JP2019118762A - Board unit of endoscope - Google Patents

Abstract

To provide a board unit of an endoscope that enables the diameter of an insertion part to be reduced.SOLUTION: A board unit 1 includes a cable 4 having an image pickup device, a core wire 11a, a dielectric body 11b, an external conductor 11c, and a shell 11d, and a circuit board 3 to which the image pickup device and the cable 4 are connected. In the circuit board 3, an external conductor land 13 to which a conductive element wire of the external conductor 11c is electrically connected and a conductive land 12 to which the core wire 11a is electrically connected are formed from the base end side to the vicinity of the tip side on a surface in the same direction, and a step is formed between the external conductor land 13 and the conductive land 12. The external conductor 11c facing the external conductor land 13 is formed with a slit part by a part of the conductive element wire being removed in an axial direction of the cable 4, and a surface with the part removed of the external conductor 11c is in contact with the external conductor land 13.SELECTED DRAWING: Figure 3

Description

  BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a substrate unit of an endoscope disposed at the tip of an insertion portion.

  Conventionally, a solid-state imaging device that can be introduced from the outside of a living body or structure to the inside to observe an area inside the living body or inside of a structure that is difficult to observe, and for capturing an optical image. Endoscopes equipped with an imaging unit and the like are widely used, for example, in the medical field and the industrial field.

  The imaging unit of the endoscope includes an objective lens for forming an image of an object, and a CCD (charge coupled device) sensor, a CMOS (complementary metal oxide semiconductor) sensor, etc., disposed on the imaging surface of the objective lens. An imaging element is provided.

  As such an endoscope, for example, an imaging unit as disclosed in WO 2016/063603 is known. The imaging unit of this conventional endoscope has a rigid substrate having a first surface to which the core of the coaxial line is connected and a second surface to which the outer conductor of the coaxial line is connected. The second surface has a step relative to the first surface, and the dimension of the step is substantially the same as the dimension difference between the outer diameter portion of the core of the coaxial wire and the outer diameter portion of the outer conductor. By having it, diameter reduction of an insertion part is achieved.

International Publication No. 2016/063603

  However, in the conventional imaging device unit, a difference in level between the outer diameter portion of the coaxial line and the outer diameter portion of the outer conductor is required for the hard substrate, and the height of the hard substrate is increased. There was a problem if it was not possible to make the diameter.

  Then, this invention is made in view of the situation mentioned above, and an object of this invention is to provide the board | substrate unit of the endoscope which can attain diameter reduction of an insertion part.

  A substrate unit of an endoscope according to one aspect of the present invention includes an imaging element, a core wire, a dielectric covering an outer periphery of the core wire, and an outer conductor formed by winding a conductor wire around the outer periphery of the dielectric. And a cable having an outer cover covering the outer periphery of the outer conductor, and a substrate to which the imaging device and the cable are connected, wherein the substrate is a conductor of the outer conductor in the same direction. A first region to which the strands are electrically connected and a second region to which the core is electrically connected are formed in the vicinity from the proximal end to the distal end, and the first region and the first region are electrically connected. A step is formed between the second regions, and a slit portion is formed on the outer conductor facing the first region by removing a part of the conductor wire in the axial direction of the cable. The removal surface of the outer conductor is in contact with the first region.

  According to the substrate unit of the endoscope of the present invention, the diameter of the insertion portion can be reduced.

It is a figure which shows the structure of the endoscope provided with the board | substrate unit of 1st Embodiment. It is a figure which shows the structure of the board | substrate unit of 1st Embodiment. It is the enlarged view to which the connection part of the circuit board and cable of FIG. 2 was expanded. It is sectional drawing of the board | substrate unit along the IV-IV line of FIG. It is a figure for demonstrating the magnitude | size of the level | step difference of a circuit board. It is a figure for demonstrating size reduction of the board | substrate unit 1 of 1st Embodiment. It is a figure for demonstrating the improvement of the connection property of a circuit board and a cable, and size reduction of a board | substrate unit. It is the enlarged view to which the connection part of the circuit board and cable which concern on the board | substrate unit of 2nd Embodiment is expanded. It is the figure which looked at the cable 4 of 3rd Embodiment from the front direction. It is the figure which looked at the cable 4 of 3rd Embodiment from the side direction. It is an expanded view of a conductor strand. It is the figure which looked at the cable 4 of 4th Embodiment from the side direction. It is the enlarged view to which the connection part of the circuit board and cable which concern on the board | substrate unit of 5th Embodiment is expanded.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The drawings used in the following description are schematically shown, and in order to show each component in a recognizable manner in the drawings, the dimensional relationship and scale of each member, etc. The scale is different, and the present invention is limited to the number of components described in these figures, the shape of the components, the ratio of the size of the components, and the relative positional relationship of the respective components. It is not limited to

