Abstract:
A probe structure is provided, including two probe heads for electrically contacting with the two objects, respectively, an elastic buffer portion forming a hollow space therein, a conductive portion being disposed within the hollow space and thereby being surrounded by the elastic buffer portion, and having two ends respectively electrically being connected to the two probe heads. When the two probe heads do not contact with the two objects electrically, the conductive portion is linearly extended between the two probe heads.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of Taiwan Patent Application No. 105122085 filed on Jul. 13, 2016, the contents of which are incorporated herein by reference in their entirety. 
       BACKGROUND OF THE INVENTION 
     Field of Invention 
       [0002]    The present invention relates to a probe structure, and more particularly to a probe structure, which is applicable in the semiconductor and wafer probing. 
       Description of Prior Art 
       [0003]    A probe structure used in the vertical probe card for tests of semiconductor wafer or integrated chip (IC) is shown as  FIGS. 1A and 1B . The probe structure of  FIG. 1A  is processed by three-dimensional microelectromechanical systems (MEMS), it is needed to transfer signals via a spring structure  10 , for example, the spring structure  10  is fixed on a fixed point  11  with screws, the transfer path of the spring is too long to make the inductive effect be generated while transferring high frequency (speed) signals. Additionally, while transferring high current, the probe might be burned because the material of the spring is not suitable or the sectional area of the spring is too small to carry the higher current. The probe structure of  FIG. 1B  comprises a spring structure  10 ′ and a probe housing  12 . The probe housing  12  makes the probe structure has a bigger exterior size which is not suitable for micro pitch (less than 100 μm). The spring structure  10 ′ is similar with the spring structure  10 . Other characteristics and problem are the same as the probe structure of  FIG. 1A . 
         [0004]    Hence, it is needed to provide a probe structure, which is applicable in semiconductor wafer or IC testing, suitable for carrying large current and can prevent occurrences of inductive effects while transferring high frequency signals, to raise the ability for transmission of high frequency (speed) signal and high current. 
       SUMMARY OF THE INVENTION 
       [0005]    In order to solve the technical issue of the conventional art, an objective of the present invention is to provide a probe structure, which is applicable in semiconductor wafer or IC testing, to raise the ability for transmission of high frequency (speed) signal and high current. 
         [0006]    According to one embodiment of the present invention, a probe structure is provided, which comprises: two probe heads, in a use state, electrically connecting with two objects; an elastic buffer portion enclosing a hollow space; a conductive portion disposed within the hollow space, and surrounded by the elastic buffer portion, the conductive portion having two ends electrically connected with the two probe heads, respectively. While in an unused state, the two probe heads do not electrically contact with the two objects, and the conductive portion is linearly extended between the two probe heads. 
         [0007]    According to the embodiment of the present invention, a portion of at least one of the probe heads is connected with the elastic buffer portion. 
         [0008]    According to the embodiment of the present invention, the elastic buffer portion extends non-linearly within the two probe heads. 
         [0009]    According to the embodiment of the present invention, the elastic buffer portion extends spirally within the two probe heads, to elastically stretch within the two probe heads. 
         [0010]    According to the embodiment of the present invention, when the two probe heads electrically contact with the two objects, the conductive portion forms an elastic deformation between the two probe heads. 
         [0011]    According to the embodiment of the present invention, the conductive portion is formed by a first soft material and a second soft material, and the first soft material is covered by the second soft material. 
         [0012]    According to the embodiment of the present invention, the two probe heads are conductive hard metal. 
         [0013]    According to the embodiment of the present invention, the two probe heads are made by a process of lithography and plating process or a machining process. 
         [0014]    According to the embodiment of the present invention, the conductive portion is made by a process of lithography, plating, and etching. 
         [0015]    According to another embodiment of the present invention, a probe structure is provided, which comprises: two probe heads, in a use state, electrically connecting with two objects; an elastic buffer portion encloses a hollow space and extends within the two probe heads with a first extending length; a conductive portion disposed within the hollow space, and surrounded by the elastic buffer portion, the conductive portion having two ends electrically connected with the two probe heads, respectively. The conductive portion extends within the two probe heads with a second extending length; the second extending length is smaller than the first extending length. 
         [0016]    According to the embodiment of the present invention, a portion of at least one of the probe heads is connected with the elastic buffer portion. 
         [0017]    According to the embodiment of the present invention, the elastic buffer portion extends spirally within the two probe heads, to elastically stretch within the two probe heads. 
         [0018]    According to the embodiment of the present invention, when the two probe heads do not electrically contact with the two objects, the conductive portion is linearly extended between the two probe heads. 
         [0019]    According to the embodiment of the present invention, when the two probe heads electrically contact with the two objects, the conductive portion forms an elastic deformation between the two probe heads. 
         [0020]    According to the embodiment of the present invention, an extending direction of the conductive portion within the two probe heads is parallel with an extending direction of the two probe heads. 
