Connection structure between circuit board and cable and probe device

Abstract

[The technical problem to be solved] The objective of this invention is to provide a probe and probe device that can be easily attached and detached from a circuit board under test and can efficiently perform tests on the circuit board under test or electronic components. Technical means to solve the problem The solution is that the first clamping piece (20) has a first clamping part (25) at one end located on the side of the circuit board under test (P) that contacts one of the surfaces of the circuit board under test (P), and the second clamping piece (30) has a second clamping part (31) at one end located on the side of the circuit board under test (P) that contacts the other surface of the circuit board. The first clamping piece (20) and the second clamping piece (30) have operating parts (26, 32) at the other end located on the side away from the circuit board under test (P) for bearing an operating force opposite to the springing force of the springing member (40).

Description

Probes and probe devices The present invention relates to a probe connected to a circuit substrate and a probe device having the probe. Typically, when conducting electrical characteristic tests on a circuit board or electronic components mounted on the circuit board, a measuring device measures the electrical characteristics when a test signal is transmitted to the circuit board. In this case, the measuring device is connected to the circuit board via a cable or the like. Patent document 1 discloses a coaxial electrical connector connected to the end of a circuit substrate. This coaxial electrical connector comprises: a center conductor having an axis parallel to the surface of the circuit substrate and extending in the axial direction; and a cylindrical outer conductor that holds the center conductor via an insulator. In the outer conductor, a pair of fixing portions for mounting toward the circuit substrate are provided so as to extend parallel to the surface of the circuit substrate. In each fixing portion, a through hole serving as a screw hole is formed extending in the vertical direction (a direction perpendicular to the surface of the circuit substrate). This coaxial electrical connector is mounted on the end of the circuit substrate by fixing the fixing portion to the end with a screw. Specifically, the fixing portion is arranged on the upper surface of the end of the circuit substrate, and the screw is screwed into the through hole and the hole portion while the through hole is aligned with the hole portion formed in the circuit substrate. [Prior Art Document] [Patent Document] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-081745 [Problems to be solved by the invention] Typically, to test a large number of circuit boards or electronic components, it is necessary to repeatedly connect each circuit board to a measuring device. Therefore, when using the coaxial electrical connector disclosed in Patent Document 1 to test circuit boards or electronic components, the coaxial electrical connector must be attached and detached from the circuit board, i.e., screw tightening and loosening operations must be performed sequentially. This complicates the detachment and attachment process, making it difficult to efficiently test multiple circuit boards or electronic components in a short period of time. The present invention was developed in light of these circumstances, and its purpose is to provide a probe and a probe device that can be easily attached to and detached from a circuit board and efficiently perform tests on circuit boards or electronic components. [Technical Means for Solving the Problem] (1) The probe of the present invention is a probe device that connects a measuring device for measuring the electrical characteristics of a circuit board or an electronic component mounted on the circuit board to the circuit board via a cable. The probe device is mounted on the end of the cable and connected to the circuit board. In the present invention, the probe comprises a signal transmission body that can be electrically connected to a signal circuit portion formed on a surface on one side of the aforementioned circuit substrate; a substrate clamping body that can clamp the aforementioned circuit substrate in the direction of its thickness; and a spring-pushing member that maintains the aforementioned substrate clamping body in a state of clamping the aforementioned circuit substrate. The aforementioned substrate clamping body comprises: a first clamping piece located on one side of the aforementioned circuit substrate for holding the aforementioned signal transmission body; and a second clamping piece located on the other side of the aforementioned circuit substrate. The aforementioned spring-pushing member is hung on the aforementioned first clamping piece and the aforementioned second clamping piece and is configured to be elastically deformable, and pushes the aforementioned first clamping piece and the aforementioned second clamping piece toward a position for clamping the aforementioned circuit substrate. The aforementioned first clamping piece has a first clamping portion at one end portion located on the aforementioned circuit substrate side that contacts one surface of the aforementioned circuit substrate, and the aforementioned second clamping piece has a second clamping portion at one end portion located on the aforementioned circuit substrate side that contacts the other surface of the aforementioned circuit substrate. At least one of the first clamping piece and the second clamping piece has an operating portion at the other end portion located away from the circuit substrate for receiving an operating force opposite to the elastic pushing force of the elastic pushing member. In the present invention, when the probe is mounted on a circuit substrate, first, an operating force opposite to the elastic force of the elastic push member is applied to the operating portion of the probe, causing the first clamping portion and the second clamping portion to be significantly separated. While maintaining this state, the probe is arranged so that the circuit substrate is located between the first clamping portion and the second clamping portion. Here, the first clamping portion is located on one side relative to the circuit substrate, and the second clamping portion is located on the other side relative to the circuit substrate. Next, the aforementioned operating force is released, and the first clamping portion and the second clamping portion are brought closer together by the elastic push member to clamp the circuit substrate. In this way, the circuit substrate is clamped by the first clamping portion and the second clamping portion, which are subjected to the elastic push member. This maintains the state in which the signal transmission element held by the first clamping piece is in contact with the circuit portion of the circuit substrate. In addition, when removing the probe from the circuit substrate, the aforementioned operating force is applied to the operating portion of the probe, causing the first clamping portion and the second clamping portion to be significantly separated, thereby releasing the state in which the circuit substrate is clamped. As described above, in the present invention, the probe can be easily attached to and detached from the circuit board simply by applying or releasing an operating force to the operating portion of the probe, thereby enabling efficient testing of the circuit board or electronic components mounted on the circuit board. (2) In the invention of (1), the clamping portion of one of the first clamping portion and the second clamping portion may include a protrusion inserted into a through space, and the through space is formed in the circuit substrate by penetrating in the direction of the plate thickness, and the clamping portion on the other side may include a receiving portion, and the receiving portion may receive the front end portion of the protrusion protruding from the through space on the side of the through space that is the other side. In the invention of (2), when the circuit substrate