BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electrical contact, and particularly to a composite electrical contact with separate rigid part and elastic wire contact part connected with the separate rigid part for electrically connecting an electronic package, such as a central processing unit (CPU), with a circuit substrate, such as a printed circuit board (PCB).
2. Description of the Prior Art
FIG. 6 discloses an electrical connector for electrically connecting an electronic package, such as a central processing unit (CPU) (not shown), with a circuit substrate, such as a printed circuit board (PCB) (not shown), comprises an insulative housing 1′ and a wire contact 2′ fixed in the housing 1′ with an insert molding method. The wire contact 2′ defines an upper mating portion 21′ extending beyond an upper surface of the insulative housing 1′ for connecting with the CPU and a bottom portion 22′ extending beyond a bottom surface of the insulative housing 1′ for connecting with the PCB. When the CPU exerts a downward force to the contact 2′, the mating portion 21′ is deformed accordingly, so as to provide a good connection between the CPU and the contact.
However, the elasticity of the mating portion is poor, the force that the CPU exerted on it may make it to be deformed permanently, thus affecting the quality of the whole connector.
In view of the above, a new electrical contact that overcomes the above-mentioned disadvantages is desired.
SUMMARY OF THE INVENTION
Accordingly, the object of the present invention is to provide a composite electrical contact which can provide good elastic deformation when pressed.
To fulfill the above-mentioned object, the present invention provides a composite electrical contact for connecting a CPU with a PCB, comprising an elastic wire contact part for electrically connected to the CPU and a separate rigid part for electrically connected to the PCB. The elastic wire contact part defines a body portion and a spring arm extending upwardly from the upper end of the body portion, the end of the spring arm defines a mating portion for electrically connected to the CPU. The separate rigid part defines a base portion connected with the body portion of the elastic wire contact part and a soldering paddle extending downwardly from the lower end of the base portion for electrically connected to the PCB. The CPU connects with only the mating portion of the elastic wire contact part and the PCB connects with only the soldering paddle of the separate rigid part to make a good electronic connection between the CPU and the PCB. The separate rigid part can share the force that the CPU exerted on the elastic wire contact part, which avoids the elastic wire contact part deformed excessively.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompany drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of the composite electrical contact in accordance with the first embodiment of the present invention;
FIG. 2 is a side elevation view of the composite electrical contact shown in FIG. 1;
FIG. 3 is an isometric view of a number of the composite electrical contacts assembled to part of the insulative housing;
FIG. 4 is a schematic, cross-sectional view of FIG. 3, taken along line IV-IV;
FIG. 5 is an isometric view of the composite electrical contact in accordance with the second embodiment of the present invention; and
FIG. 6 is an isometric view of part of a conventional connector.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION
Reference will now be made to the drawings to describe the present invention in detail.
Referring to FIGS. 1-2, a composite electrical contact 1 in accordance with the first embodiment of the preferred present invention, comprises an elastic wire-shape contact part 20 and a separate rigid connecting part 10. The separate rigid connecting part 10 is of a substantially L-shape viewed from side elevation and defines a flat base portion 11 located in a vertical plane, a curved connecting portion 12 extending downwardly and curvedly from the lower end of the base portion 11 and a rectangular board-shape soldering paddle 13 extending forwardly and flatly from the connecting portion 12. The connecting portion 12 and the solder paddle 13 together form a J-shape and since the width of the connecting portion 12 is smaller than that of the solder paddle 13, thus, a pair of cutouts 121 is formed. The soldering paddle 13 defines a bottom surface 130 for soldered to the soldering ball 60 and an upper surface 131 relative to the bottom surface 130. The base portion 11 with less elasticity is stamped of a relatively cheaper metal sheet and defines a plurality of barbs 101. The elastic wire-shape contact part 20 is made from relatively expensive high strength and temper copper alloy with a circular shape and higher elasticity and comprises a straight body portion 21 connected to the base portion 11 of the separate rigid part 10 and a spring arm 22 extending from the upper end of the body portion 21. In this embodiment of the present invention, the body portion 21 of the elastic wire contact part 20 is welded to the base portion 11 of the separate rigid part 10 at two upper and lower points thereof. Thus, when there is a downward force exerts on the spring arm 22, the deflection of the spring arm 22 is little, so the wiping length is reduced. The spring arm 22 comprises a loop portion 221 and a curved mating portion 222 at the end of the spring arm 22. In this embodiment, the mating portion 222 is curved downwardly facing to the first side edge 112 to form a substantially U-shape with curved section served as mating surface, also it can be curved downwardly facing to the second side edge 111.
Referring to FIG. 2, The bottom free end of the body portion 21 is received in one cutout 121 and contacts with side edges of the connecting portion 12 and the soldering paddle 13. At the same time, the bottom free end of the body portion 21 is between the upper surface 131 and the bottom surface 130 of the soldering paddle 13 and is flush with the bottom surface 130. When the soldering paddle 13 is soldered to the soldering ball 60, the body portion 21 is soldered with the soldering paddle 13 and the connecting portion 12 at the same time during the reflow of the melted soldering ball 60.
FIGS. 3-4 show the composite electrical contact 1 assembled to the insulative housing 30 (only shown part of the insulative housing 30 in FIGS. 3-4). The insulative housing 30 defines an upper mating surface 31 for the CPU 40, opposite lower mounting surface 32 for being assembled to the PCB 50 and multiplicity of passageways 310 there through for receiving the composite electrical contacts 1. The mating portion 222 of the elastic wire contact part 20 extends beyond the mating surface 31 for electrically connects to the CPU 40. The separate rigid part 10 is positioned steadily in the passageways 310 due to the barbs 101 engage with the sidewalls of the passageways 310 interferentially, thus the composite electrical contact 1 can also be positioned steadily in the insulative housing 30.
FIG. 5 shows the second embodiment of the preferred composite electrical contact 1, Compared with the first embodiment of the preferred composite electrical contact 1, the difference is the base portion 11 forms two crimping members 14 curved from one side edge thereof for secured receiving the body portion 21 of the elastic wire contact part 20, through this method, the elastic wire contact part 20 can also be positioned to the separate rigid part 10 steadily. In the second embodiment, the pair of crimping members 14 is formed adjacent to the loop portion 221 and the barbs 101, respectively. However, it is to be pointed out that the number and the position of the crimping members 14 is not definite, it can be changed according to the requirement.
In the above detailed description, when the CPU 40 engages with the mating portions 222 of the composite electrical contacts 1, the CPU only connects with the mating portions 222 of the elastic wire contact parts 20 and can not touch the separate rigid part 10, at the same time, the PCB 50 connects only with the separate rigid part 10 through the soldering balls 60 and can not tough the elastic wire contact part 20, through this way, make a good connection between the CPU 40 and the PCB 50, because the body portion 21 of the elastic wire contact part 20 is welded to the base portion 11 of the separate rigid part 10 at two upper and lower points thereof, so when there is a downward force exerts on the spring arm 22, the deflection of the spring arm 22 is little, so the wiping length is reduced. At the same time, the base portion 11 with less elasticity is stamped of a relatively cheaper metal sheet, which makes a cost down of the composite contact 1.
It is to be understood, even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
Patent Grant
7445461
