JPH08278466A - Imaging device - Google Patents

Abstract

(57) [Abstract] [Purpose] Production capable of accurately forming a latent image with high image quality on a photoconductor or generating an accurate electric signal corresponding to external image information in a solid-state image sensor array. It is to provide an inexpensive imaging device with good performance. An image device in which a lens member 3 including a plurality of lenses 7 and a base plate 1 on which a large number of image element arrays 2 are linearly arranged and mounted are fixed together. It has a plurality of electrodes 2b on its surface, and each electrode 2b is attached to the electrode wiring 1a on the surface of the base plate 1 via a solder powder 5 dispersed and mixed in a thermoplastic resin 4 to form a flip chip. Connected by connection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus used in an image forming apparatus such as an optical printer head or an image reading apparatus such as an image sensor.

[0002]

2. Description of the Related Art A conventional image forming apparatus, for example, an image forming apparatus used in an image forming apparatus such as an optical printer head, usually has a lens made of a resin such as polycarbonate in which a plurality of lenses are linearly arranged and supported at predetermined intervals. A plate and a base plate made of a resin such as polycarbonate on which a large number of light emitting diode element arrays are linearly arranged and mounted;
It has a structure in which each lens and each light emitting diode element array are fixed side by side so as to have a one-to-one correspondence, and each light emitting diode element of each light emitting diode element array is individually selected according to an external electric signal. The light emitting diode element functions as an image forming apparatus by causing the light emitted from the light emitting diode element to form an image on an external photoconductor through a lens to form a latent image on the photoconductor.

A light-emitting diode element array linearly arranged and mounted on the base plate generally has 64 light-emitting diode elements linearly arranged therein, which is suitable for a B4 size image forming apparatus. When used, the 32 light emitting diode element arrays are mounted on the base plate so that each of the 32 light emitting diode element arrays has a one-to-one correspondence with each lens.

Further, in the light emitting diode element array linearly arranged and mounted on the base plate, each electrode thereof is electrically connected to an electrode wiring previously attached to the surface of the base plate through a bonding wire, By connecting the electrode wiring on the surface of the base plate to an external electric circuit, the light emitting diode element of each light emitting diode element array is connected to the external electric circuit via the electrode wiring and the bonding wire.

[0005]

However, in this conventional image device, each electrode of the light emitting diode element array is connected to the electrode wiring of the base plate through a bonding wire, and the number of electrodes of the light emitting diode element array is Since it is extremely large, it takes a long time to electrically connect the electrodes of the light-emitting diode element array to the electrode wiring of the base plate, and the manufacturing workability of the image device is poor, and the image device as a product has the disadvantages of being expensive. Was there.

In the above embodiment, the image forming apparatus used in the image forming apparatus such as the optical printer head has been described as an example. However, in the image reading apparatus such as the image sensor using the solid-state image sensor array, etc. The image device used has the same drawbacks.

Therefore, in order to solve the above-mentioned drawbacks, the applicant of the present application flips each electrode formed in the vicinity of the light emitting / receiving area of the image element array onto the electrode wiring pre-deposited on the surface of the base plate by soldering. We proposed an image device connected by connection.

According to such an image device, since the electrodes of the image element array are connected to the electrode wirings attached to the base plate by flip chip connection, even if the number of electrodes of the image element array is large, all of them are the electrode wirings of the base plate. At the same time, they are electrically connected firmly, and as a result, the productivity and reliability of the image device are extremely excellent.

However, in this image device, since the distance between adjacent electrodes of each electrode formed in the vicinity of the light emitting / receiving area of the image element array is short, each electrode of the image element array is flipped to the electrode wiring of the base plate through the solder. When connecting by chip connection, a part of the solder flows out to the adjacent electrode side and electrically shorts the adjacent electrodes, and as a result, when used as an image forming apparatus, a predetermined amount of light is applied to the photoreceptor. Since it is impossible to irradiate light, a desired latent image cannot be formed, and when it is used as an image reading device, external image information is not accurately formed on the solid-state image sensor array, and external image information is not formed. It caused a drawback that it was impossible to read the information accurately.

