Abstract:
The probe card is comprised of a probe card wafer, a plurality of through via electrodes penetrating the probe card wafer; and a plurality of redistributed wiring probe needle structures, each being connected to the through via electrodes protruding from a surface of the probe card wafer.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
       [0001]    This application claims priority to Korean Patent Application No, 10-2008-0042997, filed on May 8, 2008, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference in their entirety. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Technical Field 
         [0003]    The present disclosure relates to a probe card and a probe card module using the same, and more particularly, to a probe card having a redistributed wiring probe needle structure, and a probe card module using the probe card. 
         [0004]    2. Discussion of the Related Art 
         [0005]    In general, during a semiconductor device manufacturing process, unit chips formed on a wafer are electrically tested. The electrical test of a wafer is referred to as an electronic die sort (EDS) test. 
         [0006]    The EDS test is to electrically test functions of the unit chips on a wafer. Chips that pass the EDS test are manufactured into semiconductor packages in an assembly process. Chips determined to be defective in the EDS test are scrap disposed in early stage so as to avoid unnecessary costs in the assembly process. 
         [0007]    Typically, the EDS test is performed using a tester and a probe station. The tester is an automatic test equipment (ATE) for testing electrical functions of the unit chip by applying an electrical signal such as a voltage, current, or clock to the unit chip on the wafer. The tester includes a probe card having a plurality of probe needles for applying electrical signals to the wafer. The probe station is an automatic transfer and alignment equipment for moving the wafer to accurately connect the unit chips on the wafer to the tester via the probe needles. 
         [0008]    However, to apply various electrical signals, a general probe card includes a multilayer wiring substrate (for example, a multilayer ceramic substrate formed of a printed circuit board (PCB) substrate) and a cantilever type spring probe needle installed on the multilayer wiring substrate. Since such a probe card is manufactured using a micro-electro-mechanical systems (MEMS) technology, the manufacturing and testing processes may be extremely time consuming and costly. 
         [0009]    Accordingly, there exists a need for a probe card which has a shortened manufacturing period, a low manufacturing cost, and a reduced test time. 
       SUMMARY OF THE INVENTION 
       [0010]    According to an embodiment of the present invention, there is provided a probe card comprising a probe card wafer, a plurality of through via electrodes penetrating the probe card wafer; and a plurality of redistributed wiring probe needle structures, each being connected to one of the through via electrodes and having a twisted cage shape protruding from a surface of the probe card wafer. 
         [0011]    Each of the redistributed wiring probe needle structures may be comprised of a metal ring connected to each of the through via electrodes, a plurality of bars separated from one another and connected to the metal ring, and a probe needle supportingly connected to the bars, where in each of the bars is dimensioned and shaped to connect between the metal ring and the probe needle. The diameter of the metal ring is greater than that of the probe needle. A buffer member may fill a space between the bars of each of the redistributed wiring probe needle structures. Multilayered wiring layers may be formed in the probe card wafer and electrically connected to the through via electrodes. The redistributed wring probe needle structures may be formed on a surface of the probe card wafer and connected to the through via electrodes, and connection terminals may be formed on the other surface of the probe card wafer and connected to a wiring substrate. 
         [0012]    The probe card wafer may be comprised of a first probe card wafer where a plurality of first through via electrodes and the redistributed wring probe needle structures are formed, and a second probe card wafer where a plurality of second through via electrodes electrically connected to the first through via electrodes and the redistributed wring probe needle structures on the first probe card wafer, and connection terminals connected to the second through via electrodes and the wiring substrate, are formed. The first probe card wafer may be combined to the second probe card wafer. 
         [0013]    According to another embodiment of the present invention, there is a probe card module comprising a wiring substrate connected to a tester; and a probe card electrically connected to the wiring substrate and testing a unit chip of a test wafer. The probe card may be comprised of a probe card wafer corresponding to the test wafer; a plurality of through via electrodes penetrating the probe card wafer; and a plurality of redistributed wiring probe needle structures, each being connected to each of the through via electrodes protruding from the probe card wafer. 
