JP3500244B2 - Manufacturing method of ceramic substrate - 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 of manufacturing a ceramic substrate, which is a divided circuit substrate having a plurality of end face electrodes when divided into unit blocks.

[0002]

2. Description of the Related Art In recent years, electronic devices have been made smaller and lighter and more portable, and the circuit blocks used therein have been made smaller, lighter and thinner, surface-mounted, and made more complex in response to the trend. There is.

[0003] In such a trend, ceramic circuit boards have been widely used conventionally because of their excellent heat dissipation and low dielectric loss, and have been widely applied mainly to surface mounting hybrid ICs. .

Conventionally, surface mounting hybrid ICs have been used by being soldered to a ceramic circuit board. Then, from the viewpoint of confirmation of the bonding and maintenance of reliability, the ceramic circuit board has a structure having end face electrodes. From the viewpoint of the manufacturing method, the structure of the end face electrode is roughly classified into 3
There are different types of manufacturing methods.

First, in a structure called a through-hole thick film structure, a technique such as suction is used in combination with an unfired or pre-fired ceramic substrate on which a through-hole for an end face electrode is already formed. The conductive paste is printed through the printing technology.
This is a structure achieved by coating the inner wall surface of the resin and baking it. The advantage of this method is that a large number of substrates can be processed, that is, when divided into unit blocks, each becomes a ceramic substrate having a plurality of end face electrodes, which is advantageous in reducing the number of steps.

The second structure is a structure called a single formation structure, which is a method of patterning and baking the end face electrodes into one divided into unit blocks, basically by using a thick film printing technique or the like for each end face. Achieved structure. The advantage of this method is that there is no dead space due to through holes in the mounting projected area and it is suitable for miniaturization.

The third structure is an application of the first structure. When the ceramic substrate is formed in multiple layers, a through hole is formed in each green sheet of the green sheet, and the through hole is formed. This structure is achieved by coating the inner wall surface of the hole with a conductive paste and laminating and integrating the through-hole thick film structure. The advantage is that the internal wiring and the end face electrodes can be easily joined.

[0008]

[Problems to be Solved by the Invention] However, the above 3
The structures produced by the seed manufacturing methods have the following drawbacks. In other words, in the first through-hole thick film structure, when the ceramic substrate has the internal wiring, the connection reliability between the internal wiring and the end face electrode is lacking. If the target is an unfired ceramic substrate, it may be punched by a punching method.
It is necessary to form a hole, but during formation, the internal wiring collapses and it is difficult to make contact with the end face electrode. Further, if the target is a pre-fired ceramic circuit board, the flux component for shrinkage adjustment contained in the internal wiring floats up on the inner wall surface of the through hole, which is a free surface, and there arises a problem that it is difficult to bond the end surface electrode. In order to solve this problem, an etching process or the like may be performed, but this process may corrode the ceramic mix and leads to an increase in cost. Further, when a wide end face electrode is required, it is difficult to completely coat the required width because flux components and the like float up on the inner wall surface of the through hole which is a free surface.

In the second single formation structure, it is impossible to take a large number of pieces because the end faces must be exposed. Therefore, when components are mounted on the surface of the ceramic circuit board, the mounting efficiency is greatly reduced.

Similarly to the first structure, the third structure becomes unsuitable when the width of the end face electrode is increased. That is, in this structure,
It is difficult to coat only the inner wall surface of the through hole. On the other hand, when filling the through hole formed in the green sheet with the conductor paste, the conductor paste must be removed to leave only the inner wall surface of the through hole. There is a problem in that work is required, and when the conductor paste is left as it is, an extra conductor paste is required. Further, since the through hole is formed by punching or the like for each layer, there is a problem that the inner wall surface of the through hole becomes uneven and the surface of the end face electrode tends to become uneven.