[0010]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned drawbacks, and an object thereof is to irradiate the surface of a photoconductor with light emitted from a light emitting diode element through a lens to accurately form a latent image of high image quality on the photoconductor. Productivity that can be formed on the solid-state image sensor array or can accurately form an external image information on the solid-state image sensor array through a lens and generate an accurate electric signal corresponding to the external image information on the solid-state image sensor array. To provide a good and inexpensive imaging device.

[0011]

SUMMARY OF THE INVENTION The present invention is an image device in which a lens member consisting of a plurality of lenses and a base plate on which a large number of image element arrays are linearly arranged and mounted are fixed together. The image element array has a plurality of electrodes on its surface, and each electrode is attached to the electrode wiring adhered to the surface of the base plate by flip-chip connection via solder powder dispersed and mixed in the thermoplastic resin. It is characterized by being connected.

[0012]

According to the image device of the present invention, the electrodes of the image element array are electrically connected to the electrode wirings attached to the base plate by flip-chip connection. Therefore, even if the number of electrodes of each image element array is extremely large, Everything is electrically connected to the electrode wiring of the base plate at once and firmly, and as a result, the productivity of the image device becomes extremely excellent, and the image device as a product becomes inexpensive.

According to the image device of the present invention, each electrode of each image element array is connected to each electrode wiring formed on the surface of the base plate through the solder powder dispersed and mixed in the thermoplastic resin. Therefore, even if a part of the solder tries to flow out to the adjacent electrode side, the flow-out is effectively blocked by the thermoplastic resin, and as a result, the electrical insulation between the electrodes of the image element array is maintained and the image forming apparatus is used. When used, it is possible to irradiate the photoconductor with a predetermined light at all times, so that a desired latent image can be accurately and clearly formed on the photoconductor, and when used as an image reading device, It becomes possible to accurately form the external image information on the solid-state image pickup device array and to make the solid-state image pickup device array read the external image information extremely accurately.

[0014]

The present invention will now be described in detail with reference to the accompanying drawings. 1 to 4 show an embodiment in which the image device of the present invention is adopted in an optical printer head as an image forming device, 1 is a base plate, 2 is a light emitting diode element array, and 3 is a lens member.

The base plate 1 is made of an electrically insulating material such as aluminum oxide sintered body, crystallized glass, quartz, or glass epoxy resin, and a plurality of light emitting diode element arrays 2 are linearly arranged and mounted on the lower surface thereof. ing.

The base plate 1 functions as a supporting member for supporting the light emitting diode element array 2, and as shown in FIG. 3, the electrode wiring 1a attached to the base plate 1 is flipped with each electrode 2b of each light emitting diode element array 2. The light emitting diode element arrays 2 are arrayed and mounted on the lower surface of the base plate 1 by chip connection. In this case, even if the total number of the electrodes 2b of each light emitting diode element array 2 is extremely large, all of the electrodes 2b are attached to the electrode wiring 1a attached to the surface of the base plate 1 at once.
In addition, since the electrodes 2b of the light emitting diode element array 2 and the electrode wiring 1a of the base plate 1 can be electrically connected to each other in a very short time because of the strong electrical connection
The workability and productivity of assembling the image device are greatly improved.

The base plate 1 is made of an aluminum oxide sintered body, crystallized glass, quartz, glass epoxy resin or the like. For example, when it is made of an opaque material such as an aluminum oxide sintered body, an opening is formed in the central portion. The opening is provided as a window portion for forming a light passage between the light emitting diode element array 2 and the lens 7 of the lens member 3 described later, and when it is made of a transparent material such as crystallized glass or quartz, The central area is the same as the light emitting diode element array 2
And a lens 7 to form a light passage.

When the base plate 1 is made of an opaque material such as an aluminum oxide sintered body, the center portion of the base plate 1 is perforated using a laser or the like so that the light emitted from the light emitting diode element array 2 and the lens 7 is lightened. An opening serving as a window that serves as a passage is formed in a predetermined shape.

Further, the electrode wiring 1a previously deposited on the surface of the base plate 1 is a light emitting diode element array 2
Each electrode 2b of 1 is connected to an external electric circuit, and a conductive material such as aluminum or copper is deposited on the surface of the base plate 1 by a plating method, a vapor deposition method, a sputtering method, or the like to have a predetermined thickness. It is processed into a predetermined pattern by an etching method, and then the surface is plated with nickel and gold to be adhered and formed on the surface of the base plate 1.