is clamped by the first and second clamping portions of the probe, the protrusion is inserted into the through-space of the circuit substrate, and the tip protruding from the through-space enters the receiving portion. Therefore, the protrusion is located within the through-space and the receiving portion. Furthermore, the movement of the protrusion in a direction parallel to the circuit substrate is restricted by the edge of the through-space, thereby positioning the probe relative to the circuit substrate and maintaining good contact between the signal transmitter and the signal circuit portion of the circuit substrate. (3) In the invention of (2), the protrusion may be inserted into the aforementioned through-space formed by cutting the end edge of the circuit substrate. Thus, when the probe is attached to or detached from the circuit substrate, the protrusion of the probe can be inserted or removed through the opening of the through-space formed at the end edge of the circuit substrate. Therefore, even if the probe is moved in a direction inclined relative to the thickness direction of the circuit substrate, the probe can be attached or detached, making the attachment and detachment operation easier. (4) In any one of the inventions (1) to (3), the signal transmission body may include: a dielectric held by the first clamping piece; and a central conductor held by the dielectric and capable of contacting the signal circuit portion of the circuit substrate. (5) In the invention of (4), the first clamping piece may be made of metal, electrically conductive with the outer conductor of the cable, and in contact with a ground circuit portion formed on one side of the circuit substrate. Thus, when a signal current flows through the central conductor of the signal transmission element and the signal circuit portion of the circuit substrate as a transmission path, a return current can flow through the ground circuit portion, the first clamping piece, and the outer conductor as a transmission path. (6) In the inventions of (4) and (5), the first clamping piece may be connected to the end of the cable by being installed on a mounting member provided at the end of the cable. (7) In the inventions of (4) and (5), the first clamping piece may be connected to the end of the cable via a probe connection connector provided at the end of the cable. (8) In the invention of any one of (1) to (3), the signal transmission body may have: a plate-shaped substrate made of an electrically insulating material; and a metal signal transmission path provided on the substrate along the plate surface of the substrate and capable of contacting the signal circuit portion of the circuit board. (9) In the invention of (8), the signal transmission element may include a metal ground transmission path provided on the substrate along the plate surface of the substrate, and the ground transmission path may be connected to a ground circuit portion formed on one side of the surface of the circuit substrate. By forming the signal circuit portion of the signal transmission element into a ground circuit portion connected to one side of the surface of the circuit substrate, when a current of a signal is caused to flow through the signal transmission path of the signal transmission element and the signal circuit portion of the circuit substrate as a transmission path, a return current can flow through the ground circuit portion and the ground transmission path as a ground transmission path. (10) The probe device of the present invention comprises: a probe according to any one of the inventions (1) to (9); a connector for connecting to a measuring device connected to a counterpart connector provided on the side of the measuring device; and a cable for connecting the probe to the connector for connecting to the measuring device. [Effects of the Invention] The present invention provides a probe and a probe device that can be easily attached to and detached from a circuit board and can efficiently perform tests on the circuit board or electronic components. Hereinafter, embodiments of the present invention will be described with reference to the drawings. <First embodiment> Figure 1 is a stereoscopic diagram showing a probe device 1 and a circuit substrate P according to the first embodiment of the present invention. The circuit substrate P is shown in part only, but is actually further expanded in both the X-axis direction and the Y-axis direction. In this embodiment, the X-axis direction is referred to as the "front-back direction," the X1 direction as the "front," and the X2 direction as the "back." In addition, the Y-axis direction is referred to as the "probe width direction." The circuit substrate P is a so-called test board used for performance tests of electronic components (not shown) such as IC chips. As shown in FIG1 , the mounting surface (top surface in FIG1 ) of the circuit board P includes a signal pattern P1 extending in the front-to-back direction (X-axis direction) on the mounting surface, serving as the signal circuit portion; and a ground pattern P2 extending to surround signal pattern P1, serving as the ground circuit portion. An electronic component (not shown) to be subjected to performance testing is mounted near the front end (X1-side end) of signal pattern P1. A probe device 1 (see FIG6 ) is connected near the rear end (X2-side end) of signal pattern P1 (test port). Furthermore, at the rear edge of the circuit board P in the probe width direction (Y-axis direction), notches P3 are formed on both sides of the signal pattern P1 in the probe width direction by cutting through the rear edge. Notches P3 penetrate the circuit board P in the thickness direction, i.e., the vertical direction (Z-axis direction), and open toward the rear (X2 direction). They function as positioning portions for positioning the probe 2, described later. As shown in FIG1 , a probe device 1 comprises a probe 2 connected to a circuit board P; a measuring device connection connector 3 connected to a target connector (not shown) provided on the side of a measuring device (not shown) for measuring the electrical characteristics of an electronic component; and a coaxial cable 4 (hereinafter referred to as "cable 4") extending in the front-to-back direction (X-axis direction) to connect the probe 2 and the measuring device connection connector 3. The target connector may be provided on the measuring device itself or on another device connected to the measuring device. Probe 2 is a clip-type probe attached to the front end of cable 4. Probe 2 comprises a metal substrate holder 10 that can hold circuit substrate P in its thickness direction, i.e., in the vertical direction (Z-axis direction); a metal pusher 40 that maintains substrate holder 10 in its position holding circuit substrate P; and a signal transmission element 50 (see Figure 4 ) that is electrically conductive with the signal pattern P1 of circuit substrate P held by substrate holder 10. Substrate holder 10 is movable between a closed state (see Figures 1 and 4 ) and an open state (see Figure 5 ). Figure 2 is a perspective view showing the probe 2 of the probe device 1 of Figure 1 from an oblique angle. As shown in Figures 1 and 2, the substrate holder 10 includes a first holder 20 located on the upper side (Z1 side) of the circuit substrate P for holding the signal transmission member 50, and a second holder 30 located on the lower side (Z2 side) of the circuit substrate P. Figure 3 is a perspective view of the first clamping piece 20 from an oblique angle below. As shown in Figures 1 to 3, the first clamping piece 20 is arranged so that its longitudinal direction extends along the front-to-back direction. The first clamping piece 20 comprises a base portion 21 provided at the front; a first clamping portion 25 protruding forward from the base portion 21; a first operating portion 26 provided at the rear; a first connecting portion 27 connecting the base portion 21 and the first operating portion 26; and a supported portion 28 protruding from the lower surface of the first connecting portion 27. Figure 4 is a cross-sectional view of the probe 2 mounted on a circuit board P, showing a longitudinal section