JPH02226954A - Photoelectric converter - Google Patents

Abstract

PURPOSE:To attain further miniaturization of a device to which a photoelectric converter is to be applied by adopting the constitution such that a lighting light transmits through a mount board having transparency. CONSTITUTION:A transparent sensor board 1 has an optical sensor array made by the semiconductor process or the like on its transparent and insulating board made of a quartz glass or a borosilicate glass or the like. A transparent mount board 2 has a wiring part 4 made of Ag, Ag-Pd, Ag-Pt or Au or the like formed by the thick film print method or Al, cu Mo, ITO or the like formed by the photo lithography method on the transparent and insulating board made of quartz glass, borosilicate glass, soda glass or acryl or the like. A lighting light L from a light source 3 transmits through the transparent mount board 2, an air layer 5A and the inside of the transparent sensor board 1 and irradiates an original 6, the information light reflected on the original 6 is made incident in a photodetector on the transparent sensor board 1 and outputted as a picture signal from the photodetector.

Description

[Detailed description of the invention] [Usage in business] The present invention relates to a photoelectric conversion device, and particularly to a photoelectric conversion element (
The present invention is suitable for application to a photoelectric conversion device provided with an optical sensor array.

[Prior art] As a method for miniaturizing photoelectric conversion devices, improving yields, and reducing manufacturing costs, etc.,
There are those disclosed in io-132452 and Japanese Patent Application Laid-Open No. 62-97370. These disclose a configuration in which a sensor substrate provided with an optical sensor is supported on a support (hereinafter referred to as a mounting substrate) prepared in another process.

[Problems to be Solved by the Invention] However, these conventional examples have the following problems.

First, in JP-A-60-132452, a thick film circuit as a drive circuit is formed on an insulating ceramic substrate as a mounting board, an optical sensor array part is fixed on the mounting board, and the thick film circuit is A configuration is shown in which the optical sensor array 1 and the optical sensor array 1 are connected by a wire bonding method. However, in this configuration, since the mounting board is non-light-transmitting, the arrangement of the light source is restricted, and there is a possibility that sufficient miniaturization cannot be achieved.

On the other hand, in JP-A No. 62-97370, a light-transmitting sensor substrate on which an optical sensor array is formed is fixed onto a light-transmitting mounting board, and a light-impermeable resin mold is placed on the optical sensor. A configuration with this is shown. Information light is received onto the optical sensor via the light-transmitting mounting board and the light-transmitting sensor board, and a light shielding plate is provided on the surface of the light-transmitting mounting board to prevent unnecessary light from entering.

However, in this configuration, the information light from the document surface passes through the translucent mounting board and the translucent sensor board and enters the light receiving element (optical sensor). The arrival path becomes longer, which tends to cause loss of light quantity, and stray light components due to diffused light in each layer are generated, resulting in S
There was a risk that the /N ratio would decrease or the sensor output would decrease.

On the other hand, JP-A No. 62-97370 discloses applying a transparent adhesive to the entire surface between a light-transmitting mounting board and a light-transmitting sensor board, but air bubbles may be mixed into this adhesive layer. These bubbles may cause loss of light quantity and generation of stray light components.

Furthermore, since selecting a transparent adhesive requires an adhesive with low light loss, that is, high transmittance, the degree of freedom in selecting the adhesive is reduced.

Furthermore, it is necessary to consider relaxation of stress between the light-transmitting mounting board and the light-transmitting sensor board.

[Means for Solving the Problems] The present invention aims to solve these problems, and for this purpose, a photoelectric conversion element is provided on the side facing the original for reading image information, and a light-transmitting element is provided. a light source disposed between the support body and the substrate; and a cavity provided in the optical path of the light emitted from the light source, the light emitted from the light source passes through the support, the cavity, and the substrate and is irradiated onto the original, and the reflected light is received by the photoelectric conversion element. It is characterized in that it is made to be

[Function] According to the present invention, since the illumination light is transmitted through the transparent mounting board (support body), the degree of freedom in arranging the light source is improved and miniaturization is possible. Since the structure is such that the reflected light (reflected light from It also improves. In the present invention, since the illumination light is configured to pass through the board and the mounting board, the illumination light does not have an adverse effect on each sensor due to moderate light loss and diffusion when the illumination light passes through, and the illumination light does not affect the document. Uniform illumination can be achieved.