First Embodiment
FIG. 1 is a view showing a configuration of an endoscope provided with a substrate unit of the first embodiment.

  As shown in FIG. 1, the endoscope 101 of the present embodiment has a configuration capable of being introduced into a subject such as a human body and optically imaging a predetermined observation site in the subject. The subject into which the endoscope 101 is introduced is not limited to the human body, but may be another living body, or an artificial object such as a machine or a construction.

  The endoscope 101 includes an insertion portion 102 introduced into the inside of a subject, an operation portion 103 positioned at the proximal end of the insertion portion 102, and a universal cord 104 extending from the operation portion 103. ing.

  The insertion portion 102 includes a distal end portion 110 disposed at the distal end, a bendable curved portion 109 disposed at the proximal end side of the distal end portion 110, and a manipulation portion 103 disposed at the proximal end side of the curved portion 109. And a flexible tube portion 108 having flexibility to be connected to the tip end side thereof. The endoscope 101 may have a form called a so-called rigid endoscope, which does not have a flexible portion in the insertion portion 102.

  The tip end portion 110 is provided with a substrate unit 1 described later. In addition, the operation portion 103 is provided with an angle operation knob 106 for operating the bending of the bending portion 109.

  At the proximal end of the universal cord 104, an endoscope connector 105 connected to the external device 120 is provided. The external device 120 to which the endoscope 101 is connected is connected to an image display unit 121 such as a monitor via a cable.

  In addition, the endoscope 101 has the universal cord 104, the operation unit 103, and the cable 4 inserted into the insertion unit 102. Furthermore, the endoscope 101 is inserted into the universal cord 104, the operation unit 103, and the insertion unit 102, and is an optical fiber bundle (not shown) for transmitting illumination light from the light source unit provided in the external device 120. )have.

  The cable is configured to electrically connect the endoscope connector 105 and the substrate unit 1. By connecting the endoscope connector 105 to the external device 120, the substrate unit 1 is electrically connected to the external device 120 via a cable. Supply of power from the external device 120 to the substrate unit 1 and transmission of an optical image from the substrate unit 1 to the external device 120 are performed via the cable.

  The external device 120 is provided with an image processing unit 120a. The image processing unit 120 a generates a video signal based on the image sensor output signal output from the substrate unit, and outputs the video signal to the image display unit 121. That is, in the present embodiment, the optical image (the endoscopic image) captured by the substrate unit 1 is displayed on the image display unit 121 as a video.

  Note that the endoscope 101 is not limited to the configuration connected to the external device 120 or the image display unit 121, and may have, for example, a function of part or all of the external device 120 or the image display unit 121. .

  Further, the light guide is configured to transmit the light emitted from the light source unit of the external device 120 to the illumination window as the illumination light emitting unit of the tip end portion 110. The light source unit may be disposed at the operation unit 103 or the distal end portion 110 of the endoscope 101.

  Next, the configuration of the substrate unit 1 provided at the tip end portion 110 will be described using FIGS. 2 to 5. In the following description, the direction from the substrate unit 1 toward the subject (left in each figure) may be referred to as the tip, front or object side, and the opposite direction may be referred to as base, back or image side .

  FIG. 2 is a view showing the configuration of the board unit of the first embodiment, FIG. 3 is an enlarged view of a connection portion of the circuit board and the cable of FIG. 2, and FIG. It is sectional drawing of the board | substrate unit along line -IV, and FIG. 5 is a figure for demonstrating the magnitude | size of the level | step difference of a circuit board.

  As shown in FIG. 2, the substrate unit 1 is configured to have an imaging element 2, a circuit board 3 and a cable in order from the object side to be the front. In front of the imaging element 2, an objective optical system including at least one objective lens is disposed.

