JP3142729B2 - Ceramic wiring board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic wiring board suitable for inspecting wiring patterns on the front and back surfaces of a ceramic wiring board. In particular, the present invention relates to a ceramic wiring board suitable for inspecting a wiring pattern using a CCD camera.

[0002]

2. Description of the Related Art In general, a white wiring board is used for a ceramic wiring board. In particular, a low-temperature fired board is usually white, and a relatively white conductor of Ag or Au is printed on the surface and / or the back side of the wiring pattern. It is formed as. on the other hand,
In recent years, electronic devices have been miniaturized, and accordingly, the need for miniaturization of ceramic wiring substrates has increased, and this has been responded to by miniaturization of wiring. For this reason, the importance and difficulty of the inspection process of the wiring board are increasing. The wiring pattern formed on the front and back surfaces of the ceramic wiring board is visually inspected for its shape, presence or absence of disconnection, etc. For the inspection, it is desirable to be able to use an optical automatic inspection with a CCD camera for improving the inspection accuracy. . However, when the ceramic wiring board and the wiring pattern are both white or a light color close to white as described above, the contrast between the two is weak, and the appearance inspection is difficult. In particular, there has been a problem that the pattern cannot be automatically checked using an automatic inspection machine because the pattern recognition by the CCD camera is not sufficient.

[0003]

SUMMARY OF THE INVENTION The present invention makes it easy to inspect a wiring pattern even when a white conductor having a low contrast is used for a ceramic substrate of a white color or a color close to white. It is an object of the present invention to provide a ceramic wiring board that enables inspection.

[0004]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the above-mentioned problems can be solved by forming a colored ceramic layer on substantially the entire surface and / or back surface of a ceramic substrate. Invented the invention. That is, the present invention includes the following (1) and (2). (1) One or more glass ceramic layers
In the substrate that, CoO over substantially the entire front or back surface thereof
And / or RuO ₂ , the content of which is represented by a point A (0 .0) at coordinates where CoO is the X axis and RuO ₂ is the Y axis.
5 , 0), point B ( 10, 0), point C (0, 10 ) and point
A colored glass-ceramic layer including a range surrounded by four points D (0, 0.5 ) is formed, and a silver-based or gold-based conductor layer is formed on the colored glass-ceramic layer. Glass ceramic wiring board. (2) glass-ceramic layer is CaO-Al ₂ O ₃ -Si
O ₂ -B ₂ O _{3 system, CaO-Al 2 O 3 -SiO} 2 system, MgO
—Al ₂ O ₃ —SiO ₂ —B ₂ O ₃ system and CaO—MgO—
Al ₂ O ₃ -SiO ₂ -B ₂ wherein the O ₃ glass component 40 to 70 parts by weight of one selected from the system and the remainder is characterized by having a composition is alumina (1) a ceramic wiring board according.

The color of the ceramic substrate material used in the present invention is not particularly limited. For example, low-temperature fired ceramics are particularly preferred, but alumina and various ceramic materials containing alumina as a main component can also be used. As the low-temperature fired ceramic, for example, a low-temperature fired ceramic that can be fired at 800 to 1000 ° C. described in Japanese Patent Publication Nos. 3-53269 and 3-59029 is preferably used. In particular, CaO-Al ₂ O ₃ -S
iO ₂ —B ₂ O ₃ , CaO—Al ₂ O ₃ —SiO ₂ system, MgO
—Al ₂ O ₃ —SiO ₂ —B ₂ O ₃ system and CaO—MgO—
One having a composition in which 40 to 70 parts by weight of a glass component selected from the group consisting of Al ₂ O ₃ —SiO ₂ —B ₂ O ₃ and the remainder being alumina is preferred for the present invention. A as conductor material
In addition to g- and Au-based materials, those having a white color or a color close to white can be used. Also, even if the method of forming the conductor of the front, back and inner layers is a method of firing simultaneously with the ceramic body,
Either method of forming the front and back surfaces after firing the ceramic may be used.

As the coloring substance used for the colored ceramic layer, a substance which can be colored in as small an amount as possible in order to prevent deterioration of the electric characteristics is selected. The material is not limited as long as it has good compatibility with the ceramic substrate and the conductor material for wiring and has a strong contrast with a white or nearly white conductor. For example, colored oxides such as dark blue CoO and black RuO ₂ , and a mixture of both are preferable, and Ag ₂ O—PdO is also included. As a method of forming the colored ceramic layer, a method of printing a ceramic paste containing a coloring material on a white ceramic substrate or a method of laminating colored green sheets may be used. Also, the colored ceramic layer is formed by firing simultaneously with the ceramic layer, or only the ceramic layer is fired in advance,
Either a method in which a colored ceramic paste or a colored green sheet is formed on the front surface and / or the back surface and firing is performed. Further, a layer that changes into a colored substance during firing may be used as the layer. It is preferable to provide a colored ceramic layer on the entire surface of the ceramic substrate because all the wiring patterns can be automatically inspected in the inspection process. However, if a specific portion on the substrate is important in the inspection because of electrical characteristics, vapor deposition means, etc. Is included in the present invention.

