Source: http://www.google.com/patents/US6300579?dq=5,960,411
Timestamp: 2015-04-19 18:19:25
Document Index: 465765361

Matched Legal Cases: ['art. 2', 'art.\n3', 'art. 4', 'art.\n5', 'art. 6', 'art.\n7', 'art. 9', 'art.\n10', 'art. 12', 'art. 14', 'art 101', 'art 101', 'art 102', 'art 101', 'art 102', 'art 102', 'art 102', 'art 11', 'art 11', 'art 11', 'art 11', 'art 11', 'art 11', 'arts 14', 'art 11', 'arts 15', 'arts 15', 'art 11', 'art 12', 'art 12', 'art 117', 'art 13', 'art 11', 'art 12', 'art 13', 'art 102', 'art 102', 'art 102', 'art 11', 'art 12', 'art 12', 'art 12', 'art 13', 'art 12', 'art 12', 'art 12', 'art 13', 'art 11', 'art 12', 'art 12', 'art 13', 'art 12', 'art 11', 'art 12', 'art 17', 'art 11']

Patent US6300579 - Grounding terminal and mounting structure of the same on a printed circuit board - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsThe present invention realizes proper grounding of a printed circuit board to a grounding conductor by solving the problems in soldering a grounding terminal to a printed circuit board by reflow soldering, relating to a mounting structure of a grounding terminal on a printed circuit board formed by soldering...http://www.google.com/patents/US6300579?utm_source=gb-gplus-sharePatent US6300579 - Grounding terminal and mounting structure of the same on a printed circuit boardAdvanced Patent SearchPublication numberUS6300579 B1Publication typeGrantApplication numberUS 09/301,807Publication dateOct 9, 2001Filing dateApr 28, 1999Priority dateApr 30, 1998Fee statusPaidAlso published asDE69918489D1, DE69918489T2, EP0954067A2, EP0954067A3, EP0954067B1, US6465738, US6674018, US20020053468, US20020062989Publication number09301807, 301807, US 6300579 B1, US 6300579B1, US-B1-6300579, US6300579 B1, US6300579B1InventorsHideo YumiOriginal AssigneeKitagawa Industries, Co., Ltd.Export CitationBiBTeX, EndNote, RefManPatent Citations (7), Referenced by (3), Classifications (23), Legal Events (5) External Links: USPTO, USPTO Assignment, EspacenetGrounding terminal and mounting structure of the same on a printed circuit board
US 6300579 B1Abstract
The present invention realizes proper grounding of a printed circuit board to a grounding conductor by solving the problems in soldering a grounding terminal to a printed circuit board by reflow soldering, relating to a mounting structure of a grounding terminal on a printed circuit board formed by soldering a grounding terminal to the printed circuit board. Two joint surfaces having different surface areas are formed within the joint part of the grounding terminal, and the grounding terminal is soldered to the conductive pattern on the printed circuit board corresponding to the joint surfaces by using the solder having an amount corresponding to the surface area of each joint surface. Also, the bending area as the center of elastic deformation of the contact part of the grounding terminal is formed at a predetermined distance away from the relatively small joint surface of the joint part.
a joint part having a plurality of joint surfaces for soldering the grounding terminal to a conductive pattern on a printed circuit board; a contact part extending from and being connected to the joint part via a bending part, the contact part bending back over the joint surfaces and being configured to facilitate engagement with a grounding conductor, and the contact part being elastically deformable toward a rear surface of the joint surfaces upon engaging with a grounding conductor; at least one of the joint surfaces of the joint part having a surface area which is smaller than a surface area of all remaining joint surfaces; and a restriction part extending from an end of the contact part, and the restriction part, once the contact part is deformed a predetermined extent, contacting with the joint part to restrict further elastic deformation of the contact part. 2. The ground terminal according to claim 1, wherein the bending part is formed a predetermined distance away from the joint surfaces of the joint part.
