Patent Application
20140242817
1. Field of the Invention
The present invention relates to connectors. More specifically, the present invention relates to connectors with contacts including anti-rotation elements and solder flow abatement.
2. Description of the Related Art
Connectors are used to place electrical devices in communication with one another. A connector includes contacts that transmit signals to an electrical device or another connector. The contacts of a connector may each include a raised portion to help secure and position the contacts within the connector. Further, solder may be attached to the contacts of a connector. The solder is used to form an electrical and mechanical connection between the contact and a pad on a printed circuit board.
U.S. Pat. No. 5,791,929 discloses a conventional contact 110 with raised portions. As shown in
However, the positioning feet 114 of the contact 110 provide only two points of contact for an interference fit with the connector. Accordingly, the contact 110 is only secured in the connector about a center line of the contact 110. Thus, the contact 110 is able to twist or rotate about its center line in the connector. Accordingly, an electrical and mechanical connection between the head section 111 and the corresponding contact of the device may not be sufficiently achieved because the contact 110 may twist or rotate during a connection operation between the connectors. Further, performance of the contact 110 is further reduced if the contact 110 is manufactured to have smaller sizes because smaller positioning feet 114 provide a correspondingly reduced retention force within the connector. Moreover, when a leg 117 of the contact 110 is inserted into a plated through-hole of a printed circuit board (not shown), reflowed solder from the plated through-hole may migrate along the contact 110 and interfere with the positioning feet 114. The contact 110 includes a projection 116 to help prevent wicking of solder when the leg 117 is soldered to the printed circuit board. However, solder may flow along the edges of the contact 110 around the projection 116 to the head section 111.
U.S. Pat. No. 6,702,594 discloses a conventional contact 210 including a solder block 220. As shown in
However, because the opening 216 is located in the body section 212, and thus separated from the tail section 213 and the pair of clips arms 219, solder can flow up the contact and away from the tail section 213 to the head section 211 when the solder block 220 is reflowed. The opening 216 can be insufficient to prevent solder from wicking up the contact 210 if the volume of reflowed solder is large or if the contact 210 is passed through a reflow oven multiple times. Accordingly, when the connector that includes the contact 210 is mounted to a printed circuit board, the contact 110 may have an insufficient electrical and mechanical connection with a corresponding pad of the printed circuit board if an excessive amount of solder flows up the contact 210. In particular, an insufficient amount of solder may be present between the tail section 213 and the corresponding pad of the printed circuit board. Further, due to the geometry of the opening 216, reflowed solder may migrate over the sides of the opening 216 and to the outer edges of the contact 210. The reflowed solder may also interfere with the head section 211.
To overcome the problems described above, preferred embodiments of the present invention provide a contact with anti-rotation features and solder flow abatement.
A contact according to a preferred embodiment of the present invention includes a head, a tail including an opening, a body connected at one end thereof to the head and at another end thereof to the tail, a first lance and a second lance extending from the body, a dimple raised from the body, and a solder member attached to the tail such that the solder member engages at least a portion of the opening. The first lance and the second lance are arranged to deflect when the contact is inserted into a connector; and the first lance, the second lance, and the dimple are arranged to frictionally secure the contact to the connector.
The solder member is preferably crimped to the tail. The opening preferably includes a holding section at an end of the tail opposite to the body, and the solder member is preferably attached to the tail such that the solder member fills the holding section. The opening preferably includes an abatement section extending in a direction of the body, and the solder member is preferably attached to the tail such that the solder member does not engage with the abatement section before the solder member is reflowed. The abatement section is preferably arranged such that the solder member reflows into the abatement section when the solder member is reflowed.
The first lance, the second lance, and the dimple are preferably arranged so as to not be co-linear. The first lance, the second lance, and the dimple are preferably arranged to be equidistant or substantially equidistant. The contact preferably includes a second dimple, and the first lance, the second lance, the dimple, and the second dimple are preferably arranged at or substantially at vertices of a square or rectangle. Alternatively, the first lance, the second lance, the dimple, and the second dimple are preferably arranged at or substantially at vertices of a parallelogram or trapezoid.