When CoO is used as the coloring substance, the amount is 0.3 to 10 parts by weight with respect to the ceramic material.
_{When 2} is used, 0.5 to 10 parts by weight is preferable. Co
If O is less than 0.3 parts by weight, the coloring amount is too small, and if more than 10 parts by weight, the insulation resistance is deteriorated. RuO ₂ is 0.5
If the amount is less than 10 parts by weight, the coloring is small, and if the amount is more than 10 parts by weight, the insulation resistance is deteriorated. In addition, including the case where both are used in combination, in the coordinates where CoO is the X axis and RuO ₂ is the Y axis, (0.3, 0), (10, 0), (0,
(0.5) and (0, 10). This range is shown in FIG. In order to enhance the contrast with the conductor, it is conceivable to include an oxide such as CoO, RuO ₂ , MnO ₂ , Fe ₂ O ₃ as a colorant in the substrate material. If the coloring agent is added up to this point, the characteristics of the ceramic body are deteriorated, particularly, the insulation resistance is deteriorated, and the excellent electric characteristics of the originally-owned low-temperature fired ceramic are undesirably deteriorated.

The structure, form and manufacturing method of the ceramic wiring board of the present invention are not particularly limited. It may be a single layer or a multilayer. In the case of a multilayer ceramic wiring board, a thick film multilayer printing method and a green sheet multilayer laminating method are mentioned. Further, a wiring board on only one side of the board or a double-sided wiring board may be used. In the inspection of the wiring pattern, the contrast between the dark color of the substrate surface and the white or near-white color of the wiring pattern is distinguished by an image processing method using a CCD camera, and the presence or absence of a defect as a product is determined. This operation can be performed automatically, and all the wiring patterns on the substrate can be inspected in a short time.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. A ceramic powder consisting Example _{1 CaO-Al 2 O 3 -SiO} 2 -B 2 O 3 based glass 60 parts by weight alumina 40 parts by weight, acrylic resin and toluene, and ethanol were mixed in a ball mill, a doctor blade method To form a 0.3 mm thick green sheet for forming the ceramic layer 6. Then, using the same ceramic powder, a powder obtained by adding 1 part by weight of CoO and 9 parts by weight of RuO ₂ was pasted into a paste with three rolls using ethyl cellulose and α-terpineol to form a paste A for forming a colored ceramic layer 2. did.

[0010] The green sheet obtained above is cut into a predetermined size, and only the uppermost and lower green sheet are cut out.
The paste A colored on the green sheet was formed on the entire surface of the green sheet to a thickness of about 20 μm by screen printing. As shown in FIG. 1 which is a cross-sectional view, a via hole 4 was punched out, and an Ag paste was used in that portion to fill the via hole 4 with Ag in order to establish electrical conduction between the respective layers. Next, predetermined wiring 5 was printed using Ag paste. The colored ceramic layer 2 serving as the front and back surfaces was formed by printing an Ag conductor 3 by a printing method. A predetermined number of sheets were pressurized, heated, laminated, and fired to produce a ceramic multilayer wiring board 1. When the wiring pattern formed on the uppermost and lower layers of the ceramic wiring board thus manufactured was inspected by a wiring pattern inspection device with a CCD camera, the contrast between the wiring and the board was clear, and a disconnection or short-circuit was found. It was easy.

Examples 2 to 4 A ceramic wiring board was prepared and inspected in the same manner as in Example 1 except that pastes BD were prepared by changing the coloring substance, and the surface conductor was made of Ag or Au. Table 1 shows the amounts of each component and the results. Comparative Example The same experiment as in Example 1 was performed using Paste E without using a coloring substance. Table 1 shows the results.

[0012]

[Table 1]

[0013]

As described above, according to the present invention, by providing a colored ceramic layer on the front surface and / or the back surface of the ceramic substrate, the contrast with the conductor is enhanced, and the present invention can be applied to an optical inspection apparatus using a CCD.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a ceramic wiring board according to the present invention.

FIG. 2 is a graph showing an existing range of a coloring material content in a coloring ceramic layer of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ceramic multilayer wiring board 2 Colored ceramic layer 3 Au conductor 4 Via hole 5 Wiring 6 Ceramic layer

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-148065 (JP, A) JP-B 3-53269 (JP, B2) JP-B 3-59029 (JP, B2) (58) Field (Int.Cl. ⁷ , DB name) H05K 1/03 610 C04B 33/14 H05K 1/09 H05K 3/00

Claims (2)

(57) [Claims] 1. One or more layers of glass ceramicslayer
Consists ofOn the substrate, almost all over its front surface or back surface
CoO and / or RuO_TwoAnd its content is CoO
Is the X axis and RuO_TwoIn the coordinates where is the Y axis,Point A
(0.5, 0),Point B(10,0),Point C(0,10)
as well asPoint D(0,0.5) Includes the area enclosed by the four points
A colored glass ceramic layer is formed, and the colored glass ceramic layer is formed.
A silver or gold conductor layer is formed on the lamix layer.
A glass-ceramic wiring board characterized by the following. 2. The method according to claim 1, wherein the glass ceramic layer is CaO—Al ₂ O _3.
—SiO ₂ —B ₂ O ₃ system, CaO—Al ₂ O ₃ —SiO ₂ system,
_{MgO-Al 2 O 3 -SiO 2} -B 2 O 3 system and CaO-M
_{gO-Al 2 O 3 -SiO 2} -B 2 O 3 type glass component 40 to 70 parts by weight and the remainder selected from the system is characterized by having a composition is alumina claim 1 glass cell according <br /> Lamic wiring board.