Stabilant 22 Contact Enhancer Application Notes from R.A.L. Audio
R.A.L. Audio Services
    Shop by Brand (click here) What Goes In... Comes Out!
What Goes In... Comes Out!
 Reset 
 
Search for Stabilant products. Advanced Search

Call us Toll Free at 866-455-3997

 Home  Recording  Rental  Modifications  Installation  Leasing  Policies  Contact  About  Login  

Stabilant 22 Contact Enhancer Application Notes

App. Note 21 - Gold Plate to Solder Alloy

Are there potential problems when gold-plated connectors are mated to solder-alloy-plated units?

If the connectors are designed so that there is a low contact to contact pressure, and if the connector is being operated in a high temperature, high humidity environment the mating of a gold-plated contact to a solder-alloy plated contact is no recommended under any circumstance; either with or without Stabilant 22/22A/22E. This combination, under conditions of high humidity, temperature, and high frequency operation seems to speed up the formation of a hard black deposit consisting of mixed oxides of tin and lead. This coating is a poor conductor at best and will cause contact problems.

The exception occurs where the connector is designed to maintain sufficient pressure at the point of contact so as to exclude the entry of oxygen. This condition is typically met on good-quality IC sockets. Providing the contact pressure is in the range of 500 to 800 lb./in 2 this will usually exclude oxygen from the junction and stop the problem under most circumstances; nevertheless the use of Stabilant 22/22A/22E will enhance the contact's reliability over a longer period of time.

A better solution is of course the use of gold-plated to gold-plated contacts, or eve solder-alloy-plated to solder-alloy-plated contacts, either of which may be made more reliable by Stabilant 22/22A/22E.

Can you give an example of this problem?

Yes, many of the first enhancement boards made to fit the Maclntosh™ (Apple™) computer used a "connector clip" which snapped down over the 68000 microprocessor chip on the main board. The initial design had gold-plated contacts which exerted only a low pressure over a fairly large area of the corresponding solder-alloy plated IC contact. The design of the "clip" together with the shielding effect of the board to which it was attached ensured that a high-temperature environment was created in the vicinity of the contacts. As the plastic housing for the "clip" was molded of polycarbonate plastic, which will absorb small amounts of moisture when cool, releasing it when heated up, It was not unusual to find that the enhancement board became erratic after two to three weeks of operation. Examination of the hard black film that formed at the junction of the two metals revealed that it was substantiate composed of oxides of tin and lead.

Redesign of the "clip" has significantly reduced the problem, nevertheless a number of companies servicing this equipment have still found it prudent to apply Stabilant to the contacts, and they report that this has taken care of the marginal cases.

Where the older graphic accelerator boards have still been encountered, the application of Stabilant 22 alone increased the mean time between failure from the two week period to about seven weeks; but this order of magnitude of MTBF is not acceptable in the application, and additional contact cleaning was necessary.

On the basis of solving similar problems with other types of connectors, our recommendation was that the gold-plate be changed to solder-alloy-plate, and that the contact pressure be increased either by the use of a thicker contact stock or the use of a small dome protrusion on the contact.

We have found that a solder-alloy to solder alloy contact under these circumstances, treated with Stabilant 22, will have a MTBF well in excess of several years.

Are there any inhibitory chemicals which would retard the formation of the oxides?

Yes there are, but the bulk of them are hardly the type of materials that could be used where a good contact had to be maintained.

Can any generalizations be made about the use of dissimilar metals?

It is not good engineering practice to employ a design using contacts where the surfaces are materials lying at grossly different potentials on the galvanic scale. It is an open invitation to "Galvanic corrosion". (An example of this would be a low contact pressure gold to aluminum contact.) Even if the corrosion products are conductive they often exhibit semi-conductor or rectifying properties and will often demodulate any RF signals present on the lines as well as cause rise-time problems that can "crash" the computer or peripheral using the connector. Contact pressures should be high enough to reduce the entry of oxygen into the contact pairs. While the use of Stabilants will reduce the problem by negating most of the thin film rectification problems, it is still better practice to employ connectors where the contacts are of identical materials or are close in their galvanic potential.

Revision 3


Stabilants are a product of Dayton Wright research & development and are made in Canada

NSCM/Cage Code - 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.

MATERIAL SAFETY DATA SHEETS ARE AVAILABLE ON REQUEST


Stabilant, Stabilant 22, and product type variations thereof are Trade Marks of D.W. Electrochemicals Ltd.

Copyright 2003 - 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.

