JPH10129036A - Optical printing head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To drastically enhance the mass productivity of an optical printing head by temporarily placing all of light emitting members on an insulating substrate and simultaneously slide them to align all of light emitting members at once to shorten the time required in the loading with the light emitting members to a large extent. SOLUTION: This optical printing head is constituted by loading the upper surface of an insulating substrate 1 having wiring conductors 3 formed thereon with a plurality of light emitting members 2 formed by linearly arranging a large number of light emitting elements 2a in one row. In this case, each of the light emitting members 2 has two side surfaces (n), (m) gradually becoming narrow in the opposed distance thereof and the projections 3a provided to a part of the wiring conductors 3 are brought into contact with two side surfaces (n), (m) and formed of a part of the ground electrode wirings connected to a plurality of light emitting members 2 in common.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, an optical printer head incorporated as an exposure apparatus for an electrophotographic printer or the like has a light emitting member in which a number of light emitting elements are linearly arranged on an upper surface of an insulating substrate on which wiring conductors having a predetermined pattern are formed. A plurality of light emitting elements are arranged in a line, and the light emitting elements of each light emitting member selectively emit light individually in accordance with an external electric signal, and the emitted light is disposed on the upper part thereof. An image is formed on an external photoconductor surface via a lens member, and a predetermined latent image is formed on the photoconductor to function as an optical printer head.

Each of the light-emitting members has a rectangular shape of, for example, 0.3 mm in length and 5.4 mm in width. Generally, 64 light-emitting elements are linearly arranged on one main surface. Have been. Using such a light emitting member, A4 size, 30
When forming an optical printer head of 0 dpi, 40
About 84.6 μm between each light emitting element row
Are mounted on the insulating substrate so as to be linearly arranged at a pitch of .times., And are mounted on the insulating substrate by bonding each electrode of each light emitting member to a wiring conductor on the insulating substrate with an Au wire or the like.

[0004] Further, such a light emitting member has a
It is necessary to perform alignment with a mounting accuracy of 5 to 10 μm,
For this reason, a chip mounting device having an image recognition function of performing position alignment by optically recognizing a pattern is generally used for alignment of the light emitting members. Specifically, X-
The insulating substrate is placed at a predetermined position on the Y table, and one light emitting member is taken out of the tray using a vacuum suction collet or the like, and the external shape of the two or the position of the marker formed in advance on these surfaces is read by a CCD camera or the like. In addition, image processing and pattern recognition are performed, and the operation of the XY table is automatically controlled by a computer so that these are in a predetermined positional relationship. Thereafter, the vacuum suction collet is operated to insulate the light emitting member. The mounting of the light emitting member is completed by placing the light emitting member at a predetermined position on the upper surface of the substrate, and repeating such a series of operations for all the light emitting members.

[0005]

In such a conventional optical printer head, each light-emitting member has a size of ± 5 to 10 μm.
Since it is necessary to perform alignment with the mounting accuracy of each of the above, each light emitting member must be individually mounted using the above-described image recognition method, and therefore, an In addition, an expensive chip mounting apparatus is required, and as a result, there is a disadvantage that an optical printer head as a product becomes expensive.

In the case where as many as 40 light emitting members are aligned by the above-described method, it takes a long time (about 2 minutes) to position all the light emitting members, which is not suitable for mass production. Did not.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and has a plurality of light-emitting members in which a large number of light-emitting elements are linearly arranged on an upper surface of an insulating substrate on which wiring conductors are formed. In an optical printer head mounted in a single row, each of the light emitting members has two side surfaces whose facing distance is gradually narrowed, and each of the two side surfaces has a part of the wiring conductor. The projections provided are in contact with each other.

The optical printer head according to the present invention is characterized in that the protrusion is formed as a part of a ground electrode wiring commonly connected to a plurality of light emitting members.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. (First Embodiment) FIG. 1 is a longitudinal sectional view showing a first embodiment of the optical printer head of the present invention, FIG. 2 is a plan view partially showing the optical printer head of FIG. 1, and FIG. 3 is XX of FIG. 1 is an insulating substrate, 2 is a light emitting member, 2a is a light emitting element, 3
Denotes a wiring conductor, 3a denotes a protrusion, and n and m denote side surfaces of the light emitting members located on both sides of the light emitting element row.

The insulating substrate 1 is made of an electrically insulating material such as alumina ceramics, quartz, sapphire, crystallized glass, borosilicate glass or the like, and has a plurality of wiring conductors 3 of a predetermined pattern made of a metal material such as copper on its upper surface. And the light-emitting member 2 are attached.

The wiring conductor 3 is for electrically connecting each electrode of the light emitting member 2 to an external electric circuit, and is formed of a good conductive metal material such as copper, silver or the like with a thickness of 5 to 10 μm. Is done.

