JP3231987B2 - Method for manufacturing multilayer ceramic circuit 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 method for manufacturing a multilayer ceramic circuit board, for example, a multilayer ceramic circuit board such as a voltage controlled oscillator (VCO), a mixer, a filter element, an oscillator, a coil, and a capacitor. And a method for producing the same.

[0002]

2. Description of the Related Art In general, a multilayer ceramic circuit board is formed by laminating a plurality of insulating layers such as glass-ceramic, and inside thereof is formed of a high melting point metal material such as tungsten and a low resistance material such as gold, silver and copper. Internal wiring and via hole conductors are formed.

The method of manufacturing a multilayer ceramic circuit board can be roughly divided into two methods.

One of them is to form a slip material containing a glass material and a ceramic material to be an insulating layer, to form a green sheet by a doctor blade method or the like, and then to form an NC in the green sheet at a position to be a via hole conductor.
A through hole is formed with a punch or a mold, and then a conductive paste is printed and filled on a green sheet according to the internal wiring pattern and via-hole conductor, and then a plurality of these green sheets are laminated. This is a green sheet laminating method in which laminated molded bodies are simultaneously fired at once.

The other is a printing lamination method in which an insulating paste serving as an insulating layer and a conductive paste serving as an internal wiring are alternately printed to form a printed laminated body, and the laminated molded bodies are simultaneously fired simultaneously. . In this printing lamination method,
Via-hole conductors that connect internal wirings between different insulating layers have been formed by controlling a printing pattern such that, for example, when a slip material is printed, a conductive film serving as an internal wiring located below is exposed.

[0006]

However, the above-described manufacturing method using the green sheet laminating method requires a tape molding step for forming a green sheet to be an insulating layer, and further requires the internal wiring between different insulating layers. A step of forming a through-hole serving as a via-hole conductor for connection is required. In the hole punching step, it is general to use a mold or an NC punch. In the case of the NC punch, since holes must be formed one by one, the number of steps is increased and the cost is increased.

When a plurality of types of hole diameters are formed in one green sheet, for example, when a large via hole conductor serving as a power supply or grounding conductor is desired to be set, the mold and the NC punch are replaced each time. And it becomes extremely complicated. When a through hole is formed by the NC punch, the hole diameter is limited to a minimum of about 100 μm, and the through hole cannot be formed unless it is more than 100 μm.

On the other hand, the manufacturing method based on the printing lamination method eliminates the need for the above-described tape molding step and the step of forming a through-hole serving as a via-hole conductor, and thus simplifies the manufacturing process. As means for connecting between the internal wirings to be arranged, a pattern of printing and coating of an insulating paste material serving as an insulating layer is controlled so that only a connection portion of the conductor film of the internal wiring located below is exposed. If the opening diameter is not more than 150 μm, conduction failure may occur due to sagging of the insulating paste material, and it has been difficult to achieve high-density internal wiring.
In addition, when the number of stacked conductive films increases, even if an insulating paste material is printed, the printed surface is not flattened, and when the conductive film is printed thereon, a stable conductive film cannot be formed. There was a problem.

Further, in any of the above methods, a conductor wiring pattern is formed inside a substrate, and the thickness of the conductor must be kept at most 30 μm or less before firing. The reason is that when the conductor film thickness is increased, the adhesion between the insulating layers becomes insufficient due to the influence of the step generated thereby, and poor adhesion (delamination) occurs after firing and the quality is reduced. Recently, there has been a movement to apply this multilayer ceramic circuit board to fields requiring a large current capacity, such as an in-vehicle board. To this end, it is necessary to make the conductor film as thick as possible. For this reason, there were restrictions on the conductor film thickness.

[0010]

A ceramic circuit board according to the present invention is formed by laminating a plurality of molded insulating layers.
A method for manufacturing a multilayer ceramic circuit board, in which after forming a laminated molded body having an internal wiring pattern formed at a predetermined position, firing the laminated molded body, the laminated molded body includes an insulating layer material made of ceramic, A photo-curable monomer;
The surface of the patterned insulating layer molded body containing the organic binder is exposed and cured except for the portion where the internal wiring pattern is formed, and then developed to remove the uncured portion, thereby forming the internal wiring pattern. Is formed, and a patterned insulating layer molded body in which a conductive paste is filled in the through groove is interposed at predetermined positions of the plurality of insulating layer molded bodies.

