JPH08162622A - Image device - Google Patents

Abstract

PURPOSE: To provide an image device which makes it possible to make light emitting diode elements emit light according to external electrical signals with accuracy by electrically connecting individual electrodes of an image element away surely to individual electrode wirings, and the common electrode to the common electrode wiring or to take electrical signals out of a solid-state imaging element array in accordance with external image information with accuracy. CONSTITUTION: The imaging device consists of a lens plate 3 that supports a plurality of lenses 3a; and a base plate 1 on which a large number of image element arrays 2 are arranged and mounted by flip chip connection. The lens plate 3 and the base plate 1 are secured with a spacer 5 in between in such a way that the individual lenses 3a and the individual image element arrays 2 will correspond to each other in a one-to-one relationship. A template 4 of which the thermal expansion coefficient is -3×10<-6> / deg.C-1×10<-6> / deg.C (150-250 deg.C), is installed on the surface of the base plate 1 in order to control the positions of the image element arrays 2.

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. The plate and the base plate made of aluminum oxide sintered body or glass in which a large number of light emitting diode element arrays are linearly mounted are arranged so that each lens and each light emitting diode element array have a one-to-one correspondence. It has a fixed structure, and each light emitting diode element of each light emitting diode element array is caused to selectively emit light in response to an external electrical signal, and the light emitted by the light emitting diode element is passed through a lens. An image is formed on an external photoconductor, and a latent image is formed on the photoconductor to function as an image forming apparatus.

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 each light emitting diode element of each light emitting diode element array linearly 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 the external electric circuit, each light emitting diode element 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 invention previously applied electrode wiring to the surface of the base plate in advance and connected each electrode of the image element array to the electrode wiring by the flip-chip connection method. An image device was proposed.

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 the flip chip connection method, even if the number of electrodes of the image element array is extremely large, all of them are of the base plate. The electric wiring is electrically connected at once and firmly, and as a result, the productivity and reliability of the image device are extremely excellent.

However, in this image device, when the electrodes of the image element array are connected to the electrode wirings of the base plate by the flip chip connection method, the number of electrodes of the image element array is large and the shape of each electrode is extremely small. It is difficult to accurately contact with a predetermined electrode wiring and erroneous connection easily occurs, and when erroneous connection occurs, a desired latent image cannot be formed on the photoconductor when used as an image forming apparatus, In addition, when used as an image reading device, it has a drawback that the external image information cannot be read accurately.

In order to further solve the above-mentioned drawbacks, a template for regulating the position of the image element array is attached on the base plate, and each electrode of the image element array is accurately applied to the electrode wiring of the base plate by the template. Although it may be considered that the template has a predetermined coefficient of thermal expansion, thermal expansion occurs when the electrodes of the image element array are connected to the electrode wiring of the base plate by the flip-chip connection method, and as a result, the image The electrodes of the element array cannot be accurately brought into contact with the electrode wiring of the base plate, and the same drawbacks as those of the above image device are induced.

[0011]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above drawbacks, and an object thereof is to accurately connect each electrode of an image element array to a predetermined electrode wiring of a base plate for use as an image forming apparatus. Can accurately form a latent image with high image quality on the photoconductor, and when used as an image reading device, can generate an accurate electric signal corresponding to external image information with high productivity, An object is to provide an inexpensive image device.

[0012]

The present invention comprises a lens plate for supporting a plurality of lenses, and a base plate in which a large number of image element arrays are arrayed and mounted by a flip chip connection method, and the lens plate and the base plate are provided. Each lens and each image element array are separated by a spacer.
An image device fixed side-by-side so as to correspond to a pair 1, and having a thermal expansion coefficient of -3 x 10 ^-6 / ° C to 1 x 10 ^-6 / ° C. that regulates the position of the image element array on the surface of the base plate.
It is characterized in that a template (150 to 250 ° C) is attached.

Further, the present invention comprises a lens plate supporting a plurality of lenses and a base plate in which a large number of image element arrays are arrayed and mounted by a flip chip connection method, and each lens plate and the base plate are interposed by a spacer. An image device in which the image elements array and each image element array are fixed side by side so as to correspond to each other in a one-to-one correspondence. It is characterized in that a shielding layer is applied.

[0014]

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 the flip-chip connection method. Therefore, even if the number of electrodes of the 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.

Further, according to the image device of the present invention, the coefficient of thermal expansion for regulating the position of the image element array on the surface of the base plate is −3 × 10 ⁻⁶ / ° C. to 1 × 10 ⁻⁶ / ° C. (150 to 250 ° C.). ) Or the template for controlling the position of the image element array is attached to the surface of the base plate and the heat shield layer is attached to the surface of the template, so that the electrodes of the image element array are attached to the base plate. When connecting to the electrode wiring by the flip chip connection method,
The position of the image element array is accurately positioned by the template, and the electrodes of the image element array can be easily and accurately electrically connected to the predetermined electrode wiring of the base plate.

[0016]

The present invention will now be described in detail with reference to the accompanying drawings. 1 to 3 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 plate.

