JP2000083252A - Image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an image pickup device capable of being miniaturized by increasing the package density of electric components or the like to be mounted on circuit boards. SOLUTION: A 1st circuit board 8 and a 2nd circuit board 9 with electric components 11a and 11b, and 11c respectively mounted on them on their component sides opposite to a rear side of a solid-state image pickup element 4 are placed in this image pickup device 1A assembled in a tip 49 of an electronic endoscope. In this case, the two circuit boards 8, 9 are laid out at a distance equivalent to nearly the height of the electric components 11a, 11b, 11c by mounting the electric components 11a, 11b on the 1st circuit board 8 with a room for the electronic component 11c so that the electric component 11c mounted on the 2nd circuit board 9 is laid out in the room thereby mounting the electric components with high density.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup device arranged for picking up an image at the tip of an electronic endoscope or the like.

[0002]

2. Description of the Related Art In recent years, as an image pickup device incorporated for picking up an image at the tip of an electronic endoscope, a device using a solid-state image sensor has been widely used. For example, FIG. 16 shows a conventional imaging device 1C.

As shown in FIG. 16, in an image pickup apparatus 1C, three front lenses of four lenses constituting an objective optical system 2 are mounted on a lens frame 3, and the lens frame 3 has an image pick-up by a solid-state image pickup device 4. A cover glass 5 for protecting the surface and an element holder 6 to which one remaining final lens is attached are attached in focus.

A lead leg 7, 7 extending rearward from a vertical end face of the solid-state imaging device 4 is
Is partially connected to a first substrate 8 arranged in parallel with the back surface of
Further, a second substrate 9 and a third substrate 10 arranged in parallel with the first substrate 8 behind the first substrate 8 are connected.

Electrical components 11a, 11b and 11c are mounted on a mounting surface of the first substrate 8 facing the second substrate 9 and a mounting surface of the second substrate 9 facing the first substrate 8, respectively. I have. The cables 13 of the bundled integrated cables 12 are connected to the third substrate 10 by soldering or the like.

In the image pickup apparatus 1 C, the distance between the first substrate 8 and the second substrate 9 is determined by the electric components 11 mounted on the first substrate 8.
a, 11b and electric component 1 mounted on second substrate 9
It is longer than the distance obtained by adding the height of 1c.

As shown in FIG. 17, the third substrate 10 is provided with a cable through hole 14 for soldering through the core wire of each cable 13 of the integrated cable 12 and a lead foot for soldering through the lead foot 7. The through hole 15 for the cable was provided separately from the through hole 14 for the cable.

FIG. 18 shows a conventional example of a type in which substrates 28 and 29 are formed vertically with respect to a solid-state image pickup device 24. In the conventional imaging device 21D shown in FIG.
A cover glass 25 for protecting the imaging surface of the solid-state imaging device 24 is attached to a holder 26 connected and fixed to the solid-state imaging device 3 by means of an adhesive or the like. The front ends of the upper substrate 28 and the lower substrate 29 are connected by soldering, respectively, and the substrate surfaces of the upper substrate 28 and the lower substrate 29 are arranged in parallel.

On the opposing inner mounting surfaces of the upper substrate 28 and the lower substrate 29, electric components 31a, 31
b and electrical components 31c and 31d are mounted. The cables 33 of the integrated cable 32 are connected to the rear ends of the upper board 28 and the lower board 29 at signal line connection sections (cable connection sections) 30 by soldering.

The element holder 2 for covering the cover glass 5
6 to the vicinity of the front end of the integrated cable 32 are covered with a heat-shrinkable tube 35. Also in this imaging device 21D, the upper board 28 and the lower board 29 have the electric components 31a, 31b and 31c, 31c respectively mounted thereon.
d, is configured to be vertically separated by at least the height of
The cable connection section 30 is also connected to the upper board 28 and the lower board 29 which are separated from each other.

[0011]

Conventionally, an imaging device 1C,
Substrate 8, 9, 10 or 28 used for 21D,
29 electrical components 11a, 11b, 11c or 31a, 3
1b, 31c and 31d are mounted, and the integrated cable 12 or 32 is connected.