The method of manufacturing a multilayer ceramic circuit board according to the present invention is characterized in that a slip material containing a ceramic insulating layer material, a photocurable monomer and an organic binder is thinned and dried to form an insulating layer. Forming a body, exposing and curing the surface of the insulating layer molded body, and forming a pattern insulation having a thickness corresponding to the internal wiring pattern thickness on the surface of the insulating layer molded body cured by the exposure treatment. Laminating a layer molded body, exposing and curing the surface of the pattern insulating layer molded body except for the portion where the internal wiring pattern is formed, and curing the patterned insulating layer molded body after the exposure processing. Developing, removing a formation portion of the internal wiring pattern to form a through-groove having an internal wiring pattern shape, and filling a conductive paste in the through-groove; A method comprising a step of firing the serial pattern insulating layer molded body molded laminate said formed by repeating the exposure process from the step of laminating an insulating layer molded article on the surface of the.

Although ceramic is used as the material of the insulating layer, in the present invention, the ceramic of the material of the insulating layer includes glass ceramic.

[0013]

According to the present invention, a groove having an internal wiring pattern shape is formed in an insulating layer molded body without forming an internal wiring pattern on the surface of the insulating layer molded body, and the groove is filled with a conductive paste. Since the internal wiring pattern is formed by the method described above, even if the internal wiring pattern of the multilayer ceramic circuit board is made thicker than before, delamination after firing the substrate due to insufficient adhesion between the insulating layers does not occur. The quality of a substrate having a large thickness can be improved. This makes it possible to easily manufacture a substrate having a thick internal wiring even for a substrate that is required to have a large current capacity, such as a vehicle-mounted application. In addition, since the manufacturing method is easy, there is an advantage that the manufacturing cost is low.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION A multilayer ceramic circuit board according to the present invention is obtained by laminating a plurality of molded insulating layers, producing a laminated molded body having an internal wiring pattern formed at a predetermined position, and firing the laminated molded body. The slip material used as the insulating layer molded body is a solvent-based slip material obtained by homogeneously kneading a ceramic material, a glass material, a photocurable monomer, an organic binder, and an organic solvent. It is.

In the low-temperature fired multilayer ceramic circuit board fired at 850 to 1050 ° C., the insulating layer includes:
The ceramic material and the glass material (both are referred to as solid components) are bonded to each other to improve the strength.

Examples of such ceramic materials include powders such as cristobalite, quartz, corundum (α-alumina), mullite, zirconia, cordierite, and the like.
The average particle size is preferably 1.0 to 6.0 µm, more preferably 1.5 to 4.0 µm. These ceramic materials may be used in combination of two or more. here,
The use of a ceramic material having a thickness of 1.0 to 6.0 μm makes it difficult to form a slip when the average particle diameter of the ceramic material is less than 1.0 μm. This is because exposure cannot be performed, and conversely, if the average particle size exceeds 6.0 μm, it becomes difficult to obtain a dense insulating layer.

The glass material is a glass frit containing a plurality of metal oxides, and after firing at 850 to 1050 ° C., cordierite, mullite, anorthite, serdian, spinel, garnite, willemite, dolomite, petalite and the like. As long as at least one crystal of the substituted derivative is deposited, an insulating layer with high strength can be obtained. In particular, when a crystallized glass frit that precipitates anorthite or Celsian is used, an insulating layer with higher strength is obtained, and when a crystallized glass frit that can precipitate cordierite or mullite is used, thermal expansion after firing is performed. Since the rate is low, it is optimal as a circuit board for arranging a silicon chip such as an IC on the circuit board.

The most preferred glass materials in consideration of the strength of the insulating layer and the coefficient of thermal expansion are B ₂ O ₃ , SiO ₂ , Al
It is a glass frit containing ₂ O ₃ , ZnO, and alkaline earth oxide. Since such a glass frit has a wide vitrification range and a yield point around 600 to 800 ° C.,
When firing at about 850 to 1050 ° C., it is suitable for the sintering behavior of copper-based, silver-based, and gold-based conductive materials serving as internal wiring and via-hole conductors used for low-temperature fired multilayer ceramic circuit boards.