taken at the center of the probe's width (Y-axis). As shown in Figure 4 , the base 21 comprises a retaining portion 22 for retaining the signal transmission element 50 and the front end of the cable 4, and a first plate portion 24 extending rearward from the rear end of the upper portion of the retaining portion 22. At the lower portion of the retaining portion 22, in the central region along the width of the probe, a circular hole-shaped receiving hole portion 23 is formed that extends through the front-to-back direction to accommodate the signal transmission element 50 and the front end portion of the cable 4. As shown in FIG4 , the receiving hole portion 23 includes a front hole portion 23A, a middle hole portion 23B, and a rear hole portion 23C that are sequentially connected from the front. The front hole portion 23A has stepped portions formed on its inner circumference at multiple locations along the front-to-back direction. These stepped portions form multiple spaces with different inner diameters. Of these multiple spaces, the front hole portion 23A-1 located at the frontmost position accommodates and holds the second dielectric 53, which will be described later. As shown in FIG4 , a front stepped portion 23E is formed at the boundary of the space adjacent to the front hole portion 23A-1, that is, at the rear of the front hole portion 23A-1, which has a smaller diameter than the front hole portion 23A-1. The middle hole portion 23B is formed to have a larger diameter than the front hole portion 23A, and a front step portion 23D is formed at the boundary between the middle hole portion 23B and the front hole portion 23A. The rear hole portion 23C is formed to have a larger diameter than the middle hole portion 23B, and a rear step portion 23E is formed at the boundary between the rear hole portion 23C and the middle hole portion 23B. A threaded groove (not shown) is formed on the inner circumference of the rear hole portion 23C for mounting the locking metal fastener 65, described later, located at the front end of the cable 4. The upper portion of the retaining portion 22 is formed as a first pressed portion 22F that receives the elastic force from the elastic member 40 from above. The upper surface of the first pressed portion 22F, which receives the elastic force, is formed as a flat surface at right angles to the vertical direction. As shown in Figure 4, the first plate portion 24 is provided at a position slightly offset upward relative to the first pressed portion 22F. In addition, the upper surface of the base 21 spans the range of the first pressed portion 22F and the first plate portion 24 in the front-to-back direction and is formed as an inclined surface that tilts upward as it moves toward the rear. The first clamping portions 25 are provided at both ends of the lower portion of the retaining portion 22 in the probe width direction, protruding from the front of the retaining portion 22. That is, when the probe 2 is viewed from the front, the two first clamping portions 25 are located at approximately the same height as the receiving hole 23 in the vertical direction, and sandwich the receiving hole 23 in the probe width direction. The first clamping portion 25 includes: a front piece 25A having a substantially square prism shape that protrudes forward from the front of the retaining portion 22; and a protrusion 25B having a substantially cylindrical shape that protrudes downward from the lower surface of the front piece 25A (see FIG3 ). The outer diameter of the protrusion 25B is formed to be slightly larger than the width dimension (dimension in the probe width direction) of the notch P3 of the circuit board P. As shown in FIG3 , the protrusion 25B is divided into two protruding pieces by a slit formed in the center of the probe width direction. These protruding pieces are somewhat elastically deformable in the probe width direction. As shown in Figure 1, the first operating portion 26 is formed in a roughly square plate shape connected to the rear ends of the two first connecting portions 27, and receives the pressing force (operating force) from above when the substrate clamping body 10 is operated. The first connecting portion 27 is connected to the side surfaces of the base 21 in the probe width direction (Y-axis direction), and extends obliquely upward as it moves toward the rear. The space surrounded by the first operating portion 26 and the two first connecting portions 27 forms a first receiving portion 29 for accommodating the first push piece 41 described later for accommodating the push member 40. The slightly front half of the first receiving portion 29 is blocked from below by the first pressed portion 22F and the first plate portion 24 located between the two first connecting portions 27. The supported portion 28 is provided to protrude downward from the lower surface of the middle portion of the first connecting portion 27 in the front-to-back direction. As shown in FIG3 , the supported portion 28 is substantially semicircular when viewed in the probe width direction, and its outer peripheral surface protruding and curved downward is supported by a supporting portion 34 of the second clamping piece 30 rotatably around an axis extending in the probe width direction. As shown in Figures 1, 2 and 4, the second clamping piece 30 is in the shape of a roughly square plate extending in the front-to-back direction as the longitudinal direction, and has: a second clamping portion 31 provided at the front; a second operating portion 32 provided at the rear; a second connecting portion 33 connecting the second clamping portion 31 and the second operating portion 32; a supporting portion 34 protruding from the upper surface of the second connecting portion 33; and a plate-shaped second plate portion 35 extending rearward from the second clamping portion 31. The second clamping portion 31 is located further forward than the base portion 21 of the first clamping piece 20 and further downward than the first clamping portion 25 of the first clamping piece 20. The second clamping portion 31 is larger than the base portion 21 in the probe width direction and is larger than the first clamping portion 25 in the front-to-back direction. The front end of the second clamping portion 31 is located further forward than the front end of the first clamping portion 25. A receiving portion 31A is formed at the rear of the second clamping portion 31 to pass through the second clamping portion 31 in the up-down direction. The receiving portion 31A is formed in the shape of a square hole with the probe width direction as the length direction when viewed from the top and bottom. As will be described later, when the substrate clamping body 10 is in the closed position, it can receive the protrusions 25B of the two first clamping portions 25 from above (see FIG. 4 ). The second operating portion 32 is formed into a roughly square plate shape connected to the rear ends of the two second connecting portions 33, and is shaped like the first operating portion 26 of the first clamping piece 20 turned upside down. The second operating portion 32 receives the pressing force (operating force) from below when operating the substrate clamping body 10. The second connecting portion 33 extends in the front-to-back direction to connect the rear end of the second clamping portion 31 and the front end of the second operating portion 32. As shown in Figure 2, the space surrounded by the second clamping portion 31, the second operating portion 32 and the two second connecting portions 33 forms a second receiving portion 36 for accommodating the second push piece 42 described later of the push member 40. The support portion 34 is provided to protrude upward from the upper surface of the middle portion of the second connecting portion 33 in the front-to-back direction. The support recess 34A (refer to FIG1 ) of the support portion 34 for accommodating the supported portion 28 of the first clamping piece 20 is formed to be recessed from the upper surface. The inner wall surface of the support recess 34A is formed as a concave curved surface that matches the outer peripheral surface of the supported portion 28, and supports the supported