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

The base plate 1 acts as a supporting member for supporting the light emitting diode element array 2, and as shown in FIG. 3, the electrodes 2b of each light emitting diode element array 2 are flipped to the electrode wiring 1a attached to the base plate 1. Chip connection, specifically, the light emitting diode element array 2 on the upper surface of the base plate 1, so that the electrode wiring 1a attached to the base plate 1 and the respective electrodes 2b of the light emitting diode element array 2 face each other with solder interposed therebetween. After that, the solder is heated and melted, and each electrode wiring 1a of the base plate 1 and each electrode 2b of the light emitting diode element array 2 are solder-bonded to each light emitting diode element array 2 of the base plate 1. It is mounted on the bottom surface in an array. Also, at this time, even if the total number of the electrodes 2b of each light emitting diode element array 2 is large, all of them are the base plate 1
The electrodes 2a of the light emitting diode element array 2 and the electrodes 1a of the base plate 1 are electrically connected to the electrodes 1a of the light emitting diode array 2 at once and firmly electrically connected to the electrodes 1a attached to the surface of Can be performed in an extremely short time,
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. When it is made of an opaque material such as an aluminum oxide sintered body, an opening is formed in the central portion. In the case where the opening is provided as a window portion for forming a light path between the light emitting diode element array 2 and the lens 3a supported by the lens plate 3 described later, and is made of a transparent material such as crystallized glass or quartz. The central region of the light-emitting diode itself serves as a window for forming a light passage between the light-emitting diode element array 2 and the lens 3a.

When the base plate 1 is made of an opaque material such as an aluminum oxide sintered body, the center plate of the base plate 1 is perforated using a laser or the like so that the light emitted from each light emitting diode element 2a is made into a lens.
An opening is formed in a predetermined shape as a window portion through which the light is transmitted to the 3a side.

Further, the electrode wiring 1a previously deposited on the surface of the base plate 1 functions to connect each electrode 2b of the light emitting diode element array 2 to an external electric circuit, and the surface of the base plate 1 is made of aluminum, copper or the like. A base plate is formed by applying a conductive material to a predetermined thickness by plating, vapor deposition, sputtering, etc., processing this into a predetermined pattern by etching, and then nickel plating, gold plating, or solder plating on the surface. 1 is deposited on the surface.

The base plate 1 is also fitted with a template 4 for regulating the position of the light emitting diode element array 2 on the surface to which the electrode wiring 1a is attached.

Since the template 4 regulates the position of the light emitting diode element array 2, when the electrode 2b of the light emitting diode element array 2 is connected to the electrode wiring 1a of the base plate 1 by flip chip connection, Even if there are many electrodes 2b, all of them can be brought into contact with the predetermined electrode wiring 1a of the base plate 1 easily and accurately, and as a result, each electrode 2b of the light emitting diode element array 2 can be accurately contacted with the predetermined electrode wiring 1a, Since the electric connection can be made firmly, the productivity and reliability of the image device are extremely excellent.

The template 4 has a coefficient of thermal expansion of −
3 × 10 ^-6 / ℃ ~ 1 × 10 ^-6 / ℃ (150 ~ 250 ℃) material, concretely consisting of steel or liquid crystal polymer, etc. Since the electrodes 2b of each light emitting diode element array 2 are connected to the electrode wiring 1a of the base plate 1 by the flip-chip connection method, the template 4 does not expand thermally even if heat is applied. Element array
2 can be accurately positioned, and as a result, the electrode 2b of each light emitting diode element array 2 can be easily and accurately electrically connected to the predetermined electrode wiring 1a of the base plate 1.

The template 4 may be formed by applying a heat shield layer 4b on the surface of a template substrate 4a as shown in FIG. In this case, the electrode 2b of each light emitting diode element array 2 is connected to the electrode wiring 1a of the base plate 1.
When the template 4 is connected by the flip-chip connection method, even if heat is applied to the template 4, the surface of the template 4 is covered with the heat shielding layer 4B, so that the template 4 hardly expands thermally.
As a result, the template 4 accurately positions each light emitting diode element array 2, and the electrode 2b of each light emitting diode element array 2 is connected to the predetermined electrode wiring 1a of the base plate 1.
Can be easily and accurately electrically connected.

In the template 4 shown in FIG. 4, invar or liquid crystal polymer is preferably used as the template substrate 4a, and polyimide film or silicone rubber is preferably used as the heat shield layer 4b.

Further, the heat shield layer 4b is a template substrate 4a.
It is applied to a predetermined thickness (50 to 200 μm) by baking, coating, superimposing films, etc. on the surface.

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

The light emitting diode element 2a is a GaAsP type, Ga
P-based light-emitting diodes are used, for example, in the case of a GaAsP-based light-emitting diodes, as well as heating to a high temperature the GaAs substrate at furnace First AsH ₃ and (arsine) PH ₃ and (Hosuhin) Ga (gallium ) Is contacted with a gas to grow a single crystal of n-type semiconductor GaAsP (gallium-arsenic-phosphorus) on the substrate surface, 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 light emitting diode elements 2a are 2048 (8 per 1 mm).
Are arranged linearly, and specifically, a light emitting diode element array in which 64 light emitting diode elements 2a are one unit
32 light emitting diode elements 2a are linearly arranged, and thus 2048 light emitting diode elements 2a are arranged and mounted on the base plate 1.