As the action of each component, B ₂ O ₃ , Si
O ₂ is mainly as a network former, Al ₂ O
₃ mainly acts as an intermediate, and ZnO and alkaline earth oxides mainly act as a network modifier.

Such a glass material is obtained by mixing and heating and dissolving the above-mentioned predetermined components in a predetermined ratio, followed by quenching and pulverization. The average particle size of the crushed glass frit is 1.0 to 5.0 μm, preferably 1.
5 to 3.5 μm.

Here, the reason why the average particle size of the ground glass frit is 1.0 to 5.0 μm is that the average particle size is 1.
If the thickness is less than 0 μm, it is difficult to form a slip,
Exposure light is irregularly reflected at the time of exposure to be described later, so that sufficient exposure cannot be performed. Conversely, if the average particle size exceeds 5.0 μm, dispersibility is impaired, and specifically, the powder is uniformly dissolved between ceramic powders, which are insulating materials. This is because they cannot be dispersed and the strength is extremely reduced.

The composition ratio of the above-mentioned ceramic material and glass material is such that the ceramic material is 10% by weight to 50% by weight,
It is preferably 20% to 35% by weight, and the glass material is 90% to 50% by weight, preferably 80% to 6% by weight.
5% by weight.

Here, the ceramic material is 10% by weight to 5% by weight.
The reason why the weight is 0% by weight and the glass material is 90% by weight to 50% by weight is that if the ceramic material is less than 10% by weight and the glass material exceeds 90% by weight, the glass quality of the insulating layer is excessively increased, and It is inappropriate even from the strength of
When the amount of the ceramic material exceeds 50% by weight and the amount of the glass material is less than 50% by weight, the exposure light is irregularly reflected at the time of exposure to be described later, so that sufficient exposure cannot be performed, and the denseness of the insulating layer after firing is also impaired. is there.

In addition to the above-mentioned ceramic material and glass material, the constituent materials of the slip material include a photocurable monomer which is lost by sintering, an organic binder, and an organic solvent.

Incidentally, the organic solvent mainly adjusts the viscosity of the slip and the like, and is completely lost during the binder removal process in the firing step.

The photocurable monomer of the slip material must be excellent in thermal decomposability in order to cope with a low-temperature and short-time firing step. As a photocurable monomer, it is necessary to be photopolymerized by exposure after application and drying of a slip material, and a monomer having a secondary or tertiary carbon capable of forming free radicals and chain growth addition polymerization is used. Preference is given to alkyl acrylates such as, for example, butyl acrylate having at least one polymerizable ethylenic group and their corresponding alkyl methacrylates. Further, polyethyne glycol diacrylates such as tetraethylene glycol diacrylate and methacrylates corresponding thereto are also effective. The photocurable monomer is added in such a range that it can be cured by exposure and a portion other than the exposure can be easily removed by development, and is, for example, 5 to 15% by weight based on the solid content.

The organic binder of the slip material must have good thermal decomposability as well as a photocurable monomer. At the same time, the viscosity of the slip is determined, so wettability with solids must be emphasized. According to the study of the present inventors, carboxyl groups such as acrylic acid or methacrylic acid polymers, alcoholic hydroxyl groups Preferred are ethylenically unsaturated compounds with The addition amount is preferably 25% by weight or less based on the solid content.

As described above, the photocurable monomer and the organic binder in the slip material must have good thermal decomposability, but specifically, must be capable of thermal decomposition at 600 ° C. or lower. . More preferably 500
It is below ° C. If the thermal decomposition temperature exceeds 600 ° C., it remains in the insulating layer, is trapped as carbon, changes the color of the substrate to gray, and lowers the insulation resistance of the insulating layer. In addition, it may become a void and cause delamination.

As a slip material, a sensitizer, a photo-initiating material or the like may be added as required. For example,
Examples of the photoinitiating material include benzophenones and acyloin ester compounds.

As described above, a solvent-based slip material to be an insulating layer is formed by mixing and kneading with a ceramic material, a glass material, a photocurable monomer, an organic binder, and an organic solvent. The method of mixing and kneading may be a conventionally used method, for example, a method using a ball mill. The method of thinning the slip material is, for example, a doctor blade method (knife coating method), a roll coating method, a printing method, and the like, in particular, a doctor blade method in which the surface of the insulating film after application is easily flattened. And the like are preferred. The viscosity is adjusted to a predetermined value according to the method of thinning.

