetre is about 0.059 g, roughly $2.43. Same nickel-undercut problem as ENIG. |
| Immersion silver | 4–12 µin Ag | Flat, bright white-silver when fresh. Tarnishes distinctively — iridescent purple and blue-brown creeping in from the pad edges, then grey to black. | Trivial by weight, but the tarnish pattern is a reliable finish ID. |
| HASL | Solder, deliberately uneven | Bright silver with domed, uneven pads and a visible meniscus. It looks like solder because it is solder. Lead-free HASL is the same shape but duller and greyer. | None. It's tin or tin-lead. |
| Immersion tin | 20–50 µin Sn | Flat, dull matte grey, slightly chalky. Goes grey and cloudy quickly. | None. |
| OSP | Organic film, not measurable | Bare copper colour — pink, salmon or orange, flat, sometimes faintly iridescent. Oxidises to dull brown. | None. If the pads look like plain corroded copper, that's OSP. |
Never strip ENIG. Here is the arithmetic.
- ENIG contributes roughly 0.025 g of gold per pound of board. To accumulate one troy ounce you'd have to process about 1,250 lb of board.
- The nickel underneath is 40–120× thicker than the gold. Immersion gold doesn't lift off — you have to dissolve or undercut the entire nickel layer to release it.
- That same 1,250 lb sold intact at even the low mid-grade rate of $3.25/lb is about $4,000 — roughly the value of the ounce you'd have extracted, except you also keep the copper, silver and palladium, and you buy no chemicals and handle no hazardous waste.
- The smelter pays you for it anyway. Assay-based settlement returns 98% of that gold. Stripping isn't additive — it substitutes for a payment you were already getting.
- Gold fingers are the opposite case: 10× the thickness, mechanically separable with a pair of shears, and 28× the price per pound. That's where the same effort belongs.
Removal temperatures
| Method | Temperature | Use for |
|---|---|---|
| Soldering iron + wick/pump | 350–400 °C tip | Through-hole parts, single components, gold pins |
| Hot air — small SMD | 300–350 °C, low airflow | MLCCs, tantalums, SOT, chip parts |
| Hot air — QFP / SOIC | 350–380 °C, medium airflow | Flat packs, QFPs, oscillators, ceramic ICs |
| Hot air — large BGA | 380–420 °C top + 150–200 °C bottom preheat | Northbridge, GPU, ASIC, gold-corner BGAs |
| Preheat plate / griddle | 240–280 °C (leaded 230–250, lead-free 250–280) | Bulk depopulation — scrape into a steel pan with a putty knife |
| Heat gun | 400–550 °C setting, kept moving, 2–4" standoff | Connectors, sockets, headers, bulk stripping |
| Shear / guillotine / snips | Cold | Gold fingers — cut 1–2 mm above the plating |
| Pliers + preheat | 250–280 °C board temp | ZIF sockets, through-hole connectors, ceramic DIPs |
| Torx driver / hand tools | Cold | HDD platters, head arms, magnets, magnetrons |
| Vice + side cutters | Cold | Cracking relay cases, snipping silver contacts |