Invar® 42
Invar 42 is a 42% nickel-iron controlled expansion alloy. It is specifically designed to have a coefficient of thermal expansion (CTE) that closely matches that of Silicon, 96% Alumina ceramics, and soft sealing glasses, making it critical for hermetic sealing in electronics.
- Formas comunes: Sheet, Strip, Wire, Rod.
- Característica clave: CTE matches Silicon and Ceramics (Alumina).
- Aplicación: Glass-to-Metal Sealing & Lead Frames.
- CTE: Constant rate of expansion up to 572°F (300°C).
While Invar 36 is designed for "zero" expansion, Invar 42 is designed for "matched" expansion. In semiconductor packaging, if the metal frame expands faster than the silicon chip inside it, the chip will crack. Invar 42 expands and contracts at the exact same rate as the chip, ensuring the integrity of the package during thermal cycling.
Glass-to-Metal Sealing
Forms a reliable, tight hermetic seal with hard and soft glasses, preventing gas leakage in light bulbs and vacuum tubes.
Semiconductor Packaging
The standard material for lead frames used in integrated circuits, matching the expansion of silicon chips and ceramic substrates.
Thermostat Bi-Metals
Used as the "passive" or low-expansion component in bi-metallic thermostat strips where higher temperatures (up to 300°C) are involved.
| Elemento | Contenido (%) |
|---|---|
| Níquel (Ni) | 41.0 - 42.5 |
| Hierro (Fe) | Saldo |
| Carbono (C) | 0.05 max |
| Manganeso (Mn) | 0.80 max |
| Silicio (Si) | 0.30 max |
*Note: The 42% Nickel content is tuned to shift the Curie point and expansion curve.
| Forma del producto | Standards (ASTM / AMS) |
|---|---|
| Chapa, hoja, tira | ASTM F30, AMS I-23011 (Class 5) |
| Barra, varilla, alambre | ASTM F29, ASTM F30 |
| Sealing Alloy | DIN 17745, SEW 385 |
| Temperatura | CTE (µm/m·°C) | Comparable Material |
|---|---|---|
| 30 - 300°C | 4.0 - 5.0 | Matches Silicon / Alumina (Ceramic) |
| 30 - 450°C | 6.0 - 7.0 | Matches 1075 Glass |
*Note: Expansion is consistent in the typical operating range of electronics.
Lead Frames
The metal skeleton inside chip packages that connects the microchip to the circuit board.
Ceramic Packages
Hermetic seals for high-reliability aerospace and military electronics.
Vacuum Tubes
Metal pins and feeds that must pass through glass walls without breaking the vacuum seal.
Automotive Lighting
Headlight filaments and sealed beam units requiring high-temperature glass sealing.
Need Invar 42 Strip or Wire?
We maintain stock of Invar 42 / Nilo 42 ideal for deep drawing, stamping, and photo-etching. Contact us for coil slit to your specific width.
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