The wiring conductor 3 is made of a conductive paste obtained by adding an appropriate organic solvent to a metal powder such as copper and mixing the organic solvent by a conventionally known screen printing method or the like. It is formed by printing and applying a predetermined pattern and a predetermined thickness on the upper surface and baking it at a high temperature.

Each electrode of the light emitting member 2 is flip-chip connected to the wiring conductor 3 via a solder 4. More specifically, each electrode of each light emitting member 2 is provided on a terminal portion of the wiring conductor 3. 3 and the electrodes of the light emitting member 2 are placed so as to face each other with the solder 4 interposed therebetween. Thereafter, the solder 4 is heated and melted, and the wiring conductor 3 and each electrode of the light emitting member 2 are joined by soldering. By doing so, each light emitting member 2 is mounted on the upper surface of the insulating substrate 1. At this time, all of the electrodes of each light emitting member 2 are electrically connected to the wiring conductor 3 formed on the upper surface of the insulating substrate 1 all at once through the solder 4 and firmly. 2 is electrically connected to the wiring conductor 3 in a very short time. The light emitting member 2
Is constituted by arranging a plurality of light emitting elements 2a in a straight line on a quadrangular upper surface.
a is selectively emitted individually in accordance with an external electric signal, and the emitted light is applied to an external photoconductor P via a lens 6 described later to form a predetermined latent image on the photoconductor P. .

In the case of an A4 size optical printer head, 2560 light emitting elements 2a are linearly arranged. Specifically, 40 light emitting members 2 each having 64 light emitting elements 2a as one unit are used. Pieces, 2
560 light emitting elements 2a are arranged and mounted on the insulating substrate 1,
As the light emitting element 2a, a GaAsP-based or GaP-based light-emitting diode or the like is used. For example, in the case of a GaAsP-based light-emitting diode, first, a GaAs substrate is heated to a high temperature in a furnace, and AsH ₃ (arsine) and PH are heated.
₃ A gas containing an appropriate amount of (phosphine) and Ga (gallium) is brought into contact with the substrate to grow an n-type semiconductor GaAsP (gallium-arsenic-phosphorus) single crystal on the substrate surface.
A windowed film of Si ₃ N ₄ (silicon nitride) is deposited on the surface of the single crystal, and the window is exposed to a gas of Zn (zinc) to diffuse Zn into a part of the n-type semiconductor GaAsP single crystal. It is formed by forming a p-type semiconductor and having a pn junction.

Each of the light emitting members 2 has two side surfaces n and m on both sides of the light emitting element row, the facing distance of which gradually decreases, and is mutually inclined (inclination angle: the light emitting element row). (An angle of 2 ° to 5 ° with respect to the projection) 3 a, and a plurality of projections 3 a provided on a part of the wiring conductor 3 are in contact with each of the two side surfaces n and m.

The protrusion 3a has a thickness of the light emitting member 2 of 2 mm.
When the thickness of the wiring conductor 3 is 5 μm and the thickness of the solder 4 is 30 μm, the protrusions 3 a are formed to have a thickness of 50 to 100 μm, and the protrusions 3 a contact the side surfaces n and m of the light emitting member 2. Thus, the light emitting member 2 functions to accurately define the position.

For this reason, as shown in FIG. 4, the light emitting member 2 is urged in the direction of the arrow using a vacuum suction collet to bring the side surfaces n and m of the light emitting member 2 into contact with the projections 3a. With a simple operation, the light emitting member 2 can be positioned with high accuracy in the XY directions. As a result,
An expensive chip mounting device including a CCD camera and a computer is not required, and an optical printer head as a product can be manufactured at a low cost.

When positioning the light-emitting members 2 using the projections 3a, all the light-emitting members 2 are temporarily placed on the insulating substrate 1 and all the light-emitting members are slid simultaneously. 2 can be aligned at once. Therefore, the time required for mounting the light-emitting member 2 can be significantly reduced, and the mass productivity of the optical printer head can be drastically improved.

The projections 3a are formed at predetermined positions on the wiring conductor 3 with a predetermined thickness by screen printing, electroless plating, or the like.

On the other hand, a plurality of lenses 6 supported by a lens plate made of a liquid crystal polymer are arranged above the insulating substrate 1 on which the light emitting members 2 are mounted. The light emitted from 2a is applied to the surface of the photoconductor P. The lens 6 is processed into a predetermined shape by injection molding a transparent resin such as an acrylic resin or a polycarbonate resin, or hot press molding a transparent inorganic material such as a glass.

Thus, the above-mentioned optical printer head is provided with each light emitting element 2 of the light emitting member 2 mounted on the insulating substrate 1.
A predetermined power is applied to the light emitting element 2a through the wiring conductor 3 and the like, and each light emitting element 2a is selectively and individually made to emit light in accordance with an external electric signal, and the light emitted from each light emitting element 2a is passed through the lens 6. An image is formed on an external photoconductor surface P through the photoconductor P
By forming a predetermined latent image on the surface of the sheet, it functions as an optical printer head.

