JP2002292925A - Optical printer head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-reliability optical printer head which can improve the productivity. SOLUTION: A light emitting element array chip 3 having a plurality of light emitting elements 4 and terminal electrodes 5 on an upper face is loaded on a circuit board 1 having a plurality of circuit wiring lines 2 to be electrically connected to the terminal electrodes 5. Moreover, a housing 7 for holding a lens array 6 above the light emitting element array chip 3 is placed on the circuit board 1. In this optical printer head, a connecting conductor layer 8 for electrically connecting the terminal electrodes 5 and the circuit wiring lines 2 with each other by butting into contact with the terminal electrodes and the circuit wiring lines is applied to an inner face of the housing 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical printer head used as exposure means for an electrophotographic printer or the like.

[0002]

2. Description of the Related Art Conventionally, an optical printer head has been used as an exposure means of an electrophotographic printer or the like.

As shown in FIG. 3, for example, such a conventional optical printer head includes a light emitting element array chip 13 having a plurality of light emitting elements 14 and terminal electrodes 15 on an upper surface and a circuit board 11 having a plurality of circuit wirings 12. The terminal electrode 15 and the circuit wiring 12 are mounted on the thin metal wire 1.
6, a housing 18 for holding a lens array 17 above the light emitting element array chip 13 is mounted on the circuit board 11, and image data from the outside is known. The light emitting elements 14 of the light emitting element array chip 13 are selectively and individually illuminated based on the above, and the emitted light is irradiated and imaged on an external photosensitive drum (not shown) via a lens array 17; By forming a predetermined latent image on the photosensitive drum, it functions as an optical printer head.

The latent image formed on the photoreceptor drum then undergoes a development process to become a toner image, and this toner image is transferred and fixed on the recording paper to form a predetermined print on the recording paper. .

[0005]

However, when the above-mentioned optical printer head is constituted by A3 size, 600 dpi (dots per inch), for example, the connection between the terminal electrode 15 and the circuit wiring 12 reaches about 4000. Both are individually connected by as many as about 4000 thin metal wires 16. Therefore, if these thin metal wires 16 are bonded by a conventionally well-known wire bonding method, the connection operation takes an extremely long time and cannot be used for improving the productivity of the optical printer head. At the time of use or the like, the thin metal wire 16 may fall down due to external vibration or shock,
In some cases, such a problem may occur that the optical printer head deviates from the second position, which is one of the causes of reducing the reliability of the optical printer head.

The present invention has been made in view of the above-mentioned drawbacks, and has as its object to provide a highly reliable optical printer head capable of improving productivity.

[0007]

An optical printer head according to the present invention comprises a light emitting element array chip having a plurality of light emitting elements and terminal electrodes on an upper surface, and a plurality of circuit wirings electrically connected to the terminal electrodes. An optical printer head comprising: a housing for holding a lens array above the light emitting element array chip on the circuit board, the terminal electrode being provided on an inner surface of the housing. And a connection conductor layer for pressing and contacting both of the circuit wirings and electrically connecting the circuit wirings to each other.

The optical printer head according to the present invention is characterized in that the circuit board and the housing are integrally held by a leaf spring-shaped clip for pressing the lower surface of the circuit board upward. .

Further, the optical printer head according to the present invention is characterized in that an inner surface of the housing on which the connection conductor layer is adhered projects toward the light emitting element array chip and the circuit board.

Further, in the optical printer head according to the present invention, the pressure contact force of the connection conductor layer to the circuit wiring and the terminal electrode is set to 30 gf to 10 kgf.

According to the optical printer head of the present invention, the connection conductor layer is applied to the inner surface of the housing mounted on the circuit board, and the connection conductor layer is connected to the terminal electrode of the light emitting element array chip and the circuit board. When the optical printer head is assembled by placing the housing at a predetermined position on the circuit board, the connection conductor layer is formed on the inner surface of the housing. As a result, the terminal electrodes of the light emitting element array chip and the circuit wiring on the circuit board can be connected simultaneously and collectively, and the time required for connection work is significantly shorter than when both are connected by wire bonding or the like. By shortening, the productivity of the optical printer head can be dramatically improved.