         [0021]    According to another embodiment of the present invention, a probe device is provided, each probe of the probe device comprises a probe structure, which comprises: two probe heads, in a use state, electrically connecting with two objects; an elastic buffer portion enclosing a hollow space; a conductive portion disposed within the hollow space, and surrounded by the elastic buffer portion, the conductive portion having two ends electrically connected with the two probe heads, respectively. While in an unused state, the two probe heads do not electrically contact with the two objects, and the conductive portion is linearly extended between the two probe heads. 
         [0022]    According to the embodiment of the present invention, a portion of at least one of the probe heads is connected with the elastic buffer portion. 
         [0023]    According to the embodiment of the present invention, the elastic buffer portion extends non-linearly within the two probe heads. 
         [0024]    According to the embodiment of the present invention, the elastic buffer portion extends spirally within the two probe heads, to elastically stretch within the two probe heads. 
         [0025]    According to the embodiment of the present invention, when the two probe heads electrically contact with the two objects, the conductive portion forms an elastic deformation between the two probe heads. 
         [0026]    According to the embodiment of the present invention, the conductive portion is formed by a first soft material and a second soft material, and the first soft material is covered by the second soft material. 
         [0027]    According to the embodiment of the present invention, the two probe heads are conductive hard metal. 
         [0028]    According to the embodiment of the present invention, the two probe heads are made by a process of lithography and plating process or a machining process. 
         [0029]    According to the embodiment of the present invention, the conductive portion is made by a process of lithography, plating, and etching. 
         [0030]    According to another embodiment of the present invention, a probe device is provided, each probe of the probe device comprises a probe structure, which comprises: two probe heads, in a use state, electrically connecting with two objects; an elastic buffer portion encloses a hollow space and extends within the two probe heads with a first extending length; a conductive portion disposed within the hollow space, and surrounded by the elastic buffer portion, the conductive portion having two ends electrically connected with the two probe heads, respectively. The conductive portion extends within the two probe heads with a second extending length; the second extending length is smaller than the first extending length. 
         [0031]    According to the embodiment of the present invention, a portion of at least one of the probe heads is connected with the elastic buffer portion. 
         [0032]    According to the embodiment of the present invention, the elastic buffer portion extends spirally within the two probe heads, to elastically stretch within the two probe heads. 
         [0033]    According to the embodiment of the present invention, when the two probe heads do not electrically contact with the two objects, the conductive portion is linearly extended between the two probe heads. 
         [0034]    According to the embodiment of the present invention, when the two probe heads electrically contact with the two objects, the conductive portion forms an elastic deformation between the two probe heads. 
         [0035]    According to the embodiment of the present invention, an extending direction of the conductive portion within the two probe heads is parallel with an extending direction of the two probe heads. 
         [0036]    With comparison with the conventional art, the present invention can only takes the elastic portion for buffering and the conductive portion for transferring signal, instead of taking the spring portion as the transferring path of current, hence, it is able to provide an area with higher load-current for large current test, moreover, the transferring path is reduced by not taking the spring as the transferring path of current, which can prevent occurrences of inductive effects while transferring high frequency signals, and is suitable for transmission of high frequency (speed) test. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0037]      FIG. 1A  depicts a conventional probe structure. 
           [0038]      FIG. 1B  depicts another conventional probe structure. 
           [0039]      FIG. 2A  depicts an illustrative front view of a probe structure according to one embodiment of the present invention. 
           [0040]      FIG. 2B  depicts an illustrative front view without an elastic buffer portion of  FIG. 2A . 
           [0041]      FIG. 2C  depicts an illustrative side view of the probe structure of  FIG. 2A . 
           [0042]      FIG. 2D  depicts an illustrative side view of the probe structure of  FIG. 2B . 
           [0043]      FIG. 3  depicts illustrative views of a plurality of usable shapes selectively installed in a probe head of the probe structure according to one embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0044]    In order to make the objectives, technical proposals and advantages of the present invention be much clear, below is further detailed description accompanying with the drawings to the embodiment of the present application. 
         [0045]    Please refer to  FIGS. 2A and 2B , one preferred embodiment of the present invention provides a probe structure  20 , which is applicable in semiconductor wafer or IC testing, to raise the ability for transmission of high frequency (speed) signal and high current. The probe structure  20  of the present invention comprises two probe heads  23 , in use state, are electrically connected with two objects (IC or wafer . . . ); an elastic buffer portion  21  encloses a hollow space, to extend within the two probe heads  23  with a first extending length L 1 ; a conductive portion  22  is disposed within the hollow space and is surrounded by the elastic buffer portion  21 , and has two ends are respectively electrically connected with the two probe heads  23 , to extend within the two probe heads  23  with a second extending length L 2 . Preferably, the conductive portion  22  can be a cylindrical structure, but does not limit the present invention. When in an unused state, the two probe heads  23  do not electrically contact with the two objects, the conductive portion  22  is linearly extended between the two probe heads  23 . 
