The subject matter herein relates generally to compliant pin contacts.
Electrical connectors are often mounted to a printed circuit board. The electrical connectors include one or more contacts that are electrically connected to the printed circuit board. In some applications, the contacts have compliant pins that are configured to be through-hole mounted to plated vias of the printed circuit board.
Compliant pins are typically made from strip stock by stamping a work piece to define strips having an outer tear drop shape and then piercing the center of the tear drop shaped portion of the strip to define an opening or eye. Known compliant pins are not without disadvantages. For example, when the outer edges are sheared, tool marks or scratches are created on the sheared edges. The scratches are stress concentration points that potentially lead to fractures when the compliant pin is pressed into the printed circuit board. Additionally, when the electrical connector is used in a harsh environment, such as an automotive application, an aeronautical application, a military application and the like, the electrical connector may be subject to vibration, which can cause further fraction or failure.
Another known problem is that compliant pins will sometimes first engage or interfere with the plating of the printed circuit board in a non-compliant region of the pin. When a non-compliant portion of the pin enters the printed circuit board, damage is caused to the printed circuit board and the plating may be deformed. Deformation of the via is undesirable. Some known compliant pins coin a radius on the outer edges to allow the compliant pin to travel further into the via before interfering with the plating. Coining the outer edges is difficult, time consuming and expensive. Coining the outer edges is an additional manufacturing step which adds to the overall cost of manufacturing the contact. Furthermore, coining a radius on the outer edge can cause a rough edge that can scrape the plating, which is undesirable. Additionally, manufacturing compliant pins from a strip stock results in a large amount of scrap because the material between the contacts is scrapped.
A need remains for a contact having a compliant pin that can be manufactured in a cost effective and reliable manner. A need remains for a contact having a compliant pin that reduces or eliminates tool marks, scratches and/or stress concentration points to minimize fracturing.
In one embodiment, a contact is provided having a contact body that has a front, a rear and opposite sides that extend between the front and the rear. The contact body extends between a mating end and a mounting end. The mating end is configured to be mated with a corresponding mating contact. The mounting end is configured to be through-hole mounted to a printed circuit board. The mounting end has a profiled section that defines a compliant pin. The profiled section has a necked-down portion being thinner between the front and the rear than adjacent portions of the contact body. The profiled section has an opening through the necked-down portion. The profiled section has a compliant portion at the opening. The compliant portion is wider between the sides than adjacent portions of the contact body.
In another embodiment, a contact is provided having a contact body formed from a drawn wire. The drawn wire has a front, a rear and opposite sides that extend between the front and the rear. The contact body extends between a mating end and a mounting end. The mating end is configured to be mated with a corresponding mating contact. The mounting end is configured to be through-hole mounted to a printed circuit board. The mounting end has a profiled section defining a compliant pin. The profiled section has a coined, necked-down portion being thinner between the front and the rear than adjacent portions of the contact body. The profiled section has an opening through the necked-down portion. The profiled section has a compliant portion at the opening. The compliant portion is wider between the sides than adjacent portions of the contact body.
In a further embodiment, a contact is provided having a contact body formed from a stamped strip. The strip has a front, a rear and opposite sheared sides that extend between the front and the rear. The contact body extends between a mating end and a mounting end. The mating end is configured to be mated with a corresponding mating contact. The mounting end is configured to be through-hole mounted to a printed circuit board. The mounting end has a profiled section defining a compliant pin. The profiled section has a coined, necked-down portion being thinner between the front and the rear than adjacent portions of the contact body. The profiled section has an opening through the necked-down portion. The profiled section has a compliant portion at the opening. The compliant portion is wider between the sheared sides than adjacent portions of the contact body.
The electrical connector 102 includes a plurality of contacts 110 that are configured to be mounted to the PCB 104. The contacts 110 have a contact body 111 that extends between a mating end 112 and a mounting end 114. The mating end 112 is configured to be mated with a corresponding mating contact of another electrical connector. The mounting end 114 is configured to be through-hole mounted to a corresponding plated via 108 of the PCB 104. The mounting end 114 includes a compliant pin 116, such as an eye of the needle pin, that is received in the corresponding plated via 108 and makes electrical contact with the plated via 108.
