Yes, the Stabilants have been used extensively in high humidity conditions with excellent performance. These applications range from Oceanographic and Sonar equipment, to their use on airborne connectors under tropical and/or engine-mounted equipment conditions. In addition, Stabilants are used extensively in computer an communications applications in tropical countries. All of these were done without special pre-treatment.
Whenever the Stabilants are used on connectors used in high-impedance circuit (typically circuits of 2 Megohms or higher), in an environment where the humidity was in excess of 98% relative humidity and/or in an environment where there was the possibility, because of thermal cycling under humid conditions, such that there could be moisture condensation on the surface of a circuit board.
This note applies to those applications where it is important to maintain high surface resistance (>'l Meg ohms/square), such as high impedance circuitry, or where there are very tight specifications on circuit board operations under conditions of high humidity.
When using Stabilant 22, Stabilant 22A or Stabilant 22E in very-high humidity conditions on applications such as card-edge connectors involving high-impedance circuitry, some precautions should be used to ensure that the material can work to best advantage Because Stabilants have a surface-active property (necessary to remove and hold corrosion by-products in suspension) they could also hold enough moisture such that under very high humidity conditions surface resistance's could drop to a resistance value as low as 2 x 1 0 ohms/square.
If this is unacceptable, pre-treatment of the circuit-board surface should be done in order to provide a hydrophobic (water repellent) surface between the contact and/or traces. This can be done by using one of the common fluorocarbon-oil base sprays (such as Scotchguard(TM)- 3M Corp.) to spray the critical area. Then buff of the material from the card-edge connector contacts and apply the Stabilant as usual.
The Stabilant will now be confined to the actual contact area, and the board surface will be sufficiently hydrophobic so as to maintain the required insulation resistance.
It is recommend that the Stabilants be applied only to the male portion of the connector.
An alternative treatment would be to apply the Stabilant material only to the actual metal contact, using only enough to coat the major portion of each contact.
Normally, the impedance of most circuitry encountered in TTL or even Cmos circuits is such that this specialized treatment will not be necessary. However, where electrometer or photo-multiplier or similar circuitry is encountered, or where very low leakage is a requirement (such as on Teflon insulated stay-alive batteries for computer memories) the extra time required to apply the hydrophobic fluorocarbon can substantially reduce any leakage under high humidity conditions.
Revision 2
Stabilants are a product of Dayton Wright research & development and are made in Canada
NATO Supply Code 38948
15 mL of S22A has NATO Part # 5999-21-900-6937
The Stabilants are patented in Canada - 1987; US Patent number 4696832. World-wide patents pending. Because the patents cover contacts treated with the material, a Point-of-sale License is granted with each sale of the material.
Stabilant, Stabilant 22, and product type variations thereof are Trade Marks of D.W. Electrochemicals Ltd.
© Copyright 1987, '88. '89, '90 - D.W. Electrochemicals Ltd. This note may be reproduced or copied, provided its content is not altered. The term "contact enhancer", © 1983 Wright Electroacoustics.
NOTICE: This Application Note is based on customer-supplied information, and D.W. Electrochemicals is publishing it for information purposes only. In the event of a conflict between the instructions supplied by the manufacturer of the equipment on which the Stabilant material was used, and the service procedure employed by our customer, we recommend that the manufacturer be contacted to make sure that warranties will not be voided by the procedures.
While to our knowledge the information is accurate, prospective users of the material should determine the suitability of the Stabilant materials for their application by running their own tests. Neither D.W. Electrochemicals Ltd., their distributors, or their dealers assume any responsibility or liability for damages to equipment and/or any consequent damages, howsoever caused, based on the use of this information.
Stabilant, Stabilant 22, and product type variations thereof are Trade Marks of D.W Electrochemicals Ltd.
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