SIST EN 61249-7-1:2001

Overview

SIST EN 61249-7-1:2001 is a European standard developed by the CLC that specifies requirements for copper-clad Invar materials used in interconnection structures. This standard provides a sectional specification set focused on restraining core materials, specifically copper/Invar/copper laminates. The materials covered by this standard are supplied in nominal thicknesses ranging from 0.1 mm to 2.4 mm, available either in rolls or sheet forms.

The copper/Invar/copper composite materials defined in SIST EN 61249-7-1:2001 are critical components in the manufacture of printed circuit boards (PCBs) and interconnection assemblies. The unique properties of these core materials contribute to improved dimensional stability and thermal expansion control in multilayer electronic substrates.

Key Topics

• Material Composition: Copper/Invar/copper laminates combining the electrical conductivity of copper with the low thermal expansion coefficient of Invar.
• Thickness Range: Nominal thicknesses from 0.1 mm up to 2.4 mm catering to various design and manufacturing requirements.
• Formats: Materials supplied in either rolls or sheets to accommodate different fabrication processes.
• Restraining Core Properties: Designed to minimize distortion and warping during thermal cycling and manufacturing.
• Interconnection Applications: Emphasizes use in electronic interconnect structures where precise control over thermal expansion and mechanical stability are essential.
• Specification Details: Standards requirements include mechanical, dimensional, and material property tolerances to ensure consistent quality.

Applications

SIST EN 61249-7-1:2001 copper/Invar/copper materials are widely used in the electronics industry, particularly for:

• Multilayer Printed Circuit Boards (PCBs): Serving as core materials that balance electrical performance with mechanical stability.
• High-Density Interconnection (HDI) Substrates: Ensuring minimal thermal distortion in compact and complex PCB designs.
• Flexible and Rigid-Flex Boards: Providing stable core layers for flexible electronics needing durability under thermal stress.
• Telecommunications and Computing Hardware: Enhancing reliability in critical communication and processing devices by controlling coefficient of thermal expansion (CTE).
• Aerospace and Automotive Electronics: Supporting high-reliability applications requiring stringent thermal and mechanical specifications.

The use of copper/Invar/copper core materials compliant with this standard contributes to improved manufacturing yields, longer product lifespan, and enhanced performance in demanding operating environments.

Related Standards

Professionals working with SIST EN 61249-7-1:2001 should also consider related specifications and standards within the EN 61249 series and other material standards for interconnection structures:

• EN 61249-7 Series: Covers other sectional specifications for various restraining and core materials used in PCB fabrication.
• EN 61189 Series: Standards for test methods related to materials and laminated boards in electronics.
• IPC Standards: Provides complementary guidance on PCB design, fabrication, and material properties.
• ISO 9001: Quality management principles applied to manufacturers supplying copper/Invar/copper materials.
• RoHS and Environmental Compliance: Ensuring materials meet current regulations on restricted hazardous substances in electronics manufacturing.

Adhering to SIST EN 61249-7-1:2001 helps manufacturers and designers ensure compatibility and compliance with international quality norms in electronic interconnection structures.

Keywords: Copper/Invar/copper standard, SIST EN 61249-7-1:2001, interconnection materials, printed circuit board core, restraining core materials, copper-clad Invar, multilayer PCB materials, electronic substrate specification, thermal expansion control, CLC standards.