What must be observed when processing electromechanical relays?

• Do not touch the connectors with your bare fingers. This can lower their solderability, especially if the soldering process takes place much later.

• Observe the hole pattern and hole diameters and avoid bending the connector pins: among other detrimental effects, strong mechanical tension can worsen the adjustment values of the contact springs.
• Avoid extreme shock loads, for example by dropping them. Even from a height of 0.5m and a hard impact, shock accelerations of several hundred g occur, which can equal 300 times the acceleration due to gravity. This then leads not only to bending of the connector pins, but also to permanent damage to the relay, e.g. the breaking of plastic parts or a reduction in contact force.

• Use a small amount of flux for soldering. The flux can only be allowed to overflow the top of the circuit board when using washtight relays.

• Ensure that the soldering temperature and soldering time match the datasheet. The usual thresholds are max. 270°C and max. 5s.
• Take care not to exceed a maximum temperature of 120°C on the upper side of the circuit board when preheating. This is a default for standard wave soldering processes.

• Check the compatibility of the cleaning fluid and the washing process.

• The cleaning of assembled PCBs in liquid media may only be done with washtight relays. Please observe the corresponding specifications on the datasheet.
• Take care when using ultrasonic cleaners on assembled circuit boards:
Here, cold welding of gold-plated break contacts, i.e. "sticking" of the gold layer due to strong friction processes, cannot be ruled out.
• Ultrasonic cleaning is therefore not recommended for such relays.
• For relays that use other contact materials or with make contacts: check the relays under original cleaning conditions for possible negative effects.

• If the relay is coated with, for example, lacquer or a sealing compound, Zettler electronics recommends that you contact them in advance to clarify how to properly process them.

• The use of any silicone near the relays is to be avoided.
• Assembled PCBs may only be painted if washtight relays have been processed.

Zettler electronics is certified according to DIN EN ISO 9001:2015 and offers:

• an in-house technical department with experienced engineers and product-specific measuring equipment
• expert advice on choosing components
• customised test series
• new and further development, also in compliance with special European standards or to customer specifications

Schukat electronic offers a wide range of electromechanical relays from Zettler electronics. Our customers also receive support and advice on customer-specific questions from our technical sales team.