When two or more substrates are arranged substantially in parallel, FIG.
8, electrical components 11a, 11b, 11c or 31a, 31b,
When the boards 31c and 31d are mounted, the two boards are arranged at a distance equal to or greater than the sum of the heights (thicknesses) of the electric components mounted on the boards, so that the imaging devices 1C and 2d are mounted.
1D had become larger. That is, the electric component 11
a, 11b, 11c or 31a, 31b, 31c, 3
Since the space between 1d is not sufficiently used, the imaging device 1
C and 21D are not sufficiently reduced in size.

(Purpose of the Invention) The present invention has been made in view of the above points, and has as its object to provide an image pickup apparatus capable of increasing the density of electric components and the like mounted on a substrate and reducing the size.

[0014]

A substrate having electric components mounted on a mounting surface opposed to a rear end of the solid-state imaging device;
In an imaging device comprising a cable for performing signal transmission,
By providing a space on one mounting surface where electric components mounted on the other mounting surface are arranged adjacently, and by setting the interval between the opposing board surfaces to approximately the height of the electric component,
A high-density mounting of electrical components is performed to reduce the distance between the substrates, thereby realizing miniaturization.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIGS. 1 to 10 show a first embodiment of the present invention.
FIG. 1 shows the entire configuration of an endoscope apparatus provided with a first embodiment, and FIG. 2 shows the configuration of a distal end portion of an insertion section in which the first embodiment is incorporated. FIG. 3 shows a configuration of the imaging apparatus according to the first embodiment, FIG. 4 shows a third substrate, FIG. 5 shows a third substrate in a state where lead legs and cables are fixed, and FIG. FIG. 7 shows a state in which a cable provided with a retaining portion for retaining in a through hole of three boards is fixed, FIG. 7 shows an enlarged view of the through hole, and FIG. 8 shows an example of arrangement of cables in a total cable; 9 shows an example of the arrangement of the through holes of the third substrate to which the cables of the arrangement of FIG. 8 are connected, and FIG. 10 shows a third substrate of a modified example.

An endoscope apparatus 41 shown in FIG. 1 includes an electronic endoscope 42 having an image pickup means, a video processor 43 connected to the electronic endoscope 42 and performing signal processing for the image pickup means and the like. And a monitor 44 for displaying a video signal output from the processor 43. The electronic endoscope 42 has an elongated, for example, reversible insertion section 45, and a wide-width operation section 46 is continuously provided at the rear end of the insertion section 45. A flexible universal cable 47 extends laterally from near the rear end of the operation section 46, and a connector 48 is provided at an end of the cable 47.

The insertion portion 45 has a hard distal end portion 49, a bendable bending portion 50, and a flexible portion 51 having flexibility. The bending operation knob 52 provided on the operation portion 46 is rotated. By operating, the bending portion 50 can be bent in the horizontal direction or the vertical direction. The operation unit 46
Is provided with an insertion port 53 communicating with a treatment instrument channel (not shown) provided in the insertion section 45.

As shown in FIG. 2, the tip portion 49 of the insertion portion 45
The image pickup apparatus 1A according to the first embodiment of the present invention is attached to an image pickup window provided in the distal end portion main body 54 constituting the image forming apparatus. In addition, a tip of a light guide 55 that transmits illumination light and exits from a tip surface is fixed to a lighting window adjacent to the imaging window via a base 56.

The first bending piece 5 is provided at the rear end of the tip body 54.
7 is fixed, and a second bending piece 58 is rotatably connected to a rear end of the first bending piece 57 by a rivet 59. The rear end of the second bending piece 58 is rotatably connected to the front end of a third bending piece (not shown) by a rivet. The bending portion 50 is formed so that the bending portion 50 can be bent to the side where the bending wire 60 whose tip is fixed to the first bending piece 57 by brazing or the like is pulled by rotating the bending operation knob 52. ing.

Further, the first bending piece 57 and the second bending piece 5
The curved portion 50 such as 8 is covered with a flexible rubber tube 40.

The image pickup apparatus 1A of this embodiment is basically similar to the image pickup apparatus 1C of FIG. 16 except that the first substrate 8 and the second substrate 9 are brought closer to each other, and the cable connecting portion and the total cable 12 are connected. The distance from the front end is reduced, and the structure can be further reduced.

