COPPER/INVAR/COPPER

Alloy Digest ◽  
2004 ◽  
Vol 53 (1) ◽  
Keyword(s):  
Composite Material ◽  
Thermal Expansion ◽  
Printed Circuit Boards ◽  
Heat Treating ◽  
Heat Sinks ◽  
Circuit Boards ◽  
Annealed Condition ◽  
Roll Bonding ◽  
Printed Circuit ◽  
Metallic Composite Material

Abstract Copper/Invar/Copper is a wrought metallic composite material used in printed circuit boards, power planes, metal cores, hybrid enclosures, heat sinks, and other applications where coefficients of thermal expansion (CTE) match or where constraint of thermal expansion is required or beneficial. The laminated Cu/Invar/Cu composite material is metallurgically bonded by roll bonding and normally used in the fully annealed condition. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: FE-125. Producer or source: Engineered Materials Solutions Inc.

Mounting Leadless Chip Carriers onto Printed Circuit Boards

1982 ◽  
Vol 1 (1) ◽  
pp. 38-43 ◽  
Author(s):  
D. Fishman ◽  
N. Cooper
Keyword(s):  
Thermal Expansion ◽  
Thermal Cycling ◽  
Printed Circuit Boards ◽  
Coefficient Of Thermal Expansion ◽  
Cycling Performance ◽  
Circuit Board ◽  
Circuit Boards ◽  
Acceptable Solution ◽  
Printed Circuit ◽  
Chip Carrier

It is reasoned that wide penetration of chip carriers into equipment for professional and commercial applications depends on developing methods for mounting the leadless types directly on to conventional polymer type printed circuit boards. The main problem to be overcome is fatigue failure of the solder joints due to the mismatch in thermal expansion, evidenced by poor thermal cycling performance. In this paper the thermal cycling performance is compared when four sizes of ceramic leadless chip carrier are mounted on a selection of printed circuit board materials ranging from the conventional to those specially formulated, either on the basis of matching the coefficient of thermal expansion of the chip carrier material, or to provide a layer of compliant elastomer material underneath the layer bearing the copper contact layer, so that strain due to thermal expansion mismatch is not transmitted to the solder layer. Over 400 thermal cycles (−55 to + 125°C) were recorded using proprietary versions of elastomer coated substrates. For appropriate applications the basis is thus laid for an economic and technically acceptable solution. The practical implications of two methods of soldering—wave (jet) and vapour phase—are also discussed.

scholarly journals Thioetherimide-Modified Cyanate Ester Resin with Better Molding Performance for Glass Fiber Reinforced Composites

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1458 ◽  
Author(s):  
Pengchang Ma ◽  
Chuntao Dai ◽  
Shaohua Jiang
Keyword(s):  
Thermal Expansion ◽  
Glass Fiber ◽  
Printed Circuit Boards ◽  
Cyanate Ester ◽  
Reinforced Composites ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Glass Fiber Reinforced ◽  
Dimension Stability ◽  
Processing Properties

Cyanate ester (CE) resins with higher heat resistance, lower coefficients of thermal expansion (CTEs), and lower water absorption ratios are highly desired in printed circuit boards (PCBs). In this work, a CE was modified by copolymerization with a long-chain thioether bismaleimide (SBMI) to form a thioetherimide-modified CE (SBT). The results indicated that SBT had a wider processing window and better processing properties than a common bismaleimide-modified CE resin (MBMI). After molding with a glass fiber cloth, the composites (GSBT) exhibited moisture adsorption in the range of 1.4%–2.0%, high tensile strength in the range of 311–439 MPa, good mechanical retention of 70%–85% even at 200 °C, and good dimension stability, with coefficients of thermal expansion in the range of 17.3–18.6 (×10−6 m/°C). Such GSBT composites with superior properties would be good candidates for PCB applications.

scholarly journals Materials Selection and Processing Techniques for Small Spacecraft Solar Cell Arrays

2011 ◽  
Vol 2011 (1) ◽  
pp. 000789-000799
Author(s):  
N. Meetra Torabi ◽  
Janet K. Lumpp ◽  
James E. Lumpp
Keyword(s):  
Thermal Expansion ◽  
Solar Cells ◽  
Solar Cell ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Printed Circuit Boards ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Cell Arrays ◽  
Carbon Core

Body mounted germanium substrate solar cell arrays form the faces of many small satellite designs to provide the primary power source on orbit. High efficiency solar cells are made affordable for University scale satellite programs as triangular devices trimmed from wafer scale solar cells. The smaller cells allow the array designs to pack tightly around antenna mounts and payload instruments, giving the board design more flexibility. We are investigating the reliability of solar cells attached to FR-4 and carbon core laminate printed circuit boards. FR-4 circuit boards have significantly higher thermal expansion coefficients and lower thermal conductivities than germanium. This thermal expansion coefficient mismatch between the FR-4 board and the components used cause major concern for the power system when considering a failure of the solar cells, such as a series of cracked cells or faulty solder joints. These failures are most likely to happen with a longer orbital lifetime and longer exposure to the harsh environment the satellite will experience while in orbit. Carbon core laminates provide an advanced alternative because the core thickness can be selected to more closely match the device substrate, or at least provide a wider thermal expansion coefficient range to match the components on the board. We are also comparing various methods of attaching the solar cells to the printed circuit boards, using solder paste alone and in parallel with a silicone adhesive, considering the application of these adhesives by comparing the solder joints under x-ray when applied by screen printing versus stencil printing, and looking closely at the cleaning processes for array assembly. Storage, vacuum exposure, thermal cycling, functional and vibration testing will be used to compare the survivability and performance of the solar arrays.

Development of High Heat Dissipation and Low Thermal Expansion Printed Circuit Boards

2020 ◽  
Vol 2020 (0) ◽  
pp. 0042
Author(s):  
Yohei Ito ◽  
Kenjiro Takanishi ◽  
Tatsuya Sakamoto ◽  
Keisuke Fujiwara ◽  
Hitoshi Arai
Keyword(s):  
Thermal Expansion ◽  
Printed Circuit Boards ◽  
Heat Dissipation ◽  
High Heat ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Low Thermal Expansion

Space Dependence of Divided Ground Patterns on FM-Band Cross-Talk Characteristics between Two Parallel Signal Traces on Printed Circuit Boards for Vehicles

2012 ◽  
Vol 132 (12) ◽  
pp. 1897-1903 ◽  
Author(s):  
Michihira Iida ◽  
Tsuyoshi Maeno ◽  
Jianqing Wang ◽  
Osamu Fujiwara
Keyword(s):  
Cross Talk ◽  
Printed Circuit Boards ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Space Dependence
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