The tail preferably includes a first leg and a second leg extending therefrom; a space between the first leg and the second leg preferably defines at least a portion of the opening; and the solder member is preferably attached to the first leg and the second leg.
The contact preferably includes an abatement band extending across each of an opposing pair of major surfaces of the contact. The abatement band is preferably formed either by depositing a material that solder does not adhere to on the major surfaces of the contact or by scoring the major surfaces of the contact.
The contact is preferably included in a connector, and the connector preferably includes a plurality of contacts. The head of each of the contacts is preferably arranged to engage with a corresponding contact of another connector. The solder member of each of the contacts is preferably arranged to be fused to the tail of the contact and to be fused with a pad on a printed circuit board.
A contact according to a preferred embodiment of the present invention includes a head, a tail including a continuous opening with a holding section and an abatement section, a body connected at one end thereof to the head and at another end thereof to the tail, and a solder member attached to the tail such that the solder member engages the holding section. The abatement section is arranged such that the solder member reflows into the abatement section when the solder member is reflowed.
The abatement section is preferably arranged to have a volume proportional to a volume of the solder member.
The above and other features, elements, characteristics and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the present invention with reference to the attached drawings.
Preferred embodiments of the present invention will now be described in detail with reference to
As shown in
As shown in
Preferably, the contact 10 includes two lances 14 and a dimple 15 to secure the electrical contact 10 in the connector 30 by a frictional, interference fit. The lances 14 are preferably arranged to deflect when the contact 10 is inserted into the connector 30, whereas the dimple 15 is preferably arranged to not deflect (i.e., to retain its shape) when the contact 10 is inserted into the connector 30. The contact 10 preferably includes recessed shoulders 18 to facilitate insertion and alignment of the contact 10 when the contact 10 is inserted into the connector 30. Further, any other number of lances 14 or dimples 15 can also be used. One or more of the lances 14 may be replaced with a dimple 15, or vice-versa. The lances 14 and the dimple 15 are preferably arranged to engage with the connector 30 such that contact 10 is secured in the connector 30. It is also possible to use other structures, e.g., side barbs extending in the width direction of the contact 10, to secure the contact 10 in the connector 30.
As shown in
During the soldering process, the solder member 20 reflows so that some of the solder member 20 migrates into the abatement section 16b of the contact 10 so that the solder member 20 is retained at the tail section 13 near the central longitudinal axis of the connector 10. The tail 13 of the contact 10 is preferably arranged to be connected to a printed circuit board by fusing the solder member 20 to the tail 13 of the contact 10 and to a pad on the printed circuit board. Preferably, a mechanical and electrical connection is formed between the contact 10 and the printed circuit board by reflowing the solder member 20 to fuse the tail 13 of the contact 10 to the pad on the printed circuit board.
The abatement section 16b is preferably dimensioned such that the size of the opening 16 is proportional to the amount of solder required to achieve an acceptable electrical and mechanical connection between the contact 10 and a corresponding pad on a printed circuit board. Preferably, the volume of the opening 16 is proportional to the volume of the solder member 20. Further, the shape of the holding section 16a and the abatement section 16b may be modified in order to set a particular upper limit for solder flow on the contact 10.
As shown in
As shown in
As shown in
Accordingly, by increasing the distance between the opening 56 and the head section 11, the tail section 53 of the contact 50 helps to prevent solder from wicking up the contact 50 and interfering with the head section 11, the lances 14, and the dimple 15. Thus, the contact 50 may be securely retained within a connector (not shown) that includes the contact 50, while further reducing the likelihood that reflowed solder will interfere with the head section 11, the lances 14, or the dimples 15.
As shown in
Preferably, the contact 60 includes two lances 64 and two dimples 65 to secure the contact 60 within a connector (not shown). However, any other number of lances 64 or dimples 65 can also be used, one or more of the lances 64 may be replaced with a dimple 65, or vice-versa. The lances 64 and the dimple(s) 65 are preferably arranged to engage with the connector such that contact 60 is secured in a connector. It is also possible to use other structures, e.g., side barbs extending in the width direction of the contact 60, to secure the contact 60 in the connector. Preferably, the contact 60 also includes a recessed shoulder 68 to facilitate insertion and alignment of the contact 60 when the contact 60 is inserted into a connector.