Hereinafter, the configuration of the imaging apparatus 1A of the present embodiment will be described in detail. Note that the same components as those described with reference to FIG. 2 and 3
As shown in FIG. 1, the imaging apparatus 1A includes an objective optical system 2.
The front three lenses of the three lenses are mounted on a lens frame 3, and the lens frame 3 has a cover glass 5 for protecting the imaging surface of the solid-state imaging device 4 and an element holder 6 on which one remaining final lens is mounted. It is attached with focus.

The lead leg 7 extending rearward from the vertical end face of the solid-state image pickup device 4 is partially connected to a first substrate 8 disposed in parallel with the back surface of the solid-state image pickup device 4. The second substrate 9 disposed behind the first substrate 8 in parallel with the first substrate 8 and a third substrate 10 for fixing a cable are connected.

On the mounting surface of the first substrate 8 facing the second substrate 9 and on the mounting surface of the second substrate 9 facing the first substrate 8, electric components 11a, 11b and 11c are mounted, respectively. I have. The core 13 of each cable 13 in the integrated cable 12 bundled on the third substrate 10
a is connected by soldering or the like.

The integrated cable 12 is passed through an insertion portion 45, an operation portion 46, and a universal cable 47 to a connector 48.
The connector 48 is connected to the video processor 43 so that the video processor 4
3 is connected to the signal processing unit.

In the image pickup apparatus 1A of this embodiment, the distance between the two electric components 11a and 11b mounted along the mounting surface of the first substrate 8 (in the vertical direction in FIG. Is mounted with a space slightly larger than the size (the vertical size in FIG. 2 or FIG. 3) of the electric component 11c mounted on the mounting surface of the electric component 11c.
The electric component 11c is mounted on the second substrate 9 in a state where the electric component 1c is arranged adjacent to the electric components 11a and 11b with a slight gap therebetween.

By mounting in this manner, the distance between the first substrate 8 and the second substrate 9 is reduced by the electrical components 11a, 11b, 1
1c when mounted (electric components 11a, 11b,
The height of 11c is shown as being substantially the same. ), So that they can be arranged at a distance of about the same degree, enabling high-density mounting. In other words, the second substrate 9 is arranged closer to the first substrate 8 by a distance of about the height of the electric components 11a, 11b, 11c, and compared to the conventional example of FIG. The length of the hard long portion is reduced to a height of about 11c to reduce the size.

The third substrate 10 according to the present embodiment
As shown in FIG. 4A or FIG. 4B, a cable notch 61a (or hole 6
1b), the integrated cable 12 is passed through the notch 61a or the hole 61b, and each cable 13 inside the outer skin is U-turned, and connected and fixed by soldering in through holes 62 provided along upper and lower end surfaces. ing.

FIG. 5 shows the connection fixing portion 6 at the through hole 62.
3 is shown. The core portion 13a of the cable 13 is connected and fixed to each through hole 62 by soldering, and then the lead leg 7 can be connected and fixed by soldering.

That is, each through hole 62 is connected to the cable 1
The third core wire 13a and the lead foot 7 are commonly used for connection and fixing. By doing this,
In the case of the conventional example described with reference to FIG. 17 (the cable 13 and the lead feet 7 are separated from the through holes 14 and 15
), The number of times of soldering can be reduced.

In the conventional example, it was necessary to solder the cable 13 through the through-hole 14. However, since the through-hole 62 has a cutout shape provided at the end, the core wire of the cable 13 is inserted into the inside. Passing work can be done easily.

In the present embodiment, the integrated cable 1
When the cable 2 is passed through the notch 61a or the hole 61b and the U-turn of the core wire 13a of each cable 13 is connected and fixed to the through hole 62, as shown in FIG. (Or a retaining portion) 64 is formed.

That is, as shown in FIG. 6, when the diameter of the core wire 13a is a, the diameter of the locking portion 64 at the end of the core wire 13a is b, and the width of the through hole 62 is c, b>c> a. are doing. By doing so, even if the cable 13 is pulled after the core wire 13a is connected and fixed to the through-hole 62, the locking portion 64 is larger than the width c of the through-hole 62, so that it is prevented from coming off.