         [0014]    Each of the redistributed wiring probe needle structures may comprise: a metal ring connected to each of the through via electrodes; a plurality of bars separated from one another; and a probe needle supportingly connected to the bars; wherein each of the bars is dimensioned and shaped to connect between the metal ring and the probe needle. Each of the redistributed wiring probe needle structures may comprise a plurality of bars connected to the metal ring and, when the probe needle electrically contacts a pad of the unit chip of the test wafer, the probe needle rotates. The redistributed wring probe needle structures are formed on a surface of the probe card wafer and connected to the through via electrodes, and connection terminals are formed on the other surface of the probe card wafer and connected to a wiring substrate. 
         [0015]    The probe card wafer may comprise: a first probe card wafer where a plurality of first through via electrodes and the redistributed wring probe needle structures are formed; and a second probe card wafer where a plurality of second through via electrodes electrically connected to the first through via electrodes and the redistributed wring probe needle structures on the first probe card wafer, and connection terminals connected to the second through via electrodes and the wiring substrate, are formed. A buffer member may fill the inside of each of the redistributed wring probe needle structures. 
         [0016]    According to another embodiment of the present invention, there is a probe card module comprising a wiring substrate connected to a tester, a guide member installed on a surface of the wiring substrate and having an open central portion, and a probe card electrically installed by being supported by the guide member electrically connected to the wiring substrate, and testing a unit chip of a test wafer. 
         [0017]    The probe card may be comprised of a probe card wafer corresponding to the test wafer, a plurality of connection terminals installed on a surface of the probe card wafer and connected to the wiring substrate via a plurality of microsprings, a plurality of through via electrodes penetrating the probe card wafer, and a plurality of redistributed wiring probe needle structures, each being connected to each of the through via electrodes protruding from the probe card wafer. Each of the redistributed wiring probe needle structures may be rotated when each of the redistributed wiring probe needle structures electrically contacts a pad of a unit chip of the test wafer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    Embodiments of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: 
           [0019]      FIG. 1  is a cross-sectional view of a probe card module including a probe card, according to an embodiment of the present invention; 
           [0020]      FIG. 2  is a cross-sectional view of a probe card module including a probe card, according to another embodiment of the present invention;  FIG. 3  is a cross-sectional view of a probe card module including a probe card for the comparison with the probe card modules of  FIGS. 1 and 2 , according to an embodiment of the present invention; 
           [0021]      FIGS. 4-7  are cross-sectional views of the probe card according to an embodiment of the present invention; 
           [0022]      FIGS. 8-11  illustrate a redistributed wiring probe needle structure according to an embodiment of the present invention; 
           [0023]      FIGS. 12-14  illustrate a redistributed wiring probe needle structure filled with a buffer member according to another embodiment of the present invention; and 
           [0024]      FIGS. 15-17  are cross-sectional views of a redistributed wiring probe needle structure according to an embodiment of the present invention. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0025]    Embodiments of the present invention will be described in detail by explaining exemplary embodiments of the invention with reference to the attached drawings. This invention may, however, be embodied in many different forms and should not be constructed as limited to the embodiment set forth herein. The same reference numerals in the drawings may refer to same or similar elements. 
         [0026]      FIG. 1  is a cross-sectional view of a probe card module  100  including a probe card, according to an embodiment of the present invention. 
         [0027]    Referring to  FIG. 1 , the probe card module  100  according to an embodiment of the present invention includes a body  10  mechanically connected to a tester (not shown) and a wiring substrate  12  supported by a plurality of columns  18  and  20  in the body  10 . A wiring layer  13  is formed in the wiring substrate  12 . A plurality of connection terminals  14  that are electrically connected to the tester are formed on a surface of the wiring substrate  12 . The wiring substrate  12  is formed of a printed circuit board substrate. A guide member  16  having an open central portion is installed on the other surface of the wiring substrate  12  by means of the columns  18  and  20 . A plurality of microsprings  21  are connected to the wiring layer  13  on the rear surface, i.e., the other surface of the wiring substrate  12  surrounded by the guide member  16 . The microsprings  21  are supported by a microspring interposer  22 . 
