Preventing corrosion degradation in a fluid-based switch

Details Preventing corrosion degradation in a fluid-based switch Preventing corrosion degradation in a fluid-based switch

2003-07-30

2004-08-24

Friedhofer, Michael A. (Department: 2832)

Electricity: circuit makers and breakers

Liquid contact

Reexamination Certificate

active

06781074

ABSTRACT:

BACKGROUND OF THE INVENTION
Liquid metal micro switches (LIMMS) have been made that use a liquid metal, such as mercury, gallium-bearing alloys or other liquid metal compositions, as the switching fluid. The liquid metal may make, break or latch electrical contacts. To change the state of the switch, a force is applied to the switching fluid, which causes it to change form and move. Liquid metal switches rely on the cleanness of the liquid metal for good performance. If the liquid metal forms oxide films or other types of corrosion product buildup within the switch, the proper functioning or performance of the switch may degrade or be inhibited.
For example, the oxide film or other corrosion products may increase the surface tension of the liquid metal, which may increase the energy required for the switch to change state. Films of oxide and other corrosion products may increase the tendency for the liquid metal to wet to the substrate between switch contacts, thereby increasing undesirable short circuits in the switching operation. Build up of oxide and other corrosion products may also degrade the ability of the liquid metal to wet to the switch contacts, and thereby may increase the probability of undesirable open circuits in the switching operation. The build up of oxide and other corrosion products within the liquid metal switch may also alter the effective surface tension of the liquid metal with itself, causing the liquid metal to become stringy when moved or stretched, and thereby decreasing the tendency of the liquid metal to break cleanly between switch contacts and potentially causing short circuits. Build up of large amounts of oxide or corrosion products may increase the effective viscosity of the liquid metal leading to slower switch operation over time.
It is desirable to have liquid metal that is as free of oxide and other corrosion products as practically possible in order to minimize the above mentioned negative effects. There is a need for a method to decrease or eliminate the build up of oxide or other corrosion products in liquid metal switches.
SUMMARY OF THE INVENTION
In one embodiment, a method for reducing oxides and corrosion products on a switching fluid is disclosed. The method includes depositing a switching fluid on a first substrate. The first substrate is mated to a second substrate, the first substrate and the second substrate defining therebetween a cavity holding the switching fluid. The cavity is sized to allow movement of the switching fluid between first and second states. The switching fluid is coated with a corrosion inhibitor.


