US3721746A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shielding techniques for r.f. circuitry
Assignee: Motorola Solutions Inc
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Filing: 1971-10-01
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Granted: 1973-03-20
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Expires: 1991-10-01
Abstract
Abstract A technique for shielding R.F. circuitry is disclosed wherein thin metal strips are formed by chemical etching, and include bend or fold grooves similarly etched, the strips being bent into the desired configuration at the time of assembly. Printed circuit boards with the components all on one side and the connections all on the other are placed in the compartments formed by the bent metal strips. Tabs are provided between the edges of the strips to hold the boards in place. Syntatic foam may be placed in the compartments on the component side and visco-elastic damping foam and or double sided pressure sensitive foam tape is placed between the bottom of the printed circuit board and the bottom shield cover. Covers also formed by chemical etching are attached to the top and bottom of the compartments and puncture resistant tape may be mounted on the inside of the top and bottom covers.
Inventors
- 👤 T Knappenberger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:07
CPC Classifications
H; H05; H05K; H05K9/00; H05K9/0007; H05K9/002; H05K9/0022; H05K9/0024; H05K9/0032; Y; Y10; Y10S; Y10S174/00; Y10S174/34; Y10S174/35; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/4913; Y10T29/49146
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
197 words
Means for shielding high frequency circuit components comprising: an insulating board having circuit components mounted on one side thereof; connections to said circuit components on the other side of said insulating board; a sheet metal strip forming sides surrounding said circuit board; said sheet metal strip having side edges and inwardly extending mounting tabs on the surfaces of said strip between said side edges; said insulating board being held by said mounting tabs; the space between the connection side of said circuit board and the edge of said sheet metal strip adjacent thereto defining on access chamber for said connections; the space between the circuit component side of said circuit board and the edge of said sheet metal strip adjacent thereto defining an access chamber for said componEnts; a sheet metal bottom member conforming to contour of said sheet metal strip surrounding said circuit board and being attachable to the metal strip adjacent to said connection side; a sheet metal top member conforming to the contour of said sheet metal strip adjacent to said component side; and means for achieving removable metal-to-metal contact between said top and bottom members and the adjacent edges of said metal strip.
Claim 2
Dependent Claim
197 words
Means for shielding high frequency circuit components comprising: an insulating board having circuit components mounted on one side thereof; connections to said circuit components on the other side of said insulating board; a sheet metal strip forming sides surrounding said circuit board; said sheet metal strip having side edges and inwardly extending mounting tabs on the surfaces of said strip between said side edges; said insulating board being held by said mounting tabs; the space between the connection side of said circuit board and the edge of said sheet metal strip adjacent thereto defining on access chamber for said connections; the space between the circuit component side of said circuit board and the edge of said sheet metal strip adjacent thereto defining an access chamber for said componEnts; a sheet metal bottom member conforming to contour of said sheet metal strip surrounding said circuit board and being attachable to the metal strip adjacent to said connection side; a sheet metal top member conforming to the contour of said sheet metal strip adjacent to said component side; and means for achieving removable metal-to-metal contact between said top and bottom members and the adjacent edges of said metal strip.
Claim 3
Dependent Claim
19 words
The shielding means according to claim 1 wherein said connection access chamber is filled with a visco-elastic foam tape.
Claim 4
Dependent Claim
30 words
The shielding means according to claim 1 wherein said insulating board comprises a printed circuit board having an insulating substrate and printed film circuit connectors on the connection side thereof.
Claim 5
Dependent Claim
30 words
The shielding means according to claim 1 wherein said metal-to-metal contact means includes cooperating metal tabs on said top and bottom members and the adjacent edges of said metal strip.
Claim 6
Dependent Claim
15 words
The shielding means according to claim 4 wherein said metal-to-metal contact means comprises solder joints.
Claim 7
Dependent Claim
18 words
The shielding means according to claim 4 wherein said metal-to-metal contact means comprises metallic tape and metallic adhesive.
Claim 8
Dependent Claim
17 words
The shielding means according to claim 1 wherein said component access chamber is filled with encapsulating foam.
Claim 9
Dependent Claim
14 words
The shielding means according to claim 7 wherein said encapsulating foam comprises syntactic foam.
Claim 10
Dependent Claim
26 words
The shielding means according to claim 1 wherein the inside surfaces of either of said top and bottom sheet metal members includes an attached insulating coating.
Claim 11
Dependent Claim
15 words
The shielding means according to claim 9 wherein said insulating coating comprises an insulating tape.
Claim 12
Dependent Claim
280 words
Means for shielding one or more R.F. circuit modules from each other comprising: a printed circuit board for each circuit module comprising a series of circuit components which require no shielding from each other at the frequency of use; all of said circuit components being mounted on the insulating side of said printed circuit board; printed film circuit connections to said components on the other side of said printed circuit board; sheet metal strip means forming sides surrounding each of said circuit modules; said sheet metal strip means having side edges and inwardly extending mounting tabs on the surfaces of said strip means between said side edges; said printed circuit boards being held by said mounting tabs; the spaces between the connection side of said printed circuit boards and the edges of said sheet metal strip means adjacent thereto defining access chambers for the connections of the components of each module; the spaces between the circuit component sides of said printed circuit boards and the edges of said sheet metal strip means adjacent thereto defining access chambers for the components of each module; a sheet metal bottom member conforming to the contour of the sheet metal strips surrounding each of said modules and being attachable to the metal strip adjacent to the connection side of the particular one of said modules; a sheet metal top member conforming to the contour of the sheet metal strips surrounding each of said modules and being attachable to the metal strip adjacent to the component side of the particular one of said modules; and means for achieving removable metal-to-metal contact between said top and bottom members and the adjacent edges of said metal strips.
Claim 13
Dependent Claim
280 words
Means for shielding one or more R.F. circuit modules from each other comprising: a printed circuit board for each circuit module comprising a series of circuit components which require no shielding from each other at the frequency of use; all of said circuit components being mounted on the insulating side of said printed circuit board; printed film circuit connections to said components on the other side of said printed circuit board; sheet metal strip means forming sides surrounding each of said circuit modules; said sheet metal strip means having side edges and inwardly extending mounting tabs on the surfaces of said strip means between said side edges; said printed circuit boards being held by said mounting tabs; the spaces between the connection side of said printed circuit boards and the edges of said sheet metal strip means adjacent thereto defining access chambers for the connections of the components of each module; the spaces between the circuit component sides of said printed circuit boards and the edges of said sheet metal strip means adjacent thereto defining access chambers for the components of each module; a sheet metal bottom member conforming to the contour of the sheet metal strips surrounding each of said modules and being attachable to the metal strip adjacent to the connection side of the particular one of said modules; a sheet metal top member conforming to the contour of the sheet metal strips surrounding each of said modules and being attachable to the metal strip adjacent to the component side of the particular one of said modules; and means for achieving removable metal-to-metal contact between said top and bottom members and the adjacent edges of said metal strips.
Claim 14
Dependent Claim
21 words
The means for shielding according to claim 11 wherein the sheet metal strips surrounding each module are formed by chemical milling.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-19 | 1976-09-18 | 1977-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-19 | 1980-09-18 | 1981-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-19 | 1984-09-18 | 1985-03-20 | $7700.00 | Window Closed / Lapsed |