JP2616237B2 - Complete contact image sensor and unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a complete contact image sensor for converting an optical image into an electric signal and a complete contact image sensor unit.

[0002]

2. Description of the Related Art Conventionally, in an image sensor, a semiconductor element 42 including a light receiving element 32 is fixed with a conductive adhesive on a substrate 41 on which conductor wiring is formed as shown in FIG. The layer 38 is connected with a thin metal wire such as gold or aluminum by a wire bonding method, and the structure is sealed with a transparent glass sealing material.

In the above-described conventional image sensor unit using an image sensor, the image sensor, the LED array 35 (light source) and the converging rod lens 34 must be assembled and adjusted in a holder. .

[0004]

However, in the above-described structure, complicated steps such as wire bonding are required, and a converging rod lens is adjusted in position and incorporated into the image sensor in manufacturing the image sensor unit. There is a problem that it is necessary and the size increases due to the conjugate length of the lens.

Further, at the same time improving the antistatic properties and abrasion resistance of the conductor layer, simple can read the document without a lens, is a problem to realize a high-performance full-contact type image sensor and the unit compact there were.

[0006]

According to the present invention, there is provided a semiconductor device having a light-receiving element via a photo-curable insulating resin on a light-transmitting substrate having a circuit conductor layer formed on a surface thereof. Then, an image sensor is produced by mounting the device in a face-down manner such that an extraction electrode formed on the element comes into contact with the circuit conductor layer. Here, the first invention is characterized in that a first transparent conductor layer is provided on the back surface of the translucent substrate, and a sheet resistance is provided on the back surface of the first transparent conductor layer, the sheet resistance being larger than that of the first transparent conductor layer . Perfect as two transparent conductor layers
It is formed by diffusing conductive particles into edge resin.

In a second aspect of the present invention, a first transparent conductor layer is provided on the back surface of the translucent substrate, a transparent insulating layer is provided on the back surface of the first transparent conductive layer, and a first transparent conductor layer is provided on the back surface of the transparent insulating layer . two
Formed by diffusing conductive particles into insulating resin as transparent conductive layer of
What to do.

[0008] A third aspect of the present invention is the completely contact type image sensor according to the first aspect of the invention or the completely contact type image sensor according to the second aspect of the invention.
Using Mejisensa sheds illumination from the side of the light receiving element of the transmissive substrate is mounted, the rear surface of the second transparent conductive layer as original contact surface, completely contact type image which can read the original without lens This is to create a sensor unit.

[0009]

[0010]

According to the present invention, there is provided a simple, compact and high-performance full-contact type image sensor and unit capable of reading an original without a lens by using the above-described structure to improve the anti-static property and the abrasion resistance by the above-mentioned conductor layer. Is realized.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An image sensor according to an embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1A and 1B are a front sectional view and a side sectional view of a complete contact type image sensor according to an embodiment of the first invention, and FIGS. 2A and 2B are sectional views. , Second
FIG. 2 is a front cross-sectional view and a side cross-sectional view of the complete contact image sensor according to the embodiment of the present invention. 1 (11) is a light-transmitting substrate, 2 (12) is a circuit conductor layer formed on the surface of the light-transmitting substrate 1 (11), 3 (13) is an image sensor chip used as a semiconductor element, 4 ( Reference numeral 14) denotes an electrode provided on the image sensor chip 3 (13), and 5 (15) denotes a transparent light-curable insulation for mounting the semiconductor image sensor chip 3 (13) on the translucent substrate 1 (11). Resin, 6
(16) is a protective layer for protecting the semiconductor image sensor chip 3 (13), 7 (17) is a light receiving element provided on the semiconductor image sensor chip 3 (13), 8 (1)
8) is a first transparent conductor layer provided on the back surface of the translucent substrate 1 (11), 9 is a second transparent conductor layer provided on the back surface of the first transparent conductor layer 8, and 19 is a first transparent conductor layer Reference numeral 18 denotes a transparent insulating layer provided on the back surface, and reference numeral 20 denotes a second transparent conductor layer provided on the back surface of the transparent insulating layer 19.