According to the optical printer head of the present invention,
The above-described connection conductor layer is directly adhered to the inner surface of the housing, and furthermore, this connection conductor layer is connected to the terminal electrodes of the light emitting element array chip and the circuit wiring on the circuit board by pressure welding, so that the optical printer Even if external vibrations or shocks are applied during the use of the head or the like, there is almost no problem such as the connection conductor layer coming off the terminal electrode or the circuit wiring, and it can be used to improve the reliability of the optical printer head. it can.

Further, according to the optical printer head of the present invention,
By holding the above-mentioned circuit board and the housing integrally with a leaf spring-shaped clip that presses the lower surface of the circuit board upward, the above-mentioned press-contact state can be realized with a simple structure. The circuit wiring on the circuit board and the terminal electrode of the light emitting element array chip are resiliently pressed against the connection conductor layer on the inner surface of the housing with an appropriate pressing force of, for example, 30 gf to 10 kgf by the pressing force from the clip described above. Therefore, the pressure contact state between the housing and the light emitting element array chip and the like is extremely good, and the problem that the housing and the light emitting element array chip are broken near the pressure contact portion between them when the optical printer head is assembled is effectively prevented. .

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a sectional view of an optical printer head according to an embodiment of the present invention, in which 1 is a circuit board,
2 is a circuit wiring, 3 is a light emitting element array chip, 4 is a light emitting element, 5 is a terminal electrode, 6 is a lens array, 7 is a housing, 8 is a connection conductor layer, and 9 is a clip.

The circuit board 1 is provided on an upper surface of a base made of glass, ceramic substrate, glass cloth epoxy resin or the like.
It has a structure in which a plurality of circuit wirings 2 are attached and formed, and a light emitting element array chip 3 and the like are mounted on the upper surface thereof and function as a supporting base material for supporting them.

The circuit wiring 2 on the circuit board 1 functions as a power supply line for supplying an external power supply or the like to the light emitting element array chip 3 and the like.
It is formed so as to form a predetermined pattern using a conductive material containing a metal such as silver (Ag) or copper (Cu).

When the base is made of glass, for example, the circuit board 1 first forms a thin plate-like base by a conventionally known floating method or the like, and then includes the above-described conductive material on the upper surface of the obtained base. It is manufactured by printing and applying a conductive paste in a predetermined pattern by conventionally known screen printing or the like, and then baking the conductive paste at a high temperature to attach and form the circuit wiring 2 on the upper surface of the base.

On the upper surface of the circuit board 1, a plurality of light emitting element array chips 3 are mounted.

The light emitting element array chip 3 has a plurality of light emitting elements 4 linearly arranged in the main scanning direction at a density of, for example, 600 dpi on an upper surface thereof and a large number of terminal electrodes electrically connected to the respective light emitting elements 4. 5, and each terminal electrode 5 is electrically connected to the corresponding circuit wiring 2 via a connection conductor layer 8 described later.

The light emitting element 4 is composed of, for example, a GaAlAs-based or GaAsP-based light-emitting diode element, and is formed by joining a p-type semiconductor and an n-type semiconductor (pn junction). Light emitting element 4 through 5 etc.
When power is applied to the p-type semiconductor, electrons are stored in the p-type semiconductor and n
Holes are respectively injected into the type semiconductor, are recombined in the vicinity of the pn junction, and the energy generated during the coupling is converted into light, so that the light emitting element 4 emits light at a predetermined luminance.

The light emitting device 4 is manufactured by a conventionally known semiconductor manufacturing technique, specifically, MOCVD (Metal Organic Chemistry).
ical vapor deposition) method, and is attached and mounted at a predetermined position on the circuit board 1.

Further, above the light emitting element array chip 3,
That is, the lens array 6 is provided on the light emitting surface of the light emitting element array chip 3, and the lens array 6 is mounted on the housing 7.
Holding it.

As the lens array 6, there are used a large number of fiber lenses arranged in a straight line or a rod lens array constituted by a large number of fiber lenses arranged in a staggered manner. When used as the lens array 6, when the lens array 6 is disposed between the light emitting surface of the light emitting element array chip 3 and the image forming surface of the photoconductor (not shown) and the light emitting element 4 emits light at a predetermined luminance, these elements are turned off. Irradiate the photoreceptor at 1: 1 magnification
An image is formed.

