For quotations or further information please contact us at:

3 The Business Centre, Molly Millars Lane, Wokingham, Berkshire, RG41 2EY, UK

http://www.actcrystals.com

In line with our ongoing policy of product evolvement and improvement, the above specification may be subject to change without notice

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Tel :

0044 (0)118 979 1238

Fax :

0044 (0)118 979 1283

email :

info@actcrystals.com

Issue 6 M4E

Date 30-06-06

ACT200 TAPE AND REEL

SOLDERING of SMD WATCH CRYSTALS

Reflow oven should be set up to emulate or better the maximum reflow profile shown in the diagram below. Note it is just as

important to conform to the times given as well as the temperatures.

Pre-heat should not exceed 180°C ±5°C Maximum time 120s

Peak soldering temperature should not exceed 260°C.

Time at peak temperature should not exceed 10 seconds.

Total reflow time above 120°C should not exceed 6 minutes.

WASH PROCESSES and SMD WATCH CRYSTALS

In order to achieve the optimum performance of plastic packaged watch crystals the plastic normally used is a polymer plastic

which is porous.

With some wash processes (Involving total immersion of the unit) the moisture ingress causes an impedance across the internal

crystal unit connections to stop it oscillating. In time (shortened by a drying process) the crystal will recover to its original

characteristics. The performance with regard to damp heat (humidity) is not effected by the use of this plastic.

Devices using an epoxy plastic are an option to overcome this problem should it cause any inconvenience. But this type of

package is increasingly becoming more difficult to obtain due to environmental problems with the use of epoxy plastics.

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