Further, the conductive paste of the conductor material to be the internal wiring and the via-hole conductor includes powder of at least one metal material of gold, silver, copper or an alloy thereof, a low-melting glass component, an organic binder, A mixture obtained by homogeneously kneading an organic solvent is used.

In particular, since the firing temperature is 850 to 1050 ° C., a relatively low melting point and low resistance material is selected as the metal material, and the low melting glass component is also used as the insulating layer. Considering the sintering behavior with the molded body (the one coated with the slip material and dried), its yield point is 700 ° C.
The one before and after is used.

In the method for manufacturing a multilayer ceramic circuit board according to the present invention, first, a slip material is thinned (hereinafter simply referred to as “application”) and dried on a supporting substrate to form an insulating layer molded body serving as an insulating layer.

The coating is performed by a doctor blade method, a roll coating method, a printing method using a screen having a coating area approximately equal to that of the supporting substrate, or the like. The drying is performed using a batch drying oven or an inline drying oven, and the drying condition is desirably 120 ° C. or lower. Also, rapid drying may cause cracks on the surface, so it is important to avoid rapid heating.

Here, a glass substrate,
Examples thereof include an organic film and an alumina ceramic.
This support substrate is removed before the firing step, but in the case of alumina ceramics and the like, firing is performed simultaneously,
A part of the finished multilayer ceramic substrate may be constituted. Therefore, an internal wiring or a surface wiring may be formed on this alumina support substrate.

Next, a through-hole serving as a via-hole conductor is formed in the molded insulating layer formed on the supporting substrate. Note that the lower part of the through hole is actually closed by a support substrate or the like, but is referred to as a through hole for convenience. The method of forming the through holes is performed using exposure and development. In the case of an insulating layer molded body that does not require the formation of via-hole conductors, the formation of the through-holes and the filling of the conductive paste to be the via-hole conductor are omitted.

In the exposure processing, for example, a photo target is brought close to or placed on an insulating substrate, and regions other than the through holes are irradiated with low-pressure, high-pressure, or ultra-high-pressure mercury lamp exposure light. As a result, in a region other than the through hole, the photocurable monomer causes a photopolymerization reaction.

Therefore, only the through-hole portion becomes a solubilized portion that can be removed by the developing process. Actually, the exposure accuracy is improved when the photo target is brought into contact with the molded article of the insulating layer and exposed. In addition, the optimum exposure time is determined by the thickness of the molded insulating layer, the diameter of the through hole, and the like. Incidentally, the exposure apparatus may be a general one used in so-called photoengraving technology.

In the developing treatment, a solvent such as chlorocene is brought into contact with the exposed and solubilized portion which is a through hole by, for example, a spray developing method or a paddle developing method to perform development. Thereafter, washing and drying are performed as necessary.

Next, a conductor member serving as a via-hole conductor is
It is formed by filling and drying a conductive paste. The filling method is performed by, for example, a screen printing method.

Next, a pattern to be an internal wiring is formed. First, the above-mentioned slip material is applied and dried on the insulating layer molded body filled with the via hole conductor to form a pattern insulating layer molded body having a thickness corresponding to the thickness of the internal wiring pattern. A through groove having the shape of an internal wiring pattern is formed in the insulating layer molded body for pattern. This through groove is formed by performing the same exposure processing and development processing as described above.

Next, a conductive member serving as an internal wiring pattern is formed by filling and drying the conductive paste in the through groove. The filling method is performed by, for example, a screen printing method. This through groove is also similar to the through hole for the via hole conductor.
This step is omitted for a layer that is called a through groove for convenience and does not require internal wiring.

As described above, the formation of the insulating layer molded body by applying and drying the slip material, the formation of the through-hole by exposure and development, the formation of the conductor member to be the via-hole conductor by filling the through-hole with the conductive paste, the exposure and the The formation of a through groove for forming an internal wiring pattern by development and the formation of the internal wiring pattern by filling the groove with a conductive paste basically completes the formation of the insulating layer molded body for one layer and the internal wiring pattern. This is repeated a desired number of times to complete the unfired multilayer ceramic circuit board. Thereafter, the shape is adjusted by pressing or the like as necessary, or a slit for division is formed.

