The 4J29 Nickel-Cobalt-Iron Alloy Plate, commonly referred to as Kovar, is a specialized material engineered for semiconductor packaging, vacuum tubes, and high-reliability electronic components. Known for its controlled thermal expansion, excellent mechanical properties, and corrosion resistance, 4J29 is ideal for applications requiring dimensional stability across temperature variations.
At DLX Alloy, we produce premium 4J29 plates with consistent chemical composition, precise dimensions, and superior surface finish, ensuring reliable performance in critical semiconductor and vacuum applications where even minor expansion mismatches can compromise functionality.
4J29 is a nickel-iron-cobalt alloy, with typical composition of approximately 29% nickel, 17% cobalt, and 54% iron. This alloy is engineered to provide a coefficient of thermal expansion (CTE) that closely matches borosilicate glass and ceramics, making it ideal for hermetic sealing, vacuum tubes, and semiconductor assemblies.
Key material properties include:
Low and controlled thermal expansion to minimize stress in devices
High mechanical strength and ductility for structural integrity
Corrosion and oxidation resistance for long-term reliability
Stable electrical and magnetic properties
High machinability and processability for precision cutting, forming, and finishing
DLX Alloy employs vacuum induction melting, precision rolling, and controlled annealing to produce 4J29 plates with uniform microstructure, minimal residual stress, and high surface quality, essential for semiconductor and vacuum tube applications.
Alloy Composition Table
Alloy Grades | C | S | P | Mn | Si | Ni | Cr | Co | Mo | Cu | Al | Nb | Fe | Other Elements |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1J06 | 0.04 | 0.015 | 0.015 | ≤0.10 | ≤0.15 | - | - | - | - | - | 5.5-6.5 | - | Rest | - |
1J12 | 0.03 | 0.015 | 0.015 | ≤0.10 | ≤0.15 | - | - | - | - | - | 11.6-12.4 | - | Rest | - |
1J17 | 0.03 | 0.02 | 0.02 | ≤0.60 | ≤0.20 | - | 15.5-16.5 | - | - | - | - | - | Rest | - |
1J18 | 0.03 | 0.02 | 0.02 | 0.3-0.7 | ≤0.15 | 0.5-0.7 | 17-18.5 | - | - | - | - | - | Rest | Ti: 0.3-0.7 |
1J22 | 0.04 | 0.02 | 0.02 | ≤0.3 | ≤0.3 | ≤0.5 | - | 49-51 | - | ≤0.2 | - | - | Rest | V: 0.8-1.8 |
1J30 | 0.04 | 0.02 | 0.02 | ≤0.40 | ≤0.30 | 29.5-30.5 | - | - | - | - | - | - | Rest | - |
1J36 | 0.03 | 0.02 | 0.02 | ≤0.60 | ≤0.20 | 35.0-37.0 | - | - | - | - | - | - | Rest | - |
1J38 | 0.03 | 0.05 | 0.02 | 0.3-0.6 | 0.15-0.3 | 37.5-38.5 | 12.5-13.5 | - | - | - | - | - | Rest | - |
1J46 | 0.03 | 0.02 | 0.02 | 0.6-1.1 | 0.15-0.3 | 45.0-46.5 | - | - | - | ≤0.2 | - | - | Rest | - |
0.03 | 0.02 | 0.02 | 0.3-0.6 | 0.15-0.3 | 49-50.5 | - | - | - | ≤0.2 | - | - | Rest | - | |
1J51 | 0.03 | 0.02 | 0.02 | 0.3-0.6 | 0.15-0.3 | 49-50.5 | - | - | - | ≤0.2 | - | - | Rest | - |
1J54 | 0.03 | 0.02 | 0.02 | 0.3-0.6 | 1.1-1.4 | 49.5-51 | 3.8-4.2 | - | - | ≤0.2 | - | - | Rest | - |
1J76 | 0.03 | 0.02 | 0.02 | 0.3-0.6 | 0.15-0.3 | 75.0-76.5 | 1.8-2.2 | - | - | 4.8-5.2 | - | - | Rest | - |
1J77 | 0.03 | 0.02 | 0.02 | 0.3-0.6 | 0.15-0.3 | 75.5-78 | - | - | 3.9-4.5 | 4.8-6.0 | - | - | Rest | - |
1J79 | 0.03 | 0.02 | 0.02 | 0.6-1.10 | 0.3-0.5 | 78.5-80.0 | - | - | 3.8-4.1 | ≤0.2 | - | - | Rest | - |
1J80 | 0.03 | 0.02 | 0.02 | 0.6-1.10 | 1.1-1.5 | 79.0-81.5 | 2.6-3.0 | - | - | ≤0.2 | - | - | Rest | - |
1J85 | 0.03 | 0.02 | 0.02 | 0.3-0.60 | 0.15-0.3 | 79.0-81.0 | - | - | 4.8-5.2 | ≤0.2 | - | - | Rest | - |
1J87 | 0.03 | 0.02 | 0.02 | 0.3-0.6 | ≤0.3 | 78.5-80.5 | - | - | 1.6-2.2 | - | - | 6.5-7.5 | Rest | - |
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4J29 plates are widely used where thermal expansion matching and hermetic sealing are critical:
Semiconductor packaging: substrates and frames for high-reliability electronic devices
Vacuum tubes: glass-to-metal sealing components for tubes, lamps, and sensors
Glass-to-metal and ceramic sealing: hermetic enclosures and connectors
Optical devices: precision housings and frames for laser and imaging systems
Electronic instrumentation: aerospace, scientific, and high-precision devices
Relays, switches, and sensors requiring thermal expansion compatibility
DLX Alloy provides customizable plate thickness, dimensions, and surface finishes, ensuring seamless integration into complex assemblies for semiconductors, vacuum tubes, and high-precision electronics.