Further, as shown in FIG.
R (curvature) of the land portion 62s is made smaller than the radius of the core wire 13a, the contact portion between the core wire 13a of the cable 13 and the land portion 62s is increased by the reduced R land portion 62s, and electrical connection is established. The fixing strength may be increased as well as more securely.

By fixing the connection in such a manner as to make the U-turn, the cable 13 is U-turned and sagged even when the general cable 12 is pulled when the bending portion 50 or the like is bent. By extending the portion, the pulling force can be absorbed (that is, the pulling force is not applied to the cable 13) so as to have a function of preventing disconnection.

The front end of the integrated cable 12 is shown in FIG.
The rigid length of the image pickup apparatus 1A can be shortened by being able to move to a position closer to the front solid-state image pickup device 4 as compared with the conventional example.

The arrangement of the plurality of cables 13 bundled in the integrated cable 12 is shown in FIGS.
When the arrangement order is C,..., G, H, the arrangement order of the through holes 62 on the third substrate 10 to which the cable 13 is connected becomes substantially the same as the positional relationship of the arrangement order of the cables 13 in the overall cable 12. Like that.

That is, the integrated cable 12 is connected to, for example, FIG.
When passing through the hole 61b of the third substrate 10 (or the notch 61a in FIG. 4A) of FIG.
The cables 13 indicated by C and D are bent upward in a U-shape, and the cables 13 indicated by reference signs E, F, G, and H are bent downward in a U-shape, as shown in FIG. The cables 13 indicated by the reference signs A, B, C, and D in FIG. Each of the through-holes 62 indicated by reference numerals E ', F', G ', and H' at the lower position of the third substrate 10 as shown in FIG. , G, and H can be easily set, so that connection by soldering can be easily performed.

According to the present embodiment configured as described above, the first substrate 8 on which the electric components 11a and 11b are mounted
, And the distance between the second substrate 9 on which the electric component 11c is mounted can be set to approximately half the distance of the conventional example, so that the imaging device 1A can be sufficiently reduced in size.

Further, the front end of the integrated cable 12 is passed through the third substrate 10 and the respective cables 13 are connected by soldering. By being able to move to a position close to the element 4, the hard length of the imaging device 1A can be further reduced. Therefore, this imaging device 1
The rigid length of the distal end portion 49 of the electronic endoscope 2 incorporating A can be shortened, and it can be easily inserted into a bent body cavity.

Further, in the above embodiment, the arrangement order of the through holes 62 in the third substrate 10 is as shown in FIG. 9, but as in the modification shown in FIG. 10 (A) or FIG. 10 (B). Is also good.

In FIG. 10A, the depth of the grooves of the through holes 62 on the left and right peripheral sides at the center is increased. In FIG. 10B, the through hole 62 is formed radially by making the shape of the third substrate 10 a disk.

When the third substrate 10 shown in FIG. 10A is used, when the cable 13 is connected, the structure becomes as shown in FIG. In this case, the cables 13 indicated by, for example, D and H arranged in the diagonal direction are separated from the output signal line of the solid-state imaging device 4 by a high-frequency drive signal line, respectively.

By doing so, it is possible to reduce as much as possible the effect of electromagnetic waves emitted from a high-frequency signal line becoming noise on an output signal line for transmitting an image signal.

FIG. 12 shows a configuration of an image pickup apparatus 1B according to a modification. In this imaging device 1B, the third substrate 10 is not used,
Along the upper and lower ends of the second substrate 9, for example, as shown in FIG.
A through hole 62 as shown in FIG. 11 is formed, and each cable 13 of the integrated cable 12 is connected as shown in FIG.

In this case, in FIG. 11, the overall cable 12 is formed by bending each cable 13 into a U-shape through the hole 61b and connecting the cable 13 with the through-hole 62, but in FIG. Is not provided, but is bent from the back surface side of the second substrate 9 and connected to the through hole 62 by soldering.

The rest of the configuration is the same as that of the first embodiment, and the same components are denoted by the same reference numerals and description thereof is omitted. The effect of the imaging device 1B of this modification is the first.
This is almost the same as the embodiment.

(Second Embodiment) FIG. 13 is a sectional view of an image pickup apparatus 21A according to a second embodiment of the present invention. This embodiment is of a type in which boards 28 and 29 on which electric components 31a, 31b, 31c and 31d are mounted are perpendicular to the solid-state imaging device 24, similarly to the conventional imaging device 21D shown in FIG.

