JPH01289279A - Contact-type image sensor - Google Patents

Abstract

PURPOSE:To make a device small-sized and to reduce a cost of materials by a method therein all components constituting an image sensor are mounted on both faces of one substrate. CONSTITUTION:Drive circuit components 7, signal processing circuit components 8 and a connector 9 are solderd to a substrate 1 having a wiring pattern 2. Then, a silicone-based adhesive 4 is coated on an opposite face of the substrate 1, an image sensor chip 3 where a photodetector and a drive element have been formed is placed on it and the wiring pattern 2 and electrodes on the image sensor chips 3 are bonded by using gold wires 5 or the like. By this setup, it is possible to obtain a small-sized and low-cost contact-type image sensor.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a contact type image sensor that reads manuscript information with high sensitivity, high resolution, and high speed change.

Image sensors, which are a departure from conventional technology, require not only the image sensor section, but also electrical components as a drive section to ensure consistency between the image sensor section and the device side, and amplify or serially convert the optical signal from the image sensor section. It is composed of electrical parts as a signal processing section and a connector for electrical connection with the device.

A contact-type image sensor having the above-mentioned components may be mounted on a ceramic substrate or a glass substrate bearing the Hobo stamp Jl.
There is a configuration in which an image sensor section with multiple configurations is provided on a single crystal Si substrate, the electrical components and connectors are provided on a glass epoxy substrate, and the two substrates are electrically connected using a lead frame. .

Problems to be Solved by the Invention However, with the above configuration, the external dimensions are large, so the advantage of being able to downsize the device using a contact type image sensor cannot be utilized, and 2. A separate substrate is required. Therefore, the material cost was high.

An object of the present invention is to provide a compact and inexpensive contact type image sensor with high sensitivity, high resolution, and high speed change. In other words, it is possible to mount all the components constituting the contact type image sensor on the 1st modification board.

Means for Solving the Problems In order to solve the above problems, the contact image sensor of the present invention includes a plurality of light-receiving elements formed of a thin film or single crystal 8i on one side of a flat plate with wiring on both sides, and these light-receiving elements. An image sensor section consisting of a driving element for reading an optical signal from the image sensor section is provided, and on the opposite side of the flat plate, at least an electrical component for driving the image sensor section, an electrical component for processing the optical signal from the image sensor section, and a device and an electrical connection are provided. The configuration is such that at least one of the connectors connected to the connector is provided.

By adopting a configuration that exceeds the functions, all the components that make up the image sensor can be mounted on both sides of a single board, and the height of the contact type image sensor can be reduced.
By reducing the size of the device and using only one board.

Material costs can be reduced.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings.

11 to 4 are configuration diagrams of a contact type image sensor according to an embodiment of the present invention. In Figures 1 to 4, reference numeral 1 denotes a substrate made of a glass epoxy base material, and a copper wiring pattern 2 plated with gold is provided on one surface of the substrate. In the wiring pattern 2, the drive signal line of the image sensor section and the output signal line from the image sensor section are connected to each other by steel through holes. Reference numeral 3 designates an image sensor chip in which a light receiving element and a driving element are formed on single crystal silicon, and is fixed onto the substrate 1 with an adhesive 4. Electrodes within the image sensor chip 3 are connected to a gold-plated copper wiring pattern 2 by a gold wire 5. Reference numeral 6 is a transparent finger, which improves reliability without interfering with light entering the light receiving element within the image sensor chip 3. 7 is an IC that drives the image sensor section, a transistor, a resistor,
8 is a VLA circuit component consisting of a capacitor, etc., and 8 is an XC that performs amplification or serial conversion processing on the optical signal from the image sensor section. It is a signal processing circuit component consisting of a resistor, a core 7' sensor, etc. 9 is a connector for making electrical connection with the device.

A method for mounting the contact type image sensor configured as described above will be described below.

First, the copper wiring pattern 2 in which at least the bonding pad of the gold wire 5 is plated with gold as shown in FIGS.
Cream solder is applied onto a glass epoxy board 1 having a 300° C., and out of the g-movement rotating component 7 and the signal processing circuit component 8, only the surface mount components are mounted and flow soldering is performed at about 230° C. Next, the remaining components of the power circuit component 7 and the signal processing flK component 8 and the connector 9 are soldered together by hand.

After soldering the electrical components, apply a silicone adhesive 4 on the substrate 1 shown in FIGS. 1 to 4, place the image sensor chip 3 shown in FIG. 1
Cures at 50°C. At this time, although the thermal expansion coefficients of the image sensor chip 3 and the glass epoxy substrate 1 are different, the flexible silicon adhesive material relieves the stress caused by the combination of the thermal expansion coefficients.

Next, the gold-plated copper wiring pattern 2 on the substrate shown in FIG. 1 and the electrode on the image sensor chip 3 are bonded with a gold wire 5. At this time, by keeping the stage temperature below the curing temperature of the silicone adhesive 4,
This prevents deterioration of the silicon adhesive 4 and enables wire bonding.

Furthermore, the image sensor chip 3 is molded with acrylic-based, silicon-based, or epoxy-based Hideaki tai 6. At this time as well, the mold curing temperature was set to 4
By keeping the silicone adhesive below the curing temperature of
Curing is possible while preventing deterioration of properties.

In this example, glass epoxy is used as the material for the substrate 1, but ceramics such as alumina, or printed circuit board materials such as paper, epoxy, and phenol can also be used because they can alleviate the difference in thermal expansion coefficient. Is possible. Furthermore, in this example, an image sensor section formed of a multilayer film made of single-crystal silicon was used, but the same effect can be obtained by using an image sensor section formed of a thin film on glass or quartz. . Furthermore, in this embodiment, gold wire bonding was used for the electrical connection between the wiring pattern 2 on the substrate 1 and the image sensor section, but bonding using the film carrier method also requires soldering on the substrate 1 only locally. Since heating is used, it is possible to prevent deterioration of the silicone adhesive 4 and solder separation by keeping a sufficient distance between the silicone adhesive 4 and the electrical components on the back side, so it can be used.

Effects of the Invention As is clear from the above description, according to the present invention, a contact type image sensor with high sensitivity, high resolution, and high speed can be provided in a small size and at low cost, and it is possible to provide an image sensor for input devices of information processing equipment. It is extremely effective as a sensor, and its imperial effect is significant.

[Brief explanation of the drawing]

1 to 4 are a plan view, a front view, a bottom view, and a sectional side view showing the configuration of a contact type image sensor according to an embodiment of the present invention. 1...Substrate, 2...Wiring pattern applied on both sides of the board, 3...Image sensor chip on which a light receiving element and a driving element are formed, 4...・Silicone adhesive, 6...Gold wire, 6...
Transparent resin for molding, 7... Drive circuit parts, 8
...Signal processing circuit parts, 9...Connector.

Claims (1)

[Claims] On one side of a flat plate with wiring on both sides, an image sensor section consisting of a plurality of light receiving elements formed of a thin film or single crystal Si and a driving element for reading out the optical signal of each element is provided, and on the opposite side of the flat plate, A contact image sensor comprising at least one of an electrical component that drives the image sensor section, an electrical component that processes an optical signal from the image sensor section, or a connector that electrically connects to a device.