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AXICOM

TelecomSignalRF Relays

Electromechanical relays are one of the most robust and most reliable electronic components. In order
to achieve and guarantee the excellent performance of AXICOM relays, some precautions must be
taken during transportation, storage, handling and assembly and testing of the relays.
Following this guideline enables proper treatment of the relays during thecritical phase in the relay
life.

A. Transport

In transit, care has to be taken to avoid excessive shock and vibration. Mechanical stress can lead to
changes in operating characteristics or to internal damage of the relay (see vibration and shock
resistance). If mechanical stress is suspected, the relay should be checked and tested before use.
Whenever relays arrive in damaged boxes atcustomer sides, there is a potential risk of
transportation damage.

Fig. 1: Proper packing of relays for transportation

B. Packaging

Different packaging is used depending on the relay type and with regard to any specific requirements
during shipment or production. THT relays are packed in plastic tubes with stoppers on both sides of
the tubes.
Plugs on both sides shall be removed –especially after long storage time – in order to prevent firstly
sticking of the relay on the plug and then falling down to the pick place.

C. Handling

Modern relays are high precision components that are sensitive to mechanical stress and abusive
handling. Care must be taken when handling the relay during all stages of production. Especially care
must be taken, that relays are not dropped tothe floor. Dropped relays shall not be used anymore
and shall be scraped.
AppNote THT Relays.doc

page 1

3/9/2007

AXICOM

TelecomSignalRF Relays

D. Storage

Relays should be stored in a clean area within the specified temperature limits. Extreme humidity and
condensation can cause corrosion of the metal parts on the inside as well as the outside of the relay.
THT relays do notreach the same temperature level as SMT relays and are therefore not considered
to be moisture sensitive devices.
Increasing contact resistance over a time period, due to the formation of oxides and other layers, is to
be expected for most contact materials. This degradation is dependent on the ambient atmosphere
and is more rapid at high temperatures. Special care has to be taken if relaysare tested or used with
low contact loads after being stored for prolonged periods. Deterioration of contact resistance during
storage is reduced in the case of plastic or hermetically sealed relays.

E. Testing

During incoming inspection, special care has to be taken not to bend the relay terminals. Internal
failure (e.g. breaking of coil wires) or the degradation of sealing propertiescould be the consequence.

F. Automatic handling

The handling pressure or force of automatic feeders or robots has to be adjusted to avoid mechanical
damage such as cracking the relay case. The design of the relay should be such that when held by its
case or inserted into a socket, it does not become detached.
Due to the reduced size of modern Telecom and Signal Relays, they can be placed bypick and place
machines with a speed similar to passive PCB components. It is possible to use a mechanical as well
as vacuum picker.

G. Manual handling

When relays are manually placed on PCB’s, relays shall not dropped into a bin or on a hard table.
They shall directly be picked from the tube, in order to prevent bent terminals and excess mechanical
shock.
Relays which were dropped tothe floor or from a height of more than 250 mm are potentially
damaged. After long storage at high temperature it might happen that relays are picking on the plug
and are suddenly released. This might cause a major mechanical shock and might destroy the relay.

Do not pour relays from tube not orientated to a
hard table

Relays shall be placed carefully on a plate and
the plate should be...