Further, as a method of flip-chip connecting each electrode 2b of each light-emitting diode element array 2 to the electrode wiring 1a attached to the base plate 1, as shown in FIG.
As shown in FIG. 1, the light emitting diode element array 2 is provided on the upper surface of the base plate 1, and the solder powder 5 is provided between the thermoplastic resin 4 and
The adhesive sheet A made of dispersed and mixed is sandwiched, and the electrode wiring 1a attached to the base plate 1 and the respective electrodes 2b of the light emitting diode element array 2 are placed so as to face each other, and then the light emitting diode is mounted. The element array 2 is heated to a temperature of about 180 ° C. while being pressed to the base plate 1 side, and is present in a region of the adhesive sheet A located between the electrode wiring 1 a of the base plate 1 and each electrode 2 b of the light emitting diode element array 2. This is performed by pressing only the solder particles 5 to be contacted with each other, heating and melting the solder particles 5, and connecting the electrode wiring 1a of the base plate 1 and each electrode 2b of the light emitting diode element array 2 with the heated and melted solder. In this case, the solder connecting the electrodes 2b of the light emitting diode element arrays 2 and the wiring conductors 1a attached to the surface of the base plate 1 will not flow out even if a part of the solder tries to flow out to the adjacent electrode side. It is effectively blocked by the thermoplastic resin, and as a result, the electrodes 2b of the light emitting diode element array 2 are kept electrically insulated, which makes it possible to irradiate the external photoconductor P with predetermined light at all times. A desired latent image can be accurately and clearly formed on the photoconductor P.

The adhesive sheet A is made of a thermoplastic elastomer such as vinyl chloride resin, ionomer resin, polyethylene, polyurethane, or polyamide in which a solvent is added. It is formed by mixing.

The base plate 1 includes a plurality of light emitting diode elements 2a arranged and mounted on the base plate 1, and the light emitting diode elements 2a individually and selectively emit light in response to an external electric signal. By irradiating the surface of the photoconductor P with the emitted light, a latent image for forming an image is formed on the photoconductor P.

The light emitting diode element 2a is a GaAsP type,
GaP-based light-emitting diodes are used.For example, in the case of GaAsP-based light-emitting diodes, first, the GaAs substrate is heated to a high temperature in a furnace and AsH ₃ (arsine) and PH ₃ (
A single crystal of n-type semiconductor GaAsP (gallium-arsenic-phosphorus) is grown on the substrate surface by contacting a gas containing an appropriate amount of phosphine) and Ga (gallium), and then Si ₃ is grown on the GaAsP single crystal surface.
A windowed film of N ₄ (silicon nitride) is deposited, and Zn (zinc) gas is exposed to the window to form an n-type semiconductor GaAsP.
Zn is diffused into a part of the single crystal to form a p-type semiconductor, and pn
It is formed by providing a bond.

In the case of a B4 size optical printer head, the number of the light emitting diode elements 2a is 2048 (8 per 1 mm).
Are arranged in a straight line. Specifically, 32 light emitting diode element arrays 2 each having 64 light emitting diode elements 2a as one unit are arranged in a straight line to obtain 2048 light emitting diode elements 2a. Are arrayed and mounted on the base plate 1.

On the other hand, the base plate 1 on which the light emitting diode element array 2 is arranged and mounted is provided with a lens member 3 on the upper side thereof at a predetermined distance, and the lens member 3 has a plurality of holes formed in a straight line. The lens plate 6 is arranged and formed, and the lens 7 is adhered and fixed to the lens plate 6 with an adhesive such as resin so as to close the holes.

The lens plate 6 of the lens member 3 functions as a supporting member for supporting a plurality of lenses 7 on the upper surface at a predetermined interval, and the holes allow the light emitted from each light emitting diode element 2a of the light emitting diode element array 2 to be emitted. It has the function of transmitting light to the lens 7.

Each lens 7 supported by the lens plate 6 has a function of irradiating the surface of the photoconductor P with light emitted from each diode element 2a, and is made of a transparent resin such as acrylic resin or polycarbonate resin, or glass. A lens formed of a transparent inorganic material is preferably used.

