Abstract:
The present invention relates to an electric conductor with large current capability and a method for enhancing current capability of an electric conductor, and particularly relates to a test probe with good current capability and a method for improving the current capability of a test probe. In the present invention, dents are formed on the surface of an electric conductor to make the surface rough, so that the electric conductor can have a greater surface area. The larger surface area of the electric conductor provides more paths for passage of the electric current in order to improve the current capability of the electric conductor.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to an electric conductor and a method for improving the current capability of an electric conductor, and particularly relates to a test probe and a method for improving the current capability of a test probe. 
         [0003]    2. Description of the Prior Art 
         [0004]    In the manufacturing process and package process of electronic elements, and after the manufacturing process of electronic elements is finished, a test is performed to recognize and confirm the quality of the electronic elements or chips. During the test process, it is necessary to provide an electric conductor for the electrical connection between an electronic element and a test apparatus, and for transferring test signals between the electronic element and the test apparatus. In general, a test probe is used as the electric conductor. 
         [0005]    However, as electronic elements advance in popularity and diversification, various kinds of electronic elements have been and continue to be developed. Therefore, a test apparatus needs to be able to test various kinds of electronic elements. In test processes, different kinds of electronic elements need different test conditions, such as different electric currents and different voltages. In recent years, larger electric currents often need the testing of many kinds of electric elements. A typical or commonly used test probe is often too small to endure passage of larger electric currents. Such a test probe can be said to have a low current capability because of its small size. Because of this, in the test process of electric elements requiring large electric currents, the typical test apparatus must be halted and time must be expended to change the test probe(s) to a particular test probe(s) having a higher current capability. Therefore, the test cost and the test time are increased, and the test efficiency and test rate are commensurately reduced. In some instances, manufacture of a new test probe, afresh, can be necessary when large electric current testing is needed. It can be impossible, however, to generate a test probe having sufficient current capability by directly improving the test probe commonly used. This kind of preparation of new test probes having higher current capability can disadvantageously add to the test cost of test processes requiring large electric currents. Hence, there is a need to provide an electric conductor with good current capability and a method for improving the current capability of an electric conductor, and particularly to provide a method to change a typical test probe into a test probe having high current capability using only a simple step. 
       SUMMARY OF THE INVENTION 
       [0006]    In view of the foregoing, it is an object of the present invention to provide an electric conductor with high current capability that is capable of improving the current capability of a common test probe, thereby reducing the test cost and increasing the test efficiency. 
         [0007]    Another object of the present invention is to provide a method which can be used for improving the current capability of an electric conductor, and which is capable of improving the current capability of a common test probe, thereby reducing the test cost and increasing the test efficiency. 
         [0008]    Still another object of the present invention is to provide a method for improving the current capability of a typical or common electric conductor by implementing only a simple step, without destroying the surface of the electric conductor or the plated layer on the surface of the electric conductor. This method also can be performed for increasing the hardness of the surface of the electric conductor. 
         [0009]    According to one or more of the objects, an embodiment of the present invention provides an electric conductor with high current capability. The electric conductor comprises a body, at least one conducting part disposed on the body for connecting with an electric element or elements, and a plurality of dents formed on the surfaces of the body and the conducting part. The surface of the electric conductor can be formed as a lumpy surface owing to the existence of dents formed on surfaces of the body and the conducting part. In contrast to the relatively smooth surface of a typical or common test probe, the electric conductor of the present invention has a rough surface and a correspondingly larger surface area. Therefore, the electric conductor of the present invention is capable of enduring the passage of large electric currents, and thus can be said to possess good current capability. 
         [0010]    According to the objects, another embodiment of the present invention provides a method for improving the current capability of an electric conductor, and particularly provides a method for improving the current capability of a common or typical electric conductor by way of only a simple step. This method does not destroy or damage the surface of the electric conductor or the plated layer on the surface of the electric conductor. First, an electric conductor is provided. The electric conductor can be a test probe or any conductor used to electrically connect any element with any apparatus. The electric conductor can be, for example, any sort of a test probe. Next, a plurality of dents are formed on the surface of the electric conductor for increasing the roughness and the surface area of the electric conductor. Therefore, the electric conductor allows and endures the passage of large electric current, and the current capability of the electric conductor is improved. 
         [0011]    An effect achieved by the present invention which is not present in the prior art is the provision of an electric conductor with high current capability that is capable of performing a test process with large electric current. The test process need not be interrupted to stop the test apparatus and expend time changing test probes. Accordingly, additional test cost and test time caused by the changing of test probes can be omitted, and the test efficiency can be improved. Another effect achieved by the present invention which is absent from the prior art is the provision of a method that is capable of improving the current capability and the hardness of a typical or common electric conductor (e.g., test probe) without destroying, damaging, or wearing the surface of the electric conductor or of a plated layer on a surface of the electric conductor. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1A  and  FIG. 1B  are a stereophonic view and a cross-sectional view, respectively, of an electric conductor with good current capability according to one embodiment of the present invention; 
           [0013]      FIG. 2  is a side view illustrating an electric conductor with good current capability according to another embodiment of the present invention; 
           [0014]      FIG. 3  is a stereophonic view illustrating an electric conductor with good current capability according to still another embodiment of the present invention; and 
           [0015]      FIG. 4  is a flow chart illustrating a method for improving the current capability of an electric conductor according to one embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0016]    The following is a detailed description of the embodiments of the present invention. It is appreciated that the processes and structures described below do not entirely encompass whole processes and structures. The present invention can be practiced in conjunction with various fabrication techniques, and only the commonly practiced processes are included to provide an understanding of the present invention. 