Industry Trends
The need for Kovar alloy plates is increasing in industries such as semiconductors, aerospace, optics, and precision electronics, driven by the demand for materials that maintain dimensional stability under thermal cycling.
Key industry trends impacting 4J29 usage include:
Miniaturization of semiconductor devices, requiring materials with exact CTE matching to prevent stress and failure
High-density electronic packaging, needing substrates that maintain integrity under temperature variations
Aerospace and vacuum devices, where thermal fluctuations demand materials with stable expansion
Optical and scientific instrumentation, requiring minimal thermal drift for precise measurements
DLX Alloy addresses these trends by producing 4J29 plates with tight chemical control, uniform microstructure, and precise dimensional tolerances, ensuring consistent performance in critical semiconductor and vacuum applications.
| Property / Alloy | 4J29 (Kovar) | 4J33 | 4J36 (Invar) | 4J42 |
|---|---|---|---|---|
| Nickel Content (%) | 29 | 33 | 36 | 42 |
| Cobalt Content (%) | 17 | 0 | 0 | 0 |
| CTE (20–100°C, ×10⁻⁶/°C) | 5.0 | 3.0 | 1.2 | 2.0 |
| Density (g/cm³) | 8.2 | 8.0 | 8.1 | 8.1 |
| Yield Strength (MPa) | 250–350 | 220–320 | 250–350 | 300–400 |
| Thermal Stability | Moderate | Good | Excellent | Very Good |
| Corrosion Resistance | Moderate | Good | Good | Good |
| Typical Applications | Semiconductor, vacuum tubes, hermetic sealing | Vacuum devices, sensors | Aerospace instruments, precision tools | Low-expansion frames, sealing |
| Processability | Moderate | Good | Excellent | Good |
The table highlights that 4J29 offers controlled expansion, mechanical strength, and corrosion resistance, making it suitable for hermetic sealing and semiconductor applications where precise thermal expansion is critical.
Why Choose DLX Alloy
DLX Alloy combines advanced metallurgical expertise with precision production technology to deliver superior 4J29 plates.
Advantages of DLX 4J29 plates include:
Vacuum induction melting for chemical homogeneity and minimal impurities
Precision rolling and controlled annealing to optimize microstructure and reduce internal stress
Strict dimensional control for seamless integration into semiconductor and vacuum assemblies
Custom surface finishes suitable for plating, coating, or hermetic sealing
Comprehensive testing including CTE, mechanical, and chemical analysis
These advantages ensure that DLX 4J29 plates are consistent, durable, and reliable, meeting the demands of high-precision semiconductor, optical, and vacuum tube applications.
DLX Production and Quality Assurance
DLX Alloy utilizes state-of-the-art production equipment and rigorous quality control processes:
Vacuum induction melting for chemical uniformity
Precision rolling and controlled annealing for uniform thickness and stress relief
Dimensional and surface inspections for flatness, thickness, and finish quality
CTE and mechanical property verification for every batch
DLX Alloy also offers customized 4J29 plates tailored to the specific needs of semiconductor, vacuum tube, and optical assemblies, ensuring reliable integration and performance.
Sustainability and Market Outlook
The market for Kovar alloy plates continues to expand due to growing semiconductor, optical, and aerospace industries, which require materials with stable dimensions under thermal cycling.
DLX Alloy implements sustainable production practices, including scrap recycling, waste reduction, and energy optimization during melting and rolling. With increasing high-reliability electronic and vacuum tube applications, DLX is positioned to supply high-quality, reliable 4J29 plates to global markets.
4J29 Nickel-Cobalt-Iron Alloy Plate is essential for semiconductor packaging, vacuum tubes, and high-reliability electronic assemblies, offering controlled thermal expansion, mechanical stability, and corrosion resistance. Its properties ensure dependable performance where thermal fluctuations could otherwise compromise device function.
DLX Alloy guarantees high-quality 4J29 plates with precise chemical composition, dimensional control, and thermal performance, supporting customers in semiconductor, optical, and aerospace industries worldwide.
About Us:
Our 12,000㎡ factory is equipped with complete capabilities for research, production, testing, and packaging. We strictly adhere to ISO 9001 standards in our production processes, with an annual output of 1,200 tons. This ensures that we meet both quantity and quality demands. Furthermore, all products undergo rigorous simulated environment testing including high temperature, high pressure, and corrosion tests before being dispatched, ensuring they meet customer specifications.
For all our clients, we offer timely and multilingual after-sales support and technical consulting, helping you resolve any issues swiftly and efficiently.
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FAQs:
1. What is the composition of 4J29?
Approximately 29% nickel, 17% cobalt, and 54% iron, optimized for thermal expansion compatibility with glass and ceramics.
2. What is the main benefit of 4J29 plates?
Controlled thermal expansion ensures dimensional stability and hermetic sealing in semiconductor and vacuum applications.
3. Which industries use 4J29 plates?
Semiconductors, vacuum tubes, optical devices, aerospace, and precision instrumentation.
4. How does 4J29 compare to 4J33?
4J29 includes cobalt for improved CTE matching with glass, while 4J33 provides lower expansion for general sealing.
5. Can DLX Alloy customize plate sizes and thickness?
Yes, DLX offers tailored dimensions, thicknesses, and surface finishes for specific assembly requirements.
6. Is 4J29 suitable for glass-to-metal sealing?
Yes, its CTE matches glass and ceramics, preventing stress or cracks during thermal cycling.
7. What heat treatment improves 4J29 properties?
Controlled annealing reduces internal stress and enhances thermal and mechanical stability.
8. Does DLX Alloy provide testing reports?
Yes, each batch comes with CTE, mechanical, and chemical analysis documentation.