3. A grounding terminal for mounting to a printed circuit board and engagement with a grounding conductor, the grounding terminal comprising:
a joint part having a plurality of joint surfaces for soldering the grounding terminal to a conductive pattern on a printed circuit board; a contact part extending from and being connected to the joint part via a bending part, the contact part bending back over the joint surfaces and being configured to facilitate engagement with a grounding conductor, and the contact part being elastically deformable toward a rear surface of the joint surfaces upon engaging with a grounding conductor; at least one of the joint surfaces of the joint part having a surface area which is smaller than a surface area of all remaining joint surfaces; and a restriction part extending from a surface of the joint part, and the restriction part, once the contact part is deformed to a predetermined extent, contacting with the contact part to restrict further elastic deformation of the contact part. 4. The ground terminal according to claim 3, wherein the bending part is formed a predetermined distance away from the joint surfaces of the joint part.
5. A structure having a grounding terminal mounted on a printed circuit board for contact with a grounding conductor, the grounding terminal comprising:
a joint part having a plurality of joint surfaces soldered to a conductive pattern of the printed circuit board; a contact part extending from and being connected to the joint part via a bending part, the contact part bending back over the joint surfaces and being configured to facilitate engagement with a grounding conductor, and the contact part being elastically deformable toward a rear surface of the joint surfaces upon engaging with the grounding conductor; at least one of the joint surfaces of the joint part having a surface area which is smaller than a surface area of the other joint surfaces; the grounding terminal mounted on the printed circuit board by reflow soldering, and an amount of reflow soldering corresponding to a surface area of each of the plurality of joint surfaces to be soldered; and the grounding terminal further comprising a restriction part extending from the contact part, and the restriction part, once the contact part is deformed to a predetermined extent, contacting with the joint part to restrict further elastic deformation of the contact part. 6. The ground terminal according to claim 5, wherein the bending part is formed a predetermined distance away from the joint surfaces of the joint part.
7. The structure according to claim 5, wherein remaining joint surfaces are mounted on the printed circuit board by a creamed solder.
8. A structure having a grounding terminal mounted on a printed circuit board for contact with a grounding conductor, the grounding terminal comprising:
a joint part having a plurality of joint surfaces soldered to a conductive pattern of the printed circuit board; a contact part extending from and being connected to the joint part via a bending part, the contact part bending back over the joint surfaces and being configured to facilitate engagement with a grounding conductor, and the contact part being elastically deformable toward a rear surface of the joint surfaces upon engaging with the grounding conductor; at least one of the joint surfaces of the joint part having a surface area which is smaller than a surface area of the other joint surfaces; the grounding terminal mounted on the printed circuit board by reflow soldering, and an amount of reflow soldering corresponding to a surface area of each of the plurality of joint surfaces to be soldered; and the grounding terminal further comprising a restriction part extending from a surface of the joint part, and the restriction part, once the contact part is deformed to a predetermined extent, contacting with the contact part to restrict further elastic deformation of the contact part. 9. The ground terminal according to claim 8, wherein the bending part is formed a predetermined distance away from the joint surfaces of the joint part.
10. The structure according to claim 8, wherein remaining joint surfaces are mounted on the printed circuit board by a creamed solder.
11. A method of mounting a grounding terminal on a printed circuit board for engagement with a grounding conductor, the method comprising the steps of:
forming a printed circuit board with a conductive pattern; providing a joint part with a plurality of joint surfaces; soldering the grounding terminal to the conductive pattern on the printed circuit board; forming a contact part connected to the joint part and extending the contact part back over the joint surfaces, via a bending part, such that the contact part is configured to facilitate engagement with a grounding conductor, and forming the contact part so as to be elastically deformable toward a rear surface of the joint surfaces upon engaging with a grounding conductor; forming at least one of the joint surfaces of the joint part with a surface area which is smaller than a surface area of all remaining joint surfaces; and extending a restriction part from an end of the contact part, and the restriction part, once the contact part is deformed a predetermined extent, contacting with the joint part to restrict further elastic deformation of the contact part. 12. The method according to claim 11, further comprising the step of soldering said joint surface of said grounding terminal having a relatively large surface area using creamed solder.