  The imaging device 2 is a very small rectangular electronic component. The image pickup device 2 has a plurality of elements arranged in a planar light receiving portion, which outputs an electric signal according to the incident imaging light at a predetermined timing, and is generally referred to as, for example, a CCD sensor or a CMOS sensor. Format, or various other formats are applied. The back surface on the base end side of the imaging element 2 is joined to the circuit board 3.

  The circuit board 3 as a board | substrate is comprised, for example from a multilayer board | substrate as a hard board | substrate in which the base material was comprised from the glass epoxy resin or the laminated substrate of the ceramic. The circuit board 3 is surface-bonded to the back surface of the imaging element 2 via a thermosetting adhesive or the like, a plurality of electronic components are mounted, and the core wire connecting portion 3a of the plate-like block in which electronic components not shown are embedded. And an outer conductor connecting portion 3b serving as a projecting portion extended so as to project rearward with a step from the base end central portion of the core wire connecting portion 3a.

  In the circuit board 3, a flexible printed board (hereinafter referred to as “FPC”) 5 is electrically connected to the lower surface of the core wire connection portion 3 a, and the inner lead 5 a extended from the distal end side of the FPC 5 It is electrically connected to the bumps formed on the lower front surface of the. As a result, driving power is supplied to the imaging element 2 and signals are exchanged with the circuit board 3.

  The cable 4 is a coaxial cable, and the core wire 11a, a dielectric 11b which is an insulator covering the outer periphery of the core wire, and an outer layer as a shield layer formed by winding a conductor wire around the outer periphery of the dielectric 11b. A conductor 11c and an outer cover 11d as a sheath layer formed of, for example, an insulating resin are provided to cover the outer periphery of the outer conductor 11c.

  A conductor land 12 as a first region to which the core wire 11a of the cable 4 is connected by solder is disposed on the upper surface of the circuit board 3 behind the core wire connection portion 3a.

  Further, an outer conductor land 13 as a second region is disposed on the upper surface of the outer conductor connection portion 3 b of the circuit board 3. A part of the conductor strands of the outer conductor 11c in a state in which the outer skin 11d of the cable 4 is peeled off is cut (D cut) by, for example, laser cutting in the axial direction of the cable 4 (see FIG. 5) Is formed. In other words, the slit portion 11 e is formed by cutting out a part of the conductor wire of the outer conductor 11 c in the axial direction of the cable 4.

  Then, as shown in FIG. 5, the outer periphery of the dielectric 11b exposed through the slit portion 11e and the cut surface (removed surface) of the outer conductor 11c from which a part of the conductor wire is cut (removed) It is configured to be in contact with the outer conductor land 13. The outer conductor 11c and the outer conductor land 13 are connected by solder.

  Thus, in the circuit board 3, the external conductor lands 13 to which the conductor strands of the outer conductor 11 c are electrically connected and the conductor lands 12 to which the core wire 11 a is electrically connected are formed on the surfaces in the same direction. It is formed in the vicinity from the proximal end side to the distal end side. A step is formed on the outer conductor land 13 so that the conductor land 12 is higher than the outer conductor land 13. Then, a slit 11e is formed on the outer conductor 11c facing the outer conductor land 13 by cutting a part of the conductor wire in the axial direction of the cable 4, and the dielectric exposed through the slit 11e The outer periphery of the body 11 b and the cut surface of the outer conductor 11 c are in contact with the outer conductor land 13.

  Further, as shown in FIG. 5, the height A of the step between the core wire connection portion 3a and the outer conductor connection portion 3b is substantially equal to the thickness of the dielectric 11b. By configuring the height A of the step between the core wire connection portion 3a and the outer conductor connection portion 3b to be substantially equal to the thickness of the dielectric 11b, the cable 4 can be connected substantially parallel to the circuit board 3 .

  Next, miniaturization of the substrate unit 1 of the present embodiment will be described with reference to FIG. FIG. 6 is a diagram for explaining the miniaturization of the substrate unit 1 of the first embodiment.