The base plate 1 on which the light emitting diode element array 2 is mounted is provided with a lens plate 3 on the upper part thereof with a certain distance, and a plurality of holes are linearly arranged in the lens plate 3. The lens 3a is attached so as to cover the hole while being formed.

The lens plate 3 includes a plurality of lenses 3a.
Function as a supporting member for supporting the light emitting diode elements of the light emitting diode element array 2 at a predetermined interval.
The light emitted from 2a is transmitted to the lens 3a.

Each lens 3a supported by the lens plate 3 has a function of irradiating the surface of the photoconductor P with light emitted by 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 3a is linearly adhered to the lens plate 3 at a predetermined interval by adhering a part of its outer surface to the lens plate 3 with an epoxy resin adhesive, for example.

Further, the base plate 1 on which the light emitting diode element array 2 is mounted and the lens plate 3 having a plurality of lenses 3a are fixed to the spacers 5, so that each light emitting diode element array 2 and each lens
3a and 3a are installed side by side with one-to-one correspondence with a predetermined distance.

The spacer 5 has a first alignment reference surface 5a on the top thereof and a second alignment reference surface 5b on the bottom thereof, and the first alignment reference surface 5a of the spacer 5 has a bottom surface of the lens plate 3. By fixing the outer peripheral portion of the upper surface of the base plate 1 to the second alignment reference surface 5b so that each light emitting diode element array 2 and each lens 3a are in a one-to-one correspondence with a predetermined distance between them. Has become. The spacer 5 is made of, for example, glass epoxy resin or the like.

Thus, according to the image device of the present invention, a predetermined power is applied to each light emitting diode element 2a arranged and mounted on the base plate 1 to cause each light emitting diode element 2a to selectively emit light individually. The light emitted from the light emitting diode element 2a forms an image on the surface of the external photoconductor P via the lens 3a and forms a predetermined latent image on the photoconductor P, thereby functioning as an image forming apparatus.

The present invention is not limited to the above-mentioned embodiments, but various modifications can be made without departing from the scope of the present invention. For example, in the above-mentioned embodiments, an optical printer head, etc. However, the light emitting diode element array may be replaced with a solid-state image pickup element array to be used in an image reading apparatus such as an image sensor.

[0039]

According to the image device of the present invention, since the electrodes of the image element array are electrically connected to the electrode wiring adhered to the base plate by the flip-chip connection method, the number of electrodes of the 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, the coefficient of thermal expansion for regulating the position of the image element array on the surface of the base plate is −3 × 10 ⁻⁶ / ° C. to 1 × 10 ⁻⁶ / ° C. (150 to 250 ° C.). ) Or the template for controlling the position of the image element array is attached to the surface of the base plate and the heat shield layer is attached to the surface of the template, so that the electrodes of the image element array are attached to the base plate. When connecting to the electrode wiring by the flip chip connection method,
The position of the image element array is accurately positioned by the template, and the electrodes of the image element array can be easily and accurately electrically connected to the predetermined electrode wiring of the base plate.

[Brief description of drawings]

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

2 is a cross-sectional view of the optical printer head shown in FIG.

FIG. 3 is an enlarged sectional view of a main part of the optical printer head shown in FIG.

FIG. 4 is an enlarged cross-sectional view of an essential part showing another embodiment of the present invention.

[Explanation of symbols]

 1 ... Base plate 1a ... Electrode wiring 2 ... Light emitting diode element array 2a ... Light emitting diode element 2b ... Electrode 3 ... Lens plate 3a Lens Lens template 5 Spacer P Photoreceptor

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B41J 2/455 H01L 33/00 MH04N 1/028 Z 1/036 A

Claims (2)

[Claims] 1. A lens plate for supporting a plurality of lenses, and a base plate in which a large number of image element arrays are arrayed and mounted by a flip-chip connection method. The lens plate and the base plate are provided with a spacer between each lens and each lens. An image device in which the image element array and the image element array are fixed side by side so as to have a one-to-one correspondence, and the thermal expansion coefficient that regulates the position of the image element array on the surface of the base plate is −3
An image device characterized in that a template having a temperature of × 10 ^-6 / ° C to 1 × 10 ^-6 / ° C (150 to 250 ° C) is attached. 2. A lens plate for supporting a plurality of lenses, and a base plate in which a large number of image element arrays are arrayed and mounted by a flip chip connection method. The lens plate and the base plate are provided with spacers between each lens and each lens. An image device in which image element arrays are fixed side by side so as to have a one-to-one correspondence, and a template for regulating the position of the image element array is attached to the surface of the base plate, and a heat shield layer is provided on the surface of the template. An imaging device, characterized in that: