Jake Heisler What Is an OSAT, and When Does a US One Make Sense? OSAT stands for Outsourced Semiconductor Assembly and Test. A fab makes die; an OSAT turns those die into packaged, tested parts you can put on a board. The model exists because assembly and test are ... Advanced Packaging Die Attach Sep 22, 2026
Jake Heisler What Is a Hermetic Package? Leak Rates, Materials, and When You Need One A hermetic package is a sealed cavity that keeps the outside atmosphere away from the die inside it, to a leak rate you can qualify and put on a drawing. The word sounds binary — sealed or not — but i... Advanced Packaging Hermetic Packaging Sep 21, 2026
Jake Heisler Eutectic Die Bonding: AuSn, AuSi, and What the Process Actually Requires Eutectic die bonding attaches a die to its substrate with a metallurgical joint — no polymer, no filler — formed by melting a eutectic alloy at a single, sharply defined temperature. A eutectic alloy ... Advanced Packaging Die Attach Sep 21, 2026
Jake Heisler Gold Wire Bonding: Why Au, Which Diameter, and When Aluminum Wins Gold wire bonding attaches a fine gold wire from a die pad to a package lead using a thermosonic ball bond — heat plus ultrasonic energy, with nothing melting. Gold gets used because it does not oxidi... Advanced Packaging Wire Bonding Sep 21, 2026
Jake Heisler Aluminum Wedge Bonding and Thermocompression: The Two Bonds That Aren't Thermosonic Three wire-bond regimes are in common use, and they differ in exactly one thing: what supplies the energy that welds the wire to the pad. Thermosonic — heat plus ultrasonic scrub — is the one most gol... Advanced Packaging Wire Bonding Sep 21, 2026
Jake Heisler Copper Pillar Flip Chip: When Standoff Has to Be Controlled A copper pillar bump — C2 — replaces the C4 solder ball with a plated copper post carrying a small solder cap. The post does not melt at reflow, so the gap between die and substrate is set by the heig... Advanced Packaging Flip Chip Sep 5, 2026
Jake Heisler Thermosonic Wire Bonding: What It Is, and Who Does It as a Service in the US Thermosonic wire bonding is a solid-state welding process that attaches a fine wire — almost always gold — to a bond pad using ultrasonic energy and heat together, with the part held at roughly 150 °C... Advanced Packaging Wire Bonding Aug 29, 2026
Jake Heisler GaN-on-SiC vs GaN-on-Si: What Changes for the Package Two dies can both be GaN and give you completely different packaging problems. The epi layer is the same material; what differs is the substrate it was grown on, and the substrate is what the package ... Advanced Packaging Die Attach Aug 13, 2026
Jake Heisler Flip Chip Underfill: Capillary vs No-Flow, and Why It Decides the Bump Underfill gets scheduled like a finishing operation — bump the wafer, attach the die, then fill the gap. But whether underfill can flow at all is decided by geometry that was frozen at the bump decisi... Advanced Packaging Flip Chip Aug 12, 2026
Jake Heisler Hermetic Seal Leak Testing: What MIL-STD-883 Method 1014 Actually Proves "Hermetic" sounds binary and is not. It is a statement about a leak rate — how fast gas crosses the seal — and a package either meets a specified rate or it does not. MIL-STD-883 Method 1014 is the st... Advanced Packaging Hermetic Packaging Aug 12, 2026
Jake Heisler Silver Sinter vs Solder Die Attach: When the Part Runs Hot Solder has a ceiling that is easy to miss on a datasheet. It is not about how well the joint conducts heat — it is that a solder joint's own melting point sets the temperature the finished part can su... Advanced Packaging Die Attach Aug 12, 2026
Jake Heisler Types of Wire Bonding: Ball, Wedge and Ribbon Wire bonding looks like one process with a few settings. It is really three processes that happen to share a machine, and the choice between them is usually made for you — by what metal is on the pad,... Advanced Packaging Wire Bonding Aug 12, 2026