This embodiment is an improvement of the conventional example shown in FIG. 18, in which the electric components 31c and 31d of the lower substrate 29 are placed in an empty space of the upper substrate 28 where there are no electric components 31a and 31b.
Alternatively, the core wire 33a of the cable 33 of the integrated cable 32
Are made smaller by making the soldering portions 30 adjacent to each other.
Hereinafter, the configuration will be described in detail. The same components as those in FIG. 18 will be described with the same reference numerals.

In this imaging device 21A, a cover glass 25 for protecting the imaging surface of the solid-state imaging device 24 is provided on a holder 26 which is connected and fixed to a lens frame 23 on which an objective optical system is mounted.
The front ends of an upper substrate 28 and a lower substrate 29 are connected by soldering to lead legs 27, 27 projecting vertically away from the back surface of the solid-state imaging device 24, respectively. Upper substrate 28 and lower substrate 2
The substrate surface 9 is arranged in a horizontal direction perpendicular to the imaging surface of the solid-state imaging device 24 and is parallel to each other.

On the opposing inner mounting surfaces of the upper substrate 28 and the lower substrate 29, electric components 31a and 31 are respectively provided.
b and electrical components 31c and 31d are mounted. The cables 33 of the integrated cable 32 are connected to the rear ends of the upper board 28 and the lower board 29 at signal line connection sections (cable connection sections) 30 by soldering. In addition, from the element holder 26 that covers the cover glass 5 to the integrated cable 3
2 is covered with the heat-shrinkable tube 35 up to the vicinity of the front end.

Also in this imaging device 21A, the space between the electric components 31a and 31b mounted on the upper substrate 28 is provided with a space larger than the horizontal size of the electric components 31c and 31d mounted on the lower substrate 29. Mount, lower substrate 2
The electric components 31c and 31d mounted on the cable 9 are housed in the space between them, and compared with the conventional example of FIG.
The size in the vertical direction of the portion reaching the second cable connection portion 30 is sufficiently reduced.

According to the present embodiment, as in the first embodiment, a small-sized imaging device 21A can be realized, and when incorporated into the distal end of the electronic endoscope 2, the distal end can be made smaller in diameter.

(Third Embodiment) FIG. 14 is a sectional view of a main part of an image pickup apparatus 21B according to a third embodiment of the present invention. This imaging device 21B is an imaging device 21A shown in FIG.
, The core wire 33a of the cable 33 of the integrated cable 32 is connected and fixed to the upper lead 7 of the solid-state imaging device 4 by soldering, and the strip-shaped flexible substrate 7 is attached to the lower lead 7.
1 is soldered on the front end side and fixedly connected.

The rear end of the flexible board 71 is folded back into a U-shape. When the two electric parts 31a and 31b mounted on the flexible board 71 are folded back into a U-shape, the electric parts 31a and 31b are connected to each other. The flexible substrate 71 is deformed so that
The mounting positions of the two electric components 31a and 31b are set, and the imaging device 21B is configured to be small.

The core wire 33a of the cable 33 is connected by soldering to a rear surface position near the rear end of the flexible board 71. It should be noted that in FIG.
Although not shown, the other configuration is the same as that of FIG.

FIG. 14 shows a type in which the flexible substrate 71 is bent in a U-shape. However, a type in which the flexible substrate 71 is bent in an L-shape as in the imaging device 21C of the modification shown in FIG. .

Also in this case, the flexible substrate 71 is
The flexible board 71 is deformed so that the two electric components 31a and 31b mounted on the flexible board 71 in a state of being bent into a shape are adjacent to each other in a state where they are close to each other, or the mounting position of the two electric components 31a and 31b is changed. You have set.

[Supplementary Notes] In an image pickup apparatus including a board on which electric components are mounted on a mounting surface facing a rear end side of a solid-state imaging device and a cable for performing signal transmission, electric components mounted on one mounting surface and the other mounting surface An image pickup apparatus characterized in that a space is provided adjacent to each other, and a space between opposing substrate surfaces is set to approximately the height of an electric component. 2. In a solid-state imaging device, a substrate on which electric components are mounted on the rear end side, and in an imaging device including a cable, other electric components or cable connection portions adjacent to the electric components mounted on the substrate are connected to the electric component mounting surface of the substrate. An imaging device characterized by being mounted on different surfaces.