Furthermore, by forming a gap (air layer) in the optical path between the translucent mounting board and the sensor board, the step of removing air bubbles from the adhesive when bonding the two boards together becomes unnecessary. Moreover, the range of adhesive selection is expanded.

[Example code] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIGS. 1(8) and 1(1') are a side view and a perspective view, respectively, of a photoelectric conversion device according to an embodiment of the present invention.

Here, the light-transmitting sensor substrate 1 has an optical sensor array formed by a semiconductor process or the like on a light-transmitting and insulating substrate such as quartz glass or borosilicate glass. The translucent mounting board 2 is made of translucent material such as quartz glass, borosilicate glass, soda glass, or acrylic (it may be provided with a protective film such as 5i02 to prevent elution and diffusion of alkali elements). and Heg, Heg-Pd, and Ag-PL formed by thick film printing on a substrate with insulating properties.
.

^U etc. or formed by photolithography t'
, An, Cu, Mo, ITO, or the like. For the base of these substrates, materials with similar thermal expansion coefficients are used.

The wiring IK54 connects the sensor section and a drive circuit section (not shown). Then, the light-transmitting sensor substrate 1 is bonded onto the light-transmitting mounting board 2 using the adhesive layer 5.

The adhesive 5 for fixing the translucent sensor substrate 1 and the translucent mounting substrate 2 can be formed by screen printing, line coating using a dispenser, or the like. And as the adhesive,
Examples include silicone/rubber-based room temperature curing adhesives, photo-curing acrylic adhesives, and the like. Translucent sensor board 1
A material having a coefficient of thermal expansion similar to that of each base of the translucent mounting board 2 is used. ) to bond the substrate 1.2. As a result, the optical path of the illumination light from the light source 3 is empty!
(Air layer) 5^ is formed.

Further, the light-transmitting sensor substrate 1 and the wiring portion 4 of the light-transmitting mounting board 2 are electrically connected by wire bonding, soldering, or the like.

Thus, the illumination light from the light source 3 is transmitted to the transparent mounting board 2. The original 6 passes through the air layer 58 and the translucent sensor substrate l.
The information light reflected from the document 6 enters the light receiving element on the translucent sensor substrate 1 and is outputted from the light receiving element as an image signal.

According to this example, the information light is transmitted to the mounting board 2 and the sensor board 1.
Since the light is received by the optical sensor without passing through the light, there is no reduction in the S/N ratio due to light loss or stray light components. Furthermore, according to this example, the translucent sensor board 1 and the translucent mounting board 2 can be handled as independent components, that is, they can be manufactured in separate processes, thus unifying the manufacturing process. It becomes possible to use only non-defective products in each separate inspection process, and the overall yield improves. Furthermore, since only the optical sensor section is disposed on the base of the substrate 1, it is possible to manufacture a large number of substrates 1 at once using a base material having a certain extent, and it is possible to reduce costs. Furthermore, it is also possible to mount a driving IC chip, an output amplification IC chip, etc. in addition to the wiring section 4 on the transparent mounting board 2, and in that case, further cost reduction becomes possible. Furthermore, by arranging the light source 3 on the back side of the translucent mounting board 2,
The external dimensions of the unit are further reduced.

In other words, according to this embodiment, since the illumination light is transmitted through the light-transmitting mounting board, the degree of freedom in arranging the light source is improved, that is, the light source is placed on the back side of the light-transmitting mounting board. This makes it possible to achieve further miniaturization of devices to which the photoelectric conversion device is applied.

In addition, since the information light does not pass through the light-transmitting mounting board or the light-transmitting sensor board, there is no light loss or diffusion of the information light, and the S/N ratio is improved and the sensor output is also good. becomes.

Furthermore, by using a substrate made of a material with a thermal expansion coefficient similar to that of the translucent mounting board and the translucent sensor board, it is possible to alleviate the stress caused by bonding the two, making it difficult for the board to warp or crack. .

In addition, by providing the wiring section on the translucent mounting board, miniaturization of the device is achieved, and by providing the wiring section between the translucent mounting board and the translucent sensor board, further Downsizing is also possible.

In addition, since the air layer 5A is provided in the optical path of the illumination light between the translucent mounting board 2 and the translucent sensor substrate 1, the adhesive N
The process of removing air bubbles in step 5 is not necessary, which simplifies the process.
Cost reduction can be achieved.

Furthermore, regardless of the transmittance of the adhesive, for example, a colored adhesive can be used, increasing the degree of freedom in selecting the adhesive.

