JPH06350799A - Closely contact type image sensor unit - Google Patents

Abstract

PURPOSE:To simplify connecting wiring from a semiconductor image sensor to a circuit board, and to make the assembly adjustment of an optical system member such as a lens simple, highly precise and compact. CONSTITUTION:A circuit conductive layer 13 is arrayed on the surface of a first translucent substrate 12. An electrode terminal 16 of a semiconductor image sensor 14 overlapped on the surface of the substrate 12 in face-down is brought into contact with the circuit conductive layer 13. A lens plate 18 provided on the back face of the substrate 12 is incorporated with a convergent rod lens array 19. A light emitting body 22 such as an EL which illuminates an original surface is positioned between the rear surface of the lens plate 18 and a second translucent substrate 21, and the rear surface of the substrate 21 is acted as an original abutting surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact type image sensor unit for illuminating a document surface to convert an optical image on the document surface into an electric signal.

[0002]

2. Description of the Related Art FIG. 2 shows an example of the structure of a conventional contact type image sensor unit. The semiconductor image sensor 2 in which the photoelectric conversion element array 1 is arranged is provided on the back surface of the substrate 3. A large number of electrode terminals 4 of the semiconductor image sensor 2 and a large number of circuit conductor layers 5 are wire-bonded by a fine metal wire 6 such as gold or aluminum. The semiconductor image sensor 2 and its peripheral portion are covered with a cup-shaped sealing material 7 made of transparent glass. Then, the converging rod lens 8 and the LED array 9 serving as a light emitter are
It is incorporated together with the holder 10. Reference numeral 11 indicates a document surface.

[0003]

In the conventional contact type image sensor unit thus constructed, not only the complicated wire bonding process is required, but also the photoelectric sensor of the image sensor is used for incorporating the converging rod lens. Alignment adjustment with the conversion element array is required.

Further, the spot illumination by the LED array has a problem that the illuminance distribution on the document surface tends to vary.

[0005]

In order to solve the above-mentioned problems, the present invention provides a first light-transmitting substrate having a plurality of circuit conductor layers arranged on the surface thereof, and a first light-transmitting substrate. And a semiconductor image sensor having a plurality of electrode terminals arranged on the light receiving surface side on which the photoelectric conversion element array is arranged, and a photoelectric conversion element provided on the back surface of the first transparent substrate. A lens plate containing a converging rod lens array corresponding to the array, a second translucent substrate provided on the back surface side of the lens plate and having the back surface of the lens plate as an original contact surface, and an original irradiation lamp. The semiconductor image sensor has its light-receiving surface facing the first light-transmissive substrate so that its electrode terminals are brought into contact with the circuit conductor layer.
There is provided a contact-type image sensor unit characterized in that the light-emitting body is interposed between the transparent substrate and the transparent substrate.

EL can be used for the light-emitting body. Further, the semiconductor image sensor can be fixed to the first transparent substrate with a transparent photo-curable insulating resin. Further, the first transparent substrate and the second transparent substrate can have substantially the same plate thickness.

[0007]

According to the present invention, the semiconductor image sensor is arranged on the surface of the first light-transmissive substrate having a plurality of circuit conductor layers arranged on the surface in a face-down posture with its light-receiving surfaces facing each other. In addition, since the electrode terminal of itself is brought into contact with the circuit conductor layer, wire bonding between the electrode terminal and the circuit conductor layer becomes unnecessary.

Further, since the lens plate integrally incorporating a plurality of converging rod lens arrays is used, it is not necessary to perform individual axis alignment with the photoelectric conversion element array when incorporating the converging rod lenses. Further, since the light emitter is interposed between the lens plate and the second light transmissive substrate, a surface light emitter such as an EL can be incorporated by using these plate materials, and the illuminance distribution can be made uniform and the entire unit can be made uniform. It can be made compact.

[0009]

Embodiments of the present invention will now be described with reference to the drawings.

As shown in FIG. 1, the first light-transmissive substrate 12 made of glass has a plurality of circuit conductor layers 13 made of a conductive film arranged on its surface. The semiconductor image sensor 14 stacked on the surface of the transparent substrate 12 with the light receiving surface facing downward has a photoelectric conversion element array 15 and a plurality of electrode terminals 16 arranged on the light receiving surface. It is in contact with the circuit conductor layer 13. Translucent substrate 1
The semiconductor image sensor 2 and the semiconductor image sensor 14 are integrally connected by a light-transmissive photo-curable insulating resin layer 17 provided therebetween.

The lens plate 18 provided on the back surface of the first light transmissive substrate 12 contains a converging rod lens array 19 and a light shielding film 20. The converging rod lens array 19 is in the form of a corrugated plate in which a plurality of rod lenses are arranged in a direction orthogonal to the axis thereof, and light shielding films 20 are attached to both side surfaces thereof. Since the lens plate 18 is an integrated plate-like body made by sandwiching the rod lens array 19 having the light-shielding film 20 between translucent plate materials, it is aligned with the photoelectric conversion element array 15 at the time of assembling the unit. The adjustment is remarkably easier than the case where the adjustment is performed for each element, and moreover, the axes can be aligned with high accuracy.