         [0017]    Referring to  FIG. 1A , depicted is a stereophonic view illustrating an electric conductor  10  with good current capability according to one embodiment of the present invention. The electric conductor  10  comprises a body  12  and at least one conducting part  14 , wherein the conducting part  14  is disposed on the body  12  for contacting an electric element. Furthermore, there are a plurality of small dents  16  formed and spread (e.g., distributed) on the surfaces of one or more of the body  12  and the conducting part  14  (or on the surfaces of the sidewalls of the body  12  and the conducting part  14 ). Both of the surfaces of the body  12  and the conducting part  14  become lumpy surfaces because of the dents  16  formed on the surfaces of the body  12  and the conducting part  14 . Therefore, both of the body  12  and the conducting part  14  have a rougher surface and a larger surface area. 
         [0018]    In general, electric current moves on the surface of an electric conductor, and the electric current is transferred to one or more electric elements through the surface of the electric conductor. Therefore, the larger surface area the electric conductor has, the more paths for transferring the electric current the electric conductor has. This relationship means more electric current can pass over and/or through the electric conductor at the same time providing the electric conductor with better current capability. Consequently, the current capability of an electric conductor can be said to be determined by the size of the electric conductor. The present invention uses the above-mentioned principle to form the dents  16  on surfaces of one or more of the body  12  and the conducting part  14  by, for example, one or more of shot penning, sand brush, laser beam striking, or embossing. Therefore, in contrast to common test probes currently used, the electric conductor of the present invention has a larger surface area and has better current capability because of the larger surface area. The term “laser beam striking” means a laser beam is applied to strike the surface of an object to form dents thereon. Referring to  FIG. 1B , a top view or a cross-section view illustrating the electric conductor  10  is provided, in which the peripheral line of each cross-section of said electric conductor  10  is longer than the peripheral line of each cross-section of the common test probe used currently because of the dents  16 . This characteristic means that the electric conductor  10  has a larger surface area than that of the common test probe used currently. Therefore, the electric conductor  10  can be provided with a larger surface area for electric current pass whereby the electric conductor  10  is enabled with a higher current capability. The term “peripheral line” means the circumference of a cross-section of the object and all peripheral lines of the object are integrated together to constitute the surface of the sidewalls of the object. 
         [0019]    According to a user&#39;s need and design, the electric conductor  10  can be composed of various kinds of materials, for example metal, alloy, etc. Therefore, the composition of the electric conductor  10  is not intended to be limited by the examples provided in the current disclosure of the present invention. Now, in this embodiment of the present invention, the electric conductor  10  is a pogo pin, and particularly is a test probe with single head or a pogo pin with single head. Also, in the embodiment the body  12  is the body of the test probe with a single head, and the conducting part  14  is the head of the test probe with a single head. 
         [0020]      FIG. 2  illustrates an electric conductor  10 A with good current capability according to another embodiment of the present invention. The electric conductor  10 A is a test probe with two heads. The electric conductor  10 A comprises a conducting part  14 A disposed on one end of the body  12  and another conducting part  14 B disposed on another end of the body  12 . Both of the conducting part  14 A and the conducting part  14 B are the heads of the test probe. A plurality of dents  16  are formed on the surfaces of the body  12 , the conducting part  14 A and the conducting part  14 B, thereby transforming the surface of the electric conductor  10 A to a lumpy surface and providing the electric conductor  10 A with a rougher surface and a larger surface area. The rougher surface and the larger surface area result in the electric conductor  10 A having a substantially better current capability. 
         [0021]    According to certain aspects, the electric conductor of the present invention need not be limited to the above-described embodiments in which the electric conductor is a test probe with single head or a test probe with two heads. Indeed, the electric conductor can comprise various kinds of and various shapes of, for example, test probes according to the user&#39;s need and design. For instance, a test probe with an S shape, such as, for example, manufactured by JONSTECH company, etc., can comprise an electric conductor  10 B with good current capability, as illustrated in  FIG. 3  according to still another embodiment of the present invention. The electric conductor  10 B is a test probe in the form of an electric conductor  10 B which, when viewed from the side, comprises or resembles the shape of an S shaped slab with a relatively small size. The electric conductor  10 B as depicted comprises a body  12 ′ which is the body of the S-shaped test probe, and two conducting parts  14 C and  14 D which are the curved heads of the S-shaped test probe. The conducting part  14 C and the conducting part  14 D are disposed on two (e.g., opposing) ends of the body  12 ′ respectively. Similarly, a plurality of the dents  16  are formed on the surfaces of the body  12 ′ and the conducting parts  14 C and  14 D for increasing the surface roughness and the surface area of the electric conductor  10 B. Therefore, the resulting electric conductor  10 B can have higher current capability. The S-shaped test probe can be fixed on a test apparatus by inserting two rubber strips into the two concaves of the S-shaped test probe respectively. 
