Patent Publication Number: US-2022221502-A1

Title: Connecting device for inspection

Description:
TECHNICAL FIELD 
     The present invention relates to a connecting device for inspection used for inspecting the characteristics of an inspection object. 
     BACKGROUND ART 
     Semiconductor devices to which electrical signals and optical signals are transmitted (referred to below as “optoelectronic devices”) are formed on silicon substrates or the like by use of silicon photonics. 
     To inspect the characteristics of an optoelectronic device in a wafer state, it is effective to connect the optoelectronic device and an inspecting device by use of a connecting device for inspection including electric contacts that transfer electrical signals and optical contacts that transfer optical signals (refers to Patent Literature 1 and Patent Literature 2). For example, probes formed of conductive material are used as the electric contacts for connecting the optoelectronic device and the inspecting device, and optical fibers are used as the optical contacts for connecting the optoelectronic device and the inspecting device. 
     CITATION LIST 
     Patent Literature 
     
         
         Patent Literature 1: Japanese Unexamined Patent Application Publication No. H07-201945 
         Patent Literature 2: Japanese Unexamined Patent Application Publication No. 2018-81948 
       
    
     SUMMARY OF THE INVENTION 
     Technical Problem 
     The connecting device for inspection including units provided with the electric contacts and units provided with the optical contacts formed independently of each other is typically used for inspecting the optoelectronic device. The positioning between the optoelectronic device and the connecting device for inspection requires a certain period of time to align the optoelectronic device with the respective units independently of each other. In addition, the connecting device for inspection having the configuration described above has a problem of executing a test (a multi-test) that performs an electrical measurement using electrical signals and an optical measurement using optical signals simultaneously. 
     In response to this issue, the present invention provides a connecting device for inspection having a configuration capable of facilitating an alignment with an optoelectronic device and executing an electrical measurement and an optical measurement simultaneously. 
     Solution to Problem 
     An aspect of the present invention provides a connecting device for inspection including a probe head configured to hold an electric contact and an optical contact such that tip ends of the electric contact and the optical contact are exposed on a lower surface of the probe head while proximal ends of the respective contacts are exposed on an upper surface of the probe head, and a transformer including a connecting wire arranged therein and an optical wire penetrating therethrough. A tip end of the connecting wire electrically connected to the proximal end of the electric contact and a connecting end of the optical wire optically connected to the proximal end of the optical contact are arranged in a lower surface of the transformer. A positional relationship between the tip end of the electric contact and the tip end of the optical contact on the lower surface of the probe head corresponds to a positional relationship between an electrical signal terminal and an optical signal terminal of a semiconductor device, and the optical wire is fixed to the transformer. 
     Advantageous Effects of the Invention 
     The present invention can provide the connecting device for inspection with the configuration capable of facilitating the alignment with the optoelectronic device and executing the electrical measurement and the optical measurement simultaneously. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic view illustrating a structure of a connecting device for inspection according to an embodiment of the present invention. 
         FIG. 2  is a schematic view illustrating a state in which a probe head and a transformer are attached in the connecting device for inspection according to the embodiment of the present invention. 
         FIG. 3  is a schematic view illustrating an example in which an optical wire is fixed to the transformer in the connecting device for inspection according to the embodiment of the present invention. 
         FIG. 4  is a schematic view illustrating a state in which the probe head and the transformer are separated from each other in the connecting device for inspection according to the embodiment of the present invention. 
         FIG. 5  is a schematic view illustrating an example of a tip end of an optical contact in the connecting device for inspection according to the embodiment of the present invention,  FIG. 5( a )  to  FIG. 5( d )  showing a variation in shape of the tip end of the optical contact. 
         FIG. 6  is a schematic view illustrating another example of the tip end of the optical contact in the connecting device for inspection according to the embodiment of the present invention,  FIG. 6( a )  and  FIG. 6( b )  showing a variation in shape of the tip end of the optical contact. 
         FIG. 7  is a schematic view illustrating still another example of the tip end of the optical contact in the connecting device for inspection according to the embodiment of the present invention,  FIG. 7( a )  and  FIG. 7( b )  showing a variation in shape of the tip end of the optical contact. 
         FIG. 8  is a schematic view for explaining an operation during inspection in the connecting device for inspection according to the embodiment of the present invention (Part  1 ). 
         FIG. 9  is a schematic view for explaining the operation during inspection in the connecting device for inspection according to the embodiment of the present invention (Part  2 ). 