Between the lens plate 18 and the second light-transmissive substrate 21 provided on the back side thereof, a light emitting body 22 as an original irradiation lamp made of EL (electroluminescence) is provided. The second light-transmissive substrate 21 is made of glass, and its back surface serves as a document contact surface.

The semiconductor image sensor 14 includes a photoelectric conversion element array 15 including a phototransistor group or a photodiode group on a single crystal silicon substrate (wafer).
It is obtained by incorporating an access circuit (not shown) composed of CCD, MOS or bipolar IC.

Each electrode terminal 16 is a conductive film formed by sputtering using a two-layer aluminum wiring process, and the projection length from the wafer surface is several μm.

A glass plate having a plate thickness of 1.1 mm is used as the first light-transmissive substrate 12, and a metal such as Au or Ag is printed on the surface of the glass plate so as to have a film thickness of 3 μm to 10 μm.
3 is formed. Further, an acrylate-based light-transmissive photo-curable insulating resin layer 17 is applied and formed at a predetermined position on the surface of the light-transmissive substrate 12 by a stamping method or a screen printing method, and the semiconductor image sensor 14 is formed thereon.
Are stacked in a face-down posture so that the electrode terminals 16 come into contact with a predetermined circuit conductor layer 13. After that, while applying a pressing force to the semiconductor image sensor 14, the photocurable insulating resin layer 1 is irradiated with the ultraviolet rays applied through the transparent substrate 12.
Harden 7. A synthetic resin such as transparent silicone is applied thereon by a dispenser to form a protective layer (not shown).

The lens plate 18 is fixed on the back surface of the first transparent substrate 12 with a transparent adhesive, and the lens plate 18
1 μm to 10 μm thick on the back surface of the
An EL element of 0 μm is provided as the light-emitting body 22, and on the back side thereof,
A second transparent substrate 21 made of glass having the same plate thickness (1.1 mm) as the first transparent substrate 12 is fixed with a transparent adhesive.

In the contact-type image sensor unit having such a structure, the light emitted from the light-emitting body 22 passes through the second light-transmissive substrate 21 and illuminates the document surface 11, and the optical information from the document surface 11 is transmitted. Is guided to the photoelectric conversion element array 15 by an erecting equal-magnification by the converging rod lens array 19 and converted into an electric signal.

The photoelectric conversion element array 15 of the semiconductor image sensor 14 used in this embodiment is composed of phototransistors. A bipolar IC chip was used for the thyristor shift register of the scanning circuit.

The resolution of the contact image sensor unit in which the converging rod lens array 19 is incorporated without adjustment is
MTF (Modulation-Transfer-Fanction) value is about 6
It showed a high value of 0% (4 lp / mm). Further, by using the thin film EL as the light emitter, the variation in the illuminance on the original surface was 15%, which was conventionally 5%. Furthermore, the volume of the entire unit could be halved compared to the conventional one.

[0020]

As described above, according to the present invention, since the electrode terminal of the semiconductor image sensor is brought into contact with the circuit conductor layer to obtain the connection effect, the wire bond using the fine metal wire is unnecessary. In addition, it is not necessary to form bump electrodes on the semiconductor image sensor, and the semiconductor image sensor can be mounted with high accuracy on a translucent substrate provided with a circuit conductor layer. Further, in the optical system, not only the focusing rod lens can be incorporated without adjustment but also surface emission can be achieved, so that it is possible to obtain a compact and low-cost contact image sensor unit with small variation in sensitivity. It will be possible.

[Brief description of drawings]

FIG. 1 is a side sectional view of an image sensor unit according to an embodiment of the present invention.

FIG. 2 is a side sectional view of a conventional image sensor unit.

[Explanation of symbols]

 12 1st translucent substrate 13 Circuit conductor layer 14 Semiconductor image sensor 15 Photoelectric conversion element array 16 Electrode terminal 17 Photocurable insulating resin layer 18 Lens plate 19 Rod lens array 21 Second translucent substrate 22 Light emitter

Claims (4)

[Claims] 1. A first light-transmissive substrate having a plurality of circuit conductor layers arranged on the surface thereof, and a light-receiving device provided on the surface of the first light-transmissive substrate and having a photoelectric conversion element array arranged therein. A semiconductor image sensor in which a plurality of electrode terminals are arranged on the surface side, and a lens plate provided on the back surface of the first translucent substrate and having a focusing rod lens array corresponding to the photoelectric conversion element array built therein. And a light-transmitting substrate provided on the back side of the lens plate, the back side of which is the original contact surface, and a light emitter serving as a document irradiation lamp. The semiconductor image sensor has a light receiving surface. Is brought into contact with the circuit conductor layer by facing the first translucent substrate, and the light emitter is interposed between the lens plate and the second translucent substrate. Adhesion type image that is characterized by Jisensa unit. 2. The contact type image sensor unit according to claim 1, wherein the light emitter is EL. 3. The contact type image sensor unit according to claim 1, wherein the semiconductor image sensor is fixed to the first light-transmitting substrate with a light-transmitting photocurable insulating resin. 4. The contact image sensor unit according to claim 1, wherein the first transparent substrate and the second transparent substrate have substantially the same plate thickness.