The housing 7 for holding the lens array 6 is made of, for example, a liquid crystal polymer, polyphenylene sulfide, polycarbonate, or the like, and has a frame 7a in which the lens array 6 is inserted and a circuit board 1 in the lower part.
The light-emitting element array chip 3 and the lens array 6 are maintained at a predetermined distance from each other, and a closed space is formed therebetween.

The housing 7 is manufactured to have a predetermined shape by adopting a conventionally known injection molding method or the like, and the lens array 6 is inserted into a frame 7a of the obtained housing 7. The lens array 6 is fixed at a predetermined position on the upper part of the housing by bonding and fixing the two with an adhesive mainly composed of epoxy resin or the like.

On the inner surface of the housing 7, there is provided a projecting portion 7c projecting toward the light emitting element array chip 3 and the circuit board 1, and on the surface of the projecting portion 7c, each of the light emitting element array chips 3 is provided. A connection conductor layer 8 is pressed against both the terminal electrode 5 and the circuit wiring 2 corresponding to the electrode 5.
Is formed.

The connection conductor layer 8 is made of gold (Au), aluminum (Al), tungsten (W), titanium (T
i), a conductive material such as copper (Cu) is formed to form a predetermined pattern.
The two terminals (the terminal electrode 5 and the circuit wiring 2) are electrically connected by being pressed against the terminal electrode 5 at one end and the circuit wiring 2 at the other end.

Therefore, when assembling the optical printer head, when the housing 7 is placed at a predetermined position on the circuit board 1 (see FIG. 2), the connection conductor layer 8 on the inner surface of the housing is required.
Are the terminal electrodes 5 of the light emitting element array chip 3 and the circuit wiring 2
At the same time, all the terminal electrodes 5 and the circuit wirings 2 corresponding to the respective electrodes 5 are connected collectively, and the terminal electrodes 5 of the light emitting element array chip 3 are Compared with the case where the circuit wiring 2 is connected by a conventionally known wire bonding or the like, the time required for the connection work can be remarkably reduced, and the productivity of the optical printer head can be remarkably improved.

In this case, the connection conductor layers 8 are directly adhered to the inner surface of the housing 7, and these connection conductor layers 8 are connected to the terminal electrodes 5 of the light emitting element array chip 3 and the circuit on the circuit board 1. Since it is connected to the wiring 2 by pressure contact, even if external vibrations or shocks are applied during use of the optical printer head or the like, there occurs a problem that the connection conductor layer 8 is detached from the terminal electrode 5 or the circuit wiring 2. There is almost no problem, and it can be used for improving the reliability of the optical printer head.

The connection conductor layer 8 is formed on the inner surface of the housing 7 in a predetermined pattern by employing a conventionally known thin film method or thick film method. For example, when the connection conductor layer 8 is formed by a thin film method, first, the above-described conductive material is applied to the inner surface of the housing 7 to a predetermined thickness by a vacuum deposition method, a sputtering method, a CVD method, or the like. Deposition by processing into a predetermined pattern by etching technology
It is formed.

The pressure contact force of the connection conductor layer 8 with respect to the circuit wiring 2 and the terminal electrode 5 is preferably set to 30 gf to 10 kgf. It is possible to securely connect the circuit wiring 2 and the like, and effectively prevent a problem that an excessively large load is applied to the press-contact portion of each member and the member is damaged.

A plurality of clips 9 for integrally holding the circuit board 1 and the housing 7 are used for press contact between the connection conductor layer 8 and the terminal electrodes 5 and the like.

The clip 9 is formed in a substantially U-shape by subjecting a predetermined plate made of stainless steel or the like to sheet metal processing, and has both ends locked on the upper surface of the housing 7 and provided near the center. By pressing the bent portion 9a against the lower surface of the circuit board 1, the circuit wiring 2 and the light emitting element array chip 3 on the circuit board 1 are resiliently pressed against the connection conductor layer 8 on the inner surface of the housing.

As described above, the circuit board 1 and the housing 7
Is integrally held by a leaf spring-shaped clip 9 that presses the lower surface of the circuit board 1 upward, so that the above-mentioned press-contact state can be realized with a simple structure. The circuit wiring 2 on the substrate 1 and the terminal electrodes 5 of the light emitting element array chip 3 are resiliently pressed against the connection conductor layer 9 on the inner surface of the housing by the pressing force from the clip 9 described above. The state of pressure contact with the light emitting element array chip 3 and the like is extremely good, and problems such as breakage of the housing 7 and the light emitting element array chip 3 near the pressure contact portion between the two when the optical printer head is assembled are effectively prevented. become.

