I am not talking about the diode part of the LED, which is different depending on the color, what I am asking, is what is the material used in the conducting pins and the insulating cover? I am assuming the cover is some sort of plastic, and the pins are some sort of metal, but does anyone know the specific material these are made from? I have searched data sheets, but can only find the elements that make up the diode inside.

5mm LED

  • \$\begingroup\$ Look for the RoHS declaration forms for some representative parts. They should give a breakdown of all the materials in the product, not just the chip itself. \$\endgroup\$
    – The Photon
    Jul 29, 2016 at 2:24
  • \$\begingroup\$ This is a high-efficiency LED. The center is a gold-lined bowl with a oreo-cookie shaped emitter in the center, which emits photons out the sides, which reflect off the gold 'mirror'. This intense beam of light hits the lens, which can change the color and controls focus. A really tight beam would have a theta of only 6 degrees. Dangerous to stare at without eye protection if light is at or close to full intensity, which takes only about 15mA, 20mA maximum. This is NOT an answer. Just pointing out the category of this LED. \$\endgroup\$
    – user105652
    Jul 29, 2016 at 2:42

1 Answer 1


Generally the plastic part is epoxy and the leadframe is mild steel with tin plating.

This is not a complete description- the exact composition of the resin will include additives, for example. The bonding wire might be gold or possibly some other metal. There's a small amount of adhesive to bond the die to the lead frame too. Maybe there is some mold release compound clinging to the outside of the plastic.

A reputable manufacturer should be able to tell you the package composition with reasonable precision.


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