Welding of Reed Switches

Welding of reed switch leads to single-strand wire is a specialized process often necessary for high temperature applications or when custom lead lengths are required that standard configurations cannot accommodate. This procedure involves cropping the reed switches to the desired length and then welding them to the wire or single-strand cable.

Reed switch leads typically consist of a composition of approximately 50% nickel and 50% iron. Post-assembly, these leads are plated with gold or tin to enhance the quality of welding or soldering connections. Welding is generally preferred over soldering due to its ability to minimize heat transfer to the seal area. This is crucial because sudden heating during soldering or welding can cause mismatched expansions between the leads and the glass-to-metal seal, potentially leading to seal cracking or loosening.

During the welding of reed switch leads, precautions must be taken to prevent the development of cracks in the glass-to-metal seals. Additionally, it’s important to note that welding can induce magnetic fields sufficient to inadvertently actuate the reed switch, possibly causing unintended current flow through the contacts and resulting in welding of the contacts.

To mitigate these risks, it is recommended to weld one lead at a time rather than both simultaneously. This approach helps maintain control over the process and reduces the likelihood of unintended consequences such as premature seal failure or contact welding.

When requesting assemblies involving welded reed switches, adhering to specified tolerances is crucial to ensure consistency and reliability in the final product. Manufacturers and assemblers follow these guidelines to meet stringent quality standards and ensure that welded reed switch assemblies perform reliably in demanding applications across various industries. It is also recommended that the reed switch manufacturer accommodates these steps into the product process before shipping goods to the customer as 100% function tests can be carried out after modifications.