         FIG. 10  is a schematic view for explaining the operation during inspection in the connecting device for inspection according to the embodiment of the present invention (Part  3 ). 
         FIG. 11  is a plan view illustrating an example of a structure of an optoelectronic device as a target to be inspected. 
         FIG. 12  is a plan view illustrating an example of positions of guide holes provided in a bottom guide plate of the probe head in the connecting device for inspection according to the embodiment of the present invention. 
         FIG. 13  is a plan view illustrating the bottom guide plate of the probe head in the connecting device for inspection according to the embodiment of the present invention,  FIG. 13( a )  to  FIG. 13( e )  showing a variation in arrangement of units composing the bottom guide plate. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Some embodiments of the present invention are described below with reference to the drawings. The same or similar elements illustrated in the drawings are denoted below by the same or similar reference numerals. It should be understood that the drawings are illustrated schematically, and the proportions of the thicknesses of the respective elements in the drawings are not drawn to scale. It should also be understood that the dimensional relationships or proportions between the respective drawings can differ from each other. The embodiments described below illustrate devices or methods for embodying the technical idea of the present invention, but the respective embodiments are not intended to be limited to the materials, shapes, structures, or arrangements of the constituent elements as described herein. 
     A connecting device for inspection according to an embodiment of the present invention illustrated in  FIG. 1  is used for inspecting an optoelectronic device including an electrical signal terminal to which an electrical signal is transmitted and an optical signal terminal to which an optical signal is transmitted. The optoelectronic device as used herein can be presumed to be, but not necessarily, a semiconductor device such as a silicon photonic device and a vertical cavity surface emitting laser (VCSEL). The optoelectronic device as a target to be inspected, not illustrated in  FIG. 1 , is arranged such that a surface provided with the optical signal terminal and the electrical signal terminal (also collectively referred to below as “signal terminals”) is opposed to the connecting device for inspection. 
     The connecting device for inspection illustrated in  FIG. 1  includes electric contacts  10 , optical contacts  20 , a probe head  30  holding the electric contacts  10  and the optical contacts  20  such that the respective tip ends are exposed on the lower surface of the probe head  30 , and a transformer  40  arranged on the probe head  30 . A relative positional relationship between the electric contact  10  and the optical contact  20  as viewed in a surface normal direction of the lower surface of the probe head  30  (referred to below as a “planar view”) corresponds to a relative positional relationship between the electrical signal terminal and the optical signal terminal of the optoelectronic device as a target to be inspected. In particular, the respective electric contacts  10  and the respective optical contacts  20  are held by the probe head  30  with a predetermined positioning accuracy so as to be reliably connected to the respective signal terminals of the optoelectronic device as a target to be inspected during the inspection. The phrase “reliably connected” as used herein refers to a state in which the electric contact  10  and the optical contact  20  are connected to the signal terminals of the optoelectronic device so as to ensure a predetermined measurement accuracy. 
     The tip end of the electric contact  10  is electrically connected to the electrical signal terminal of the optoelectronic device as a target to be inspected. The tip end of the optical contact  20  is optically connected to the optical signal terminal of the optoelectronic device as a target to be inspected. The optical connection leads the optical signal to be transmitted between the optical signal terminal of the optoelectronic device and the optical contact  20 . 
     The transformer  40  is equipped therein with connecting wires  41 . The tip ends on one side of the connecting wires  41  are arranged in the lower surface of the transformer  40 , and are electrically connected to the proximal ends of the electric contacts  10  exposed on the upper surface of the probe head  30 . The tip ends on the other side of the connecting wires  41  are arranged in the upper surface of the transformer  40 . 
     The transformer  40  is also provided with optical wires  42  penetrating the transformer  40 . Connecting ends on one side of the optical wires  42  arranged in the lower surface of the transformer  40  are optically connected to the proximal ends of the optical contacts  20  exposed on the upper surface of the probe head  30 . The optical wires  42  penetrating the transformer  40  further extend upward from the transformer  40 . The optical wires  42  used are optical members that include optical guides, and optical fibers are preferably used in this case as the optical wires  42 , for example. 