  The board unit 1A on the left side in FIG. 6 shows a conventional configuration for connecting the circuit board 3A and the cable 4A substantially in parallel. In the conventional substrate unit 1A, a part of the outer conductor 11C is not cut off, and the outer periphery of the outer conductor 11C is in contact with the outer conductor land 13A and is connected by solder or the like. The circuit board 3A of the conventional board unit 1A has a height B in order to connect the core wire 11A and the conductor land 12 substantially in parallel.

  On the other hand, in the substrate unit 1 of the present embodiment on the right in FIG. 6, part of the conductor strands of the outer conductor 11 c in the state in which the outer skin 11 d of the cable 4 is peeled is cut away in the axial direction of the cable 4 It has the slit part 11e formed by being carried out. By providing the slit portion 11e, the difference in level between the outer conductor 11c and the core 11a can be reduced. Thereby, since the level | step difference of the circuit board 3 can be made small, the circuit board 3 can be made into the height C smaller than the height B of the conventional circuit board 3A.

  As described above, in the substrate unit 1 of the present embodiment, the height of the circuit board can be made lower than that of the conventional substrate unit 1A. As a result, in the substrate unit 1 of the present embodiment, the diameter of the insertion portion 102 can be reduced as compared to the conventional case.

  The circuit board 3 is inclined relative to the insertion axis, the cable 4 is inclined relative to the insertion axis, or the circuit board 3 and the cable 4 are inclined relative to the insertion axis. In this case, the connectivity between the circuit board 3 and the cable 4 is poor, and miniaturization of the board unit 1 becomes difficult.

  In this embodiment, a part of the conductor strands of the outer conductor 11c is cut away in the axial direction of the cable 4 to form the slit portion 11e, thereby improving the connectivity between the circuit board 3 and the cable 4, and the board The miniaturization of the unit 1 is realized.

  The improvement of the connectivity between the circuit board 3 and the cable 4 and the miniaturization of the board unit 1 will be described with reference to FIG. FIG. 7 is a diagram for describing the improvement in the connectivity between the circuit board and the cable, and the miniaturization of the board unit.

  The board unit 1A on the left side in FIG. 7 shows a conventional configuration in the case where the circuit board 3A is inclined relative to the insertion axis. The imaging device 2A and the circuit board 3A may deviate from the light receiving axis of the imaging device 2A and the longitudinal axis of the circuit board 3A due to a manufacturing error or the like. When the light receiving axis of the imaging element 2A is aligned with the insertion axis, the circuit board 3A is displaced with respect to the insertion axis. Further, the substrate unit 1A is configured in alignment with the axis of the cable 4A at the insertion axis.

  In this case, as shown in FIG. 7, the distance between the circuit board 3A and the core 11A increases, and the possibility of connection failure increases. Further, since the height when the substrate circuit 3A and the cable 4A are connected is increased, the outer diameter of the substrate unit 1A is increased, and the diameter of the insertion portion 102 can not be reduced.

  On the other hand, in the substrate unit 1 of the present embodiment on the right in FIG. 7, part of the conductor strands of the outer conductor 11 c in the state in which the outer skin 11 d of the cable 4 is peeled is cut away in the axial direction of the cable 4 It has the slit part 11e formed by being carried out. By providing the slit portion 11e, the distance between the circuit board 3 and the core wire 11a can be reduced, and the possibility of connection failure can be reduced. Moreover, since the height at the time of connecting the substrate circuit 3 and the cable 4 is reduced by providing the slit portion 11 e, the outer diameter of the substrate unit 1 is reduced, and the diameter of the insertion portion 102 can be reduced.

  As described above, in the present embodiment, the provision of the slit portion 11 e improves the connectivity between the circuit board 3 and the cable 4 even when the circuit board 3 is inclined relative to the insertion axis, and The miniaturization of the substrate unit 1 can be realized.

  In the example of FIG. 7, the case where the circuit board 3 is inclined relative to the insertion axis has been described, but the cable 4 may be inclined relative to the insertion axis, or the circuit board 3 and the cable Even when 4 is relatively inclined with respect to the insertion axis, it is possible to realize the improvement of the connectivity between the circuit board 3 and the cable 4 and the miniaturization of the board unit 1.

Second Embodiment
Next, a second embodiment will be described.