3. In an image pickup apparatus comprising a plurality of substrates on which electric components are mounted on the rear end side of a solid-state imaging device and a cable, the electric components mounted on the substrate and the electric components and cable connection mounted on another substrate adjacent to each other are avoided. An imaging apparatus characterized in that a unit is located. 4. In an image pickup apparatus including a plurality of substrates on which electric components are mounted on the rear end side of a solid-state imaging device and a cable, the electric components mounted on the substrate are mounted on another substrate which is arranged adjacent to and substantially parallel to the substrate. An imaging device characterized by positioning electrical parts and cable connection parts.

5. In an image pickup device including a plurality of substrates on which electric components are mounted on a rear end side of a solid-state imaging device, an electric component mounted on another substrate which is adjacently arranged in a substantially parallel manner except for the electric components mounted on the substrate. An imaging device characterized by being located. (Effects of Supplementary Notes 1 to 5) By effectively utilizing the space around the electric components mounted on the board, the rigid length can be reduced and the imaging unit can be reduced in size.

[0062]

As described above, according to the present invention, there is provided an image pickup apparatus comprising a board on which electric components are mounted on a mounting surface opposed to a rear end side of a solid-state image sensor and a cable for signal transmission. A space is provided on one of the mounting surfaces where the electric components mounted on the other mounting surface are arranged adjacently, and the distance between the opposing board surfaces can be set to approximately the height of the electric components. Can be mounted at high density, and the space between the substrates can be reduced to achieve miniaturization.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an endoscope apparatus including a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a distal end portion of an insertion section into which the first embodiment is incorporated.

FIG. 3 is a cross-sectional view illustrating a configuration of the imaging device according to the first embodiment.

FIG. 4 is a front view showing a third substrate.

FIG. 5 is a front view showing a third substrate in a state where lead legs and cables are fixed.

FIG. 6 is a perspective view showing a state in which a cable provided with a retaining portion for retaining in a through hole of a third substrate is fixed.

FIG. 7 is an enlarged view showing a through hole portion in an enlarged manner.

FIG. 8 is a diagram showing an example of the arrangement of cables in a comprehensive cable.

FIG. 9 is a view showing an example of the arrangement of through holes in a third board to which the cables having the arrangement shown in FIG. 8 are connected;

FIG. 10 is a view showing a third substrate according to a modified example.

FIG. 11 is a view showing a state in which a cable is connected to a third substrate according to a modified example.

FIG. 12 is a cross-sectional view illustrating a configuration of an imaging device according to a modification.

FIG. 13 is a cross-sectional view illustrating a configuration of an imaging device according to a second embodiment of the present invention.

FIG. 14 is a cross-sectional view illustrating a configuration of a main part of an imaging device according to a third embodiment of the present invention.

FIG. 15 is a cross-sectional view illustrating a configuration of an imaging device according to a modification.

FIG. 16 is a configuration diagram showing a first conventional example.

FIG. 17 is a view showing a third substrate of FIG. 16;

FIG. 18 is a configuration diagram showing a second conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1A ... Imaging device 2 ... Objective optical system 3 ... Lens frame 4 ... Solid-state imaging device 5 ... Cover glass 6 ... Element holder 7 ... Lead legs 8 ... First substrate 9 ... Second substrate 10 ... Third substrate 11a, 11b, 11c ... Electrical parts 12 ... Comprehensive cable 13 ... Cable 13a ... Core wire 41 ... Endoscope device 42 ... Electronic endoscope 45 ... Insertion part 49 ... Tip part 61a ... Notch 61b ... Hole 62 ... Through hole 63 ... Connection fixing part 64 … Locking part

Claims (1)

[Claims] 1. An image pickup apparatus comprising: a substrate on which electric components are mounted on a mounting surface opposed to a rear end side of a solid-state imaging device; and a cable for performing signal transmission. An imaging apparatus, comprising: a space in which electric components to be mounted are arranged adjacent to each other; and a space between opposing substrate surfaces is set to approximately the height of the electric components.