     The connecting device for inspection illustrated in  FIG. 1  further includes distributing wires  70  coupled with the other tip ends of the connecting wires  41  arranged inside the transformer  40 , and a main substrate  60  provided thereon with electric terminals  61  electrically connected to the connecting wires  41  via the distributing wires  70 . The distributing wire  70  are connected to the electric terminals  61  by soldering, for example. The main substrate  60  is also provided thereon with an optical terminal  62  coupled with the connecting ends on the other side of the optical wires  42 . 
     The main substrate  60  is provided with an electric circuit (not illustrated) electrically connected to the distributing wires  70  via the electric terminals  61 . A preferable example of the main substrate  60  to be used is a printed substrate (a PCB). An inspecting device (not illustrated) is electrically connected to the electrical signal terminal of the optoelectronic device as a target to be inspected via the main substrate  60 . 
     The inspecting device and the optical wires  42  are connected to each other via the optical terminal  62  provided on the main substrate  60 . For example, all of the optical wires  42  may be connected to the inspecting device collectively at a single position of the main substrate  60  by use of optical connectors for the optical terminal  62 . Alternatively, a plurality of optical terminals  62  connected to the tip ends of the optical contacts  20  may be provided on the main surface of the main substrate  60  so as to connect the inspecting device with the respective optical contacts  20  independently of each other. The optical signals in this case may be input to the inspecting device after being converted to the electrical signals, or may be input directly to the inspecting device, which depends on the specifications of the inspecting device. For example, the optical wires  42  and the inspecting device may be connected to each other via a photoelectric converting unit mounted on the main substrate  60  so as to use the input/output signals of the inspecting device as the electrical signals. 
     The optical signal terminal and the optical contact  20  are typically optically connected to each other in a state of being adjacent to each other but separately from each other. The connecting device for inspection illustrated in  FIG. 1  enables the optical contact  20  and the electric contact  10  to be connected to the optoelectronic device simultaneously during the inspection of the optoelectronic device. 
     Upon the inspection of the optoelectronic device, the tip end of the electric contact  10  is electrically connected to the electrical signal terminal of the optoelectronic device, and the tip end of the optical contact  20  is optically connected to the optical signal terminal of the optoelectronic device. For example, the electrical signal is input to the optoelectronic device from the tip end of the electric contact  10 , and the optical signal output from the optoelectronic device is input to the tip end of the optical contact  20  so that the optical signal is detected by the inspecting device. The connecting device for inspection thus functions as a probe card that connects the inspecting device to the optoelectronic device as a target to be inspected. 
     A preferable example of the optical contact  20  to be used is an optical fiber. For example, the optical signal is emitted toward the end surface of the optical fiber located adjacent to the optical signal terminal from the optical signal terminal of the optoelectronic device. The optical contact  20  is not limited to the optical fiber, and may be any optical member that includes an optical guide. The optical guide of the optical fiber and the like is preferably configured to have a refractive index substantially equal to that of the optoelectronic device. In the case of being used for a silicon photonic device, the optical contact  20  is formed of a material having a refractive index conforming to silicon. 
     A preferable example of the electric contact  10  to be used is a probe formed of a conductive material. The electric contact  10  may be any type of probe. 
     A stiffener  50  having higher strength than the main substrate  60  is fixed to the main substrate  60 . The stiffener  50  is used as a supporting body for ensuring mechanical strength of the connecting device for inspection so as to prevent the main substrate  60  from being bent and for fixing the respective constituent members to the connecting device for inspection. 
     Positioning pins  94  are used for aligning the lower surface of the probe head  30  in parallel with the main surface of the optoelectronic device and for adjusting an attachment angle of the probe head  30  with respect to the transformer  40 , for example. The positioning pins  94  are also used for positioning the probe head  30  with the transformer  40  so as to align the positions in the horizontal direction between the tip ends of the distributing wires  70  (the connecting wires  41 ) arranged in the transformer  40  and the upper parts of the electric contacts  10  and between the tip ends of the optical wires  42  and the upper parts of the optical contacts  20 . 
     As described above, the probe head  30  is attached to the main substrate  60  and the transformer  40  with the supporting bolts  93  and the positioning pins  94 . This structure facilitates the removal and attachment of the probe head  30  with respect to the main substrate  60 , and thus facilitates the maintenance of the probe head  30  accordingly. 