In addition, since the adhesive is partially applied and cured, even if there is a difference in the coefficient of thermal expansion between the translucent mounting board 2 and the translucent sensor board l, stress will be reduced due to the elasticity of the adhesive. can be alleviated.

FIGS. 2A and 2B are an exploded perspective view and a cross-sectional view of the main parts of another embodiment of a photoelectric conversion device to which the present invention can be applied, respectively. In addition, in FIG. 2 (8), for example, the adhesive 5 provided near both sides is not shown.

In this example, a light shielding layer 7 is provided between the light-transmitting mounting board 2 and the light-transmitting sensor board 1. The light shielding N7 is arranged around the slit-shaped window part 7^ that is appropriately determined according to the optical path, and can be formed using the same process and the same metal material as the wiring part 4, or the screen It may also be formed using a non-transparent resin by a printing method, a dispensing method, or the like.

In any case, according to the configuration shown in FIG. 2, in addition to the basic effect described in FIG. For example, by blocking the diffused reflection component on the transparent mounting board 2, the resolution of the output signal can be improved.

In the configuration shown in FIG. 1 described above, the adhesive 5 may be made non-transparent to function as a light-shielding layer, and in this case, the step of separately providing the light-shielding layer 7 is not necessary. In other words, the adhesive 5 shown in FIG.
This makes it possible for the material itself to function as a light-shielding layer.

FIG. 3 shows a more detailed cross-sectional structure of the photoelectric conversion device according to the embodiment shown in FIG. 1 or 2. FIG.

Here, a matrix wiring section 9, an illumination window 10, a light receiving element 11
, a charge storage section (capacitor section) 12, and a light sensor including a switching thin transistor (TPT) 13 for transferring the accumulated charge at an appropriate timing.

The light-transmitting sensor board 1 configured in this manner is supported on the light-transmitting mounting board 2 via the adhesive layer 5 (the optical path portion is an air layer 5A). All of these parts can be formed using the same manufacturing process. The layer structure of each part is, for example, C' formed on the substrate, a light-shielding layer lower electrode 15 of the sensor section, an insulating layer of silicon hydrogenated nitride (SiNx: If) placed above it, and a hydrogenated silicon layer above it. Semiconductor layer of amorphous silicon (a-5i+ll),
It consists of an n'a-5i+H ohmic layer on top of the ohmic layer, and an upper electrode of the first order placed above the ohmic layer.

The optical sensor section having such a configuration has a passivation layer 19.
Further, on this passivation layer 19, a thin plate glass 14 having a thickness of, for example, 50 μm is placed via an adhesive layer 20.
will be provided. The original slides on this thin glass 14, and the thin glass 14 allows the Vf between the light receiving element 11 and the original 6 to be lowered. It functions as a spacer layer that keeps the distance constant, and also functions as a wear-resistant layer.

In this configuration, the illumination light emitted from the back side of the translucent mounting board 2 passes through the translucent mounting board 2 and the translucent sensor board 1, passes through the illumination window 10, and reaches the surface of the thin glass 14. The original 6 is illuminated. Then, the information light L' reflected by the original 6 enters the light receiving element 11.

FIG. 4 is an exploded perspective view showing an example of a unitized configuration of a photoelectric conversion device having the above basic configuration.

5(A) is a plan view of the sensor unit, FIG. 5(B) is a side view thereof, FIG. 5(C) is a rear view thereof, and FIG. 5(D) is a DD' A cross-sectional view taken along the line E-E' is also shown in FIG. In the illustrated example, a translucent sensor board 1 is adhesively fixed onto a translucent mounting board 2, and this translucent mounting board 2 is attached to a base plate 22.
and further press down with the IC cover 23. Next, the light fA3 is fixed to the lower surface of the base plate 22. and,
From the unit, flexible wiring 24 and connector 2
An image signal can be output via 5.

Furthermore, the sensor unit 10 configured in this way
0 can be used to configure facsimile machines, image readers, and various other devices.

FIG. 6 shows an example of an image processing apparatus (for example, a facsimile) configured using the sensor unit 100 according to this example.

Here, 102 is a feeding roller for feeding the original 6 toward the reading position, and 104 is a separation piece for reliably separating and feeding the original 6 one by one. 108 is provided at a reading position facing the sensor unit l-100 and reads the original 6.
This is a platen roller that regulates the surface to be read and conveys the document 6.

