Patent Publication Number: US-9853375-B2

Title: Pin attach converter

Description:
BACKGROUND 
     The present disclosure relates to electrical circuits, and more specifically, to an adapter for attaching a compliant electrical contact to a solder tail electrical contact. 
     Printed circuit board electrical connector can include compliant press fit pin connectors and solder tail connectors. Compliant press fit pin connectors may be used on thick printed circuit boards (e.g., backplanes) that make it difficult to attach solder tail connectors. Solder tail connectors may be used on thin or flexible printed circuit boards where enough of the pin sticks through the board for the soldering process. 
     SUMMARY 
     According to embodiments of the present disclosure, a pin attach converter for coupling an electrical contact to a printed circuit board may include a compliant region having a first length adapted to traverse an aperture in a printed circuit board and provide mechanical and electrical registry with at least one wall of the aperture. The pin attach converter may also include an adapter region coupled to the compliant region, and having a cavity with a second length and adapted to receive the electrical contact, where the second length extends along a same longitudinal axis as the first length, and the cavity is adapted to provide mechanical and electrical registry with the electrical contact. 
     Various embodiments are directed towards a pin attach converter for coupling an electrical contact to a printed circuit board. The pin attach converter may include a compliant region having a shoulder portion and a compliant portion coupled to the shoulder portion along a longitudinal axis of the compliant region, and configured to compress by interference a wall of an aperture in a printed circuit board to provide at least one of mechanical and electrical registry the wall. The pin attach converter may further include an adapter region having a first end with an opening forming a cavity having a height extending along a same longitudinal axis and adapted to receive an electrical contact, and a closed second end coupled to the compliant region along a the longitudinal axis. 
     The above summary is not intended to describe each illustrated embodiment or every implementation of the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings included in the present application are incorporated into, and form part of, the specification. They illustrate embodiments of the present disclosure and, along with the description, serve to explain the principles of the disclosure. The drawings are only illustrative of certain embodiments and do not limit the disclosure. 
         FIG. 1  schematically depicts an embodiment of a pin attach converter. 
         FIG. 2  schematically depicts a perspective view of an embodiment of a pin attach converter with an electrical contact in a cavity of an adapter region and a compliant region inserted into an aperture of a printed circuit board, according to various embodiments. 
         FIG. 3  schematically depicts an embodiment of a pin attach converter with the adapter region configured to couple to an electrical contact by crimping, according to various embodiments. 
         FIG. 4  schematically depicts a cross sectional view of an electrical connector having a set of solder tail contacts soldered to a set of pin attach converters, according to various embodiments. 
     
    
    
     While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. 
     DETAILED DESCRIPTION 
     Aspects of the present disclosure relate to electrical circuits, and more particular aspects relate to an adapter for attaching a compliant electrical contact to a solder tail electrical contact. While the present disclosure is not necessarily limited to such applications, various aspects of the disclosure may be appreciated through a discussion of various examples using this context. 
     Embodiments of this disclosure are directed towards a pin attach converter that enables electrical connectors having solder tail contacts to be used in printed circuit board (PCB) applications configured to receive a compliant press fit electrical contacts. 
     An electrical connector may include a coupling portion and a contact portion. The coupling portion may interface with, for example, another connector, an electronic component, or a PCB application (e.g., through a via or aperture in the PCB). The contact portion may be configured to interface or couple with electrical traces in/on a PCB. The contact portion of some connectors may include either a compliant or a solder tail section. 
     Electrical connector contacts having a compliant contact section may enable printed circuit board applications to be assembled without the use of electrical solder. The compliant section of these connectors may be a flat electrical pin, with at least a portion of the pin (e.g., a complaint region) having cross section that may be nominally larger than an aperture in a PCB configured to receive the contact (e.g., in a plated through-hole mounting scheme). The aperture may be a cylindrical opening in the PCB having plated walls contacting electrical traces. When the compliant contact is inserted into the aperture, the walls of the aperture may compress a compliant region of the contact (e.g., like a spring), providing mechanical and electrical registry with the contact. 
     An electrical connector contact having a solder tail contacts may enable printed circuit board applications to be assembled using soldering processes such as wave soldering. The solder tail contact may be a pin (e.g., a narrow cylindrical electrical contact) that extends from the coupling section. The solder tail may be inserted into an aperture of a PCB, and may be electrically and mechanically bonded to an electrical trace by soldering. 
