Product category:
Electronics Manufacturing, Tools and Instruments
News Release from: Tecan | Subject: Pin-in-hole reflow
Edited by the Engineeringtalk Editorial
Team on 18 March 2002
Reflector shield protects during reflow
A novel thin-metal reflector shield now allows pin-in-hole reflow soldering of both SMD and traditional leaded components in a single operation.
Pin-in-hole reflow (PIHR), the technique of soldering both SMD and traditional leaded components in a single operation, has been confirmed as eminently feasible with the introduction of thin-metal reflector shields, which simply drop over temperature-sensitive components to protect them from thermal damage Pioneered by Weymouth based Tecan, the reflow reflector shield is custom built to fit over leaded components, such as connectors, crystal oscillators and switches, during the reflow process
This article was originally published on Engineeringtalk on 12 Mar 2001 at 8.00am (UK)
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Typically, these components are those which were not originally designed to cope with reflow oven temperatures.
Until now, they have presented problems for PCB producers because they have to be hand, or wave-soldered as a second operation, following the re-flow of SMD components.
The reflow reflector shield completely negates the need for two operations.
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In the reflow oven the shield reflects heat energy, thereby preventing damage to the component body, while simultaneously allowing conducted heat from the bottom of the PCB to reflow the solder paste effectively, ensuring a good joint every time.
The shields can allow a fully populated mixed-component PCB to be reflowed in a single operation, eliminating the need for costly and time-consuming secondary soldering of any kind.
The adoption of the shield saves time, improves quality, increases efficiency and boosts yields.
"The reflow reflector shield effectively ensures the feasibility of the pin-in-hole re-flow process", said Tecan divisional manager, Tony Weldon.
"With the advent of the shield, PCB producers have a real alternative to a two-process operation.
Manufacturers can now adopt an alternative technique with predictable success.
We have already produced shields for particularly challenging individual needs, such as precision crystal oscillators and electrolytic capacitors, even PCMIA headers with the combination of very-high pin counts, multirow format and close pitch.
All of which can now be processed in a single reflow operation with accurately defined paste volumes for optimum results, overall savings can be tremendous".
In addition to ensuring thermal protection, at present-day PIHR temperatures, typically 200 to 230C, the shields are also capable of efficient operation at even higher temperature, for example those required for lead-free reflow.
A typical reflow shield will reduce the temperature affecting the component it protects by 20 to 40C, depending on its design.
Holes in the sides and base of the shields optimise heat flow characteristics allowing fumes and contaminants to escape while thermal protection is maintained.
The shield can be hand located, or machine pick and placed.
The company offers a total PIHR service which incorporates all the aspects necessary to produce optimum results, from reflector shields to stencil design and provision.
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