JP2005167014A - Multilayer wiring and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve adhesion of a first metal electrode surface by impregnating the first metal electrode with a low-melting-point material and to realize large adhesive force when an adhesive layer with insulation property is formed on the first metal electrode. <P>SOLUTION: The manufacturing method of multilayer wiring includes a step where a paste containing a metal frit is baked on a substrate 111 to form a first metal electrode 112, a step to apply a low-melting-point paste 110 containing a glass frit onto the first metal electrode 112, a step to melt the low-melting-point paste 110 and impregnate the first metal electrode 112 with it, a step to form an adhesive layer with insulation property on the smoothened surface of the first metal electrode 112, and a step to form a second metal electrode on the adhesive layer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a multilayer wiring forming technique suitable for parts of an image forming apparatus, a printed circuit board, and the like, and more particularly to a multilayer wiring suitable for a flat work such as a large area glass or an epoxy board, and a method for manufacturing the same. It is.

  In place of a conventional CRT, as an image forming apparatus capable of emitting light of the same quality, a plurality of electron-emitting devices connected to wiring and wiring are arranged on one of the planes in a vacuum container having a pair of opposing flat surfaces. And an image forming member that forms an image by irradiating an electron beam emitted from the electron source and disposed on the other plane facing the electron source. . In the image forming apparatus, the X-direction wiring is formed on the Y-direction wiring via the insulating layer in the matrix (MTX) form for the electron source driving wiring.

  FIG. 4 is a diagram illustrating a method of forming a matrix-like wiring in a conventional image forming apparatus (see Patent Document 1 below).

In FIG.
(Step-a) The device electrodes 42 and 43 of the surface conduction electron-emitting device are formed on the rear plate 41 by sputtering film formation and photolithography. The material is a laminate of 5 nm Ti and 100 nm Ni. The element electrode interval was set to 2 μm (FIG. 4A).
(Step-b) Subsequently, a Y paste 44 was formed by printing and baking a silver paste in a predetermined shape. The wiring is extended to the outside of the electron source formation region and becomes an electron source driving wiring. The wiring has a width of 100 μm and a thickness of about 10 μm (FIG. 4B).
(Process-c) Next, the insulating layer 45 is formed by the printing method similarly using the paste which has PbO as a main component and mixed the glass binder. This is to insulate the Y-direction wiring 44 from the X-direction wiring described later, and was formed to have a thickness of about 20 μm. Note that a notch is provided in the part of the element electrode 43 so as to connect the X-direction wiring and the element electrode (FIG. 4C).
(Step-d) Subsequently, an X-direction wiring 46 is formed on the insulating layer 45 (FIG. 4D). The method is the same as that for Y-direction wiring, and the width of the wiring is 300 μm and the thickness is about 10 μm. Subsequently, a conductive film 47 made of PdO fine particles is formed (FIG. 4E).

As described above, conventionally, after forming the wiring of the first metal electrode (Y-direction wiring), the wiring for the second metal electrode (X-direction wiring) is formed after applying the adhesive serving as the insulating layer.
Japanese Patent Laid-Open No. 10-326581 (FIG. 4)

  However, when the first metal electrode is formed using silver paste, the surface and the inside of the first metal electrode are fired in a porous state with the size of the silver filler contained in the paste, and an insulating layer is formed on the lower wiring. When fired, the contact area itself often decreases, and peeling may occur after firing. If an insulating layer is installed directly on the surface of the porous lower wiring, air enters the voids in the lower wiring and bubbles are generated. By heating in the next process, the bubbles burst and pinholes are generated in the insulating layer. There was a problem that a short circuit occurred or the wiring itself was cut.

  In order to overcome this problem, adhesive strength, which is not necessary as the performance of the insulating layer, has a high priority, and as a result, higher performance as an adhesive than an insulating paste is required, and material selection is narrowed. It was done.

  The present invention improves the adhesion of the surface of the first metal electrode by impregnating the low melting point material on the first metal electrode in the MTX multilayer wiring required for the flat display, and provides an insulating adhesive. The present invention provides a multilayer wiring capable of obtaining a higher adhesive force when formed on a first metal electrode, and a method for manufacturing the same.

  In order to solve the above problems, the multilayer wiring of the present invention has a first metal electrode obtained by firing a paste containing metal on a substrate and impregnating with a low melting point paste, and has insulation on the first metal electrode. An adhesive layer and a second metal electrode are formed on the insulating layer.

  The method for producing a multilayer wiring of the present invention includes a step of baking a paste containing a metal on a substrate to form a first metal electrode, a step of impregnating a low melting point paste on the first metal electrode, It has the process of forming the adhesive agent layer which has insulation on 1 metal electrode, and the process of forming a 2nd metal electrode on the said adhesive bond layer, It is characterized by the above-mentioned.

  According to the present invention, the first metal electrode is impregnated with a low-melting-point paste to fill the voids, and the surface of the first metal electrode is smoothed to prevent the above-mentioned disconnection and short-circuit due to pinholes between the multilayer wirings. Strong multilayer wiring can be formed. The multilayer wiring of the present invention is used as an electron source driving wiring of an image forming apparatus, and can improve reliability.

  The planar display MTX multilayer wiring process of the present invention is achieved by the following apparatus and means.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating an example of a multilayer wiring configuration according to an embodiment of the present invention.

  A first metal electrode 112, an adhesive layer 113, and a second metal electrode 114 are sequentially formed on the substrate 111.