     As illustrated in  FIG. 2 , the probe head  30  includes a plurality of guide plates arranged between the upper surface and the lower surface separately from each other in the vertical direction through which the electric contacts  10  and the optical contacts  20  each penetrate. The probe head  30  illustrated in  FIG. 2  includes a bottom guide plate  31  located adjacent to the respective tip ends of the electric contacts  10  and the optical contacts  20 , and a top guide plate  32  located adjacent to the respective proximal ends of the electric contacts  10  and the optical contacts  20 . A spacer  33  is interposed between the outer edge region of the bottom guide plate  31  and the outer edge region of the top guide plate  32  so as to provide a hollow region  330  between the top guide plate  32  and the bottom guide plate  31 . The respective guide plates need to have predetermined mechanical strength so as to support the electric contacts  10  and the optical contacts  20 . In view of this, a ceramic plate having mechanical strength and easily provided with penetration holes is preferably used as the respective guide plates. 
     The probe head  30  further includes a first guide film  34  and a second guide film  35  (also collectively referred to below as “guide films”) arranged between the bottom guide plate  31  and the top guide plate  32 . The electric contacts  10  and the optical contacts  20  penetrate the guide films. The first guide film  34  is arranged adjacent to the bottom guide plate  31 , and the second guide film  35  is arranged substantially in the middle between the bottom guide plate  31  and the top guide plate  32 . The guide films do not need to have great mechanical strength, and a film made of resin can be used as the respective guide films, for example. 
     The electric contacts  10  and the optical contacts  20  penetrate through guide holes provided in the respective guide plates and the respective guide films. As illustrated in  FIG. 2 , the position of the top guide plate  32  and the position of the bottom guide plate  31  through which the common electric contact  10  and the common optical contact  20  penetrate are displaced from each other in the planar view (referred to below as an “offset arrangement”). 
     The offset arrangement leads the respective electric contacts  10  to be bent by elastic deformation between the bottom guide plate  31  and the top guide plate  32  inside the hollow region  330 . When each electric contact  10  comes into contact with the optoelectronic device, the electric contact  10  is further bent and buckled so as to be pressed against the optoelectronic device with a predetermined pressure. The offset arrangement thus can bring the electric contact  10  into contact with the optoelectronic device stably. The arrangement of the guide films in the hollow region  330  can prevent the respective electric contacts  10  in the bent state from coming into contact with each other. 
     The optical contacts  20  are also bent inside the hollow region  330 , as in the case of the electric contacts  10 . The electric contacts  10  and the optical contacts  20  bent inside the hollow region  330  do not easily fall out of the guide holes even if the electric contacts  10  and the optical contacts  20  do not fixed to the probe head  30  with an adhesive. The electric contacts  10  and the optical contacts  20  are thus held by the probe head  30  stably. 
     The connecting wires  41  may be part of the distributing wires  70 . In particular, part of the distributing wires  70  is inserted to the penetration holes formed in the transformer  40 , and the tip ends of the distributing wires  70  are exposed on the lower surface of the transformer  40 . The tip ends of the distributing wires  70  and the proximal ends of the electric contacts  10  exposed on the upper surface of the probe head  30  are connected to each other during the attachment of the transformer  40  and the probe head  30 . For example, resin may be injected to gaps between the penetration holes formed in the transformer  40  and the distributing wires  70  and then cured so as to fix the distributing wires  70  to the transformer  40 . This can ensure the fixation of the positions of the tip ends of the distributing wires  70 . 
     The proximal ends of the optical contacts  20  exposed on the upper surface of the probe head  30  are led to be optically connected to the connecting ends of the optical wires  42  arranged in the lower surface of the transformer  40  upon the attachment of the transformer  40  and the probe head  30 . For example, optical fibers are used as the optical wires  42  in which the tip ends on one side are opposed to the proximal ends of the optical contacts  20  and the other tip ends are connected to the optical terminal  62 . When the optical fibers are used for both the optical contacts  20  and the optical wires  42 , the end surfaces of the respective optical fibers are joined to each other so as to optically connect the optical contacts  20  and the optical wires  42  together. 
     The transformer  40  is provided with first penetration holes  411  in which the connecting wires  41  are arranged and second penetration holes  412  in which the optical wires  42  are arranged, as illustrated in  FIG. 3 . 
     The first penetration holes  411  each include a large-diameter electric penetration hole  411   a  having an inner diameter larger than a diameter of the connecting wire  41  and a small-diameter electric penetration hole  411   b  having an inner diameter substantially the same as the diameter of the connecting wire  41 , in which the respective electric penetration holes communicate with each other in the extending direction of the first penetration hole  411 . The small-diameter electric penetration hole  411   b  is located closer to the lower surface of the transformer  40  than the large-diameter electric penetration hole  411   a.    
