How to clean Excelitas Infrared Emitting Diodes (IREDs)?

Infrared Emitting Diodes (IREDs) are solid state light sources emitting in the near infrared part of the spectrum. The emission wavelength is closely matched to the response peak of silicon photodiodes and phototransistors. This product line provides a broad range of lens and power output options. Both top and side radiating cases are available as well as a wide range of emission beam profiles. These IREDs may be operated in either CW or pulsed operating modes.

IREDs with wavelengths 770 nm, 870 nm 880 nm, 940 nm, and 950 nm are offered for applications like smoke detection, encoders, transmissive and reflective optoswitches.

Recommended Cleaning Agents

Excelitas offers many devices in a number of package styles which employ a wide range of construction techniques. Package styles include:

1. hermetically sealed glass/metal packages
2. cast and molded leadframe packages
3. ceramic or metal headers covered with a layer of clear epoxy (blob-top construction).

Some packages are more resistant to attack by chemical cleaning than others. Blob-top construction is the least resistant. Cast or molded leadframe packages offer better resistance. Of course, the glass/metal hermetic packages are the most chemically resistant of all.

In many cases the devices will be exposed to a post solder cleaning operation which uses one or more solvents to remove the residual solder flux and ionic contaminants. Only certain cleaning solvents are compatible with the plastics typically used in optoelectronic device packages.

This listing of recommended/not-recommended solvents represents only a very small percentage of available chemical cleaning agents. Even with this list of recommended solvents it is important to be aware that:

1. Solvent exposure times should be as short as
2. The exact requirement of the cleaning process will vary from customer to customer and application to
3. Additives and concentrations will vary from supplier to

Because of these uncertainties, our recommendation is that all customers carefully evaluate their own cleaning process and draw their own conclusions about the effectiveness and reliability of the process. Excelitas cannot assume any responsibility for damage caused by the use of any of the solvents above or any other solvents used in a cleaning process.

Article based on Application Notes from Excelitas Technologies  Photometric and Radiometric Terms application note