         [0028]    The microsprings  21  connected to the wiring substrate  12  are connected to a wafer probe card  40 . The probe card  40  is supported and guided by the guide member  16  and the wiring substrate  12 . The probe card  40  is electrically connected to the wiring substrate  12  via the microsprings  21 . The probe card  40  contacts a pad  154  of each of a plurality of unit chips  153  of a test wafer  152  to thereby determine good or bad unit chips  153 . The test wafer  152  is accommodated on a probe station  150 . The pad  154  is formed of an aluminum layer. 
         [0029]    In the present embodiment, the probe card module  100  includes various elements such as the wiring substrate  12 , the guide member  16 , and the probe card  40 . However, the probe card module  100  may be referred to as a probe card. 
         [0030]    The probe card  40  of the present embodiment includes a pair of first and second probe card wafers  24  and  30  in a wafer scale corresponding to the test wafer  152 . The test wafer  152  and the first and second probe card wafers  24  and  30  are formed of a silicon wafer. A plurality of connection terminals  34  are installed on a surface of each of the first and second probe card wafers  24  and  30  to be connected to the wiring substrate  12  via the microsprings  21 . A plurality of first and second through via electrodes  26   a  and  32  are respectively installed in the first and second probe card wafers  24  and  30 . The first and second through via electrodes  26   a  and  32  may be formed using a wafer processing process (fabrication process). Multilayered wiring layers  28  are formed in the first probe card wafer  24 . The multilayered wiring layers  28  are electrically connected to the first and second through via electrodes  26   a  and  32 . 
         [0031]    The probe card  40  includes a redistributed wiring probe needle structure  26   b  having a twisted cage, which are connected to the first and second through via electrodes  26   a  and  32  and protrudes downwardly (perpendicularly) from the first and second probe card wafers  24  and  30 . The redistributed wiring probe needle structure  26   b , may be formed using a redistributed wiring process that is used for wafer processing (fabrication process). The redistributed wiring probe needle structure  26   b  rotates when the probe card  40  electrically contacts the pad  154  of each unit chip of the test wafer  152 . Then, the redistributed wiring probe needle structure  26   b  contacts the pad  154  with friction to remove foreign or impurity materials on the pad  154  so that contact reliability between the redistributed wiring probe needle structure  26   b  and the pad  154  can be greatly improved. 
         [0032]    The probe card  40  may include a first probe card  40   a  and a second probe card  40   b  coupled to the first probe card  40   a . The probe card  40  may be formed of a single probe card wafer. The first probe card  40   a  includes the first through via electrodes  26   a  and the redistributed wiring probe needle structure  26   b  installed in the first probe card wafer  24 . 
         [0033]    The second probe card  40   b  includes the second probe card wafer  30  coupled to the first probe card wafer  24 . The second probe card  40   b  also includes the second through via electrodes  32  installed in the second probe card wafer  30  and electrically connected to the through via electrodes  26   a  and the redistributed wiring probe needle structure  26   b , and the connection terminals  34  connected to the second through via electrodes  32  and the wiring substrate  12 . The first probe card wafer  24  and the second probe card wafer  30  may be combined by using a combination layer or adhesive layer  36 . 
         [0034]      FIG. 2  is a cross-sectional view of a probe card module  100 ′ including a probe card, according to another embodiment of the present invention. 
         [0035]    Referring to  FIG. 2 , the structure of the probe card module  100 ′ is the same as that of the probe card module  100  of  FIG. 1 , except for attaching the probe card  40  to the wiring substrate  12  without using the guide member  16  and the microsprings  21 . That is, in the probe card module  100 ′ of the present embodiment, the connection terminals  34  formed on the rear surface of the wiring substrate  12  and the probe card  40  of a wafer scale are directly connected to each other. Thus, the wiring substrate  12  and the probe card  40  can be easily connected. 
         [0036]    FIG,  3  is a cross-sectional view of a probe card module  200  including a probe card for the comparison with the probe card modules of  FIGS. 1 and 2 . 
