The present invention generally relates to electrical circuit connections, and more particularly relates to an electrical interconnection between a substrate and an electrical device without requiring the need for a solder joining process.
Electronic packages commonly employ various surface mount electronic devices connected to electrical circuitry on a substrate, such as a printed circuit board. The printed circuit board generally includes a dielectric substrate in single or multiple layers and electrical circuitry typically in the form of conductive circuit traces. The electrical circuitry also typically includes electrical conductive contact pads for making electrical connections to electrical components, such as surface mount devices. Various types of electrical connectors exist for forming the electrical connection between the surface mount components and the electrical circuitry on the substrate.
Thru-hole electrical connectors have been employed for use in automotive electronic controllers and other applications. The conventional thru-hole connectors are generally reliable and robust, however, a number of disadvantages exist. With surface mount technology, many electronic packages require a solder reflow process to manufacture the circuit assembly. When using a thru-hole connector, an additional manufacturing process is typically required to mount the electrical connector to the circuit board, such as a wave or selective wave solder or pin-in-paste process. Additionally, the thru-hole connector typically consumes all layers of the circuit board and, thus, the connector footprint area generally cannot be used for other purposes.
Another conventional surface mount connector technology employs the use of gull wing-type surface mount connectors which are soldered to the surface of the circuit board. These types of connectors have been employed in the automotive environment. However, gull wing-type surface mount connectors have low shear force ratings and may experience reliability problems due to cracked solder joint interconnections between the connector leads and the printed circuit board. Additionally, the ceramic-based packages generally use a wire bonded connector header. The wire bonding process can be cumbersome and also typically adds a manufacturing process step.
It is therefore desirable to provide for a reliable electrical connection that enables electrical interconnection between the circuit board and another electrical device in a manner that is easy to manufacture. It is further desirable to provide for such an electrical connector that consumes a small amount of the substrate and does not require application of a solder connection process.
In accordance with the teachings of the present invention, an electrical connector assembly and method of assembling an electrical connector to a substrate are provided. According to one aspect of the present invention, the electrical connector assembly includes a substrate and electrical circuitry formed on the substrate. The electrical connector assembly also has an electrically conductive pin having at least one pointed member disposed at least partially in contact with the electrical circuitry on the substrate. The electrical connector assembly further includes a holder for securing the conductive pin such that the pointed member of the conductive pin is held in contact with the electrical circuitry on the substrate.
According to another aspect of the present invention, an electrical connector assembly is provided that includes a substrate having electrical circuitry including a contact pad. The connector assembly has an electrically conductive pin pressed into contact with the contact pad. The electrical connector assembly also includes a shroud engaged to the conductive pin. The assembly further includes an overmolding material disposed at least partially between the shroud and the substrate to secure the conductive pin in contact with the contact pad.
According to a further aspect of the present invention, a method of assembling an electrical connector assembly to a substrate is provided. The method includes the step of providing a substrate having electrical circuitry. The method includes the step of disposing an electrically conductive pin on the electrical circuitry, and forcing the conductive pin into contact with the second electrical circuitry on the substrate. The method further includes the step of holding the conductive pin such that the conductive pin maintains contact with the electrical circuitry.
Accordingly, the electrical connector assembly and method of the present invention advantageously do not require a solder connection process to connect the conductive pin and electrical circuitry. According to some aspects, the electrical connector assembly consumes a small amount of volume, and is easy to manufacture to provide a reliable connector assembly.
These and other features, advantages and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims and appended drawings.
The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
Referring now to
The substrate 12 is shown disposed on top of backplate 28, such as an aluminum plate that provides a support structure in the bottom and side walls. The backplate 28 may have upstanding pins 29 and ribs 31 extending from the bottom wall. Pins 29 are aligned to extend into holes 13 formed in substrate 12. Pins 29 and ribs 31 support and align the substrate 12. The substrate 12 may be otherwise configured with or without a backplate.
The substrate 12 may employ a known substrate material, such as low temperature co-fired ceramic (LTCC) or FR4, and may be a rigid or non-rigid substrate. The substrate 12, described in one exemplary embodiment as a printed circuit board, has first electrical circuitry formed on the top surface thereof including contact pads 16. The contact pads 16 have an exposed surface for contacting the terminal ends of connector pins 20 to form the electrical connections according to the present invention. The substrate 12 may further include electrical circuitry extending through the substrate, including circuitry 14 formed in intermediate layers and on the bottom surface. It is also contemplated that one or more electrical devices may be connected via one or more electrical connector assemblies 15 to the top, bottom and/or side walls of the substrate 12, without departing from the teachings of the present invention.