     Embodiments of the present disclosure are based on the recognition that there are situations where an electrical connector having compliant pin contacts may be needed for use in a PCB application, but available connectors may be tooled for solder tail applications. Having the connectors tooled for a specific PCB application may not be cost effective. Additionally, when the PCB is thick, as in a backplane application, soldering the connector to the PCB can add time and difficulty to the application. Various embodiments of the present disclosure may enable an electrical connector having a solder tail contact to be used in PCB applications requiring compliant pin contacts. 
     Referring now to the figures,  FIG. 1  schematically depicts an embodiment of a pin attach converter  100 , according to various embodiments. The pin attach converter  100  may include adapter region  105 , shoulder region  108 , compliant region  110 , and tip region  112 . The pin attach converter  100  may be a single mechanically and electrically contiguous unit formed using know materials (e.g., metallic alloys such as copper, silver, and/or tin) and methods (e.g., stamping, casting, and/or welding). Furthermore, at least a portion of pin attach converter  100  may be coated with a conductive metallic alloy (e.g., copper, silver, and/or tin). 
     The adapter region  105  may include an outer wall  120 , and an inner wall  125  formed by a cavity  115 . The outer wall  120  may be cylindrical with a diameter D1 and a height H1 (e.g., a first height). The outer wall  120  may also form other three-dimensional shapes, including polyhedrons which is perpendicular to the diameter D1. A cross section of adapter region  105  taken perpendicular to a longitudinal axis A 1  (e.g., an axis parallel to the height of adapter region  105  or outer wall  120 ) may, for example, be circular, rectangular, triangular, or hexagonal. At least a portion of outer wall  120  may be coated with a metallic alloy (e.g., copper, silver, and/or tin), or an insulating material (e.g., rubber, or plastic). 
     The cavity  115  may be cylindrical with a diameter D2, and a wall  125  (e.g., the inner wall) having a height H2 (e.g., a second height) extending into adapter region  105  parallel to the longitudinal axis A 1 . In some embodiments, the cavity  115  may have a first cylindrical portion with a height defined by wall  125  and circular cross section having diameter D2. The cavity  115  may also have a conical tip region  130  having a tip and circular cross section of the cylindrical portion for a base. The magnitude of diameter D2 and the height of wall  125  may be selected to accommodate an electrical contact having a given length and diameter (e.g., the diameter D2 may be larger than a diameter of the electrical contact, while the height of wall  125  may be tall enough to enable cavity  115  to receive at least a portion of the electrical contact). In certain embodiments, the second conical tip region  130  may extend parallel to the longitudinal axis A 1  into the shoulder region  108 . The cavity  115  (and thus the wall  125 ) and conical tip region  130  may form other three-dimensional shapes, including, for example, polyhedrons such as cuboids. 
     Shoulder region  108  may be conical with a first base having a circular cross section of diameter D1 and a second base having a circular cross section of diameter D3. In some embodiments, the first base may have a diameter larger than D2, creating a surface (e.g., a ledge) for pressing the pin attach converter  100  into an aperture of a PCB. In certain embodiments, the first and/or second base(s) may have a rectangular, triangular or other polygonal cross section. The cross section of the first and/or second base(s) may be different from the cross section of outer wall  120  and cavity  115 . 
     The compliant region  110  may correspond with a compliant portion of a compliant pin. Compliant region  110  may include a base or stem (not shown) coupling complaint region  110  to shoulder region  108 . In some embodiments, compliant region  110  may have a substantially flat shape defined by an outer wall  140  having diameter D4, an inner wall  145 , and a central cavity or eye  150 . The compliant region may also have a length D5 extending parallel to the longitudinal axis A 1 . The outer wall  140  may be coated with a conductive metallic alloy that may withstand the stress of the pin attach converter  100  being inserted into a PCB aperture without stripping (e.g., without the outer wall losing the metallic coating). 
     The tip region  112  may be substantially flat and include a base portion (not shown) coupling the tip region to the compliant region  110 . In some embodiments, tip region  112  may be an integral part of compliant region  110 . 
       FIG. 2  schematically depicts a perspective of an embodiment of a pin attach converter  100  with an electrical contact  205  in a cavity of an adapter region  105  and a compliant region  110  inserted into an aperture of a PCB  210 . 