 Contact Us 
Shopping Cart more
  View detailed Shopping Cart contents.0 items
Stabilant
Stabilant 22 Contact Enhancer

Stabilant 22 Contact Enhancer

We carry the complete line of Stabilant products. Looking for something not listed here? Please contact us.
Stabilant 22
APPLICATION NOTES
1. Electronic Equipment
2. Computer cards
3. Schadow switches
4. Mic connectors
5. RTS & Dual plug patch bays
6. Biomedical Electronics
7. Computing & Peripherals
8. Cable TV
9. Robotics
10. Environmental Impact
11. Recording studios
12. Broadcast equipment
13. Mobile Radio
14. Educational computing
15. Stereo systems
16. Aid to IC insertion
17. Navigational equipment
18. Card edge conn. problems
19. Complex process control
20. Automotive service
21. Gold plating/solder alloy
22. Very high humidity
23. High current thermal runaway
24. Car stereo systems
25. Plastic element pots.
26. Farm machinery & trucks
27. Model & hobby
28. RF case seals
29. Outdoor environments
30. Computer crashes
31. Relays & switches
32. Silicone problems
33. Tin-plated contacts
34. Solder flux & resin residue
35. Post application color tinting
36. Aircraft connectors w/ flurosilicones
37. Avoiding unsafe solvents
38. S22 R&D Design Goals
39. Stabilant use on PLCC's
40. Sensor problem solution
41. Repair of flood damage
42. Marine electrical & electronics
43. All Cameras & Video Equipment
44. SCSI removable SCA drives, caddies & connections
45. Home Theater & Computer Connectors

Some of these application notes are repetitive of material in other application notes. We realize this. But some were written as a reference to a contact problem in a particular field or application.

NOTICE: This data has been supplied for information purposes only. While to our knowledge it is accurate, users should determine the suitability of the material for their application by running their own tests. Neither R.A.L. Audio Services, D.W. Electrochemicals Ltd., their distributors, or their dealers assume any responsibility or liability for damages to equipment and/or consequent damages, howsoever caused, based on the use of this information.
Product Categories
 Audio Services
 Used Equipment
 Stabilant 22
 Accessories - Misc.
 Acoustical
        Treatments

 Bass Management
 Cable / Wire /
        Connectors

 Cases / Racks /
              Covers

 Consoles & Mixers
 Crossovers
 Digital Audio
 Direct Boxes / DI's
 DJ Stuff
 Guitars / Basses
 Guitar / Bass
        Accessories

 Headphones
 Headphone Amplifiers
 Microphones
 Microphone
              Preamplifiers

 Microphone
        Accessories

 Power Amplifiers
 Power Supplies /
              Conditioners

 Re-Amplifiers
 Replacement Parts
 Rigging / Safety
              Cables

 Signal Distribution
 Signal Processors
 Speakers / Monitors
 Speaker Management
 Splitters &
              Isolators

 Stage Lighting /
              Trusses

 Studio Lighting
 Sync's / Clocks /
              R.C.s

 Tape Recorders
 Test Equipment
 Wireless
View All Specials
View Latest Additions
View All Products By:
Category or Manufacturer
Stabilant 22
REVIEWS
Over the years, Stabilant 22 has been highly parsed in publications that target a wide range of electronics applications including:
* Andrew Marshall's Audio Ideas Guide
* BYTE Magazine (7 articles)
* Windows Magazine
* Q.S.T. Amateur Radio
* Model Railroads (2 articles)
* Motor Magazine
Stabilant 22
TECHNICAL NOTES
1. MSDS - Stabilant 22
2. General Information
4. MSDS - Stabilant 22A
5. MSDS - Stabilant 22E
9. MSDS - Stabilant 22L
20. Military Applications
21. Elastomer Compatibility
22. Effectiveness of Stabilants
24. Connector Harmonic Distortion
39. Signal rise time

There are gaps in the sequence numbers below because some Technical Note s were written by the manufacturer for specific companies and are confidential.

NOTICE: This data has been supplied for information purposes only. While to our knowledge it is accurate, users should determine the suitability of the material for their application by running their own tests. Neither R.A.L. Audio Services, D.W. Electrochemicals Ltd., their distributors, or their dealers assume any responsibility or liability for damages to equipment and/or consequent damages, howsoever caused, based on the use of this information.
Stabilant
Stabilant 22 Contact Enhancer

Stabilant 22 Contact Enhancer

We carry the complete line of Stabilant products. Looking for something not listed here? Please contact us.

Get Adobe Reader All prices in US dollars.
Sales tax will be added to all purchases delivered in California.
Prices, products, and specifications subject to change without notice.
All trademarks and registered trademarks are owned by their respective companies.
We accept Visa, Mastercard, Discover and American Express