The contacts 110 may have any size or shape depending on the particular application. In the illustrated embodiment, the contact 110 defines a vertical contact where the contact 110 extends along a contact axis with the mating end 112 and the mounting end 114 generally aligned along the contact axis. In alternative embodiments, the contacts 110 may other shapes. For example, the contacts 110 may be right angle contacts where the mating end 112 is oriented generally perpendicular with respect to the mounting end 114.
In the illustrated embodiment, the contact 110 constitutes a spring beam contact, where the mating end 112 is curved and is configured to be mated to a blade type contact. The mating end 112 may be deflected by the blade contact when mated thereto, creating a spring bias against the blade contact. In alternative embodiments, the contact 110 may be a pin type contact that is configured to be received in a socket contact. Alternatively, the contact 110 may be a socket contact configured to receive a pin contact. Other types of contacts are possible in alternative embodiments.
In an exemplary embodiment, the contact 110 is formed from a drawn wire that may be shaped during a metal forming manufacturing process into a desired configuration for mating with the mating contact and the PCB 104, as well as for being received in the electrical connector 102. The compliant pin 116 is formed from the drawn wire during the metal forming manufacturing process.
In an alternative embodiment, rather than being formed from a drawn wire, the contact 110 may be formed from a stamped strip, where the contact 110 is cut from a blank or work piece into a predetermined shape. The mating end 112 and mounting end 114 may then be shaped during a metal forming manufacturing process, such as to form the compliant pin 116. Other processes may be used to form the contacts 110 in alternative embodiments.
The press 120 includes an upper die 122 and a lower die 124 that are used to shape the contact 110. For example, the upper and lower dies 122, 124 may be used to form the compliant pin 116 (shown in
In an exemplary embodiment, the press 120 is used to coin the contact 110 to form the compliant pin 116. During the coining operation, the contact 110 is subjected to sufficiently high forces or stresses to induce plastic flow on the front 128 and the rear 132 to change the shape of the contact 110. For example, the contact 110 may be thinned out between the front 128 and the rear 132, while also widening the contact 110 between the opposite sides in the region where the contact 110 is thinned.
In the illustrated embodiment, the press surface 126 includes a center section 134 and angled sections 136, 138 flanking the center section 134. The angled sections 136, 138 may be angled with respect to the center section 134 at any angle. The angles of the angled sections 136, 138 with respect to the center section 134 may be controlled to define the shape of the compliant pin 116. Optionally, the angled section 136 may be angled at a different angle than the angled section 138. The lengths of the center section 134 as well as the angled sections 136, 138 may be controlled to control the final shape of the compliant pin 116. Optionally, the length of the angled section 136 may different than the length of the angled section 138. The press surface 126 may include other sections in alternative embodiments, such as additional angled sections that are angled at different angles than the angled sections 136, 138.
The press surface 130 includes a center section 144 and angled sections 146, 148 flanking the center section 144. The angled sections 146, 148 may be angled with respect to the center section 144 at any angle. The angles of the angled sections 146, 148 with respect to the center section 144 may be controlled to define the shape of the compliant pin 116. Optionally, the angled section 146 may be angled at a different angle than the angled section 148. The lengths of the center section 144 as well as the angled sections 146, 148 may be controlled to control the final shape of the compliant pin 116. Optionally, the length of the angled section 146 may different than the length of the angled section 148. The press surface 130 may include other sections in alternative embodiments, such as additional angled sections that are angled at different angles than the angled sections 146, 148.
In the first stage 150, a drawn wire 160 is provided. The drawn wire 160 has a tip 162 at an end thereof. The end of the drawn wire 160 is processed to form the compliant pin 116. The drawn wire 160 is presented at the press 120 (shown in
In the profiled section 164, the front 128 and rear 132 are pressed inward towards one another and flattened to a predetermined profile defined by the press surfaces 126, 130 (shown in
In the profiled section 164, the contact 110 is wider from side 168 to side 170 than the side to side width of the drawn wire 160 interior (e.g., above) the profiled section 164. Optionally, the press surfaces 126, 130 may be profiled to form a bulbous or tear drop shape. The outer profile, defined by the sides 168, 170 has a continuous, convex curvature. In an exemplary embodiment, the outer profile is shaped to define an eye of the needle pin.