  FIG. 8 is an enlarged view of a connection portion of a circuit board and a cable according to a board unit of the second embodiment. In addition, in FIG. 8, about the structure similar to FIG. 3, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  As shown in FIG. 8, in the substrate unit 1B of this embodiment, a part of the conductor wire of the outer conductor 11c is cut off at the D portion from the tip of the outer conductor land 13 to the base end of the circuit board 3 ing. On the other hand, the substrate unit 1B is configured without being cut off at the portion E where the circuit substrate 3 does not overlap in the axial direction of the cable 4. The other configuration is the same as that of the first embodiment.

  The board unit 1B can perform positioning with the circuit board 3 at the end surface (the position of the F portion) of the E portion where the external conductor 11c is exposed. Since the substrate unit 1B is improved in accuracy as compared to the case where the substrate unit 1B is positioned with the circuit board 3 at the front end surface (the position of the G portion) of the outer cover 11d, the positioning accuracy can be improved compared to the first embodiment. .

  An outer conductor land may be provided on the side surface on the base end side of the circuit board 3, and the outer conductor land and the outer conductor 11c of the E portion may be connected by soldering. With such a configuration, in the substrate unit 1B, the connection area of GND is increased, and the EMC countermeasure can be improved.

Third Embodiment
Next, a third embodiment will be described.

  FIG. 9 is a view of the cable 4 of the third embodiment viewed from the tip direction, FIG. 10 is a view of the cable 4 of the third embodiment viewed from the side direction, and FIG. It is an expanded view of a line. In FIGS. 9 and 10, the same components as in FIG. 3 are assigned the same reference numerals and descriptions thereof will be omitted.

  As shown in FIG. 9, in the present embodiment, a part of the conductor strands of the outer conductor 11 c is cut in the axial direction of the cable 4. By cutting the outer conductor 11c, the length of the periphery of the tip surface of the outer conductor 11c is reduced, and the connection strength with the circuit board 3 is reduced. In order to maintain the connection strength with the circuit board 3, the cable 4 of the present embodiment satisfies the relationship of “the length of the periphery of the end surface of the core wire 11 a <the length of the periphery of the end surface of the outer conductor 11 c” Configured

  As shown in FIG. 10, the winding angle of the conductor wire of the outer conductor 11c is θ, and the length of the cable 4 in the axial direction of the slit portion 11e from which the conductor wire of the outer conductor 11c is cut is L. As shown in FIG. 11, when the conductor strands of the outer conductor 11c are cut away, an area which is cut away unnecessarily is generated. The unnecessary cut-out region increases the winding angle of the conductor wire of the outer conductor 11c by θ, or increases the axial length of the slit portion 11e in the axial direction of the cable 4 by L.

  If the area to be cut off unnecessarily increases, the connectivity between the outer conductor 11c and the outer conductor land 13 is lost. The cable 4 of the present embodiment is configured to satisfy the relationship of “L × tan θ <0.3” in order to maintain the connectivity between the outer conductor 11 c and the outer conductor land 13.

  As described above, the cable 4 satisfies the relationship of “area of tip end surface of core wire 11 a <area of tip end surface of outer conductor 11 c” and “L × tan θ <0.3”. The connection strength between the outer conductor 11c and the outer conductor land 13 is maintained.

Fourth Embodiment
Next, a fourth embodiment will be described.

  FIG. 12 is a side view of the cable 4 of the fourth embodiment. In FIG. 12, the same components as in FIG. 3 are assigned the same reference numerals and descriptions thereof will be omitted.

  The core wire 11 a and the outer conductor 11 c of the cable 4 are connected to the conductor lands 12 and the outer conductor lands 13 of the circuit board 3 by soldering, respectively. The solder is generally considered to protrude from the connecting portion due to surface tension.

  In this case, there is a possibility that the core wire 11a and the outer conductor 11c may short-circuited by the solder which has been protruded from the connection portion.

  Therefore, in the case of the cable 4 of this embodiment, the distance from the outer peripheral surface of the dielectric 11b to the outer peripheral surface of the outer conductor 11c is M, and the distance of the dielectric 11b protruding from the tip end surface of the outer conductor 11c is N. , “N> M / 2” is satisfied. The distance M from the outer peripheral surface of the dielectric 11 b to the outer peripheral surface of the outer conductor 11 c is, for example, 10 μm to 70 μm.