     The connecting wire  41  is inserted first to the large-diameter electric penetration hole  411   a . When the connecting wire  41  is a part of the distributing wire  70 , the connecting wire  41  that serves as the tip end of the distributing wire  70  is first inserted to the first penetration hole  411 . This facilitates the insertion of the distributing wire  70  to the first penetration hole  411 . The connecting wire  41  is then inserted to the small-diameter electric penetration hole  411   b  communicating with the large-diameter electric penetration hole  411   a . The tip end of the connecting wire  41  is fixed to the inside of the small-diameter electric penetration hole  411   b  with a resin  80 . The accurate positioning of the tip end of the connecting wire  41  is thus ensured, since the inner diameter of the small-diameter electric penetration hole  411   b  and the diameter of the connecting wire  41  are substantially the same. The first penetration hole  411  including the large-diameter electric penetration hole  411   a  and the small-diameter electric penetration hole  411   b  communicating with each other can facilitate the insertion of the connecting wire  41  to the first penetration hole  411  and achieve the accurate positioning of the tip end of the connecting wire  41 . 
     The second penetration holes  412  each include a large-diameter electric penetration hole  412   a  having an inner diameter larger than a diameter of the optical wire  42  and a small-diameter electric penetration hole  412   b  having an inner diameter substantially the same as the diameter of the optical wire  42 , in which the respective electric penetration holes communicate with each other in the extending direction of the second penetration hole  412 . The small-diameter electric penetration hole  412   b  is located closer to the lower surface of the transformer  40  than the large-diameter electric penetration hole  412   a.    
     The connecting end of the optical wire  42  optically connected to the proximal end of the optical contact  20  is inserted first to the large-diameter electric penetration hole  412   a , so that the optical wire  42  is easily inserted to the second penetration hole  412 . The optical wire  42  is then inserted to the small-diameter electric penetration hole  412   b  communicating with the large-diameter electric penetration hole  412   a . The connecting end of the optical wire  42  is fixed to the inside of the small-diameter electric penetration hole  412   b  with the resin  80 . The accurate positioning of the connecting end of the optical wire  42  is thus ensured, since the inner diameter of the small-diameter electric penetration hole  412   b  and the diameter of the optical wire  42  are substantially the same. The second penetration hole  412  including the large-diameter electric penetration hole  412   a  and the small-diameter electric penetration hole  412   b  communicating with each other can facilitate the insertion of the optical wire  42  to the second penetration hole  412  and achieve the accurate positioning of the connecting end of the optical wire  42 . 
     As described above, the fixation of the connecting wire  41  and the optical wire  42  to the transformer  40  is achieved by the injection of the resin  80  to the gap between the first penetration hole  411  formed in the transformer  40  and the connecting wire  41  and the gap between the second penetration hole  412  formed in the transformer  40  and the optical wire  42 . The curing of the resin  80  fixes the position of the tip end of the connecting wire  41  electrically connected to the proximal end of the electric contact  10  and the position of the connecting end of the optical wire  42  optically connected to the proximal end of the optical contact  20 . This can ensure both the electrical connection between the electric contact  10  and the connecting wire  41  and the optical connection between the optical contact  20  and the optical wire  42 . 
     In the connecting device for inspection described above, the probe head  30  and the transformer  40  are detachably attached to each other. In particular, as illustrated in  FIG. 4 , the probe head  30  and the transformer  40  can be separated from each other in the state in which the electric contacts  10  and the optical contacts  20  are still positioned in the probe head  30 . 
     The detachable attachment of the probe head  30  and the transformer  40  can ensure the effects such as easiness of maintenance of the connecting device for inspection. For example, a repair or a replacement of the probe head  30  can be executed in the state in which the optical wires  42  are kept inside the transformer  40 . This can reduce the time required for the maintenance. The replacement of the electric contacts  10  and the optical contacts  20  in the probe head  30  can each be executed one by one, since the electric contacts  10  and the optical contacts  20  are not fixed to the probe head  30 . 
     The proximal ends of the electric contacts  10  exposed on the upper surface of the probe head  30  are led to be electrically connected to the tip ends on one side of the connecting wires  41  arranged in the lower surface of the transformer  40  upon the attachment of the transformer  40  and the probe head  30 . At the same time, the proximal ends of the optical contacts  20  exposed on the upper surface of the probe head  30  are led to be optically connected to the connecting ends of the optical wires  42  arranged in the lower surface of the transformer  40 . 
