We have adopted a numbering system to fully describe the devices that are available from its factory in Lutterworth. The additional code is printed on each device (subject to space availability) alongside the DATE CODE and rotated by 90 degrees.

Semelab RoHS Product Code descriptions

Following the JEDEC JESD 97 - but with additions, we apply the following two digit code to fully describe the ability of SEMELAB products to meet or exceed the RoHS requirements:-

The two digit code contains a letter (E, R or G) to indicate the level of compliance with the second digit being a number (1 to 9) to indicate the type of lead finish.

The first digit of the code describes the degree to which each product is Pb free and RoHS compliant:

  • The code "Ex" indicates that the termination material is Pb Free - but the device is not RoHS compliant.

  • The Code "Rx" indicates that the device is fully RoHS compliant but using an exemption as currently understood from the EU authorities.

  • The code "Gx" indicates that the device is fully RoHS complaint and is, in addition, completely "green" i.e. does not require the use of any of the exemptions mentioned above.


The second digit of the code indicates the termination finish as follows:

  • x1 - SnAgCu (not to be included in category e2)

  • x2 - Sn alloys with no Bi or Zn excluding SnAgCu

  • x3 - Sn

  • x4 - Precious metal (Ag, Au, NiPd, NiPdAu etc but excluding Sn)

  • x5 - contains Bi

  • x7 - low temperature solders (<150C) containing Indium (no Bi)


In practice, the Lutterworth site uses SnAgCu (category x1) for most of its wire ended devices, x3, Sn (matt tin) for plastic encapsulated discrete products and x4 - gold for ceramic surface mount devices along with several of the older small signal metal case parts. Termination finish could change to meet any customer's specific needs.

Devices qualified to DESC, BS, CECC specifications will continue to respect the build standard and termination finish as demanded by the version of DECS, BS, CECC specifications ordered. Pre-RoHS products - remain available on request.

Traditionally built hermetically sealed devices are maintained in production to satisfy the makers of High Reliability equipment (usually exempt from the RoHS regulations) where "no changes" are demanded usually on reliability and predictability grounds.