[0011]

A method of manufacturing a ceramic substrate according to the present invention comprises an insulating substrate formed by laminating a plurality of insulating layers made of ceramics, and internal wiring formed between the insulating layers. In a method of manufacturing a ceramic substrate that becomes a divided circuit board having a plurality of end face electrodes when divided by a dividing groove formed in an insulating substrate, an insulating layer material made of ceramics, a photocurable monomer,
A step of forming a thin layer of a slip material containing an organic binder to form an insulating layer molded body, and a step of performing an exposure treatment on the surface of the insulating layer molded body except at least the position where the end face electrode is formed and curing the same. And a step of developing the insulating layer molded body after the exposure processing to form an annular end face electrode through groove at a position where the end face electrode is formed, and filling the end face electrode through groove with a conductive paste. And a step of forming an internal wiring pattern by printing a conductive paste on the surface of the insulating layer molded body, and an exposure treatment on the insulating layer molded body filled with the conductive paste in the end face electrode through groove A division groove for dividing each of the divided circuit boards is formed in the laminated molded body formed by repeating the step of stacking the previous insulating layer molded body and the steps from the exposure process to the stacking, to penetrate the annular end surface electrode. Inside the groove Forming so as to pass through the Jo body, characterized by comprising; and a step of firing a molded laminate said dividing grooves are formed. After firing, it is desirable to plate the surface of the end face electrode with a metal having good solder wettability.

In the present invention, the insulating layer material made of ceramics is used, but the ceramic in this case also includes glass ceramics.

[0013]

According to the present invention, it is possible to realize a ceramic circuit board which has good connection reliability between the internal wiring and the end face electrodes, has a small number of manufacturing steps, and can be manufactured in large numbers. Furthermore, since a large number can be taken, there is an advantage that the mounting efficiency becomes high when the components are mounted on the surface of the ceramic circuit board.

In the manufacturing method of the present invention, the concept of forming the end face electrode in the thickness direction of the insulating layer for each insulating layer is basically the same as the third method described in the prior art. However, unlike the case where a through hole is formed as in the third method, a portion corresponding to an end face electrode (end face electrode through groove)
The method is characterized in that it is a forming method in which the end face electrode conductor is embedded in. According to this method, it was impossible to manufacture the through-hole method due to the problem that the embedded conductor was detached. For example, a wide end face electrode was formed by forming an end face electrode with a width of 1 mm on the end face of a substrate with a thickness of 1 mm. Will be possible.

In the ceramic substrate manufactured according to the present invention, the dividing groove for dividing each unit block straddles the cylindrical conductive member portion serving as the end face electrode, so that the dividing groove is used to form the ceramic substrate of the present invention. When divided into, the divided circuit board with the end face electrodes exposed on the outer peripheral surface is formed.

In the method for manufacturing a ceramic substrate of the present invention,
Since the annular through-hole for the end surface electrode is formed in the stacking direction of the insulating layers, the conductor member forming the end surface electrode is formed into a tubular shape in the thickness direction of the ceramic substrate after the stacking and integration. The conductor member forming the end face electrode is formed in a closed loop shape when viewed in the plane direction. Since the conductor member forming the end face electrode is formed in a closed loop shape (annular shape) in this way, when the ceramic substrate is divided, all electrodes can be formed on the end face electrode portions of the divided circuit board, and the divided circuit board is formed. The connection reliability with the mounted motherboard can be further improved. However, a closed loop may not be formed depending on the manufacturing method. A closed loop structure is possible by carrying out the manufacturing method of the present invention, but in the case of the green sheet laminating method, columnar missing parts exist. However, since it remains only in minute portions, it is not a problem in practice, and is shown here as a tubular shape in consideration of the presence of these missing portions.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION A method for manufacturing a ceramic substrate according to the present invention comprises exposing a molded insulating layer to light and developing it to form an annular through-hole for an end face electrode at a position to be an end face electrode, and forming a conductor paste in this groove. Is filled, and the above steps are repeated to produce a ceramic substrate having a plurality of divided circuit boards each having an end face electrode when divided.

Further, in the manufacturing method of the present invention, the columnar body having the same composition as that of the insulating layer is present inside the tubular conductive member filled in the end face electrode through-groove after the lamination and integration. Since the end face electrodes having a sufficient area cannot be formed if the structure is divided along the dividing groove with this structure, the columnar body inside the cylindrical conductive member must be removed before the division. Is used as a hybrid IC unit block (before division), any process may be performed. For example, it may be performed after the lamination and integration and before firing, or after firing.