     Various kinds of shapes can be used for the tip end of the optical contact  20  opposed to the optoelectronic device. For example, when an optical fiber  21  including a core  211  and a clad  212  is used as the optical contact  20 , the tip end of the optical fiber  21  can have various shapes, as illustrated in  FIG. 5( a )  to  FIG. 5( d ) . 
       FIG. 5( a )  illustrates a straight shape in which the end surface of the optical fiber  21  and the lower surface of the probe head  30  are located on the same plane. The straight shape enables the processing of the probe head  30  most easily. 
       FIG. 5( b )  illustrates a flanged shape in which the opening of the guide hole formed on the lower surface of the probe head  30  has a smaller diameter than the end surface of the optical fiber  21 . The flanged shape leads the tip end of the optical fiber  21  to come into contact with the flange of the guide hole, so as to stably hold the position of the end surface of the optical fiber  21 . 
       FIG. 5( c )  and  FIG. 5( d )  each illustrate a shape in which the end surface of the optical fiber  21  is curved.  FIG. 5( c )  illustrates a case in which the opening of the guide hole formed on the lower surface of the probe head  30  has a tapered shape, and  FIG. 5( d )  illustrates a case in which the opening of the guide hole formed on the lower surface of the probe head  30  has a spherical surface. The curved end surface of the optical fiber  21  facilitates the concentration of light emitted from the optoelectronic device on the optical fiber  21 . 
     As illustrated in  FIG. 6( a )  and  FIG. 6( b ) , the tip end of the optical fiber  21  with the circumference covered with a coating film  25  may be set to be located below the lower surface of the probe head  30 .  FIG. 6( a )  illustrates a case in which the guide hole through which the optical fiber  21  having a straight-shaped tip end penetrates has a flanged shape in which the lower part is narrowed. This shape leads the coating film  25  provided along the circumference of the optical fiber  21  to come into contact with the flange of the guide hole, so as to stably hold the position of the optical fiber  21 .  FIG. 6( b )  illustrates a case in which the circumference of the optical fiber  21  having a curved tip end is covered with the coating film  25 . The coating film  25  in this case also comes into contact with the flange of the guide hole. The coating film  25  thus serves as a stopper so as to prevent the optical fiber  21  from coming off the guide hole. The coating film  25  to be used is a resin film, for example. The tip end of the optical fiber  21  may be provided with a lens. 
     The use of the coating film  25  as a stopper for stopping the optical fiber  21  in the probe head  30  as described above can eliminate the use of resin for fixing the optical fiber  21  to the probe head  30 . The coating film  25  leads the optical fiber  21  to be tightly attached to the probe head  30 . 
     As illustrated in  FIG. 7( a )  and  FIG. 7( b ) , the tip end of the optical fiber  21  not covered with the coating film  25  may be set to be located below the lower surface of the probe head  30 . The optical fiber  21  not covered with the coating film  25  has a smaller outer diameter, contributing to a reduction in pitch, as compared with the optical fiber  21  covered with the coating film  25 . 
     In the case in which the tip end of the optical fiber  21  does not protrude below the lower surface of the probe head  30 , the probe head  30  has a probability of coming into contact with the optoelectronic device when the tip end of the optical fiber  21  is brought closer to the optoelectronic device. The tip end of the optical fiber  21  that protrudes below the probe head  30 , as illustrated in  FIG. 6( a )  and  FIG. 6( b )  or  FIG. 7( a )  and  FIG. 7( b ) , can be brought closer to the optoelectronic device that is still separated from the probe head  30 . 
     The connecting device for inspection according to the embodiment is used for inspecting the optoelectronic device as follows. The respective electric contacts  10  and the optoelectronic device are positioned with each other with the connecting device for inspection having a configuration in which the tip end of the electric contact  10  extends by a tip-end length T 1  below the lower surface of the probe head  30 , as illustrated in  FIG. 8 . The tip-end length T 1  is about 200 μm, for example. 
     The positioning is executed such that a stage having a mount surface on which the optoelectronic device is mounted is moved in a direction parallel to the mount surface or is rotated about a central axis in a surface normal direction of the mount surface. This positioning may be executed while an alignment mark provided in the connecting device for inspection is captured by an imaging device such as a CCD camera mounted on the stage. 