  As described above, by setting the distance M to 10 μm to 70 μm and satisfying the relationship of “N> M / 2”, the cable 4 prevents a short circuit between the core wire 11 a and the outer conductor 11 c.

Fifth Embodiment
Next, a fifth embodiment will be described.

  FIG. 13 is an enlarged view of a connection portion of a circuit board and a cable according to a board unit of the fifth embodiment.

  As shown in FIG. 13, an outer conductor land 14 as a third region is disposed on the side surface on the base end side of the circuit board 3 of the board unit 1C. The outer conductor 11c of the cable 4 is cut (D-cut) by cutting a part of the conductor wire in the axial direction of the cable 4 from the end face of the outer conductor 11c by a predetermined length, and the outer skin 11d A conductor wire 11 f formed by forming up to the end face of

  Then, the conductor wire 11 f subjected to forming processing is connected to the external conductor land 14 disposed on the side surface on the base end side of the circuit board 3 by soldering.

  With the above configuration, in the substrate unit 1C of the present embodiment, the connection area of GND is increased, and the EMC countermeasure can be improved.

  The present invention is not limited to the above-described embodiment, and various changes, modifications, and the like can be made without departing from the scope of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Board | substrate unit, 2 ... Imaging element, 3 ... Circuit board, 3a ... Core wire connection part, 3b ... Outer conductor connection part, 4 ... Cable, 5 ... Flexible printed circuit board, 5a ... Inner lead, 11a ... Core wire, 11b ... dielectric material Body 11c Outer conductor 11d Outer shell 11e Slit 11f Outer conductor 12 Conductor land 13 Outer conductor land 14 Outer conductor land 101 Endoscope 102 Insertion portion 103 ... Operation part, 104 ... Universal cord, 105 ... Endoscope connector, 106 ... Angle operation knob, 108 ... Flexible tube part, 109 ... Curved part, 110 ... Tip part, 120 ... External device, 120 a ... Image processing part, 121: Image display unit.

Claims (7)

An imaging device,
A cable having a core wire, a dielectric covering the outer periphery of the core wire, an outer conductor formed by winding a conductor wire around the outer periphery of the dielectric, and an outer cover covering the outer periphery of the outer conductor;
A substrate to which the imaging element and the cable are connected;
Have
In the substrate, in the same direction, a first region to which the conductor wire of the outer conductor is electrically connected and a second region to which the core wire is electrically connected are provided from the base end side It is formed near the tip side,
A step is formed between the first region and the second region,
In the outer conductor facing the first region, a slit portion is formed by removing a part of the conductor strand in the axial direction of the cable,
A substrate unit of an endoscope, wherein the removal surface of the outer conductor is in contact with the first region.   The substrate unit of an endoscope according to claim 1, wherein the size of the step between the first area and the second area is substantially equal to the thickness of the dielectric.   The outer conductor is characterized in that a part of the conductor strands of the outer conductor is removed in the axial direction of the cable from the tip of the first region to the base end of the substrate. Item 2. A substrate unit of an endoscope according to Item 2. Let the winding angle of the conductor wire of the outer conductor be θ,
When the axial length of the cable in the slit portion is L,
The substrate unit of an endoscope according to any one of claims 1 to 3, wherein the condition of L x tan θ <0.3 is satisfied.   The said cable is comprised so that the area of the front end surface of the said core wire may satisfy | fill the relationship smaller than the area of the front end surface of the said outer conductor, The any one of the Claims 1-4 characterized by the above-mentioned. Endoscope board unit. Let M be the distance from the outer peripheral surface of the dielectric to the outer peripheral surface of the outer conductor,
Assuming that the distance of the dielectric protruding from the tip end surface of the outer conductor is N,
The substrate unit of the endoscope according to any one of claims 1 to 5, wherein the condition of N> M / 2 is satisfied. The outer conductor is formed by removing a portion of the conductor strand in the axial direction of the cable by a predetermined length from the tip end surface of the outer conductor, and forming from the removed portion to the tip end surface of the outer sheath Have conductor strands,
The endoscope according to any one of claims 1 to 6, wherein the substrate has a third region to which the conductor wire subjected to the forming process is connected to the side surface on the proximal side. Mirror substrate unit.

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