Batteries: thermoelectric and photoelectric – Photoelectric – Cells
Reexamination Certificate
1999-12-27
2001-02-27
Diamond, Alan (Department: 1753)
Batteries: thermoelectric and photoelectric
Photoelectric
Cells
C136S244000, C136S251000, C136S259000, C136S292000, C136S293000, C136S290000, C257S461000, C257S433000, C257S434000
Reexamination Certificate
active
06194651
ABSTRACT:
The invention relates to an electrostatic discharge (ESD) protection arrangement for a solar cell assembly (SCA), particularly for the use as a component of orbiting solar generators. The SCA is constructed of a cover glass provided with a conductive vapor deposit, a bonding layer and a solar cell.
German Patent Document DE 36 06 464 A1 discloses a device for preventing a static charge on solar generators in which the surface and the side faces of the cover glass and the bonding layer are electrically conductive.
ESD protection is necessary in order to avoid charging of the cover glasses of the solar cells (silicium or gallium arsenide) to an unacceptably high potential during orbit. Unacceptably high charge potentials can destroy sensitive electronic components on the satellite, and can even cause a failure of the entire solar generator.
Two different methods have been developed for ESD protection, and have been qualified for applications in space operations. The two methods have in common that they require high expenditures and have a limited potential for conversion to a reproducible, simple and mainly inexpensive series production. These are as follows:
Protection in the CLUSTER Satellite Project
Because of its cylindrical shape, in the CLUSTER solar generator, the conductive cover glasses are jointly contacted and grounded by means of spiral wires. This principle was found to be successful but has several disadvantages:
It can be used only in cylindrical generator surfaces up to a certain radius of curvature;
it is successful only at a low satellite spin rate;
it makes the cell repairs which may be necessary after mounting more difficult and more expensive, because the applied spiral wires must be removed and cannot be reused.
Protection Used in the XMM Satellite Project
In this approach, the spaces between the cells are provided with so-called bonding agent crosses, and subsequently small silver plates are applied by means of conductive bonding agents. This results in a connection of all conductive cover glasses which are grounded jointly without, however, having any contact with the individual solar cells.
The following disadvantages were found:
High labor expenditures. Several thousand bonding agent crosses must be applied manually by means of an injector;
after the manufacturing, an expensive cleaning process is required for removing disturbing bonding agent residue;
manufacturing tolerances, which cannot be excluded, may result in short circuits which require considerable reworking.
It is an object of the invention to provide a secure arrangement for discharging the electrostatic charge of solar cells in applications in space operations, so that disturbances on the solar cells and panels are avoided and a discharge-free environment is created for the highly sensitive instruments on a satellite.
This and other objects and advantages are achieved by the ESD protection arrangement according to the invention for a solar cell assembly which has a cover glass with a conductive vapor deposit, a bonding layer and a solar cell. According to the invention, at least a portion of the side face of the solar cell array has a conductive layer or strip which connects the conductive layer on the cover glass and the solar cell.
It is the concept of the invention that the forming charge potential on the cover glasses is not, as in the prior art, discharged by means of an entire conductive surface layer; rather, the cover glass of each cell is grounded individually onto the solar cell itself.
REFERENCES:
patent: 4832755 (1989-05-01), Barton et al.
patent: 4915743 (1990-04-01), Schilling
patent: 5542988 (1996-08-01), Bogus
patent: 36 06 464 (1987-09-01), None
patent: 37 33 645 (1989-04-01), None
patent: WO 94/19831 (1994-09-01), None
patent: WO 99/59210 (1999-11-01), None
Japanese Patent Abstract No. 60-189272, vol. 010, No. 032 [E-379], Feb. 7, 1986.
Institute of Electrical and Electronics Engineers, Dec. 5-9, 1994, pp. 2058-2061 entitled “Teflon Bonding of Solar Cell Assemblies Using Pilkington CMZ & CMG Coverglasses—Now a Production Process” by Kitchen et al.
Altstaedter Dieter
Stark Joachim
Diamond Alan
Dornier GmbH
Evenson McKeown Edwards & Lenahan PLLC
LandOfFree
Electrostatic discharge for solar cell does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electrostatic discharge for solar cell, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electrostatic discharge for solar cell will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2577615