Each lens 7 is linearly adhered to the lens plate 6 at a predetermined interval by adhering a part of the outer surface to the lens plate 6 with an epoxy resin adhesive.

Furthermore, the base plate 1 on which the light emitting diode element array 2 is mounted and the lens member 3 having a plurality of lenses 7 are fixed to the spacers 8, so that each light emitting diode element array 2 and each lens 7 are fixed.
And are placed side by side so as to correspond one-to-one with a predetermined distance.

The spacer 8 has a first alignment reference surface 8a on the upper portion thereof and a second alignment reference surface 8b on the lower portion thereof, and the first alignment reference surface 8a of the spacers 8, 8 is formed.
The lower surface of the lens plate 6 and the second alignment reference surface 8
The light emitting diode element array 2 and the lenses 7 are fixed by abutting and fixing the outer peripheral portion of the upper surface of the base plate 1 to b.
There is a one-to-one correspondence with a certain distance between and. Thus, according to the image device of the present invention, each light emitting diode element 2a is individually and selectively emitted by applying a predetermined electric power to each light emitting diode element 2a arranged and mounted on the base plate 1. The light emitted by 2a is irradiated onto the surface of the external photoconductor P via the lens 7 of the lens member 3 to form an image, and a predetermined latent image is formed on the photoconductor P to function as an image forming apparatus.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. For example, in the above-mentioned embodiments, the lens member 3 is used. Although the lens plate 6 supporting a plurality of lenses 7 is used, it may be replaced with a so-called selfoc lens in which a large number of rod-shaped self-focusing lenses are arranged.

In the above-described embodiment, the case of using it in an image forming apparatus such as an optical printer head has been described as an example. Instead of a solid-state image sensor array instead of a light emitting diode element array, an image reading apparatus such as an image sensor may be used. Can also be used.

[0033]

According to the image device of the present invention, since the electrodes of the image element array are electrically connected to the electrode wirings attached to the base plate by flip chip connection, the number of electrodes of each image element array is extremely large. All of them will be electrically connected to the electrode wiring of the base plate at once and firmly, and as a result, the productivity of the image device will be extremely excellent, and the image device as a product will be inexpensive.

Further, according to the image device of the present invention, each electrode of each image element array is connected to each electrode wiring formed on the surface of the base plate through the solder powder dispersed and mixed in the thermoplastic resin. Therefore, even if a part of the solder tries to flow out to the adjacent electrode side, the flow-out is effectively blocked by the thermoplastic resin, and as a result, the electrical insulation between the electrodes of the image element array is maintained and the image forming apparatus is used. When used, it is possible to irradiate the photoconductor with a predetermined light at all times, so that a desired latent image can be accurately and clearly formed on the photoconductor, and when used as an image reading device, It becomes possible to accurately form the external image information on the solid-state image pickup device array and to make the solid-state image pickup device array read the external image information extremely accurately.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment in which an image forming apparatus of the present invention is applied to an optical printer head as an image forming apparatus.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is a partially enlarged cross-sectional view for explaining a connection state between an electrode wiring of a base plate and an electrode of an image element array.

FIG. 4 is a partial enlarged cross-sectional view for explaining a state where the electrode wiring of the base plate and the electrodes of the image element array are flip-chip connected.

[Explanation of symbols]

 1 ... Base plate 2 ... Light emitting diode element array 2a ... Light emitting diode element 2b ... Electrode 3 ... Lens member 4 ...・ Thermoplastic resin 5 ・ ・ ・ ・ ・ ・ ・ ・ Solder powder 6 ・ ・ ・ ・ Lens plate 7 ・ ・ ・ ・ Lens P ・ ・ ・ ・ Photoconductor

Claims (1)

[Claims] 1. An image device in which a lens member including a plurality of lenses and a base plate on which a large number of image element arrays are linearly arranged and mounted are fixed together, and each image element array is provided on the surface thereof. It has a plurality of electrodes, and each of the electrodes is connected to the electrode wiring attached to the surface of the base plate by flip-chip connection via solder powder dispersed and mixed in the thermoplastic resin. Image device.