     For example, when a captured image of the alignment mark provided in the connecting device for inspection is obtained by the imaging device mounted on the stage, the information on the relative position between the stage on which the optoelectronic device is mounted and the connecting device for inspection is acquired through image processing executed for the captured image. The position and the direction of the stage, for example, are adjusted in accordance with the information on the relative position so that the tip end of the electric contact  10  can be located at a position in contact with the electrical signal terminal of the optoelectronic device. 
     The tip end of the electric contact  10  is then brought into contact with the electrical signal terminal (not illustrated) of the optoelectronic device  100 , as illustrated in  FIG. 9 , in a state in which the tip end of the electric contact  10  and the position of the electrical signal terminal of the optoelectronic device  100  conform to each other in the planar view. Since the positional relationship between the tip end of the electric contact  10  and the tip end of the optical contact  20  corresponds to the positional relationship between the electrical signal terminal and the optical signal terminal of the optoelectronic device  100 , the optical contact  20  is also positioned so as to conform to the optical signal terminal of the optoelectronic device  100 . 
     Next, as illustrated in  FIG. 10 , the optoelectronic device  100  and the connecting device for inspection are brought closer to each other so that the electric contact  10  is pressed at a predetermined stylus pressure against the electrical signal terminal of the optoelectronic device  100 . For example, overdrive is applied so as to press the tip end of the electric contact  10  against the optoelectronic device  100 . 
     The optoelectronic device  100  and the connecting device for inspection are brought closer to each other such that a gap T 2  between the tip end of the optical contact  20  and the optical signal terminal of the optoelectronic device  100  reaches a gap that allows the optical contact  20  and the optical signal terminal to be optically connected to each other. The gap between the tip end of the optical contact  20  and the optoelectronic device  100  can be regulated in a predetermined range depending on the setting of the tip-end length T 1  of the electric contact  10  and the setting of the overdrive. For example, the gap T 2  is about 100 μm when the tip-end length T 1  of the electric contact  10  is set to 160 μm and the overdrive of 60 μm is applied. 
     In the connecting device for inspection illustrated in  FIG. 1 , the electric contacts  10  and the optical contacts  20  are each arranged in the probe head  30  with a predetermined positioning accuracy. As described above, the positioning of the electric contact  10  with the electrical signal terminal of the optoelectronic device  100  enables the simultaneous positioning of the optical contact  20  with the optical signal terminal of the optoelectronic device  100 . This facilitates the alignment between the connecting device for inspection and the optoelectronic device  100 . The simultaneous positioning with the predetermined positioning accuracy between the electric contact  10  and the electrical signal terminal of the optoelectronic device  100  and between the optical contact  20  and the optical signal terminal of the optoelectronic device  100  can also enables the simultaneous execution of the electrical measurement and the optical measurement for the optoelectronic device  100 . 
     The connecting device for inspection to be aligned with the optoelectronic device  100  provided with the electrical signal terminal  101  and the optical signal terminal  102  as illustrated in  FIG. 11  is described below.  FIG. 11  illustrates the optoelectronic device  100  with a case of a VCSEL in which the electrical signal terminal  101  is a signal input terminal, and the optical signal terminal  102  is a light-emission surface. 
     The plural optoelectronic devices  100  are arranged in a wafer. As illustrated in  FIG. 12 , the probe head  30  is prepared that includes a plurality of units  310  each arranged such that a guide hole  301  for electric contact and a guide hole  302  for optical contact respectively correspond to the position of the electrical signal terminal  101  and the position of the optical signal terminal  102 .  FIG. 12  is a plan view illustrating the bottom guide plate  31 . The single unit  310  corresponds to the single optoelectronic device  100 . The probe head  30  thus has a configuration in which the plural units  310  are each arranged such that the tip end of the electric contact  10  and the tip end of the optical contact  20  respectively correspond to the electrical signal terminal and the optical signal terminal of each optoelectronic device  100 . 
     The electric contacts  10  and the optical contacts  20  are inserted to the guide holes provided in the guide plates and the guide films of the probe head  30 . This sets the positions of the respective tip ends of the electric contacts  10  and the optical contacts  20 . 
     The plural optoelectronic devices  100  are typically arranged in a grid state in the wafer. The units  310  are thus typically positioned to correspond to the positions of the optoelectronic devices  100  arranged in the grid state. The positions of the units  310  may be varied depending on the arrangement of the optoelectronic devices  100  in the wafer.  FIG. 13( a )  to  FIG. 13( e )  illustrate a variation in the arrangement of the units  310 . 