13. A method of mounting a grounding terminal on a printed circuit board for engagement with a grounding conductor, the method comprising the steps of:
forming a printed circuit board with a conductive pattern; providing a joint part with a plurality of joint surfaces; soldering the grounding terminal to the conductive pattern on the printed circuit board; forming a contact part connected to the joint part and extending the contact part back over the joint surfaces, via a bending part, such that the contact part is configured to facilitate engagement with a grounding conductor, and forming the contact part so as to be elastically deformable toward a rear surface of the joint surfaces upon engaging with a grounding conductor; forming at least one of the joint surfaces of the joint part with a surface area which is smaller than a surface area of all remaining joint surfaces; and extending a restriction part from a surface of the joint part, and the restriction part, once the contact part is deformed a predetermined extent, contacting with the contact part to restrict further elastic deformation of the contact part. 14. The method according to claim 13, further comprising the step of soldering said joint surface of said grounding terminal having a relatively large surface area using creamed solder.
Conventionally, a mounting structure of a grounding terminal on a printed circuit board for grounding the printed circuit board, in which a grounding terminal is mounted on the surface of the printed circuit board and pressed against a grounding conductor, is known. FIG. 5 is a plan view of such a conventional grounding structure and FIG. 6 is a longitudinal sectional view along line VI�VI of FIG. 5. As shown in FIG. 6, the grounding terminal 100 is soldered to the conductive pattern 201 on the printed circuit board 200 with solder 202. Then, the grounding terminal 100 is pressed against the grounding conductor, thereby grounding the printed circuit board 200. To illustrate the structure simply, the grounding conductor 300 is not shown in FIG 5.
The grounding terminal 100 is formed by bending a strip-like thin sheet metal member with a width of α, for example, 0.8 mm, and has a joint part 101 with a longitudinal length of β, for example, 3.5 mm. One surface of the joint part 101 is a joint surface 101 a which is soldered to the conductive pattern 201 on the printed circuit board 200. Also, the grounding terminal has a contact part 102 which adjoins the joint part 101 and is bent in the upper direction. An outer surface 102 a of the contact part 102 is pressed against the grounding conductor 300. As the result of load by the grounding conductor, the contact part 102 is elastically deformed around the bending area γ, and is pressed against the grounding conductor 300 by restoring force caused by the elastic deformation, thereby electrically connecting the printed circuit board 200 and the grounding conductor 300 properly,
When the aforementioned grounding terminal is soldered to the printed circuit board, reflow soldering is usually employed. Reflow soldering comprises the steps of previously applying a suitable amount of solder to the point to be jointed, fixing the grounding terminal to the point temporarily, and melting the solder by using an external heat source, and all these steps are performed automatically. An advantage of reflow soldering is that by allowing a suitable amount of solder to be applied, it prevents solder from being placed at inappropriate points of the printed circuit board, and thus prevents improper soldering such as a defective bridge. Also, there is another advantage that in the case where a relatively small mounting member as aforementioned is to be mounted, self-alignment effect can be expected That is, even if the temporarily fixed member deviates a little from the conductive pattern of the printed circuit board, the member is moved to the right position by surface tension of the melted solder.