P is a recording medium in the form of roll paper in the illustrated example,
Image information read by the sensor unit 100 or, in the case of a facsimile machine, image information transmitted from the outside is formed. Reference numeral 110 is a recording head for forming the image, and various types such as a thermal head and an inkjet recording head can be used. Further, this recording head may be of a serial type or a line type. A platen roller 112 transports the recording medium P to a recording position by the recording head 110 and regulates the recording surface thereof.

Reference numeral 120 denotes an operation panel equipped with switches for receiving operation inputs, a display section for notifying messages and other device statuses, and the like. Reference numeral 130 denotes a system control board, which is provided with a control section for controlling each section, a processing section for image information of the optical sensor drive IJ circuit section 9, a transmitting/receiving section, and the like. 140 is a power source for the device.

In the embodiments described above, a configuration was described in which the document is read in close contact with or in close proximity to the photoelectric conversion device and the document 6 without interposing an optical system between the photoelectric conversion device and the document 6. The present invention can also be effectively applied to a configuration in which an image of light (light) is formed on a light receiving element via an optical system.

That is, as shown in FIG. 7, even if the configuration uses an optical system member 8 such as a convergent light transmitter array or a fiber plate between the translucent sensor substrate 1 and the original 6,
The present invention can be easily applied.

Moreover, although the wiring portion is formed on the transparent mounting board in the upper side, it may be provided on another member. In this case, for example, the wiring may be directly drawn out from the light-transmitting sensor substrate using flexible wiring or the like.

[Effects of the Invention] As explained above, according to the present invention, according to the present embodiment, since the illumination light is transmitted through the mounting board having translucency, the degree of freedom in arranging the light source is increased. In other words, it becomes possible to arrange the light source on the back side of the light-transmitting mounting board, and further miniaturization of the device to which the photoelectric conversion device is applied can be achieved.

In addition, since the information light does not pass through the light-transmitting mounting board or the light-transmitting sensor board, there is no light loss or diffusion of the information light, and the S/N ratio is improved and the sensor output is also good. becomes.

Furthermore, since an air layer is provided in the optical path of the illumination light between the light-transmitting mounting board and the light-transmitting sensor board, the process can be simplified by eliminating the need for removing air bubbles from the viewing layer. Cost reduction can be achieved.

Furthermore, regardless of the transmittance of the adhesive, for example, a colored adhesive can be used, increasing the degree of freedom in selecting the adhesive.

In addition, since the adhesive is partially applied and cured, even if there is a difference in thermal expansion coefficient between the translucent mounting board and the translucent sensor curtain plate, the elasticity of the adhesive will reduce stress. It can be relaxed.

[Brief explanation of the drawing]

1(^) and (B) are respectively a side view and a perspective view of a photoelectric conversion device according to one embodiment of the present invention, and FIGS. 2(A) and (B) are respectively a side view and a perspective view of a photoelectric conversion device according to another embodiment of the present invention. An exploded perspective view and a schematic cross-sectional view of the photoelectric conversion device according to the example, FIG. 3 is similar to FIG.
), (B) A more detailed cross-sectional view of the photoelectric conversion device according to the embodiment, FIG. 4 is an exploded perspective view showing an example of a sensor unit configured using the photoelectric conversion device, and FIG. 5 (^), ( B), (C), (D) and (E) are respectively a plan view, a side view, a back view, a sectional view taken along the line DD and a sectional view taken along the line EE', and FIG. FIG. 7 is a cross-sectional view showing an example of an image processing apparatus to which the present invention can be applied. FIG. 7 is a schematic cross-sectional view showing still another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Translucent sensor board, 2... Transparent mounting board (support body), 3... Light source, 4... Wiring part, 5... Adhesive layer, 5^... Air layer, 6... original, 7... light shielding layer, 8... optical system member. Figure 2 CB) Figure 5 (E)

Claims (1)

[Scope of Claims] 1) A substrate having a light-transmitting property and having a photoelectric conversion element provided on the side facing the original for reading image information; a support supporting the substrate and having a light-transmitting property; , a light source provided on the side of the support opposite to the support surface of the substrate, and a gap disposed between the support and the substrate and provided in an optical path portion of the light emitted from the light source. The light emitted from the light source is transmitted through the support, the gap, and the substrate, and is irradiated onto the document, and the reflected light is received by the photoelectric conversion element. Photoelectric conversion device. 2) The photoelectric conversion device according to claim 1, wherein the void portion is formed by disposing an adhesive layer between the support body and the substrate except for the optical path portion.