         [0037]    The structure of the probe card module  200  of  FIG. 3  is the same as that of the probe card module  100  of  FIG. 1 , except for the structure of a probe card  210 . The probe card  210  of  FIG. 3  is connected to the wiring substrate  12  via the microsprings  21 . The probe card  210  includes a multilayered wiring substrate  202  having a multilayered wiring layer  206 , a guide plate  204  connected to the multilayered wiring substrate  202 , and a probe needle  208  of a spring type installed in the guide plate  204 . The multilayered wiring substrate  202  is formed of a PCB substrate. 
         [0038]    In the probe card  210  of  FIG. 3  the multilayered wiring substrate  202  and the probe needle  208  are manufactured using a microelectromechanical system (MEMS) technology. 
         [0039]    The probe card  40  of  FIGS. 1 and 2  of the present embodiment is formed of the probe card wafers  24  and  30  of a wafer scale instead of the multilayered wiring substrate  202  and the guide plate  204  of the comparative example. The probe card  40  of a wafer scale of  FIGS. 1 and 2  uses a wafer level processing technique and a wafer level package technique, instead of the MEMS technology, so that a manufacturing period can be shortened and a manufacturing cost can be reduced. Also, the probe card  40  of a wafer scale of the present invention can probe (test) at once unit chips on a wafer so that a test time can be remarkably reduced. 
         [0040]    The structure of a probe card of a wafer scale and a manufacturing method thereof will be described below. 
         [0041]      FIGS. 4-7  are cross-sectional views for explaining the structure and manufacturing method of the probe card according to an embodiment of the present invention. 
         [0042]    Referring to  FIGS. 4 and 5 , to manufacture the probe card  40  of the present invention, the first probe card wafer  24  is prepared and the multilayered wiring layers  28  and a plurality of holes  50  are formed using the wafer-level processing technique. Then, as shown in  FIG. 5 , a surface of the first probe card wafer  24  is polished to form a plurality of through via holes  52 . The polishing process of the first probe card wafer  24  may be performed using a chemical mechanical polishing process. 
         [0043]    Referring to  FIG. 6 , a conductive layer is formed in each of the through via holes  52  so as to form the through via electrodes  26   a . Then, the redistributed wiring probe needle structure  26   b  connected to the through via electrodes  26   a  and protruding from a surface of the first probe card wafer  24  is formed, thereby completing the first probe card  40   a . The fabrication of redistributed wiring probe needle structure  26   b  will be described below in detail. 
         [0044]    Referring to  FIG. 7 , the second probe card wafer  30  in which the second through via electrodes  32  are formed using the wafer-level processing technique is provided. In the probe card modules  100  and  100 ′, the second probe card wafer  30  is prepared to adjust the thickness of the probe card  40  in the guide member  16 . The second probe card wafer  30  is coupled to the first probe card wafer  24  using the combination layer or adhesive layer  36 . 
         [0045]    Then, the second through via electrodes  32 , electrically connected to the through via electrodes  26   a  and the redistributed wiring probe needle structure  26   b , are formed in the second probe card wafer  30 . The connection terminals  34 , for example, solder balls, connecting to the wiring substrate  12 , are formed on the second through via electrodes  32  of the second probe card wafer  30 , using the wafer-level packaging technique, thereby completing the second probe card  40   b.    
         [0046]    Although in  FIGS. 4-7  the probe card  40  is formed by using the first and second probe card wafers  24  and  30 , the probe card  40  may be formed by using a single probe card wafer. The redistributed wiring probe needle structure  26   b  used for the probe card  40  will be described below in detail. 
         [0047]      FIGS. 8-11  illustrate a redistributed wiring probe needle structure according to an embodiment of the present invention. FIG,  8  is a cross-sectional view of a portion A of  FIG. 7 .  FIG. 9  is an enlarged cross-sectional view of the redistributed wiring probe needle structure  26   b .  FIG. 10  is an enlarged plan view of the redistributed wiring probe needle structure  26   b .  FIG. 11  is a perspective view of the redistributed wiring probe needle structure  26   b.    