However, there are the following problems in reflow soldering of the above conventional grounding terminal
(1) The grounding terminal 100 is moved to the right position by self-alignment effect by surface tension of the melted solder, and then is finally positioned by hardening of the melted solder. During the hardening process of the solder, the grounding terminal 100 sometimes deviates from the right position on the printed circuit board 200 because of, for example, vibration. This results from the fact that since the amount of the solder is large, the thermal capacity of the solder is large, and thus it takes time for the solder to harden If the grounding terminal 100 deviates from the right position, the contact part 102 may not be pressed against the grounding conductor 300 in an appropriate state. Furthermore, the requirements of highly precise mounting performance for allowing high density mounting are not satisfied
Wherefore, an object of the invention is to provide a mounting structure of a ground terminal on a printed circuit board formed by soldering, wherein by solving the problems caused by reflow soldering of the grounding terminal to the printed circuit board, the printed circuit board is properly grounded to a grounding conductor
FIGS 3 and 4 show modifications of the restriction part, respectively, in the invention;
The grounding terminal 10 in the embodiment is formed by bending a strip-like thin sheet metal member. The longitudinal center part of the metal member is a joint part 11, within which the metal member is bent such that the longitudinal section of the metal member forms a trapezoid, in other words, a groove lid is formed on one side of the joint part 11. Two surfaces oppositely positioned across the groove 11 d are joint surfaces 11 a and 11 b. In this case, the groove 11 d is formed at a predetermined distance away from the longitudinal center of the joint part 11, and thus one joint surface 11 a is smaller than the other joint surface 11 b. The metal member is bent in the upper direction at both ends of the joint part 11. At one end, the metal member is bent approximately perpendicularly to the joint part 11, and the bent part is further bent approximately perpendicularly so as to form a U-shaped longitudinal section with the joint part 11. Rectangular plate-like parts 14, which are bent perpendicularly in the direction of the joint part 11, are formed on both sides of the edge of the metal member. Also, projection parts 15 projecting from both sides of the metal member are formed at a predetermined distance away from the edge. The projection parts 15 are made by being separated from the neighboring member of the same shape when the strip-like thin sheet metal member is stamped out from a sheet metal
The other end of the metal member is bent at the end of the joint part 11 so as to form a V-shaped longitudinal section The peak of the V-shaped part has a gently curved longitudinal section instead of an acute one. A part which also has a gently curved longitudinal section from the peak of the V-shape part toward the edge of the metal member forms, together with the V-shaped part, a contact part 12. The part from the end of the contact part 12 to the edge having a straight longitudinal section is bent in the direction of the joint part 117 and forms a restriction part 13.
The mounting structure of the invention is formed by soldering specifically by reflow soldering, the grounding terminal 10 having the joint part 11, the contact part 12, and the restriction part 13 as above mentioned to the printed circuit board 20.
(B) When the temperature of the grounding terminal 100 reaches the melting point of the solder earlier than the conductive pattern 201 of the printed circuit board 200, what is called wicking phenomenon occurs. Wicking phenomenon, here, means a phenomenon that the solder 202 is sucked up along the bending area γ forming the center of elastic deformation of the contact part 102 shown in FIG. 6. In this case, since the solder 202 adheres and hardens around the bending area γ, the elastic deformation performance of the contact part 102 is lowered, and thus it is sometimes impossible to attain elastic deformation enough for the contact part 102 to be pressed against the grounding conductor 300 and conduct electricity to the grounding conductor 300.
A further advantage is as follows: in the mounting structure of the embodiment, the bending area γ is formed at a predetermined distance away from the relatively small joint surface 11 a of the joint part 11. As a result, since the creamed solder 22 a applied on the smaller joint surface 11 a is not sucked up, by wicking phenomenon, to the bending area y of the contact part 12, the solder 22 a does not adhere around the bending area γ. This prevents the elastic deformation performance of the contact part 12 from declining because of the solder adhering around the bending area γ. Thus, the aforementioned problem (B) is solved and the contact part 12 is appropriately pressed against the grounding conductor 30.