     For example, the units  310  are arranged next to each other in both an X direction and a Y direction, as illustrated in  FIG. 13( a ) . The units  310  may be arranged next to each other only in the X direction and arranged with intervals interposed therebetween in the Y direction, as illustrated in  FIG. 13( b ) . The units  310  may be arranged with intervals interposed therebetween in the X direction and arranged next to each other in the Y direction, as illustrated in  FIG. 13( c ) . 
     The units  310  may also be arranged with intervals interposed therebetween in both the X direction and the Y direction, as illustrated in  FIG. 13( d ) , or may be arranged diagonally in the planar view, as illustrated in  FIG. 13( e ) . 
     As described above, the connecting device for inspection according to the embodiment includes the electric contacts  10  and the optical contacts  20  positioned in the probe head  30  with a predetermined positioning accuracy so as to ensure the reliable connection of the respective tip ends. The accurate correspondence of the positional relationship between the electric contacts  10  and the optical contacts  20  to the positional relationship between the respective signal terminals of the optoelectronic devices enables the positioning of the electrical signal terminals of the optoelectronic devices with the electric contacts  10 , so as to achieve the accurate positioning of the optical contacts  20  with the optical signal terminals of the optoelectronic devices accordingly. The configuration of the connecting device for inspection thus facilitates the alignment with the optoelectronic devices. In addition, the provision of the electric contact  10  and the optical contact  20  in the same unit  310  enables the simultaneous execution of the electrical measurement and the optical measurement for the optoelectronic device. 
     In the connecting device for inspection, the tip ends of the connecting wires  41  are arranged in the transformer  40  so as to be electrically connected to the proximal ends of the electric contacts  10  provided in the probe head  30  upon the attachment of the probe head  30  and the transformer  40 . In addition, the connecting ends of the optical wires  42  are arranged in the transformer  40  so as to be optically connected to the proximal ends of the optical contacts  20  provided in the probe head  30  upon the attachment of the probe head  30  and the transformer  40 . This configuration enables the detachable arrangement between the probe head  30  and the transformer  40 , and facilitates the maintenance of the connecting device for inspection accordingly. 
     Other Embodiments 
     While the present invention has been described above with reference to the embodiment, it should be understood that the present invention is not intended to be limited to the descriptions and the drawings composing part of this disclosure. Various alternative embodiments, examples, and technical applications will be apparent to those skilled in the art according to this disclosure. 
     While the embodiment has been illustrated above with the case in which the connecting wires  41  provided inside the transformer  40  are part of the distributing wires  70 , the transformer  40  used may be a multi-layer wiring substrate such as a multi-layer organic (MLO) substrate or a multi-layer ceramic (MLC) substrate. The use of the wiring substrate as the transformer  40  that uses the connecting wires  41  as a conductive layer can expand the intervals between the respective tip ends on one side of the connecting wires  41  connected to the distributing wires  70  more than the intervals between the respective tip ends on the other side of the connecting wires  41  connected to the proximal ends of the electric contacts  10 . This facilitates the expansion of the intervals between the respective distributing wires  70 . The wiring substrate, when used as the transformer  40 , is provided with the penetration holes through which the optical wires  42  penetrate in a region in which the connecting wires  41  are not arranged. 
     The electric contacts  10  used may be spring pins instead of the probes bent inside the probe head  30 . 
     It should be understood that the present invention includes various embodiments not disclosed herein. 
     REFERENCE SIGNS LIST 
     
         
         
           
               10  ELECTRIC CONTACT 
               20  OPTICAL CONTACT 
               30  PROBE HEAD 
               31  BOTTOM GUIDE PLATE 
               32  TOP GUIDE PLATE 
               33  SPACER 
               34  FIRST GUIDE FILM 
               35  SECOND GUIDE FILM 
               40  TRANSFORMER 
               41  CONNECTING WIRE 
               42  OPTICAL WIRE 
               50  STIFFENER 
               60  MAIN SUBSTRATE 
               70  DISTRIBUTING WIRE 
               80  RESIN 
               100  OPTOELECTRONIC DEVICE 
               101  ELECTRICAL SIGNAL TERMINAL 
               102  OPTICAL SIGNAL TERMINAL