Thus, the above-described optical printer head selectively emits the light emitting elements 4 of the light emitting element array chip 3 individually on the basis of image data from the outside, and transmits the emitted light to the outside through the lens array 7. By irradiating and forming an image on the photoreceptor to form a predetermined latent image on the photoreceptor, it functions as an optical printer head.

The latent image formed on the photoreceptor then becomes a toner image through a developing process, and the toner image is transferred and fixed on the recording paper, whereby a predetermined image is recorded on the recording paper. Becomes

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made without departing from the gist of the present invention.

For example, in the above-described embodiment, a driver IC for controlling light emission and driving of the light emitting element 4 may be mounted on the circuit board 1.

In the above embodiment, the LED array head has been described as an example.
For example, the present invention is applicable to an EL head, a plasma dot head, a liquid crystal shutter head, a fluorescent head, a PLZT, and the like.

[0040]

According to the optical printer head of the present invention, the connection conductor layer is applied to the inner surface of the housing mounted on the circuit board, and the connection conductor layer is connected to the terminal electrode of the light emitting element array chip. Because it was configured to press-contact both circuit wirings on the board and electrically connect them,
When assembling the optical printer head by mounting the housing at a predetermined position on the circuit board, the terminal electrodes of the light emitting element array chip and the circuit wiring on the circuit board are simultaneously and collectively connected by the connection conductor layer on the inner surface of the housing. The time required for the connection operation can be significantly reduced as compared with the case where both are connected by wire bonding or the like, and the productivity of the optical printer head can be dramatically improved.

According to the optical printer head of the present invention,
The above-described connection conductor layer is directly adhered to the inner surface of the housing, and furthermore, this connection conductor layer is connected to the terminal electrodes of the light-emitting element array chip and the circuit wiring on the circuit board by pressure welding. Even when external vibrations or shocks are applied during the use of the device, there is almost no problem that the connection conductor layer is detached from the terminal electrode or the circuit wiring, and the reliability of the optical printer head can be improved. .

Further, according to the optical printer head of the present invention,
By holding the above-mentioned circuit board and the housing integrally with a leaf spring-shaped clip that presses the lower surface of the circuit board upward, the above-mentioned press-contact state can be realized with a simple structure. The circuit wiring on the circuit board and the terminal electrode of the light emitting element array chip are resiliently pressed against the connection conductor layer on the inner surface of the housing with an appropriate pressing force of, for example, 30 gf to 10 kgf by the pressing force from the clip described above. Therefore, the pressure contact state between the housing and the light emitting element array chip and the like is extremely good, and the problem that the housing and the light emitting element array chip are broken near the pressure contact portion between them when the optical printer head is assembled is effectively prevented. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of an optical printer head according to an embodiment of the present invention.

FIG. 2 is a sectional view for explaining a method of assembling the optical printer head of FIG. 1;

FIG. 3 is a cross-sectional view illustrating a configuration of a conventional optical printer head.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Circuit board, 2 ... Circuit wiring, 3 ... Light emitting element array chip, 4 ... Light emitting element, 5 ... Terminal electrode, 6 ... Lens array, 7 ... Housing, 8.
..Connection conductor layers, 9 clips

Claims (4)

[Claims] 1. A light emitting element array chip having a plurality of light emitting elements and terminal electrodes on an upper surface is mounted on a circuit board having a plurality of circuit wirings electrically connected to the terminal electrodes. In an optical printer head having a housing for holding a lens array above the light emitting element array chip mounted on a substrate, an inner surface of the housing is pressed into contact with both the terminal electrode and the circuit wiring to hold both. An optical printer head having a connection conductor layer for electrical connection. 2. The optical printer head according to claim 1, wherein the circuit board and the housing are integrally held by a leaf spring-shaped clip for pressing a lower surface of the circuit board upward. 3. The optical printer head according to claim 1, wherein an inner surface of the housing on which the connection conductor layer is attached projects toward the light emitting element array chip and the circuit board. 4. An optical printer head according to claim 2, wherein a pressure contact force of said connection conductor layer to said circuit wiring and said terminal electrode is set to 30 gf to 10 kgf.