portion 28 rotatably. The second plate portion 35 is provided between the two second connecting portions 33, blocking the slightly front half of the second accommodating portion 36 from above. As shown in FIG4 , the front portion of the second plate portion 35 is formed as a second pressed portion 35A that receives the elastic thrust from the elastic thrust member 40 from below. The lower surface of the second plate portion 35 is formed as an inclined surface that tilts downward as it moves toward the rear. The elastic member 40 is made by bending a metal strip in the direction of its thickness. As shown in Figure 4, it forms a roughly horizontal U-shape with a forward opening. It is suspended between the first and second clamping pieces 20 and 30 and is elastically deformable. The elastic member 40 comprises a first elastic piece 41 located at the top, a second elastic piece 42 located at the bottom, and two elastic portions 43 connecting the front ends of the first and second elastic pieces 41 and 42. As shown in Figure 4, the first push piece 41 extends along the upper surface of the first clamping piece 20 in an inclined downward direction as it moves forward, and the front end portion is bent in an inclined direction toward the front and upward. The portion of the first push piece 41 that protrudes downward at the bent position forms a first push portion 41A that serves as the upper surface of the first pressed portion 22F that pushes from above. As shown in Figure 4, the second push piece 42 extends along the lower surface of the second clamping piece 30 in an inclined upward direction as it moves forward, and the front end portion is bent in an inclined direction toward the front and downward. The portion of the second push piece 42 that protrudes upward at the bent position forms a second push portion 42A that serves as the lower surface of the second pressed portion 35A that pushes from below. Elastic portions 43 are provided at both ends of the resilient member 40 in the probe width direction. These portions are bent into a substantially horizontal C-shape, opening forward, and serve to connect the rear ends of the first resilient portion 41A and the second resilient portion 42A. In this embodiment, the two resilient portions 43 are spaced apart in the probe width direction, allowing the cable 4 to be inserted between the two resilient portions 43 and mounted on the first clamping piece 20. The elastic part 43 of the elastic push member 40 is elastically deformed in the thickness direction of the plate, and the first elastic push piece 41 and the second elastic push piece 42 are displaced in the up and down directions, that is, in a manner of approaching or separating from each other. When the elastic push member 40 has been installed on the substrate clamping body 10, the elastic part 43 is elastically deformed, and the first elastic push piece 41 and the second elastic push piece 42 are displaced in a manner of increasing the distance between them. As a result, the first elastic push piece 41 and the second elastic push piece 42 are pushed by the elastic force (restoring force) of the elastic part 43 to the first elastic push part 41A and the second elastic push part 42A of the substrate clamping body 10, thereby clamping the substrate clamping body 10 and maintaining the substrate clamping body 10 in a closed state. As shown in Figure 4, the signal transmission body 50 is accommodated in the receiving hole portion 23 of the first clamping piece 20 and retained by the retaining portion 22. The signal transmission body 50 has: a first dielectric 51 accommodated and retained in the middle hole portion 23B; a second dielectric 53 accommodated and retained in the front hole portion 23A; and a central conductor 52 accommodated in the front hole portion 23A and the middle hole portion 23B and retained by the first dielectric 51 and the second dielectric 53. The first dielectric 51 and the second dielectric 53 are annular components made of an electrically insulating material such as resin and are arranged in a posture with the front-to-back direction as the axial direction. The first dielectric 51 is arranged at the rear end of the middle hole portion 23B. In addition, the second dielectric 53 has a smaller diameter than the first dielectric 51 and is arranged in the front hole portion 23A-1. In this embodiment, the first clamping piece 20, which has a receiving hole 23 for receiving the first dielectric 51, the second dielectric 53, and the center conductor 52, is made of metal. Therefore, the first dielectric 51, the second dielectric 53, the center conductor 52, and the first clamping piece 20 together function as a coaxial electrical connector. In this case, the first clamping piece 20 functions as an outer conductor. The center conductor 52 is a metal terminal extending in the front-to-back direction. Its intermediate portion in the front-to-back direction is press-fitted and retained by the first dielectric 51, and its distal portion is press-fitted and retained by the second dielectric 53. The distal end of the center conductor 52 protrudes outward from the distal end opening of the distal end hole 23A-1, forming a pin-shaped front contact portion 52A capable of contacting the signal pattern P1 (see FIG. 1 ) on the circuit board P from above. Furthermore, at the rear end of the center conductor, a plurality of elastic pieces are formed that are elastically deformable in the radial direction of the intermediate hole 23B, forming a rear contact portion 52B capable of contacting the center conductor 61 of the cable 4, described later. When the signal transmission body 50 is mounted on the retaining portion 22, first, the center conductor 52 is inserted from the rear into the hole portion at the center of the first dielectric 51, and the center conductor 52 is retained by the first dielectric 51. Next, the first dielectric 51 is pressed from the front into the receiving hole portion 23. At this time, the first dielectric 51 is pressed until it contacts the front step portion 23D. Furthermore, the second dielectric 53 is pressed from the front into the front end hole portion 23A-1, and the front end side portion of the center conductor 52 is inserted from the rear into the hole portion at the center of the second dielectric 53, and the center conductor 52 is retained by the second dielectric 53. At this time, the second dielectric 53 is pressed until it contacts the front step portion 23E. As a result, the signal transmission body 50 is retained in the retaining portion 22 while being contained in the front hole portion 23A and the middle hole portion 23B. Cable 4 is a coaxial cable, the front end of which is inserted from the front into rear hole 23C of first clamping piece 20. It comprises: a metal center conductor 61 inserted from the front; a dielectric 62 made of an electrically insulating material such as resin that covers and holds the outer circumference of center conductor 61; a metal braided wire shield, or outer conductor 63, that covers and holds the outer circumference of dielectric 62; and a cover 64 made of an electrically insulating material such as resin that covers and holds the outer circumference of outer conductor 63. As shown in FIG4 , at the front end of cable 4, portions of dielectric 62, outer conductor 63, and cover 64 are cut away, resulting in a state where outer conductor 63 is exposed from the front end of cover 64, dielectric 62 is exposed from the front end of outer conductor 63, and center conductor 61 is exposed from the front end of dielectric 62. The exposed portion of center conductor 61 forms contact portion 61A for contact with center conductor 52 of signal transmission element 50. At the front end of the cable 4, a metal locking metal fastener 65, a resin (e.g., electronic wire cross-linked soft flame-retardant polyolefin resin) heat shrink tube 66, and a metal wire tube 67 are externally inserted as mounting components. The locking metal fastener 65 is a tubular component extending in the front-to-back direction, and is arranged in a manner that spans the boundary position between the exposed portion of the outer conductor 63 and the front end of the outer cover 