At the third stage 154, an opening 172 is provided in the profiled section 164. The opening 172 may be formed by piercing or punching through the profiled section 164. Other presses may be used to form the opening 172. First and second legs 174, 176 are defined on opposite sides of the opening 172. The first and/or second leg 174, 176 may be deflected when the compliant pin 116 is loaded into the PCB 104 (shown in
The contact 110 is manufactured to form the compliant pin 116 at the mounting end 114. In an exemplary embodiment, the contact 110 is coined to form the profiled section 164 and then punched to form the opening 172 to define the compliant portion 178.
As shown in
The front 128 includes a flat surface 180 and tapered surfaces 182, 184 flanking the flat surface 180. The lengths of the tapered surfaces 182, 184 as well as the angles of the tapered surfaces 182, 184 are controlled by the press surface 126 (shown in
The rear 132 includes a flat surface 186 and tapered surfaces 188, 190 flanking the flat surface 186. The lengths of the tapered surfaces 188, 190 as well as the angles of the tapered surfaces 188, 190 are controlled by the press surface 130 (shown in
As shown in
When the front 128 and the rear 132 are necked-down, outer surfaces 192, 194 of the sides 168, 170, respectively, are forced outward. In an exemplary embodiment, the outer surfaces 192, 194 of the sides 168, 170, at least in the compliant portion 178 may be rounded or curved between the front 128 and the rear 132. Such rounding occurs naturally when the front 128 and the rear 132 are coined. The rounding of the outer surfaces 192, 194 may be beneficial when coupling the compliant pin 116 to the plated via 108.
In the first stage 220, a drawn wire 230 is provided and may be presented to a press that has upper and lower dies that are profiled differently than the upper and lower dies 122, 124 (shown in
In the illustrated embodiment, the drawn wire 230 includes a front 232 and a rear 234 that are profiled to define a necked-down portion 236 that has continuously curved surfaces along the profiled section 212, rather than having flat surfaces and tapered surfaces, such as those provided on the contact 110.
At the third stage 224, an opening 238 is provided in the profiled section 212. The opening 238 extends through the thinnest part of the necked-down portion 236 between the front 232 and the rear 234. A compliant portion 240 of the contact 210 is defined within the necked-down portion 236 at the opening 238.
In the first stage 320, a stamped strip 330 is provided. The stamped strip 330 is stamped from a blank or work piece. In an exemplary embodiment, a plurality of stamped strips 330 could be provided and connected along a carrier. The stamped strip 330 includes a front 332, a rear 334 and opposite sides 336, 338. During the stamping process that forms the stamped strip 330, the work piece is cut or sheared along the sides 336, 338. The sides 336, 338 define sheared sides, and may be referred to hereafter as sheared sides 336, 338.
At the second stage 322, the stamped strip 330 is coined to form the profiled section 312. When stamped, the sides 336, 338 are generally parallel to one another. The stamped strip 330 may be coined in a similar manner as the contact 110 (shown in
When the profiled section 312 is coined, the sides 336, 338 are forced outward which tends to spread and/or almost entirely eliminates marks on the sides 336, 338 formed during the stamping or shearing process. Removing the scratch marks tends to eliminate fractures in the compliant pin 316 when loaded into the PCB 104 (shown in
At the third stage 324, an opening 348 is provided in the profiled section 312. The opening 348 may be formed by piercing or punching through the profiled section 312. The opening 348 is punched or otherwise formed in the necked-down portion 340.
It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Dimensions, types of materials, orientations of the various components, and the number and positions of the various components described herein are intended to define parameters of certain embodiments, and are by no means limiting and are merely exemplary embodiments. Many other embodiments and modifications within the spirit and scope of the claims will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means—plus-function format and are not intended to be interpreted based on 35 U.S.C. §112, sixth paragraph, unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.