Finally, firing is performed. The firing step includes a binder removal step and a firing step.
C)), the organic components of the insulating layer molded body, the internal wiring pattern, and the conductor member of the via hole conductor are eliminated, and then the insulating layer molded body, the internal wiring pattern, and the conductor member to be the via hole conductor are collectively subjected to a predetermined atmosphere and a predetermined temperature. Baking.

The multilayer ceramic circuit board thus obtained is subjected to various processes on the surface of the board. For example, printing and printing a thick film conductor pattern on the surface layer,
The thick film resistor and the thick film protective film are printed and baked, a thin film conductor pattern is formed, a plating coating process is performed, and various electronic components including an IC chip are joined.

In the formation of the surface thick film conductor pattern, the thick film resistor, and the thick film protective film, printing is performed on the above-mentioned laminated molded body formed after the insulating layer molded body and the internal wiring pattern are multilayered. The firing may be performed simultaneously in the firing step of the unfired multilayer ceramic circuit board. Further, only a part of the surface thick film conductor pattern, for example, only the surface land electrode connected to the conductor member serving as the uppermost via hole conductor may be printed on the unfired multilayer ceramic circuit board and fired at the same time.

In the above example, the through-groove was formed by exposure and development, and the internal wiring pattern was formed by filling the groove with the conductive paste. However, the through-groove was formed on the pattern insulating layer molded body by a method other than exposure and development. May be formed.

[0048]

Embodiments of the present invention will be described below. FIG.
1 is a cross-sectional view of a multilayer ceramic circuit board according to the present invention.
In this embodiment, a multilayer ceramic circuit board which is fired at a low temperature and uses gold, silver and copper conductors as internal wiring conductors will be described.

The multilayer ceramic circuit board 10 according to the present invention
Are insulating layers 1a to 1f, internal wiring 2, via-hole conductor 3
The surface wiring 4, the thick film 5, and various electronic components 6 are formed on the surface of the circuit board 10.

The insulating layers 1a to 1f are made of a glass-ceramic material and have a thickness of 40 to 150 μm. The internal wiring 2 is arranged between the plurality of insulating layers 1a to 1f. The internal wiring 2 is made of a gold-based, silver-based, or copper-based metal material, for example, a silver-based conductor. The internal wiring 2 between the different insulating layers 1a to 1f is
Are connected by a via-hole conductor 3 penetrating through the substrate. This via-hole conductor 3 is also made of a gold-based material like the internal wiring 2.
It is made of a silver-based or copper-based metal material, for example, a silver-based conductor.

On the surface of the multilayer ceramic circuit board 10,
A surface wiring 4 connected to the via-hole conductor 3 of the insulating layer 1a is formed. On this surface wiring 4, a thick-film resistor film 5 and a thick-film protective film (not shown) are formed as necessary. Various types of electronic components 6 including ICs, plated, and ICs are joined by soldering or bonding thin wires.

Such a multilayer ceramic circuit board 10
Are manufactured by the manufacturing process shown in FIG.

<Description of Materials Used> First, the insulating layer 1a
A slip material of 〜1f is created.

Examples of the solvent-based slip material include glass materials such as SiO ₂ , Al ₂ O ₃ , ZnO, MgO, and B ₂ O.
_A glass-ceramic powder comprising 70% by weight of a crystallized glass powder containing ₃ as a main component and 30% by weight of an alumina powder as a ceramic material; a photocurable monomer such as polyoxyethylated trimethylolpropane triacrylate; It is prepared by mixing an organic binder such as alkyl methacrylate and a plasticizer with an organic solvent such as ethyl carbitol acetate, and kneading the mixture in a ball mill for about 48 hours.

In the above embodiment, a solvent-based slip material is prepared. However, as described above, a photocurable monomer having a hydrophilic functional group added thereto, for example, a polyfunctional methacrylate monomer, an organic binder, for example, An aqueous slip material kneaded with ion-exchanged water may be prepared by using a carboxyl-modified alkyl methacrylate.

Further, a conductive paste for forming the internal wiring 2 and the via hole conductor 3 is prepared. The conductive paste is a low melting point and low resistance metal material such as silver powder, and a borosilicate low melting point glass such as B ₂ O ₃ —SiO ₂ —BaO.
_{Glass, CaO-B 2 O 3 -SiO} 2 glass, CaO-
And _{Al 2 O 3 -B 2 O 3} -SiO 2 glass, an organic binder, such as ethyl cellulose, an organic solvent, for example 2,2,4-trimethyl-1,3 Pentajio - Rumonoisobuchire - mixed bets homogeneous in a ball mill It is made by kneading.