The mounting structure of the embodiment provides another advantage as follows: a restriction part 13 adjacent to the contact part 12 of the grounding terminal 10 is formed so that the stress caused to the contact part 12 by the elastic deformation thereof will not exceed the elastic limit. When the contact part 12 is elastically deformed to a predetermined extent, the restriction part 13 restricts the elastic deformation by contacting and pressing its edge to a surface 11 c on the reverse side of the joint surface 11 b of the joint part 11. The predetermined extent means the extent of elastic deformation which does not allow the stress caused to the contact part 12 to exceed the elastic limit. This prevents a permanent deformation of the contact part 12 even though a heavy load is applied thereto. Although the restriction part 13 is formed adjacent to the contact part 12 of the grounding terminal 10 in FIG. 2, it may be possible to form a restriction part on the reverse side of the joint surfaces 11 a and 11 b of the joint part 11 as shown in FIGS. 3 and 4 such that the restriction part is pressed against the contact part 12. In a modification shown in FIG. 3) a member 16 is formed as part of the metal member such that the member 16 extends from a side end of the top surface of the above mentioned trapezoid part and bent in the upper direction, allowing the top edge of the member 16 to function as a restriction part In a modification shown in FIG. 4, the trapezoid part of FIG. 2 is redesigned to have a significant elevation, and the trapezoid part 17 functions as a restriction part.
Also, in the mounting structure of the embodiment, the creamed solder 22 a and 22 b is applied to both of the two joint surfaces 11 a and 11 b formed within the joint part 11 of the grounding terminal 10. However, in order to prevent tombstone phenomenon, only the solder applied on the larger joint surface 11 b needs to be creamed solder 22 b. In other words, to prevent tombstone phenomenon, the adhesion on the larger joint surface 11 b is necessary to resist against the surface tension of the solder which is melted first on the smaller joint surface 11 a. Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS3504095Jan 30, 1968Mar 31, 1970Instr Specialties Co IncShielding gasketsUS4679889 *Oct 31, 1985Jul 14, 1987North American Specialties CorporationSolder-bearing leadsUS5029254Mar 23, 1990Jul 2, 1991Instrument Specialties Company, Inc.Clip mounted electromagnetic shielding deviceUS5441429 *Aug 18, 1993Aug 15, 1995North American Specialties CorporationSolder-bearing landUS5749741 *Jul 12, 1996May 12, 1998Minnesota Mining And Manufacturing CompanyElectrical connector with ground clipJPS5853372A Title not availableJPS62195978A Title not available* Cited by examinerReferenced byCiting PatentFiling datePublication dateApplicantTitleUS6465738 *Sep 13, 2001Oct 15, 2002Kitigawa Industries Co., Ltd.Grounding terminal and mounting structure of the same on a printed circuit boardUS8760885 *Jan 12, 2012Jun 24, 2014Pegatron CorporationElectronic deviceUS20120182704 *Jan 12, 2012Jul 19, 2012Pegatron CorporationElectronic device* Cited by examinerClassifications U.S. Classification174/267, 29/843International ClassificationH01R4/64, H05K3/34, H01R13/24, H05K7/02, H05K1/18, H01R4/48, H01R43/02, H05K7/14, H01R4/02, H01R12/36Cooperative ClassificationH01R4/64, H05K3/341, H05K2201/1031, H05K1/0215, H01R43/0256, H01R9/091, H01R13/24, H05K2201/09663European ClassificationH05K1/02C1, H05K3/34C, H01R9/09BLegal EventsDateCodeEventDescriptionApr 17, 2014ASAssignmentOwner name: KITAGAWA INDUSTRIES CO., LTD., JAPANFree format text: ADDRESS CHANGE;ASSIGNOR:KITAGAWA INDUSTRIES CO., LTD.;REEL/FRAME:032707/0316Effective date: 20140411Feb 27, 2013FPAYFee paymentYear of fee payment: 12Apr 9, 2009FPAYFee paymentYear of fee payment: 8Apr 11, 2005FPAYFee paymentYear of fee payment: 4Jun 4, 1999ASAssignmentOwner name: KITAGAWA INDUSTRIES, CO., LTD., JAPANFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:YUMI, HIDEO;REEL/FRAME:009998/0316Effective date: 19990526RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services