64 in the front-to-back direction. The front end of the locking metal fastener 65 is located slightly behind the front end of the outer conductor 63. A thread (not shown) is formed on the outer peripheral surface of the front end of the locking metal fastener 65, and the thread is screwed into the thread groove of the rear hole 23C of the first clamping piece 20, so that the locking metal fastener 65 and thus the cable 4 are installed on the first clamping piece 20. The heat shrink tube 66 is a tubular member extending in the front-to-rear direction, and is arranged in a manner that spans the boundary position between the rear end of the locking metal fastener 65 and the outer cover 64 in the front-to-rear direction. By being in close contact with the outer peripheral surfaces of both the locking metal fastener 65 and the outer cover 64, the locking metal fastener 65 and the outer cover 64 are maintained. The wire tube 67 is a tubular member extending in the front-to-back direction. It is inserted externally into the exposed portion of the outer conductor 63 and internally into the front portion of the locking metal fastener 65. The wire tube 67 is soldered to the outer peripheral surface of the outer conductor 63 and can be electrically conductive with the outer conductor 63. A protruding portion 67A is formed at the front end of the wire tube 67, protruding radially outward. The protruding portion 67A is pressed forward toward the rear step portion 23E of the first clamping piece 20 by screwing the locking metal fastener 65 into the rear hole 23C of the first clamping piece 20. As a result, the outer conductor 63 of the cable 4 is electrically conductive with the first clamping piece 20 via the wire tube 67. As shown in Figure 4, when the locking metal fastener 65 is installed toward the first clamping piece 20 and the cable 4 is installed, the contact portion 61A of the center conductor 61 of the cable 4 enters the middle hole portion 23B of the first clamping piece 20 from the front, and contacts and presses against the multiple rear contact portions 52B of the center conductor 52, forming a state in which electrical conduction is possible. As shown in Figure 1, a measuring device connection connector 3 is attached to the rear end of the cable 4. The measuring device connection connector 3 is a coaxial electrical connector comprising an outer conductor, a dielectric material that receives and holds a central conductor, and a dielectric material held within the dielectric material. The measuring device connection connector 3 has the same structure as a typical coaxial electrical connector, so a detailed description thereof will be omitted. Next, the instructions for using the probe device 1 will be described. First, the measuring device connection connector 3 installed at the rear end of the cable 4 is connected to the target connector (not shown) provided on the measuring device (not shown) side. Next, an operating force opposite to the elastic push force of the elastic push member 40 is applied to the operating portion of the probe 2 installed at the front end of the cable 4, that is, the first operating portion 26 of the first clamping piece 20 and the second operating portion 32 of the second clamping piece 30 (hereinafter collectively referred to as "operating portion 26, 32" as needed), to open the substrate clamping body 10. Specifically, the operating portions 26 and 32 are grasped with fingers and pressed in a manner to counteract the elastic push force of the elastic push member 40. As a result, the first operating portion 26 is displaced in a manner close to the second operating portion 32, and the first clamping piece 20 is displaced in a lever-like manner with the supported portion 28 as a fulcrum. As the first clamping piece 20 is displaced, the first clamping portion 25 of the first clamping piece 20 is displaced upward to separate from the second clamping portion 31 of the second clamping piece 30, as shown in Figure 5 , and the substrate clamping body 10 is opened. In this opened state, a gap greater than the thickness of the circuit board P is formed between the lower end of the protrusion 25B of the first clamping portion 25 and the receiving portion 31A of the second clamping portion 31 in the vertical direction. Next, while the substrate clamping body 10 is maintained in the open position, the probe 2 is positioned between the first clamping portion 25 and the second clamping portion 31 so that the rear end portion (the end on the X2 side) of the circuit substrate P is present. Here, the first clamping portion 25 is positioned above the circuit substrate P, and the second clamping portion 31 is positioned below the circuit substrate P. Furthermore, at this point, the protrusion 25B of the first clamping portion 25 is positioned directly above the notch P3 of the circuit substrate P. Next, the aforementioned operating force is released, and the resilient force of the resilient member 40 brings the first clamping portion 25 and the second clamping portion 31 closer together, as shown in Figures 4 and 6 , clamping the rear end of the circuit board P. As a result, the front contact portion 52A of the center conductor 52 contacts the signal pattern P1 of the circuit board P from above, establishing electrical continuity. Furthermore, the front portion 25A of the first clamping portion 25 contacts (interfaces) the ground pattern P2 of the circuit board P from above, establishing electrical continuity. Furthermore, when the rear end of the circuit substrate P is clamped by the first clamping portion 25 and the second clamping portion 31, the protrusion 25B of the first clamping portion 25 is inserted from above into the notch P3 of the circuit substrate P. Furthermore, the lower end of the protrusion 25B, which protrudes downward from the notch P3, enters the receiving portion 31A of the second clamping portion 31 from above (see FIG. 4 ). Therefore, the protrusion 25B is located within the notch P3 and the receiving portion 31A. The movement of the protrusion 25B in a direction parallel to the circuit substrate P, specifically in the front (X1 direction) and in the probe width direction (Y1 and Y2 directions), is restricted by the edge of the notch P3. This allows the probe 2 to be positioned relative to the circuit substrate P, effectively maintaining the contact between the front contact portion 52A and the signal pattern P1, and the contact between the front piece 25A and the ground pattern P2. As described above, the outer diameter of the protrusion 25B is formed to be slightly larger than the width of the notch P3. Furthermore, in this embodiment, the two protrusions forming the protrusion 25B are slightly elastically deformable in the probe width direction. Therefore, the two protrusions of the protrusion 25B press against the inner edge of the notch P3 extending in the front-to-back direction, elastically deforming to approach each other in the probe width direction, and in this state, enter the notch P3. At this time, the two protrusions are in contact with the aforementioned inner edge of the notch P3, thus effectively positioning the protrusion 25B, and thus the probe 2, relative to the circuit board P. Furthermore, in this embodiment, the protrusion 25B is divided into two protrusions, but it may also be divided into three or more protrusions. Alternatively, the protrusion 25B may be formed as an undivided columnar shape (e.g., a cylindrical shape). In this case, the protrusion's dimension in the probe width direction is set to be smaller than the width of the notch P3 of the circuit board P. In the aforementioned usage instructions, after positioning the protrusion 25B of the first clamping portion 25 directly above the notch P3 of the circuit substrate P, the probe 2 is inserted from above into the notch P3. However, it is not necessary to insert the protrusion 25B straight through the notch P3 from above. In this embodiment, the notch P3, serving as a through-space in the circuit substrate P, is opened rearward. Therefore, when attaching or detaching the probe 2 from the circuit substrate P, the protrusion 25B can be inserted or removed through the rear opening of the notch P3 