<Explanation of the manufacturing process>
On the prepared supporting substrate, application and drying are performed to form a lowermost insulating layer molded body.

Specifically, as shown in FIG. 2A, first, the above-mentioned slip material is applied and dried on the support substrate 15 by a doctor blade method, and the insulating layers 1a to 1f in FIG. An insulating layer molded body 31f constituting the lowermost insulating layer 1f is formed. Here, a mylar film is used as the supporting substrate 15 and is removed before the firing step. The drying condition after application is drying at 60 to 80 ° C. for 20 minutes, and the thickness of the thinned and dried insulating layer molded body 31f is smaller than the thickness of the insulating layer 1f by 50 μm, which is the conductor film thickness. 50 μm.

Next, a through hole is formed in the insulating layer molded body 31f. The formation of the through-hole consists of exposure processing, development processing,
The drying is performed.

More specifically, in the exposure process, as shown in FIG. 2B, a photo target 33 is placed on the insulating layer molded body 31f so that the area where the through hole is formed is shielded from light. Then, exposure is performed using an ultra-high pressure mercury lamp (10 mW / cm ² ) as a light source.

As a result, in the insulating layer molded body 31f in the region where the through hole is formed, the photopolymerization reaction of the photocurable monomer does not occur, and in the insulating layer molded body 31f other than the region where the through hole is formed. Causes a photopolymerization reaction. Here, the part where the photopolymerization reaction has occurred is called an insolubilized part, and the part where the photopolymerization reaction does not occur is called a solubilized part. In addition, 50 μm
The insulating layer molded body 31f of the order is an ultra-high pressure mercury lamp (10 mW
/ Cm ² ) for about 5 to 10 seconds, exposure can be performed.

In the developing treatment, the solubilized portion of the insulating layer molded body 31f is removed with a developing solution. Specifically, spray developing is performed using an aqueous triethanolamine solution as a developing solution. By this developing treatment, as shown in FIG. 2C, the through-hole 35 having a diameter of 80 to 100 μm is formed in the insulating layer molded body 31f.
Can be formed. After that, the insulating layer molded body 31f
Unnecessary residues generated by development are completely removed by washing and drying processes.

Next, filling of the through hole 35 with the conductive paste
Dry to form a conductor member. Specifically, FIG.
As shown in (2), the above-described conductive paste is filled in the through-hole 35 formed in the above-described process, and dried. The conductor member 36 to be the via-hole conductor 3 is formed by printing using a screen that can print only the portion corresponding to the through hole 35, and then dried at 80 ° C. for 10 minutes.

Next, an internal wiring pattern to be the internal wiring 2 is formed. First, as shown in FIG. 2E, the above-mentioned slip material is applied and dried by the doctor blade method on the insulating layer formed body 31f on which the conductor member 36 to be a via-hole conductor is formed. A patterned insulating layer molded body 38f having a thickness of 50 μm corresponding to the wiring film thickness on the layer 1f is formed. As shown in FIG. 2 (f), an exposure process, a development process, and a washing / drying process are performed in the same manner as in the case where the above-described through hole 35 is formed in the pattern insulating layer molded body 38f. As shown in FIG. 2 (g), a through groove 37 for forming an internal wiring pattern is formed. Further, as shown in FIG. 2 (h), the above-mentioned conductive paste is filled in the through-groove 37 by screen printing to form an internal wiring pattern 39 serving as the internal wiring 2, and then at 80 ° C. for 10 minutes. dry.

In this manner, a patterned insulating layer molded body 38f including the internal wiring pattern 39 and an insulating layer molded body 31f including the via hole conductor 3 are formed.