As shown in
Various preferred embodiments of the present invention use three or four points of contact, while conventional contacts use at most one or two points of contact. Because adding points of contact adds to the cost of manufacturing of a contact, unnecessary points of contact are not added. Although using three or four points of contact increases the cost of manufacturing the contacts 10, 50, and 60, it allows the contacts 10, 50, and 60 to be manufactured smaller than conventional contacts, while still providing a sufficient frictional, interference fit to retain the contacts 10, 50 and 60 within a connector.
As shown in
Preferably, a male connector that includes the contact 60 is arranged to engage with a female connector that includes the contact 10 and/or the contact 50. In particular, the outer surfaces of the first arm 61a and second arm 61b are preferably arranged to engage with the inner surfaces of the first arm 11a and second arm 11b. Accordingly, the male connector that includes the contact 60 preferably includes clearance at the head section 61 to provide clearance for joining with the head section 11. It is noted that, while a connector that includes the contact 60 may have a narrower cross-section than that of the connector 30, the connector that includes the contact 60 preferably has a pitch similar to that of the connector 30 to ensure that the contact 60 is aligned with the contact 10 and/or the contact 50. As shown in
According to the preferred embodiments of the present invention, the holding sections 16a, 56a, and 66a and the abatement sections 16b, 56b, and 66b of the openings 16, 56, and 66 direct reflowed solder of the solder member 20 to the center of the bottom of the tail sections 13, 53, and 63. Accordingly, the reflowed solder of the solder member 20 is directed towards a corresponding pad on a printed circuit board to form a mechanical and electrical connection between the contact 10, 50, or 60 and the printed circuit board. The solder member 20, as shown in
Moreover, to help further prevent solder from wicking into the head sections 11 and 61 according to the preferred embodiments of the present invention, such as when multiple passes of reflow soldering are performed, an abatement band is preferably included in the contacts 10, 50, and 60. The abatement band is preferably formed as a narrow strip that extends horizontally across both planar surfaces of the contacts 10, 50, and 60, and is preferably located at or near an edge of the abatement sections 16b, 56b, and 66b. The abatement band may include scoring (for example, laser scoring) and/or a material to which solder does not adhere (e.g., nickel). The abatement band is preferably included in contacts with small dimensions or low profiles to supplement the wicking prevention provided by the abatement sections 16b, 56b, and 66b. Preferably, the abatement band is arranged at a predetermined distance from the bottom of the tail sections 13, 53, and 63 (i.e., the connection point between the contact 10, 50, and 60 and the corresponding pad on a printed circuit board). As one example, the abatement portion can be located directly above the opening 16, 56, or 66 and can extend across the entire width of both sides of the contact 10, 50, or 60.
The contacts 10, 50, and 60 according to the preferred embodiments of the present invention are preferably formed by stamping, for example, by progressive die stamping. Further, the lances 14 and 64 according to the preferred embodiments of the present invention are preferably formed by punching the contacts 10, 50, and 60 after stamping, for example.
The head sections 11 and 61 of the contacts 10, 50, and 60 are preferably formed as a tulip connection point defined by first arms 11a and 61a and second arms 11b and 61b. Preferably, when the contact 60 engages with the contact 10 or the contact 50, the outer surfaces of the first arm 61a and second arm 61b engage with the inner surfaces of the first arm 11a and second arm 11b, thereby providing two connection points between the contact 60 and the contact 10 or the contact 50. Accordingly, the tulip connection point defined by first arms 11a and 61a and second arms 11b and 61b provides:
The contacts 10, 50, and 60 according to the preferred embodiments of the present invention preferably include a copper alloy base and plating formed of tin, a tin alloy (e.g., a tin-lead alloy), gold, or a gold alloy at the head section and tail section (e.g., sections of the contact that may directly connect to a corresponding contact, a printed circuit board, or other electrical device). Further, the abatement band may include nickel, a nickel alloy, a wax, or similar substance that solder does not adhere to. The connector 30 according to the preferred embodiments of the present invention is preferably made from an insulating material, for example, any plastic, thermoplastic, rubber, or similar non-metallic material.
As shown in
As shown in
While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.