of the circuit substrate P. Therefore, even if the probe 2 is moved in a direction tilted relative to the vertical direction, the protrusion 25B does not interfere with the circuit substrate P, allowing the probe 2 to be attached and detached, making the installation and detachment process much simpler. In this embodiment, the first clamping piece 20 is made of metal. Its rear stepped portion 23E contacts the conduit 67 connected to the outer conductor 63, and its front piece portion 25A contacts the ground pattern P2 of the circuit board P. Therefore, while a signal current flows through the center conductor 61, center conductor 52, and signal pattern P1 as a transmission path, a return current can flow through the ground pattern P2, first clamping piece 20, conduit 67, and outer conductor 63 as a transmission path. In this embodiment, the entire first clamping piece 20 is made of metal. However, if the aforementioned return current is to flow, only a portion of it may be made of metal. In this case, for example, only the retaining portion 22 and the first clamping portion 25 of the first clamping piece 20 can be made of metal, and the remaining portions can be formed of a material other than metal (for example, an electrically insulating material such as resin). In addition, in this embodiment, in addition to the first clamping piece 20, the second clamping piece 30 and the elastic push member 40 are also made of metal. However, the second clamping piece 30 and the elastic push member 40 do not necessarily need to be made of metal. For example, the second clamping piece 30 and the elastic push member 40 can be made of an electrically insulating material such as resin. Furthermore, when removing the probe 2 from the circuit board P, the aforementioned operating force is applied to the operating portions 26 and 32 of the probe 2 to widely separate the first clamping portion 25 and the second clamping portion 31, thereby releasing the clamping of the rear end of the circuit board P. Thus, in this embodiment, the probe 2 can be easily attached to and detached from the circuit board P simply by applying or releasing the operating force to the operating portions 26 and 32 of the probe 2. This allows for efficient testing of the circuit board P or electronic components mounted thereon. <Second Embodiment> In the first embodiment, the signal transmission body 50 held by the first clamping piece 20 is configured to cooperate with the metal first clamping piece 20 to function as a coaxial electrical connector. However, in the second embodiment, the signal transmission body is configured by a circuit substrate and a coaxial electrical connector mounted on the circuit substrate, which is different from the first embodiment. The probe device of this embodiment is the same as the first embodiment except for the form of the signal transmission body, the form in which the signal transmission body is held, and the form in which the signal transmission body is connected to the cable. Here, the description focuses on the differences from the first embodiment, and the description of the parts that are the same as the first embodiment is omitted. Figure 7 is an enlarged cross-sectional view of a portion of the probe device according to the second embodiment, showing a longitudinal section taken at the center of the probe width. In the probe 102 of this embodiment, the signal transmission member 70 comprises a circuit board 80 held on the lower surface of the retaining portion 122 of the first clamping piece 120, and a coaxial electrical connector 90 (hereinafter referred to as the "substrate-side coaxial connector 90") mounted on the lower surface of the circuit board 80. The circuit board 80 comprises a plate-shaped base material 81 made of an electrically insulating material such as resin, and a metal signal transmission path (not shown) and a metal ground transmission path (not shown) disposed along the lower surface of the base material 81. In this embodiment, the signal transmission path is formed as a signal pattern extending in the front-to-rear direction, and the ground transmission path is formed as a ground pattern extending along the signal transmission path on both sides of the signal transmission path in the probe width direction. As shown in Figure 7, the front end of the circuit board 80 protrudes forward of the retaining portion 122. Furthermore, substrate-side coaxial connector 90 is a male coaxial electrical connector that is soldered to the bottom surface of circuit substrate 80 and is connected from below by cable-side coaxial connector 200, described later. Substrate-side coaxial connector 90 includes a center conductor 91 and an outer conductor 92. Center conductor 91 is connected to the signal transmission path of circuit substrate 80, while outer conductor 92 is connected to the ground transmission path of circuit substrate 80. A female coaxial electrical connector 200 (hereinafter referred to as "cable-side coaxial connector 200") is provided at the front end of the cable 4, which is mated and connected to the substrate-side coaxial connector 90. The cable-side coaxial connector 200 is a so-called right-angled coaxial electrical connector, with the vertical direction, which is perpendicular to the longitudinal direction of the cable 4, or the front-to-back direction, serving as the connector connection direction. The cable-side coaxial connector 200 includes a center conductor 201 and an outer conductor 202. The center conductor 201 is connected to the center conductor 61 of the cable 4, and the outer conductor 202 is connected to the outer conductor 63 of the cable 4. As shown in Figure 7, the cable-side coaxial connector 200 is fitted and connected to the substrate-side coaxial connector 90 from below. At this time, the center conductor 201 of the cable-side coaxial connector 200 is connected to the center conductor 91 of the substrate-side coaxial connector 90, and the outer conductor 202 is connected to the outer conductor 92 of the substrate-side coaxial connector 90. Since the substrate-side coaxial connector 90 and the cable-side coaxial connector 200 have the same structure as conventional coaxial electrical connectors, their detailed description will be omitted here. Furthermore, in this embodiment, the substrate-side coaxial connector 90 serves as a male connector and the cable-side coaxial connector 200 serves as a female connector. Alternatively, the substrate-side coaxial connector 90 serves as a female connector and the cable-side coaxial connector 200 serves as a male connector. In this embodiment, as shown in FIG7 , when probe 2 is attached to circuit board P, the tip of circuit board 80 contacts circuit board P from above. At this point, the tip of the signal transmission path of circuit board 80 contacts signal pattern P1 (see FIG1 ) of circuit board P from above, and the tip of the ground transmission path of signal transmission body 70 contacts ground pattern P2 (see FIG1 ) of circuit board P from above. Therefore, while a signal current flows through center conductor 61, center conductor 201, center conductor 91, signal transmission path, and signal pattern P1 as a transmission path, a return current can flow through ground pattern P2, ground transmission path, outer conductor 92, outer conductor 202, and outer conductor 63 as a transmission path. <Third embodiment> In the first embodiment, the cable 4 is connected to the signal transmission body 50 by screwing the locking metal fastener 65 provided at the front end of the cable 4 into the rear hole 23C of the first clamping piece 20. However, in the third embodiment, the cable is connected to the signal transmission body by fitting the coaxial connector provided at the front end of the cable into the rear hole of the first clamping piece, which is different from the first embodiment. The probe device of this embodiment is the same as the first embodiment except for the form of the receiving hole of the first clamping piece, the holding form of the signal transmission body, and the connection form between the signal transmission body and the cable. Here, the description will focus on the points that are different from the first