     As shown in  FIG. 2 , the adapter region  105  may receive a length of electrical contact  205  in the cavity  115 . The electrical contact  205  may be a solder tail contact of an electrical connector. The electrical contact  205  may have any length, diameter, or geometry that can be accommodated by cavity  115 . The electrical contact  205  may be electrically and/or mechanically coupled to the adapter region  105  using solder (e.g., electrical solder) deposited, for example, contiguously in cavity  115  and on the electrical contact by know soldering processes. When soldering is used to couple the electrical contact  205  to adapter region  105  the dimensions of the electrical contact and the diameter of the cavity  115  may be selected to enable an amount of solder to be deposited between the electrical contact and the inner wall  125  of the cavity. The adapter region  105  may be made of a metallic alloy having a higher melting point than the solder. The adapter region  105  may also be coated with a heat-resistive material. In some embodiments, a charge solder or other coupling material may be deposited into conical tip region  130  and into at least a portion of cavity  115  before the electrical contact  205  is coupled to the adapter region  105 . In certain embodiments, the electrical contact  205  may be coupled to adapter  105  by other coupling methods, including crimping, and/or compression/swage coupling where a plurality of teeth radially extending from at least one wall of the cavity  115  towards a center of the cavity for engagement with the electrical contact. 
     The shoulder region  108  may limit the depth to which the pin attach converter  100  may be inserted into the aperture  215 . For example, when the first and/or second base(s) of shoulder region  108  is wider than a diameter D6 of aperture  215 , the pin attach converter  100  may be inserted into the aperture up to a depth determined by the first and/or second base(s). In embodiments where the first and/or second base(s) have a diameter that is wider than the diameter of outer wall  120 , shoulder region  108  may form a ledge (not shown) for pushing the pin attach converter  100  into aperture  215 . 
     The compliant region  110  may be inserted into aperture  215  to a depth determined by shoulder region  108 . The diameter of compliant region  110  may correspond with the diameter D6 such that the compliant region achieves mechanical and electrical registry with the walls  220  when inserted into aperture  215 . In some embodiments, the diameter of the compliant region  110  may be compressed (e.g., reduced in width or magnitude) by interference or contact with the walls  220 . The length of the compliant region  110  may be selected to enable a large enough mechanical and electrical contact between the compliant region and the walls  220  to stably support the pin attach converter  110  (e.g., to enable the pin attach converter to support an electrical contact  205  in a PCB application without being damaged electrically or mechanically). 
     The tip region  112  may be inserted into the aperture  215  to a depth determined by the length of compliant region  110  and the thickness D7 of the PCB  210 . The tip region  112  may serve as a positioning or insertion guide for the pin attach converter  100  by, for example, signaling to an insertion mechanism that the pin attach converter is inserted to an appropriate depth. In some embodiments, the tip region  112  may traverse a second aperture  225  of the PCB  210 . 
       FIG. 3  schematically depicts an embodiment of a pin attach converter  300  with the adapter region  305  configured to couple to an electrical contact by crimping, according to various embodiments. The pin attach converter  300  may be an embodiment of the pin attach converter  100  with the exception that the adapter region  305  has been modified to support an electrical contact by crimping. As shown in  FIG. 3 , a portion of an outer wall  320  and an inner wall  325  was removed from an adapter region  305  of the pin attach converter  300  to create an opening  335  having walls  340 , width or diameter D8, and height D9. When the adapter region  305  is crimped, the opening  335  may enable walls  340  to collapse onto and secure an electrical contact inserted into a cavity  315  of the pin attach converter  300 . The width D8 and height D9 may be selected to enable the crimped adapter region  305  to support an electrical contact in a given PCB application. A circular cross section  330  of the adapter region  305  extending from outer wall  320  inward to inner wall  325  may be perforated, stamped or made of a thinner or weaker material than the rest of the pin attach converter  300  to facilitate crimping. 
       FIG. 4  schematically depicts a view of an electrical connector  400  having a set of solder tail contacts  410  soldered to a set of pin attach converters  420 , according to various embodiments. The electrical connector  400  includes coupling portion  405 , and a contact portion having solder tail contacts  410 . The solder tail contacts can be coupled to pin attach converters  420  using an electrical solder  415 . A connecting portion  425 , contiguous with a shoulder regions of pin attach converters  420 , may structurally link the pin attach converters. The connecting portion  425  may also provide a surface or ledge for applying a force to insert the pin attach converters  420  in PCB  430 . 
     The descriptions of the various embodiments of the present disclosure have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.