         [0022]    However, in any electric conductor of the embodiments of the present invention, one or several plated layers could be formed on the surface of the body, the surface of the conducting part or both surfaces of the body and the conducting part for providing various functions. For example, a plated layer or layers can form either or both of a protective layer for protecting the body and/or conducting part from oxidization or an impact endurance layer for improving the impact resistance of the electric conductor. The protective layer can be, but is not limited to, an Au layer, and the impact endurance layer can be, but is not limited to, a Ni layer. Such items can be composed of various materials according to the user&#39;s need. The dents on the electric conductor can comprise dents on the surface of the electric conductor and/or dents on a plated layer formed over an impact endurance layer, wherein the plated layer is not damaged and worn to expose the underlying plated layer or the surface of the electric conductor under the plated layer. 
         [0023]    The present invention further provides a method for improving the current capability of an electric conductor while not damaging or wearing the surface of the electric conductor or the plated layer on the surface of the electric conductor. With reference to  FIG. 4 , a flow chart is presented illustrating the method for improving current capability of an electric conductor according to one embodiment of the present invention. First, an electric conductor is provided at step  400 . The electric conductor can be any conductor for electrically connecting an element with an apparatus or for electrically connecting one apparatus with another apparatus, for example a common or typical test probe, a test probe with single head, a test probe with two heads, or a test probe with an S shape. The composition and the shape of the electric conductor described above are not mentioned again. One or more plated layers can be formed on the surface of the body of the electric conductor, on the surface of the conducting part of the electric conductor, or on the surfaces of both of the body and the conducting part for providing various functions, such as that of a protective layer for protecting the body and/or conducting part from oxidization or an impact endurance layer for improving the impact resistance of the electric conductor. 
         [0024]    Next, at step  402  a plurality of dents are formed on surfaces of the body and the conducting part by a process such as shot penning, sand brush, laser beam striking, or embossing. The surface of the electric conductor is transformed to a lumpy surface as a result of the dents, and the electric conductor consequently has a better current capability because of the lumpy surface. Consistent with principles mentioned above, when plating is present on the surface of the electric conductor, the dents can be formed on either or both of the surfaces of the electric conductor and the plated layer. Therefore, the present invention provides a method for improving the current capability of a common electric conductor using a simple step, which is capable of effectively improving the current capability of a typical or common electric conductor currently used. 
         [0025]    When the dents are formed on surfaces of both the body and the conducting part of the electric conductor by shot penning or sand brush, small particles are applied to impact or strike the surface of the electric conductor to form the dents on the surface of the electric conductor. If there is a plated layer on the surface of the electric conductor, the small particles can be directed to impact or strike the surfaces of the electric conductor and the plated layer thereby forming dents on the surfaces of the electric conductor and the plated layer. The small particles are softer than the electric conductor and/or softer than the plated layer on the surface of the electric conductor. Therefore, when the small particles are applied to impact or strike the surface of the electric conductor and the plated layer on the electric conductor, only dents are formed on the surface of the electric conductor or the plated layer on the electric conductor without any damage and wearing to the electric conductor. The small particles are steel balls, glass sand particles, or sand, but are not intended to be limited to such items. Various small particles can be applied according to the kind of electric conductor to be used and the user&#39;s needs. It may be necessary in certain implementations that the surfaces of the electric conductor and the plated layer thereon are not damaged and worn by the small particles. Furthermore, the hardness of the electric conductor is increased as a result of the arrangement of the crystal lattice of the electric conductor being changed by the small particle impacts or the crystal lattice of the electric conductor being deformed by the small particle impacts. 
         [0026]    Similarly, a laser beam striking or embossing technique can be applied only to impact or oppress the surface of the electric conductor or the plated layer thereon for forming the dents on the surface of the electric conductor or the plated layer thereon, or on both of the surfaces of the electric conductor and the plated layer. Therefore, a lumpy surface can be formed on the electric conductor for increasing the surface area of the electric conductor. It may be necessary that the surface of the electric conductor and the plated layer thereon are not damaged and worn by this way, either. 
         [0027]    Accordingly, the present invention provides an electric conductor with a high current capability. The surface area of the electric conductor is increased by the formation of dents for obtaining better current capability. In accordance with the present invention, stopping of the test apparatus and expending time to change test probes can be avoided. Accordingly, additional test costs and test times caused by having to change test probes can be omitted, and the test efficiency can be improved. Furthermore, the present invention provides a method for improving the current capability of an electric conductor by forming dents on a typical or common electric conductors in a simple manner. By the method of the present invention, the roughness of the surface of the electric conductor and the surface area of the electric conductor are increased for improving the current capability of the electric conductor, while not destroying, damaging, or wearing the surface of the electric conductor or the plated layer on the surface of the electric conductor.