A method of manufacturing the complete contact type image sensor having the above configuration will be described. First, a light receiving element 7 (1) such as a phototransistor or a photodiode is formed on a single crystal silicon substrate (wafer) using a semiconductor process.
7) and a device provided with an access circuit (not shown) such as a CCD, a MOS, and a bipolar IC. Each electrode 4 (14)
With respect to (2), the structure is such that it protrudes from the wafer surface by about several μm by a sputtering method using a two-layer Al wiring process. Thereafter, the wafer is cut by a high-precision dicing technique, and the semiconductor image sensor chip 3 (1
Make 3). Next, a metal such as copper is deposited on the surface of a light-transmitting substrate 1 (11) such as polyarylate (PA), polyethersulfone (PES), or polyethylene terephthalate (PET) having a thickness of 25 μm to 200 μm by a vapor deposition method. 3μm to 20μm using sputtering or sputtering method or foil
.mu.m, and the circuit conductor layer 2 is formed later by photolithography.
Form (12). Further, on the back surface of the translucent substrate 1 (11), a photocurable insulating resin obtained by diffusing conductive particles such as antimony tin oxide in urethane acrylate is applied.
First transparent conductor layer 8 having a thickness of 1 μm to 5 μm by irradiating ultraviolet rays
(18) is formed. Further, a second transparent conductor layer having a larger sheet resistance than the first transparent conductor layer 8 and formed in the same manner is formed on the back surface of the first transparent conductor layer 8. An acrylate-based photocurable insulating resin is applied to the back surface of the first transparent conductor layer 18 and irradiated with ultraviolet light to have a thickness of 5 μm to 20 μm.
μm transparent insulating layer 19 is formed.
9, a second transparent conductor layer having a thickness of 1 μm to 5 μm
The first transparent conductor layer 8 (18) is formed by any method. A predetermined amount of an acrylate-based transparent photocurable insulating resin 5 (15) is applied to a predetermined position of the translucent substrate 1 (11) by a stamping method, a screen printing method, or the like, and the semiconductor image sensor chip 3 is formed thereon. (13) to electrode 4 (1
4) is arranged face down so as to abut a predetermined circuit conductor layer 2 (12). Thereafter, while applying a predetermined pressure from above the semiconductor image sensor chip 3 (13), the transparent light-curable insulating resin 5 (15) is applied to the transparent substrate 1 (15).
Ultraviolet irradiation is performed through (11) to cure and complete the mounting. Further, a resin such as transparent silicone is applied thereon with a dispenser or the like to form a protective layer 6 (16).

In this image sensor, the light receiving element 7 (17) detects light information through the transparent substrate 1 (11) and the transparent light-curable insulating resin 5 (15), and converts this into an electric signal. It has become.

As the transparent photo-curable insulating resin 5 (15), a urethane acrylate-based or epoxy acrylate-based ultraviolet-curable resin is preferable from the viewpoint of adhesiveness and photosensitivity.

When the image sensor having the structure shown in FIGS. 1 and 2 is formed, a polyarylate film is used for the light-transmitting substrate 1 (11), and a copper foil is adhered thereon, and the circuit conductor layer is formed by photolithography. 2 (12) was formed.

The first transparent conductor layer 8 (18) and FIG.
For the transparent insulating layer 19, a wear-resistant resin such as a nylon-based resin or a urethane-based resin is selected, and the second transparent conductor layer 20 obtained by mixing a transparent conductive fine powder such as tin oxide with the binder resin of FIG.
Is provided on the back surface of the light-transmitting substrate 1 (11), grounding the ground improves the antistatic and abrasion resistance dramatically.

FIG. 3 is a side sectional view of a complete contact type image sensor unit according to an embodiment of the third invention. 31 is a light source (LED array) for illuminating the original 30, 21 is a translucent substrate, 22 is a circuit conductor layer formed on the surface of the translucent substrate, 23 is an image sensor chip used as a semiconductor element, and 24 is Electrodes provided on the semiconductor image sensor chip 23, 25 is a transparent light-curing insulating resin for mounting the semiconductor image sensor chip 23 on the translucent substrate 21, and 26 is a transparent resin for protecting the semiconductor image sensor chip 23. A protective layer, 27 is a light receiving element provided on the semiconductor image sensor chip 23, 28 is a first transparent conductor layer provided on the back surface of the translucent substrate 11, and 29 is provided on the back surface of the first transparent conductor layer 28. The second transparent conductor layer 30 is a document to be read.