Next, the steps of coating and drying the insulating film are repeated again to form a second-layer insulating layer molded body from the bottom. That is, as shown in FIG. 3, after applying and drying an insulating layer molded body 31e to be the insulating layer 1e, a through hole 35 is formed by exposure and development processing, and a conductor member 36 to be the via hole conductor 3 is formed.
And then applying and drying a pattern insulating layer molded body 38e, forming a through groove 37 by exposure and development processing, and repeatedly forming an internal wiring pattern 39 to be the internal wiring 2. In this manner, the second-layer insulating layer molded body 31b and the pattern insulating layer molded body 38b from the top are formed.
A through hole 35 is formed by exposure and development, and a conductor member 36 serving as the via-hole conductor 3 and a wiring pattern 39 serving as the internal wiring 2 are printed and filled. Only the top layer is insulating layer 1
After forming only the insulating layer molded body 31a having a thickness corresponding to the film thickness a, forming the through hole 35, and printing and filling the conductor member 36 to be the via-hole conductor 3, a predetermined number of laminated molded bodies is formed. I do.

Finally, a conductor film to be the surface wiring 4 is printed and
It is formed by drying. This is because each of the insulating layer molded bodies 31a to 31a
At the time of firing of 31f, the pattern insulating layer molded bodies 38b to 38f, the wiring pattern 39 serving as the internal wiring 2, and the conductor member 36 serving as the via hole conductor 3, the conductor film serving as the surface wiring 4 is also to be fired collectively. Things.

Next, if necessary, the shape of the laminated molded product is adjusted by pressing, and the support substrate 15 is removed.
In general, for mass production, a single ceramic substrate having a large number of laminated molded bodies as shown in FIG. 3 is manufactured. In this case, it is necessary to form a dividing groove. Becomes

Next, firing is performed. The firing includes a binder removal step and a main firing step. The binder removal step is performed in a temperature range of approximately 600 ° C. or less, and the insulating layer molded body 31 a
To 31f, a pattern insulating layer molded body 38b to 38f, an internal wiring pattern 39, an organic binder contained in the conductor member 36, and a photocurable monomer are eliminated. 1050 ° C,
For example, it is a baking process of a peak at 900 ° C. for 30 minutes.

As a result, the internal wiring 2 and the via hole conductor 3 are formed between the six insulating layers 1a to 1f, and a multilayer ceramic circuit board having the surface wiring 4 formed thereon is achieved.

Thereafter, as a surface treatment, printing and baking of the thick-film resistive film 5 and the thick-film protective film, plating, and bonding of electronic components 6 including IC chips are further performed.

The surface wiring 4, the thick film 5, and the electronic components 6 may be formed only on the upper surface or the lower surface of the circuit board 10.

Further, the surface wiring 4 is made of an insulating layer molded body 31a.
~ 31f, 38b ~ 38f on the surface of the sintered body fired,
Printing, drying, and baking in a predetermined atmosphere may be performed.

For example, when an Ag-based conductor is used for the internal wiring 2,
In the case where a Cu-based conductor is used as the surface wiring 4, a laminated molded body composed of the insulating layer molded bodies 31a to 31f, 38b to 38f and the conductor film of the internal wiring pattern 39 is fired in an oxidizing atmosphere or a neutral atmosphere and fired. Cu on the surface of the sintered body
The system conductor is printed and dried, and fired at a temperature of 780 ° C. (eutectic point of Ag and Cu) in a neutral atmosphere or a reducing atmosphere.

When the support substrate 15 is an alumina ceramic substrate, it may be left as a lower layer of the multilayer ceramic circuit board without being removed before firing. In this case, via-hole conductors and internal wiring patterns may be formed in advance on the alumina ceramic substrate serving as the support substrate 15.

According to such a manufacturing method, the through hole 35 for the via hole conductor 3 and the through groove 37 for forming the internal wiring are formed by exposure and development using the photo target 33. , Photo target 33
Depending on the pattern, through holes 35 having a plurality of diameters and through grooves 37 having various shapes can be arbitrarily formed.
This is extremely useful when the internal wiring of the ground conductor or the internal wiring of the voltage is used in the power supply in the multilayer ceramic circuit board, since the hole diameter, shape and thickness can be arbitrarily set in consideration of the conductivity.

Further, the conventional manufacturing method, that is, the mold and the NC
A multi-layer ceramic having a high-density internal wiring 2 is capable of forming a through-hole 35 with a diameter, for example, 80 μm, which cannot be obtained by punching a punch or connection by a printing pattern of a slip material, and with high relative positional accuracy. The circuit board can be easily manufactured.