         [0048]    As shown in  FIG. 8 , the through via electrodes  26   a  are installed in the first probe card wafer  24 . The redistributed wiring probe needle structure  26   b  is installed at the through via electrodes  26   a  to protrude from a surface of the first probe card wafer  24 . A buffer member  54  may be formed of a material exhibiting a superior elasticity, for example, a silicon material, around the redistributed wiring probe needle structure  26   b , if necessary. Even when the buffer member  54  is formed, a probe needle  60  at a tip end of the redistributed wiring probe needle structure  26   b  protrudes externally. 
         [0049]    As shown in  FIGS. 9-11 , the redistributed wiring probe needle structure  26   b  has a twisted cage shape. That is, the redistributed wiring probe needle structure  26   b  includes a metal ring  56  connected to each of the through via electrodes  26   a , a plurality of bars  58  separated from one another and connected to the metal ring  56 , and the probe needle  60  connected to and supporting the bars  58 . Each of the bars is dimensioned and shaped to connect between the metal ring and the probe needle to form a cage shape. 
         [0050]    In  FIGS. 9-11 , the buffer member  54  is not shown for the convenience of explanation. The diameter of the metal ring  56  is greater than that of the probe needle  60 . The probe needle  60  may be a solid cylinder or hemispherical. Referring back to  FIG. 1 , when the redistributed wiring probe needle structure  26   b  having a twisted cage shape moves so that the probe needle  60  located at the tip end (lower end) of the redistributed wiring probe needle structure  26   b  contacts the pad  154  of each unit chip of the test wafer  152 , the probe needle  60  can be mechanically rotated. Accordingly, the redistributed wiring probe needle structure  26   b  of the present invention causes friction with the pad  154  so that contact ability between the probe needle  60  and the pad  154  can be improved and reliability of test can be improved. 
         [0051]      FIGS. 12-14  illustrate a redistributed wiring probe needle structure filled with a buffer member according to another embodiment of the present invention.  FIGS. 12 and 14  are enlarged cross-sectional views of a redistributed wiring probe needle structure  26   b ′ according to another embodiment of the present invention.  FIG. 13  is an enlarged plan view of the redistributed wiring probe needle structure  26   b ′ of  FIG. 12 . 
         [0052]    The structure of the redistributed wiring probe needle structure  26   b ′ of  FIGS. 12-14  is the same as that of the redistributed wiring probe needle structure  26   b  of  FIGS. 9-11 , except that the inside of the redistributed wiring probe needle structure  26   b ′ having a twisted cage is filled with the buffer member  54 . That is, in the redistributed wiring probe needle structure  26   b ′ of  FIGS. 12-14 , the buffer member  54  fills a space between the bars  58  surrounding the metal ring  56  and the probe needle  60  protrudes externally. In other words, the redistributed wiring probe needle structure  26   b ′ of  FIGS. 12-14  has the buffer member  54  inside which is stable to high temperature and exhibits a superior elasticity. 
         [0053]    Referring back to  FIG. 1 , when the redistributed wiring probe needle structure  26   b ′ of  FIGS. 12-14  moves so that the probe needle  60  located at the tip end (lower end) of the redistributed wiring probe needle structure  26   b ′ contacts the pad  154  of each unit chip of the test wafer  152 , the probe needle  60  is rotated and mechanically stably contacts the pad  154 . When the buffer member  54  is formed in the redistributed wiring probe needle structure  26   b ′, a test can be performed according to a temperature history from high temperature to low temperature so that durability of a probe card can be greatly improved. 
         [0054]      FIGS. 15-17  are cross-sectional views for explaining a method of manufacturing a redistributed wiring probe needle structure according to an embodiment of the present invention. 