The full-contact image sensor unit shown in FIG. 3 uses the LED array from above with the back surface of the second transparent conductor layer on the back surface of the light-transmitting substrate of the full-contact image sensor shown in FIG. The original is illuminated through the transparent protective layer, the transparent light-curable insulating resin, the light-transmitting substrate and the first and second transparent conductor layers, and light information from the original is transmitted to the first and second transparent conductor layers, The light guides directly to the light receiving element through the substrate and the transparent light-curable insulating resin to read the information of the document.
At this time, the thickness of the light-transmitting substrate is 25 μm to 200 μm.
Using a thin polyarylate film of about m, optical information from an original can be read at a high resolution without light crosstalk without a lens system (MTF value 60% (4 lp
/ Mm)), and at the same time, the size of the image sensor unit itself could be significantly reduced. Further, by providing a conductive layer on the back surface of the light-transmitting substrate and grounding the conductive layer, it is possible to eliminate static electricity generated by rubbing of the original and reduce noise. Furthermore, light transfer efficiency is 2-3 times better than using a conventional lens system.
Approximately twice as much, contributing to the cost reduction of the light source (LED array).

The semiconductor image sensor chip used here employs a phototransistor as a light receiving element, and the scanning circuit employs a bipolar IC chip using a thyristor shift register.

[0021]

As described above, according to the present invention, the wiring (wire bonding) operation of the semiconductor image sensor element by the fine metal wire is not performed, and the semiconductor element is not formed with the bump electrode and the circuit conductor layer is formed. It is possible to provide an inexpensive fully-contact image sensor that can be mounted with high reliability on a light-transmitting substrate provided with.

Further, in the image sensor unit of the present invention, an original can be read very simply, compactly and at low cost.

[Brief description of the drawings]

FIG. 1A is a front cross-sectional view of a complete contact image sensor according to an embodiment of the first invention; FIG. 1B is a side cross-sectional view of a complete contact image sensor according to an embodiment of the first invention;

FIG. 2A is a front cross-sectional view of a full contact image sensor according to an embodiment of the second invention; FIG. 2B is a side cross-sectional view of a full contact image sensor according to the embodiment of the second invention;

FIG. 3 is a front sectional view of a complete contact image sensor unit according to an embodiment of the third invention;

FIG. 4 is a configuration diagram of a conventional image sensor.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 translucent substrate 2 circuit conductor layer 3 semiconductor image sensor chip 4 electrode 5 transparent photocurable insulating resin 6 transparent protective layer 7 light receiving element 8 first transparent conductor layer 9 second transparent conductor layer 11 translucent substrate 12 circuit conductor Layer 13 Semiconductor image sensor chip 14 Electrode 15 Transparent light-curing insulating resin 16 Transparent protective film 17 Light receiving element 18 First transparent conductor layer 19 Transparent insulation layer 20 Second transparent conductor layer 21 Translucent substrate 22 Circuit conductor layer 23 Semiconductor image Sensor chip 24 Electrode 25 Transparent light-curing insulating resin 26 Transparent protective layer 27 Light receiving element 28 First transparent conductor layer 29 Second transparent conductor layer 30 Document 31 Light source (LED array) 32 Light receiving element 33 Sealing glass 34 Focusing rod lens Array 35 LED array 36 Document 37 Holder 38 Circuit conductor layer 39 Electrode 40 Fine metal wire 41 Board 42 Semiconductor image sensor chip

Claims (3)

(57) [Claims] 1. A light-transmitting substrate having a circuit conductor layer formed on a surface thereof, and a semiconductor element having a light-receiving element mounted on the surface of the light-transmitting substrate via a transparent photocurable insulating resin. The semiconductor element is face-down, and has a structure in which an extraction electrode formed on the element is in contact with the circuit conductor layer.On the back surface of the light-transmitting substrate, a first transparent conductor layer is further provided. the rear surface of the first transparent conductive layer, the sheet resistance has provided a large second transparent conductive layer from the first transparent conductive layer, the second transparent conductor layer is a conductor particles in an insulating resin
A perfect contact type image sensor formed by diffusing 2. A light-transmitting substrate having a circuit conductor layer formed on a surface thereof, and a semiconductor element having a light-receiving element mounted on the surface of the light-transmitting substrate via a transparent photocurable insulating resin. The semiconductor element is face-down, and has a structure in which an extraction electrode formed on the element is in contact with the circuit conductor layer.On the back surface of the light-transmitting substrate, a first transparent conductor layer is further provided. A transparent insulating layer is provided on the back surface of the first transparent conductive layer, and a second transparent conductive layer is provided on the back surface of the transparent insulating layer.
A perfect contact type image sensor formed by diffusing body particles . 3. The light-transmitting substrate according to claim 1 , wherein a light source is mounted on a side of the light-transmitting substrate on which the semiconductor element is mounted, at a position close to the semiconductor element. complete contact type image sensor unit in which the original contact surface and the other surface of the substrate.