         [0046]    Preferably, a portion of at least one of the probe heads  23  is connected with the elastic buffer portion  21 , and the elastic buffer portion  21  extends non-linearly within the two probe heads  23 . In the embodiment, the elastic buffer portion  21  is an extendable elastic element. For example, the elastic buffer portion  21  is a spiral spring fixed on a specific position (such as the fixed point  11 ′) of any one of the probe heads  23  with screws. With micro spring machining process to make the elastic buffer portion  21  extends spirally within the two probe heads  23 . In use state, the two probe heads  23  electrically contact with the two objects, the conductive portion  21  can perform an elastic stretch between the two probe heads  23 , in other words, the amplitude of the extrusion is taken as the reciprocated stroke for test. The spiral path of the elastic buffer portion  21  (spiral spring) is a first extending length L 1 . 
         [0047]    In the probe structure of the embodiment, in use state, the two probe heads  23  electrically contact with the two objects, the current&#39;s transmission is transferred via the conductive portion  22  instead of the spiral path of elastic buffer portion  21  (spiral spring), hence, the conduction path between the two probe heads  23  is a second extending length L 2  which is linearly extended within the two probe heads  23 . Because the second extending length L 2  is a vertical and linear (straight line) extending length, the second extending length L 2  will far smaller than the first extending length L 1  (the spiral path of the spiral spring), the inductive effect decreased and the cylinder cross-area of the conductive portion  22  is bigger, which is able to carry larger current. 
         [0048]    Please further refer to  FIGS. 2C and 2D ,  FIG. 2C  depicts an illustrative side view of the probe structure  20  of  FIG. 2A ,  FIG. 2D  depicts an illustrative side view of the probe structure  20  of  FIG. 2B . Preferably, the conductive portion  22  is formed by a first soft material  221  which is disposed at inner layer and a second soft material  222  which is disposed at outer layer, in other words, the first soft material  221  is covered by the second soft material  222 . The conductive portion  22  is made by a process of lithography, plating, and etching, the conductive portion  22  can be cut by desired dimension. For the soft characteristic of the first soft material  221  and the second soft material  222 , when the two probe heads  23  electrically contact with the two objects, the elastic buffer portion  21  forms an elastic deformation by suffering an extrusion, the conductive portion  22  can deform accordingly without effecting the transferring quality. Where, the first soft material  221  and the second soft material  222  can be formed by any of polyester-based polymer, styrene-based polymer, cellulose-based polymer, polyethersulfone-based polymer, polycarbonate-based polymer, acrylic polymer, polyolefinic polymer, polyamide-based polymer, polyimide-based polymer, sulfone-based polymer, polyethersulfone-based polymer, polyether ether kotone-based polymer, polyphenylene sulfide-based polymer, vinyl alcohol-based polymer, vinylidene chloride-based polymer, vinyl butyral-based polymer, acrylate-based polymer, polyoxymethylene-based polymer, epoxy-based polymer, polyethylene terephthalate (PET), Polyethylene Naphthalate (PEN), polysiloxane, and Polyamic acid (PAA). 
         [0049]    Preferably, the two probe heads  23  are conductive hard metal, the two probe heads  23  are made by a process of lithography and plating process or a machining process. It is able to make the two probe heads  23  as the desired shape according to the actual quests.  FIG. 3  depicts illustrative side views of a plurality of usable shapes selectively installed in a probe head  23  of the probe structure  20  according to one embodiment of the present invention. The probe head  23  can be cylinder or cuboid. The types of  FIG. 3  are: flat head probe  30 , round head probe  31 , pointed head probe  32 , paw head probe  33 . 
         [0050]    Besides the conductive portion  22  of the probe structure  20  of  FIGS. 2A-2D  are vertical extending lengths (such as straight line), in the other embodiments of the present invention, the elastic buffer portion  21  can be designed as tilt extending length (tilt line) or non-linear extending length (such as curved extending length). Only if the inside of the elastic buffer portion  21  forms a hollow space and extends within the two probe heads  23  with a first extending length L 1 , and the conductive portion  22  extends within the two probe heads  23  with a second extending length L 2 , the second extending length L 2  is smaller than the first extending length L 1 , which are enclosed within the present invention. 
         [0051]    Additionally, the embodiments of the present invention can be setup on the probe device of the tests of wafer and semiconductor, the probe head  23  of the probe device  20  and the conductive portion  22  can be rotatively fixed via a screw nut structure, latch structure, or welding process, and the first soft material  221  and the second soft material  222  can be tightly contacted with each other or have a gap. 
         [0052]    In comparison with the conventional art, the present invention can only takes the elastic portion for buffering and the conductive portion for transferring signal, instead of taking the spring portion as the transferring path of current, hence, it is able to provide an area with higher load-current for large current test. Moreover, the transferring path is reduced by not taking the spring as the transferring path of current, which can prevent occurrences of inductive effects while transferring high frequency signals, and is suitable for transmission of high frequency (speed) test. 
         [0053]    The above are only preferred embodiments of the present invention, which are not intended to limit the present invention. Any modifications, equivalent replacements or improvement within the spirit and principles of the present invention should be included within the scope of protection of the present invention.