Further, since the divided circuit boards thus divided are finally mounted by soldering, the end surface electrodes of the divided circuit boards must be able to be joined by soldering. Therefore, considering simultaneous firing with ceramics including glass ceramics, ceramics is a material that can be fired at about 800 to 1,000 ° C., and the constituent metals of the terminal electrodes are silver, palladium, platinum, copper, and silver and palladium. One of these alloys is the main component, and among these, silver-based alloys or copper are preferable. Since silver has solder erosion, tin plating or the like is preferably applied on a nickel base. Also,
Since it is impossible to directly connect tungsten or molybdenum with solder, it is preferable to plate the surface of tungsten or molybdenum in this case as well.

The manufacturing method of the present invention will be described in detail.

First, the slip material to be the insulating layer is a solvent-based slip material obtained by homogeneously kneading a glass ceramic or ceramic material, a photocurable monomer, an organic binder, and an organic solvent.

When a so-called low temperature fired ceramics fired at 850 to 1050 ° C. is used as a composite circuit block, a ceramic material and a glass material (both are referred to as a solid component) are generally used for the insulating layer. .

Here, the average particle size of the ceramic material is 1.
When the thickness is less than 0 μm, it is difficult to make slipping, and the exposure light is diffusely reflected at the time of exposure to be described later, so that sufficient exposure cannot be performed. On the contrary, if the average particle diameter exceeds 6.0 μm, it is difficult to obtain a dense insulating layer.

In addition to the above-mentioned ceramic material, the constituent material of the slip material contains a photo-curable monomer that is lost by sintering, an organic binder, and further an organic solvent. An aqueous slip material may be used instead of the solvent slip material.

The photo-curable monomer of the solvent-based slip material must have excellent thermal decomposability in order to cope with a low temperature and short time firing process. The photo-curable monomer must be photo-polymerized by exposure after coating and drying of the slip material, which can form free radicals and chain-growth addition polymerization, and has a secondary or tertiary carbon. Alkyl acrylates such as butyl acrylates having at least one polymerizable ethylenic group and their corresponding alkyl methacrylates are effective. Polyethylene glycol diacrylates such as tetraethylene glycol diacrylate and their corresponding methacrylates are also effective. The photo-curable monomer is added in such a range that it is cured by exposure and the portion other than exposed is easily removed by development, and is, for example, 5 to 15% by weight or less based on the solid component.

The organic binder of the solvent-based slip material must have good thermal decomposability like the photocurable monomer. Specifically, it must be capable of thermal decomposition at 600 ° C or lower. More preferably, it is 500 ° C. or lower. When the thermal decomposition temperature exceeds 600 ° C., it remains in the insulating layer and is trapped as carbon, causing the substrate to change color to gray, and also lowering the insulation resistance and Q value of the insulating layer. Also, it may become void and cause delamination.

Further, as the slip material, a sensitizer, a photoinitiating material, etc. may be added as required. For example,
Examples of the photoinitiator-based material include benzophenones and acyloin ester compounds.

As described above, the glass-based ceramic or ceramic material, the photo-curable monomer, the organic binder, and the organic solvent are mixed and kneaded together to form a solvent-based slip material that serves as an insulating layer. The mixing / kneading method may be a conventionally used method, for example, a method using a ball mill. A method for thinning the slip material is, for example, a doctor blade method (knife coating method), a roll coating method, a printing method, or the like, and in particular, a doctor can easily flatten the surface of the insulating layer molded body after coating. A blade method or the like is suitable. The slip material is adjusted to have a predetermined viscosity according to the thinning method.

Further, the conductive paste of the conductor material to be the end face electrodes is obtained by homogeneously kneading the powder of at least one metal material of silver alloy or copper, the low melting point glass component, the organic binder and the organic solvent. Those are preferably used. The conductive paste of the conductive material to be the internal wiring and the via hole conductor may be the same as that of the end face electrode,
It may be made of silver as a main component. 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 point glass component also serves as an insulating layer. Considering the sintering behavior with the body (slip material applied and dried), a material whose yield point is around 700 ° C. is used.

In the method for manufacturing a ceramic circuit board of the present invention, first, a slip material is thinned (hereinafter
The coating is simply applied) and dried to form an insulating layer molded body that will become an insulating layer.