  FIG. 1 shows the case where there is one first metal electrode 112, adhesive layer 113, and second metal electrode 114. For example, in the electron source driving wiring of the image forming apparatus, the first metal electrode 112 is An insulating adhesive layer 113 formed by adhering a metal wire or a metal plate positioned and arranged on the substrate 111 and having a plurality of lines arranged in a line at regular intervals so as to cover the first metal electrode 112. A second metal electrode 114 is formed by bonding a metal wire or a metal plate so as to be orthogonal to the first metal electrode 112 at a predetermined interval in a direction perpendicular to the first metal electrode. Are formed.

  FIG. 2 is a diagram showing an outline of an example of a paste supply apparatus used in the embodiment of the present invention.

  101 is a paste supply device, 102 is a paste supply unit, 103 is a paste tank unit, and 104 is a surface plate, on which a substrate 111 is installed. The paste supply unit 102 is a controllable ink jet, dispenser, or the like.

Using the supply device of FIG. 2, an actual multilayer wiring was formed in the following manner. Samples used are as follows.
・ Substrate 111 ... PD200 (width 300 mm x length 200 mm thickness 2.8 mm)
・ Paste for first metal electrode 112... Metal, for example, silver paste (Noritake)
・ Low melting point paste 110 ... Glass frit paste (Dupont)
FIG. 3 is an explanatory diagram of a process of impregnating the first metal electrode with the low melting point paste in the embodiment of the present invention.

  In FIG. 3, the first metal electrode 112 is a state in which silver paste is baked in a baking furnace at 500 ° C. on the substrate in the previous step, and the substrate 111 is positioned and placed on the surface plate 104 (FIG. 3 (A )).

A paste 110 containing a glass frit having a low melting point is supplied from the paste supply unit 102 installed on the XY stage onto the first metal electrode 112 (line width 50 μm, thickness 10 μm) by about 1 × 10 (−13) m ³ (first 1 metal electrode 1 mm length) is applied (FIG. 1B). Here, the said low melting point means that melting | fusing point is low compared with the adhesive agent for forming the adhesive bond layer mentioned later.

  Next, the low melting point paste 110 is melted at about 350 ° C. and impregnated in the first metal electrode 112 formed of silver paste. By impregnating the porous portion of the surface of the first metal electrode 112 with the low melting point paste 110, the gap is filled and the surface of the first metal electrode 112 is smoothed (FIG. 1C).

  Then, in order to form the adhesive layer 113 having insulating properties, an adhesive having insulating performance, for example, a paste containing PbO as a main component and mixed with a glass binder is applied by a screen printer manufactured by Microtech Co., Ltd. Form. Further, a second metal electrode 114 was formed and then fired for about one hour in a tunnel furnace set at 488 ° C.

  The multi-layer wiring thus produced, the adhesive force between the first metal electrode 112 and the adhesive layer 113 was cross-cut (scratched 11 parallel coatings at a 0.5 mm pitch with a steel needle applied with a 200 gf load, and further tested. The piece was rotated 90 ° and similarly 11 pieces were scratched, and the number of the 100 grids formed was examined.

  As a result, the validity of this experiment was verified, with 14 to 18% peeling of the wiring made by the conventional method not impregnated with the low melting point paste and 7 to 12% peeling of the multilayer wiring by this experiment.

  Further, even in cross-sectional SEM (scanning electron microscope) observation, no cavities or disconnections due to the first metal electrode were found.

The figure which shows an example of the multilayer wiring structure in embodiment of this invention The figure which shows the outline of an example of the paste supply apparatus used for embodiment of this invention Explanatory drawing of the process of impregnating a 1st metal electrode with a low melting-point paste in embodiment of this invention The figure which shows the formation method of the matrix-like wiring in the conventional image forming apparatus

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Paste supply apparatus 102 Paste supply part 103 Paste tank part 104 Surface plate 111 Substrate 110 Low melting point paste 112 1st metal electrode 113 Adhesive layer 114 2nd metal electrode

Claims (8)

  A first metal electrode obtained by firing a paste containing metal on a substrate and impregnated with a low melting point paste, an adhesive layer having insulation on the first metal electrode, and a second metal electrode on the adhesive layer And a multi-layer wiring.   The multilayer wiring according to claim 1, wherein the low melting point paste is a paste containing glass frit.   3. The multilayer wiring according to claim 1, wherein the first metal electrode and the second metal electrode are a plurality of metal wires or metal plates, and are a matrix-like wiring orthogonal to each other at a predetermined interval. .   A step of baking a paste containing metal on a substrate to form a first metal electrode; a step of impregnating a low melting point paste on the first metal electrode; and an adhesive layer having an insulating property on the first metal electrode And a step of forming a second metal electrode on the adhesive layer. A method for manufacturing a multilayer wiring, comprising: forming a second metal electrode on the adhesive layer.   The method for producing a multilayer wiring according to claim 4, wherein the low melting point paste is a paste containing glass frit.   6. The method of manufacturing a multilayer wiring according to claim 4, wherein the step of impregnating the low melting point paste is performed by melting.   The first metal electrode and the second metal electrode are a plurality of metal wires or metal plates, and are matrix-like wirings orthogonal to each other at a predetermined interval. A method for producing the multilayer wiring described.   An image forming apparatus comprising the multilayer wiring according to claim 1 as an electron source driving wiring.

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