         [0055]    Referring to  FIG. 15 , a bump pattern  70  is formed on the first probe card wafer  24  where the through via electrodes  26   a  are formed. The bump pattern  70  is formed by forming a polymer pattern on the first probe card wafer  24  using the wafer processing technique and applying a heat treatment thereto. The bump pattern  70  may be formed by a variety of wafer processing processes. A seed metal layer  72  is formed on the bump pattern  70  and the first probe card wafer  24 . The seed metal layer  72  is formed as a Ti, Cu, Au, or Ni layer using a vacuum deposition method. 
         [0056]    Referring to  FIG. 16 , a photoresist pattern  74  is formed on the seed metal layer  72  to expose the upper portions of the through via electrodes  26   a . The photoresist pattern  74  is formed using a photolithography process. The shape of the photoresist pattern  74 , that is, the shape of the interior of the photoresist pattern  74 , is formed to be the same as that shown in  FIGS. 9-11 . Next, a redistributed wiring layer  76  is formed by forming a metal pattern on the seed metal layer  72  in the photoresist pattern  74 , using a plate method, for example, electroplating or electroless plating. The redistributed wiring layer  76  can be formed in other various methods, in addition to the plate method. 
         [0057]    The redistributed wiring layer  76  may be formed as a conductive metal layer. The redistributed wiring layer  76  is formed of a base metal layer formed of a Ni based or Fe based alloy layer to maintain mechanical elasticity and a metal layer formed by depositing a copper layer or silver layer exhibiting a high conductivity on the base metal layer to evaluate an electrical characteristic. In addition, the redistributed wiring layer  76  is formed of the base metal layer and the metal layer and may further include a rigid gold layer suitable for an electrical contact structure on the outermost surface of the redistributed wiring probe needle structure  26   b  contacting the pad  154  of the test wafer  152 . 
         [0058]    Referring to  FIG. 17 , after the photoresist pattern  74  is removed, the seed metal layer  72 , except for a portion where the redistributed wiring layer  76  is formed, is removed. Next, the bump pattern  70  is removed. Finally, the redistributed wiring probe needle structure  26   b  including the seed metal layer  72  and the redistributed wiring layer  76  is formed. Although it is not illustrated in  FIG. 17 , the buffer member  54  may be formed in the redistributed wiring probe needle structure  26   b  in a molding method, as necessary. 
         [0059]    As described above, the probe card of the embodiments of the present invention is formed of a wafer, that is, a wafer scale probe card. Accordingly, the wafer scale probe card exhibits a shortened manufacturing period and a low manufacturing cost by using the wafer-level process technique and the wafer-level packaging technique. Also, the probe card can remarkably reduce a test time by probing (testing) a plurality of unit chips on a wafer at once. Furthermore, the probe card of the embodiments of the present invention can be formed of a silicon wafer that is subject to a test so that the test can be performed according to a change in temperature, that is, a temperature history. 
         [0060]    The probe card of the embodiments of the present invention includes a unique redistributed wiring probe needle structure to improve durability and reliability thereof. In the probe card, the redistributed wiring probe needle structure is of a twisted cage type. Accordingly, when a needle located at the leading end (the lower end) of the redistributed wiring probe needle structure contacts a pad of a unit chip of a wafer subject to a test, the needle rotates to cause friction with the pad. Thus, the contact ability between the probe needle and the pad is improved so that reliability of the test can be improved. 
         [0061]    In the wafer scale type probe card of the embodiments of the present invention, the buffer member, for example, a silicon layer, which has a low thermal expansion coefficient so as to be stable against a high temperature and has a superior elasticity, can be provided around the probe needle locating at the leading end of the redistributed wiring probe needle structure of a twisted cage type, as necessary. 
         [0062]    The present embodiments of the invention provide a wiring substrate connected to a tester and a probe card module including the above-described wafer probe card connected to the wiring substrate so that the unit chip of the wafer subject to a test can be tested. By doing so, the wafer scale probe card is formed of a silicon wafer and the buffer member is formed in and around the redistributed wiring probe needle structure so that the test according to the temperature history either at a high temperature or at a low temperature is made easy and also greatly improve the reliability of the probe card. Also, the probe card and the probe card module of the present invention can be used for a variety of wafer tests such as an EDS test and a burn-in test. 
         [0063]    While this invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.