Further, unlike the case of the conventional green sheet laminating method, a tape forming step for forming a green sheet to be an insulating layer is not required, and
Furthermore, since there is no need to use a die or an NC punch to form a through-hole serving as a via-hole conductor for connecting internal wiring between different insulating layers, the number of steps is significantly reduced, and a multilayer ceramic circuit board is manufactured at low cost. A method can be manufactured.

Further, since the thickness of the internal wiring pattern 39 can be controlled by the thickness of the insulating layer molded body, an internal wiring having an arbitrary thickness can be formed. Further, even if the thickness of the internal wiring is increased, there is no step difference due to the increase in the conductor film thickness as in the conventional case, and the adhesion between the insulating layers can be improved.

Further, since the insulating layer molded body is formed by applying the slip material serving as the insulating layer, the surface of the insulating layer molded body is always in a flat state regardless of the lamination state of the conductor layer molded body of the internal wiring. Since it can be maintained, the conductor film can be formed on the insulating layer molded body with high accuracy.

In the above-described embodiment, the low-temperature fired multilayer ceramic circuit board using a low melting point metal material of Au, Ag, or Cu as the internal wiring 2 has been described. It may be a multilayer ceramic circuit board made of a high melting point metal material such as molybdenum and fired at about 1300 ° C. In this case, it is necessary to set the composition of the glass material of the slip material as a predetermined component, and further set the mixing ratio with the ceramic material to a predetermined value.

[0082]

As described above, according to the present invention, even if the internal wiring pattern of the multilayer ceramic circuit board is made thicker than before, the delamination after firing the board due to insufficient adhesion between the insulating layers can be achieved. This does not occur, and the quality of a substrate having a thick internal wiring can be improved. As a result, a substrate having a large internal wiring thickness can be easily manufactured even for a substrate for an in-vehicle use or the like that requires a large current capacity, and the manufacturing method itself is easy. It can be cheap.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a multilayer ceramic circuit board obtained by a manufacturing method of the present invention.

FIG. 2 is a process diagram illustrating a method for manufacturing a multilayer ceramic circuit board according to the present invention.

FIG. 3 is a cross-sectional view showing a laminated molded article of the present invention.

[Explanation of symbols]

 1a to 1f insulating layer 2 internal wiring 3 via-hole conductor 4 surface wiring 5 thick resistor film 6 electronic component 10 multilayer ceramic circuit board 15 ... Support substrate 31a-31f ... Insulating layer molded body 33 ... Photo target 35 ... Through hole 36 ... Conductor member 37 ... Through groove 38b-38f ... Pattern insulating layer molding Body 39 ・ ・ ・ Internal wiring pattern

Continuation of the front page (56) References JP-A-49-41854 (JP, A) JP-A-7-15143 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05K 3 / 46

Claims (2)

(57) [Claims] 1. A method of manufacturing a multilayer ceramic circuit board, comprising: laminating a plurality of insulating layer molded bodies, producing a laminated molded body having an internal wiring pattern formed at a predetermined position, and firing the laminated molded body. The laminated molded body, the surface of the pattern insulating layer molded body containing an insulating layer material made of ceramic, a photocurable monomer, and an organic binder, except for the portion where the internal wiring pattern is formed After being exposed and cured, by developing and removing the uncured portion, a through groove having an internal wiring pattern shape is formed, and the pattern insulating layer molded body in which the conductive paste is filled in the through groove. Is provided at predetermined positions of the plurality of insulating layer molded bodies. 2. A step of thinning and drying a slip material containing a ceramic insulating layer material, a photocurable monomer, and an organic binder to form an insulating layer molded body, and the insulating layer molded body. A step of exposing and curing the surface of the substrate, a step of laminating a pattern insulating layer molded body having a thickness corresponding to the internal wiring pattern thickness on the surface of the insulating layer molded body cured by the exposure treatment, Exposing and curing the surface of the insulating layer molded body except for the part where the internal wiring pattern is formed, and developing the patterned insulating layer molded body after the exposure processing to form the internal wiring pattern forming part. Removing and forming a through-groove in the form of an internal wiring pattern; filling the through-groove with a conductive paste; and forming the insulating layer molded body on at least the surface of the pattern insulating layer molded body. Method for manufacturing a multilayer ceramic circuit board characterized by comprising a step of firing the laminate molded body formed by repeating the exposure process from the step of laminating.