(Second Embodiment) Next, a second embodiment of the optical printer head of the present invention will be described with reference to FIG. The first
Members having the same functions as those of the optical printer head of the embodiment are denoted by the same reference numerals, and redundant description will be omitted.

In the optical printer head of the second embodiment,
The light emitting member 2 is placed directly on the upper surface of the insulating substrate 1 to connect each electrode of the light emitting member 2 to the wiring conductor 3 by a bonding wire 4 ′. A ground electrode wiring 5 commonly connected to the plurality of light emitting members 2 is brought into contact with the two side surfaces n and m,
The light emitting member 2 is positioned by the ground electrode wiring 5.

The ground electrode wiring 5 is for connecting all the light emitting members 2 to a reference potential (for example, a ground potential), and is formed of a metal such as copper or silver to a thickness of 50 to 100 μm. 2 is electrically connected to the ground terminal 2 via a bonding wire (not shown).

Also in the optical printer head of the second embodiment, the two side surfaces n and m of each light emitting member 2 are provided so as to gradually reduce the facing distance, and the ground electrodes are provided on these side surfaces n and m. Since the wires 5 are in contact with each other, the respective light emitting members 2 are accurately positioned by the ground electrode wires 5, and the positioning operation of the light emitting members 2 can be easily performed. As a result, an optical printer head as a product can be manufactured at low cost, and the time required for mounting the light emitting member 2 can be greatly reduced.

The present invention as described above is not limited to the above-described embodiment, and various modifications and improvements can be made without departing from the spirit of the present invention. For example, as shown in FIG. An optical printer head is formed by attaching the ground electrode wiring 5 and the individual electrode wiring 3 that are in contact with the side surfaces n and m of the member 2 on separate insulating substrates 1A and 1B, respectively, and superimposing them. Alternatively, the optical printer head may be configured by disposing the light emitting surface of the light emitting member so as to face the insulating substrate. In such a case, since the insulating substrate is located on the light emitting surface side of the light emitting member, the insulating substrate is made of quartz, sapphire, or crystallized so that the beam from the light emitting member can be transmitted through the substrate. It must be formed of a light-transmitting material such as glass or borosilicate glass.

In the above-described embodiment, when the light shielding plate 7 is arranged between the adjacent light emitting members 2, the light emitted from each light emitting element 2a of the light emitting member 2 by the light shielding plate 7 is reduced. As a result, the light emitted from each light emitting element 2a is radiated and imaged on the surface of the external photoconductor P via only the lens 6 facing the light, and the light is sharp and accurate on the photoconductor P. A latent image can be formed. Therefore, it is preferable to arrange the light shielding plate 7 between the adjacent light emitting members 2.

In the above-described embodiment, an example has been described in which an LED printer head is formed by using an LED array as a light emitting element array. However, an EL head, a plasma dot head, a liquid crystal shutter head, a fluorescent head, a PLZT
And the like can also be applied to optical printer heads.

[0029]

According to the optical printer head of the present invention, each light-emitting member is provided with two side surfaces whose opposing distance is gradually narrowed, and each side surface is brought into contact with a projection provided on a part of the wiring conductor. Thus, the light-emitting member is urged in a predetermined direction using a vacuum suction collet or the like, and the light-emitting member is raised in the X-Y direction by a very simple operation of bringing the protrusion into contact with the side surface of the light-emitting member. Positioning can be performed with high accuracy. As a result, an expensive chip mounting device having an image recognition function is not required, and an optical printer head as a product can be manufactured at low cost.

Further, in the optical printer head of the present invention, when the light emitting members are mounted on the insulating substrate, all the light emitting members are temporarily placed on the insulating substrate, and all the light emitting members are slid simultaneously. Can be aligned at once. Therefore, the time required for mounting the light emitting member can be significantly reduced, and the mass productivity of the optical printer head can be drastically improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of an optical printer head according to the present invention.

FIG. 2 is a plan view partially showing the optical printer head of FIG. 1;

FIG. 3 is a sectional view taken along line XX of FIG. 2;

FIG. 4 is a plan view schematically showing a positioning operation of the light emitting member.

FIG. 5 is a sectional view showing a second embodiment of the optical printer head of the present invention.

FIG. 6 is a sectional view showing another embodiment of the optical printer head of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insulating substrate 2 ... Light emitting member 2a ... Light emitting element 3, 5 ... Wiring conductor 3a, 5 ... Projection part P ... Photoconductor

Claims (2)

[Claims] An insulating substrate on which a wiring conductor is formed;
In an optical printer head including a plurality of light-emitting members in which a large number of light-emitting elements are linearly arranged, the light-emitting members each have two side surfaces in which a facing distance is gradually narrowed, An optical printer head, wherein a projection provided on a part of the wiring conductor abuts on each of the two side surfaces. 2. The optical printer head according to claim 1, wherein said projection is formed by a part of a ground electrode wiring commonly connected to a plurality of light emitting members.