embodiment, and the parts that are the same as the first embodiment are given the same symbols as the parts of the first embodiment and the description is omitted here. Figures 8 and 9 are enlarged cross-sectional views of a portion of the probe device of the third embodiment, showing a longitudinal section at the center position in the width direction of the probe. Here, Figure 8 shows the state before the probe 302 and the cable 4 are connected, and Figure 9 shows the state after the probe 302 and the cable 4 are connected. In this embodiment, as shown in Figure 8, the receiving hole portion 323 of the retaining portion 322 of the first clamping piece 320 is connected in sequence from the front to form a front hole portion 323A, an intermediate hole portion 323B, and a rear hole portion 323C. The inner diameter increases in the order of the rear hole portion 323C, the front hole portion 323A, and the intermediate hole portion 323B. The cylindrical dielectric 351 that holds the signal transmission body 350 is pressed into the front hole portion 323A. The inner diameter of the rear portion of the rear hole portion 323C is formed to be larger than that of the other portions. The inner circumferential surface of the rear end side of the rear portion protrudes slightly inward in the radial direction. This protruding portion forms a locking portion 323C-1 that can be locked with the annular member 403 of the cable-side coaxial connector 400 described later. The center conductor 352 of the signal transmission body 350 is pressed into and held by the dielectric 351. A cable-side coaxial connector 400, serving as a probe connection connector, is provided at the front end of the cable 4. The cable-side coaxial connector 400 includes a center conductor 401 and an outer conductor 402. The center conductor 401 is connected to the center conductor 61 of the cable 4, and the outer conductor 402 is connected to the outer conductor 63 of the cable 4. As shown in Figure 8, the center conductor 401 has a pin-shaped male contact 401A formed at the front end, and a female contact 401B having a plurality of elastic pieces formed at the rear end. The female contact 401B contacts the contact 61A of the center conductor 61 of the cable 4. Furthermore, a ring-shaped member 403 made of an electrically insulating material such as resin is attached to the outer circumference of the front end of the outer conductor 402. When connecting the cable 4 to the first clamping piece 320, the cable-side coaxial connector 400 is inserted from the rear and engaged with the rear hole 323C of the first clamping piece 320. At this point, as shown in Figure 9, the annular member 403 of the cable-side coaxial connector 400 engages the locking portion 323C-1 of the rear hole 323C in the forward and backward direction, thereby preventing the cable-side coaxial connector 400 from accidentally disengaging in the rear direction. When the cable-side coaxial connector 400 is engaged, the center conductor 401 contacts the center conductor 352 of the signal transmission element 350, and the outer conductor 402 contacts the inner surface of the rear hole 323C. To remove the cable 4 from the first holding piece 320, simply grasp the cable-side coaxial connector 400 with your fingers and, using a pulling force greater than the locking force of the annular member 403 and the locking portion 323C-1, retract the cable-side coaxial connector 400 rearward. As a result, the cable-side coaxial connector 400 can be easily removed from the rear hole 323C. Thus, in this embodiment, the cable 4 can be easily attached and detached from the first holding piece 320 simply by inserting and removing the cable-side coaxial connector 400 from the rear hole 323C. In the first to third embodiments, the through-space of the circuit substrate P is formed by the notch portion P3. However, the shape of the through-space is not limited thereto. For example, as shown in the modified example of FIG10 , the through-space may be formed by a circular hole portion P4 that passes through the circuit substrate P in the vertical direction. The inner diameter of this hole portion P4 is set to be larger than the outer diameter of the protrusion of the first clamping portion. In this way, when the through-space is used as the hole portion, when the probe is mounted on the circuit substrate P, the protrusion of the first clamping portion, which is the substrate clamping body in the open state, is positioned directly above the hole portion P4 of the circuit substrate P, and then the probe is inserted into the hole portion P4 from above. Furthermore, the shape of the hole portion does not necessarily need to be circular, and may be, for example, a square. In the first to third embodiments, the probe device is used for performance testing of electronic components such as IC chips mounted on a circuit substrate. However, it can also be used for performance testing of a circuit substrate itself without mounting electronic components, for example, instead of this performance test. 1: Probe device 2: Probe 3: Connector for connecting measuring device 4: Cable 10: Substrate clamp 20: First clamp 25: First clamp 25B: Protrusion 26: First operating portion 30: Second clamp 31: Second clamp 31A: Receiving portion 32: Second operating portion 40: Pushing member 50: Signal transmission element 51: Dielectric material 52: Center conductor 65: Locking metal fastener (mounting member) 70: Signal transmission element 80: Circuit board 81: Base material 102: Probe 120: First clamp 302: Probe 320: First clamp 350: Signal transmission element 351: Dielectric material 352: Center conductor P: Circuit board P1: Signal pattern (signal circuit portion) P2: Ground pattern (ground circuit portion) P3: Notch (through-space) P4: Hole (through-space) [Figure 1] is a perspective view of a probe device according to a first embodiment of the present invention shown together with a circuit substrate, showing the state before being mounted on the circuit substrate. [Figure 2] is a perspective view of the probe of the probe device of Figure 1 shown from an oblique lower perspective. [Figure 3] is a perspective view of the probe of the first clamping piece of Figure 2 shown from an oblique lower perspective. [Figure 4] is a cross-sectional view of the probe of Figure 2 mounted on a circuit substrate, showing a longitudinal section taken at the center of the probe's width. [Figure 5] is a perspective view of the probe device of Figure 1 shown together with a circuit substrate, showing the state before being mounted on the circuit substrate. [Figure 6] is a perspective view of the probe device of Figure 1 shown together with a circuit substrate, showing the state after being mounted on the circuit substrate. [Figure 7] is an enlarged cross-sectional view of a portion of the probe device according to a second embodiment of the present invention, showing a longitudinal section taken at the center of the probe's width. [Figure 8] is an enlarged cross-sectional view of a portion of the probe device according to a third embodiment of the present invention, showing a longitudinal section taken at the center of the probe's width just before the probe is connected to a cable. [Figure 9] is an enlarged cross-sectional view of a portion of a probe device according to a third embodiment of the present invention, showing a longitudinal section taken at the center of the width direction, with the probe and cable connected. [Figure 10] is a perspective view of a circuit board according to a modified example of the present invention. 1: Probe device 2: Probe 3: Connector for connecting measuring device 4: Cable 10: Substrate holder 20: First clamping piece 21: Base 22: Maintaining 22F: First pressed part 25: First clamping part 26: First operating unit 27: First connecting part 28: supported portion 29: Containment Unit 1 30: Second clamping piece 31: Second clamping part 31A: Receiving Department 32: Second operating unit 33: Second connecting part 34: Supporting part 34A: Support recess 40: Push component 41: First push piece 43: Elastic part P: Circuit board P1: Signal pattern (signal circuit part) P2: Ground pattern (ground circuit) P3: Notch (through space)