The electrical connector assembly 15 provides for easy to assemble and reliable electrical interconnection between the circuit board 12 and other electrical device(s). The electrical connector assembly 15 includes one or more electrically conductive pins 20. The conductive pins 20 are disposed adjacent to and aligned with the contact pads 16 on circuit board 12, and are forced into contact therewith by way of a holder. In the embodiment shown, twenty-four conductive pins 20 are shown mounted within a single shroud 30 and arranged in two parallel rows. However, it should be appreciated that one or more electrically conductive pins 20 may be employed in various arrangements in the electrical connector assembly 15 according to the present invention.
The conductive pins 20 are shown generally configured as elongated cylindrical shaft pins having a first terminal end with one or more pointed members 22 for contacting electrical circuitry 16 on the substrate 12 and an opposite second end 26 for allowing connection to an external electrical device (not shown). The conductive pins 22 are made of an electrically conductive material such as copper, or a copper alloy such as beryllium copper or brass. The elongated shafts of the conductive pins 20 are shown extending through respective openings 33 in a bottom wall of the shroud 30 and each includes a barb 24 connected or locked within the respective opening 33 to the shroud 30. The shroud 30 is a dielectric such as plastic that may be molded around the conductive pins 20 to form the integral assembly. The first terminal end of each conductive pin 20 has one or more pointed members 22 (e.g., teeth). In the embodiment shown in
The shroud 30 is shown having an upper flat surface 34 around the perimeter and ribs or pegs 32 on the bottom surface. The shroud 30 is disposed on top of substrate 12 and may be aligned therewith by ribs or pegs 32 engaging slots or holes 13 in substrate 12. A mold assembly made up of upper mold member 40 and lower mold member 42 forces the shroud 30 on the upper peripheral surface 34 to be forced toward the circuit board 12 so as to drive the conductive pins 20 at the first terminal end with pointed members 22 into the contact pad 16 on substrate 12. In the embodiment shown in
During assembly of the electronic package 10, the upper mold member 40 and lower mold member 42 are forced together so as to engage the shroud 30 at surface 34 and push the shroud 30 with conductive pins 20 downward toward circuit board 12. In doing so, the first terminal end of conductive pins 20 at the pointed members 22 engage in solder layer 18 of the respective contact pads 16 to form a physical and electrical contact thereto.
The electrical connector assembly 15 further includes a holder for securing the conductor pins 20 and shroud 30 in place to provide electrical and physical contact between the conductive pins 20 and the respective contact pads 16 on the circuit board 12. According to one embodiment, the holder is a mold compound 36 that essentially molds the shroud 30 and conductive pins 20 against the circuit board 12. In one exemplary embodiment, the mold compound 36 may include an overmolding material, such as an epoxy mold compound that bonds the assembly 15 together. The overmolding material 36 also serves to provide an overmolded package 10. The overmolding material 36 is essentially disposed in any location and shape sufficient to operate as a holder to secure the shroud 30 and conductive pins 20 in contact against the substrate 12. According to one exemplary embodiment, the overmolding material 36 may be an epoxy mold compound such as thermoset materials commercially available as Cookson 200SH-01 or Henkle MG33F-0602. The overmolding material 36 essentially cures to adhere the components of the assembled package together.
During assembly of the overmolded package 10 and its electrical connector assembly 15, the backplate 28, circuit board 12 and connector assembly 15 are enclosed by a mold which is then filled with the mold compound 36. One example of a mold is illustrated in dashed lines surrounding package 10 in
The resultant structure of the overmolded package 10 is locked together after the overmold compound 36 is cured. The second terminal end 26 of conductive pins 20 within shroud 30 are adapted to matingly engage terminal connectors of another electrical device that would extend within the female receptacle of shroud 30. The second terminal ends 26 of conductive pins 20 thereby serve to form electrical connections with other devices according to any known connector assembly.
Referring to
Referring to
Accordingly, the electrical connector assembly 15 according to the present invention advantageously provides for a reliable and easy to manufacture electrical connection that does not require a solder joining process. The resulting electrical connector assembly 15 consumes a small amount of space and is cost affordable.
It will be understood by those who practice the invention and those skilled in the art, that various modifications and improvements may be made to the invention without departing from the spirit of the disclosed concept. The scope of protection afforded is to be determined by the claims and by the breadth of interpretation allowed by law.
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Number | Date | Country | |
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