REFERENCES:
patent: 2312672 (1943-03-01), Pollard, Jr.
patent: 2564081 (1951-08-01), Schilling
patent: 3430020 (1969-02-01), Tomkewitsch et al.
patent: 3529268 (1970-09-01), Rauterberg
patent: 3600537 (1971-08-01), Twyford
patent: 3639165 (1972-02-01), Rairden, III
patent: 3657647 (1972-04-01), Beusman et al.
patent: 3955059 (1976-05-01), Graf
patent: 4103135 (1978-07-01), Gomez et al.
patent: 4158118 (1979-06-01), Graf
patent: 4200779 (1980-04-01), Zakurdaev et al.
patent: 4238748 (1980-12-01), Goullin et al.
patent: 4245886 (1981-01-01), Kolodzey et al.
patent: 4336570 (1982-06-01), Brower
patent: 4419650 (1983-12-01), John
patent: 4434337 (1984-02-01), Becker
patent: 4475033 (1984-10-01), Willemsen et al.
patent: 4505539 (1985-03-01), Auracher et al.
patent: 4582391 (1986-04-01), Legrand
patent: 4628161 (1986-12-01), Thackrey
patent: 4652710 (1987-03-01), Karnowsky et al.
patent: 4657339 (1987-04-01), Fick
patent: 4742263 (1988-05-01), Harnden, Jr. et al.
patent: 4786130 (1988-11-01), Georgiou et al.
patent: 4797519 (1989-01-01), Elenbaas
patent: 4804932 (1989-02-01), Akanuma et al.
patent: 4988157 (1991-01-01), Jackel et al.
patent: 5278012 (1994-01-01), Yamanaka et al.
patent: 5415026 (1995-05-01), Ford
patent: 5502781 (1996-03-01), Li et al.
patent: 5644676 (1997-07-01), Blomberg et al.
patent: 5675310 (1997-10-01), Wojnarowski et al.
patent: 5677823 (1997-10-01), Smith
patent: 5751074 (1998-05-01), Prior et al.
patent: 5751552 (1998-05-01), Scanlan et al.
patent: 5828799 (1998-10-01), Donald
patent: 5841686 (1998-11-01), Chu et al.
patent: 5849623 (1998-12-01), Wojnarowski et al.
patent: 5874770 (1999-02-01), Saia et al.
patent: 5875531 (1999-03-01), Nellissen et al.
patent: 5886407 (1999-03-01), Polese et al.
patent: 5889325 (1999-03-01), Uchida et al.
patent: 5912606 (1999-06-01), Nathanson et al.
patent: 5915050 (1999-06-01), Russell et al.
patent: 5972737 (1999-10-01), Polese et al.
patent: 5994750 (1999-11-01), Yagi
patent: 6021048 (2000-02-01), Smith
patent: 6180873 (2001-01-01), Bitko
patent: 6201682 (2001-03-01), Mooij et al.
patent: 6207234 (2001-03-01), Jiang
patent: 6212308 (2001-04-01), Donald
patent: 6225133 (2001-05-01), Yamamichi et al.
patent: 6278541 (2001-08-01), Baker
patent: 6304450 (2001-10-01), Dibene, II et al.
patent: 6320994 (2001-11-01), Donald et al.
patent: 6323447 (2001-11-01), Kondoh et al.
patent: 6351579 (2002-02-01), Early et al.
patent: 6356679 (2002-03-01), Kapany
patent: 6373356 (2002-04-01), Gutierrez et al.
patent: 6396012 (2002-05-01), Bloomfield
patent: 6396371 (2002-05-01), Streeter et al.
patent: 6408112 (2002-06-01), Bartels
patent: 6446317 (2002-09-01), Figueroa et al.
patent: 6453086 (2002-09-01), Tarazona
patent: 6470106 (2002-10-01), McClelland et al.
patent: 6487333 (2002-11-01), Fouquet
patent: 6501354 (2002-12-01), Gutierrez et al.
patent: 6512322 (2003-01-01), Fong et al.
patent: 6515404 (2003-02-01), Wong
patent: 6516504 (2003-02-01), Schaper
patent: 6559420 (2003-05-01), Zarev
patent: 6633213 (2003-10-01), Dove
patent: 6646527 (2003-11-01), Dove et al.
patent: 6647165 (2003-11-01), Hu et al.
patent: 2002/0037128 (2002-03-01), Burger et al.
patent: 2002/0146197 (2002-10-01), Yong
patent: 2002/0150323 (2002-10-01), Nishida et al.
patent: 2002/0168133 (2002-11-01), Saito
patent: 2003/0035611 (2003-02-01), Shi
patent: 0593836 (1994-04-01), None
patent: 2418539 (1979-09-01), None
patent: 2458138 (1980-12-01), None
patent: 2667396 (1992-04-01), None
patent: 36-18575 (1961-10-01), None
patent: SHO47-21645 (1972-10-01), None
patent: 62-276838 (1987-12-01), None
patent: 63-294317 (1988-12-01), None
patent: 8-125487 (1996-05-01), None
patent: 9-161640 (1997-06-01), None
patent: WO99-46624 (1999-09-01), None
TDB-ACC-NO: NB8406827, “Integral Power Resistors For Aluminum Substrate”, IBM Technical Disclosure Bulletin, Jun. 1984, US, vol. 27, Issue No. 1B, p. 827.
Bhedwar, Homi C., et al., “Ceramic Multilayer Package Fabrication”, Electronic Materials Handbook, Nov. 1989, pp. 460-469, vol. 1 Packaging, Section 4: Packages.
Simon, Jonathan, et al., “A Liquid-Filled Microrelay With a Moving Mercury Microdrop”, Journal of Microelectromechanical Systems, Sep. 1997, pp. 208-216, vol. 6, No. 3.

Affiliated with

Also associated with

Rating

Preventing corrosion degradation in a fluid-based switch does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Preventing corrosion degradation in a fluid-based switch, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Preventing corrosion degradation in a fluid-based switch will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3290137