Claims

1. A connection structure between a circuit board and a cable, comprising a measuring device for measuring the electrical characteristics of a circuit board under test or the electrical characteristics of electronic components mounted on the circuit board under test, and a probe device for relaying the circuit board under test via a cable, the probe device being mounted at the end of the cable and connected to the circuit board under test, characterized in that it comprises: a signal transmitter electrically connected to a signal circuit portion formed on one side of the circuit board under test; a board clamping body for clamping the circuit board under test in its thickness direction; and a spring-loaded member for maintaining the board clamping body in a state where the board under test is clamped, the board clamping body comprising: a first clamping piece located on one side of the circuit board under test for holding the signal transmitter; and a second clamping piece located on the other side of the circuit board under test. The aforementioned spring-pushing member is attached to the aforementioned first clamping piece and the aforementioned second clamping piece and is configured to be elastically deformable, so as to spring the aforementioned first clamping piece and the aforementioned second clamping piece toward the position of clamping the aforementioned circuit board under test. The aforementioned first clamping piece has a first clamping portion at one end located on the side of the aforementioned circuit board under test, which contacts one of the surfaces of the aforementioned circuit board under test. The aforementioned second clamping piece has a second clamping portion at one end located on the side of the aforementioned circuit board under test, which contacts the other surface of the aforementioned circuit board under test. At least one of the aforementioned first clamping piece and the aforementioned second clamping piece has an operating portion at the other end located on the side away from the aforementioned circuit board under test for bearing an operating force opposite to the spring-pushing force of the aforementioned spring-pushing member.

2. The connection structure between the circuit board and the cable as described in claim 1, wherein, One of the aforementioned first clamping portion and the aforementioned second clamping portion has a protrusion that penetrates through a through space, which is formed on the aforementioned circuit board under test by penetrating through the aforementioned board thickness direction. The other clamping portion has a receiving portion that receives the front end of the aforementioned protrusion that protrudes from the aforementioned through space on the side opposite to the through space.

3. The connection structure between the circuit board and the cable as described in claim 2, wherein, The aforementioned protrusion can be inserted into the aforementioned through space formed by cutting open the edge of the aforementioned circuit board under test.

4. The connection structure between the circuit board and the cable as described in any of claims 1 to 3, wherein, The aforementioned signal transmitter has: a dielectric material held in the aforementioned first clamping piece; and a central conductor held in the aforementioned dielectric material, which can contact the signal circuit section of the aforementioned circuit board under test.

5. The connection structure between the circuit board and the cable as described in claim 4, wherein, The aforementioned first clamping piece is made of metal, is electrically conductive to the outer conductor of the aforementioned cable, and can contact the grounding circuit portion formed on one side of the aforementioned circuit board under test.

6. The connection structure between the circuit board and the cable as described in claim 4, wherein, The aforementioned first clamping piece can be connected to the end of the aforementioned cable by means of a mounting member installed at the end of the aforementioned cable.

7. The connection structure between the circuit board and the cable as described in claim 4, wherein, The aforementioned first clamping piece can be connected to the end of the aforementioned cable by means of a probe connection connector fitted onto the end of the aforementioned cable.

8. The connection structure between the circuit board and the cable as described in any of claims 1 to 3, wherein, The aforementioned signal transmitter has: a plate-shaped substrate made of an electrically insulating material; and a metal signal transmission path disposed along the surface of the aforementioned substrate and capable of contacting the signal circuit section of the aforementioned circuit board under test.

9. The connection structure between the circuit board and the cable as described in claim 8, wherein, The aforementioned signal transmitter has a ground transmission path made of metal disposed along the surface of the aforementioned substrate, and the aforementioned ground transmission path can contact a ground circuit portion formed on one side of the aforementioned circuit board under test.

10. A probe device, characterized by having: a connection structure between a circuit board and a cable as described in claim 1; a connector for connecting a measuring device, connected to an object connector disposed on the side of the measuring device; and a cable, wherein the connection structure between the circuit board and the cable is connected to the connector for connecting the measuring device.

Images