Seam sealing, or seam welding, is a variation of resistance spot welding most often used to join the lids to the cans of electronic packages. The process uses two motor-driven electrode wheels positioned on opposite sides of the package and rolled along the perimeter, conducting current through both components to create the seal.
Hermetic seam sealing completely seals the package into an airtight metal or ceramic housing using one of two processes: parallel gap resistance seam welding or opposed electrode projection resistance welding. It’s key to manufacturing sensitive microelectronic devices used in industrial and commercial communications, transportation, military and aerospace industries, which often include optical sensors, pressure sensors, communications devices, thermal and laser imaging and power amplifiers.
Hermetically sealing these packages prevents degradation of the electronic components inside and extends lifetime usefulness by protecting these highly sensitive components from contaminants such as air and moisture. Implantable medical devices, like pacemakers and defibrillators, also require hermetic sealing to protect both the device and the patient.
Two Types of Microelectronic Packages
There are two primary types of packages: metallic tub and ceramic (Figure 1).
The preferred material for metallic tub base packages is Kovar, which has a similar coefficient of thermal expansion (CTE) as glass. The material prevents the metal-to-glass seals of the package’s feedthrough connectors from leaking due to material expansion from heat generated during the welding process.
Ceramic packages are made of a ceramic substrate with a brazed metal seal ring. Kovar is also used in ceramic packages; the Kovar is brazed onto the ceramic base as a seal ring to which the lid is welded.
Parallel Gap Resistance Seam Welding
Parallel gap seam welding is one of two ways to execute a hermetic seal. A seam welder with rolling wheel electrodes is connected to a power supply that delivers electric current across the electrodes through the lid and the package. The seam welder delivers multiple overlapping weld spots, thus creating a continuous weld (Figures 2 and 3).
Seam sealing, or seam welding, is a variation of resistance spot welding most often used to join the lids to the cans of electronic packages. The process uses two motor-driven electrode wheels positioned on opposite sides of the package and rolled along the perimeter, conducting current through both components to create the seal.
Hermetic seam sealing completely seals the package into an airtight metal or ceramic housing using one of two processes: parallel gap resistance seam welding or opposed electrode projection resistance welding. It’s key to manufacturing sensitive microelectronic devices used in industrial and commercial communications, transportation, military and aerospace industries, which often include optical sensors, pressure sensors, communications devices, thermal and laser imaging and power amplifiers.
Hermetically sealing these packages prevents degradation of the electronic components inside and extends lifetime usefulness by protecting these highly sensitive components from contaminants such as air and moisture. Implantable medical devices, like pacemakers and defibrillators, also require hermetic sealing to protect both the device and the patient.
Two Types of Microelectronic Packages
There are two primary types of packages: metallic tub and ceramic (Figure 1).
The preferred material for metallic tub base packages is Kovar, which has a similar coefficient of thermal expansion (CTE) as glass. The material prevents the metal-to-glass seals of the package’s feedthrough connectors from leaking due to material expansion from heat generated during the welding process.
Ceramic packages are made of a ceramic substrate with a brazed metal seal ring. Kovar is also used in ceramic packages; the Kovar is brazed onto the ceramic base as a seal ring to which the lid is welded.
Parallel Gap Resistance Seam Welding
Parallel gap seam welding is one of two ways to execute a hermetic seal. A seam welder with rolling wheel electrodes is connected to a power supply that delivers electric current across the electrodes through the lid and the package. The seam welder delivers multiple overlapping weld spots, thus creating a continuous weld (Figures 2 and 3).
Read more: Hermetic Seam Sealing Enables Reliable Welds and Protects Electronic Devices from Harsh Environments