JPH04305974A - Image sensor - Google Patents

Abstract

PURPOSE:To provide inexpensive image sensors having high reliability by making it possible to mount semiconductor image sensor chips on boards easily and in a short time, without conventional complex wiring (wire bonding) work by the use of thin metal wire and without the formation of bump electrodes. CONSTITUTION:The surface of a translucent board 11 on which a circuit conductor layer 12 is formed is made rough, and a semiconductor image sensor chip 13 having photodetectors 17 is mounted with the face downward on this surface through the medium of photosetting insulating resin 15 so that its electrodes 14 may be made to abut on the circuit conductor layer 12, and an image sensor is constituted. And it becomes possible to manufacture inexpensive and compact image sensors having high reliability easily and in a short time.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image sensor that converts an optical image into an electrical signal.

0002

2. Description of the Related Art Conventionally, in an image sensor, as shown in FIG. 3, a semiconductor element 21 including a light-receiving element 22 is fixed onto a substrate 20 on which conductor wiring is formed using a conductive adhesive, and an electrode 25 of the semiconductor and a circuit conductor are connected to each other. The layer 24 is connected with a thin metal wire made of gold, aluminum, or the like by a wire bonding method, and then sealed with a transparent glass sealing material from above.

0003

[Problems to be Solved by the Invention] However, the above configuration requires complicated steps such as wire bonding.

0004

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a semiconductor element having a light-receiving element on a light-transmitting substrate on which a circuit conductor layer is formed, via a photocurable insulating resin. An image sensor is created by mounting the device face down so that the lead-out electrode formed on the device comes into contact with the circuit conductor layer. Here,
This is to roughen the surface of the light-transmitting substrate.

[0005]

[Operation] The present invention improves the adhesion between the photocurable insulating resin and the light-transmitting substrate, increases the adhesion between the semiconductor element and the light-transmitting substrate, and improves the reliability of the image sensor with the above-described structure. It is something that makes you

[0006]

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.

FIG. 1 is a front sectional view of an image sensor according to an embodiment of the present invention, and FIG. 2 is a side sectional view of an image sensor according to an embodiment of the present invention. 11 is a transparent substrate, 12 is a circuit conductor layer formed on the surface of the transparent substrate 11, 13 is an image sensor chip used as a semiconductor element, 14 is an electrode provided on the image sensor chip 13, 15 is a semiconductor image sensor chip 13
16 is a protective layer for protecting the semiconductor image sensor chip 13 , 17 is a transparent photocurable insulating resin for mounting on the transparent substrate 11 , and 17 is the semiconductor image sensor chip 1
This is the light receiving element provided in 3.

A method of manufacturing the image sensor configured as described above will be explained. First, using a semiconductor process, a light receiving element 17 such as a phototransistor or photodiode and a CCD or MO are mounted on a single crystal silicon substrate (wafer).
S, a device equipped with an access circuit (not shown) such as a bipolar IC is made. Each electrode 14 has a structure that protrudes from the wafer surface by several micrometers by using a two-layer Al wiring process and a sputtering method. Thereafter, this wafer is cut using high-precision dicing technology to produce semiconductor image sensor chips 13. Next, a transparent substrate 1 such as polyarylate (PA), polyethersulfone (PES), or polyethylene terephthalate (PET)
1, a metal such as copper is formed using a vapor deposition method, a sputtering method, or a foil, and later a circuit conductor layer 12 is formed using a photolithography method. A predetermined amount of acrylate-based transparent photocurable insulating resin 15 is applied to a predetermined position of the translucent substrate 11 by a stamping method, screen printing method, etc.
A semiconductor image sensor chip 13 is placed thereon face down so that the electrode 14 is in contact with a predetermined circuit conductor layer 12. Thereafter, while applying pressure from above the semiconductor image sensor chip 13, the transparent photocurable insulating resin 15 is irradiated with ultraviolet light through the transparent substrate 11 to be cured, completing the mounting. Further, a resin such as silicone is applied thereon using a dispenser or the like to form a protective layer 16.

In this image sensor, a light receiving element 17 detects optical information through a transparent substrate 11 and a transparent photocurable insulating resin 15, and converts this into an electrical signal.

As the transparent photocurable insulating resin 15, urethane acrylate-based or epoxy acrylate-based ultraviolet curable resins are preferred from the viewpoint of adhesiveness and photosensitivity.

When producing the image sensor having the structure shown in FIG. 1, a polyarylate film was used as the transparent substrate 11, copper foil was pasted thereon, and a circuit conductor layer was formed by photolithography.

[0012] By roughening the surface of this polyarylate film, the adhesiveness with the transparent photocurable insulating resin 15 is improved, and it is
), low temperature (-40℃) and thermal shock (-40℃~+85℃)
) and other tests, dramatically improving reliability as an image sensor and making it possible to put it into practical use.

[0013]

As described above, according to the present invention, a semiconductor image sensor element can be connected to a circuit conductor layer without wiring (wire bonding) using thin metal wires, and without forming bump electrodes in a semiconductor element. It is possible to provide an inexpensive image sensor that can be mounted with high reliability on a light-transmitting substrate provided with an image sensor.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of an image sensor in an embodiment of the present invention.

FIG. 2 is a side sectional view of an image sensor in an embodiment of the present invention.

FIG. 3 is a cross-sectional view of a conventional image sensor.

[Explanation of symbols]

11 Transparent substrate 12 Circuit conductor layer 13 Semiconductor image sensor chip 14
Electrode 15 Transparent photocurable insulating resin 16 Protective film 17 Light receiving element 20 Substrate 21 Semiconductor image sensor chip 22
Light receiving element 23 Sealing glass 24 Circuit conductor layer 25 Electrode 26 Fine metal wire

Claims (2)

[Claims] 1. A semiconductor device comprising: a light-transmitting substrate on which a circuit conductor layer is formed; and a semiconductor element having a light-receiving element mounted on the surface of the light-transmitting substrate via a photocurable insulating resin; An image sensor characterized in that 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. 2. The image sensor according to claim 1, wherein the surface of the light-transmitting substrate is roughened.