Examples of the supporting substrate include a glass substrate, an organic film, and alumina ceramic. This support substrate is removed before the firing step.

As a coating method, a doctor blade method, a roll coating method, a printing method using a screen having a coating area substantially the same as the supporting substrate, or the like is used.

Next, a ring-shaped through hole for an end surface electrode which becomes an end surface electrode and a through hole which becomes a via hole conductor are formed in the insulating layer molded body formed on the supporting substrate. Although the lower portions of the through-groove and the through-hole are actually closed by a support substrate or the like, they are referred to as the through-groove and the through-hole for convenience.

The through groove and the through hole are formed by exposure and development. For the insulating layer molded body that does not require the formation of via-hole conductors, the formation of the through holes and the subsequent filling of the conductive paste are omitted.

In the exposure process, for example, a photo target is brought close to or placed on the insulating layer molded body, and the regions other than the through groove and the through hole are irradiated with low-pressure, high-pressure, and ultra-high-pressure mercury lamp exposure light. . As a result, the photocurable monomer causes a photopolymerization reaction in regions other than the through groove and the through hole. Therefore, only the penetrating groove and the penetrating hole become the solubilized portion that can be removed by the developing process.

The developing treatment is carried out by bringing a solvent such as chlorocene into contact with the exposed and solubilized portion which is a through groove or a through hole by, for example, a spray developing method or a paddle developing method. afterwards,
Wash and dry as necessary.

Next, a conductor member serving as an end face electrode and a via-hole conductor is formed by filling a through groove or through hole of the insulating layer molded body with a conductive paste and drying. The filling method is, for example, a screen printing method.

Next, a pattern to be the internal wiring is printed and dried using a conductive paste. The printing method is, for example, a screen printing method. If the internal wiring is not needed, this step is omitted. The internal wiring pattern may be formed after the through groove is formed.

As described above, the formation of the insulating layer molded body by applying and drying the slip material, the formation of through-grooves and through-holes by exposure and development, and the formation of the pattern of the conductor member and the internal wiring by the printing of the conductive paste, Basically, the formation of the insulating layer molded body and the internal wiring pattern for one layer is completed, and this is repeated a desired number of times to complete the unfired laminated molded body. After that, a shape is adjusted by pressing or the like as needed, and slits (division grooves) for division are formed.

Next, the columnar body inside the tubular conductor member filled in the end face electrode through groove is removed. Although it is not limited in the present invention that this step is carried out in the unfired state of the ceramic circuit board as described above, it is preferable to remove it after forming the laminated molded body for ease of processing. As a method, a punching method with a die is preferable, but a method using a drill is also practical.

Thereafter, a division groove for dividing each divided circuit board is formed in the laminated molded body so as to pass through the columnar body inside the annular end surface electrode through groove.

Finally, firing is performed. The firing process consists of a binder removal process and a firing process.
At (° C), the organic components of the insulating layer molded body, internal wiring patterns, end face electrodes, and conductor members of the via-hole conductor disappear. After that, the insulating layer molded body which becomes the insulating layer and the internal wiring pattern, the end face electrode, and the conductor member which becomes the via-hole conductor are collectively fired at a predetermined atmosphere and a predetermined temperature.

[0043]

FIG. 1 is a perspective view of a divided circuit board obtained by dividing a ceramic substrate manufactured by the manufacturing method of the present invention along a dividing groove. In FIG. 1, reference numeral 1 denotes a divided circuit board, and terminals such as input / output terminals, power supply terminals, and ground terminals are shown as end surface electrodes 2. Figure 1
In the above, the end surface electrodes 2 are formed on the four side surfaces of the divided circuit board 1 at a total of 10 positions. A surface layer electrode (wiring) 3 is formed on the surface of the divided circuit board 1, and a chip component 4 such as a resistor or a capacitor is connected to the surface layer electrode 3. A cavity 5 is formed in the divided circuit board 1, and a semiconductor bare chip 6 is housed in the cavity 5 and connected to the surface layer electrode 3 by a wire.

Such a divided circuit board 1 is obtained by dividing a ceramic board, which is a collection of the divided circuit boards 1 as shown in FIG. 2, along the dividing grooves.

In this embodiment, a case where the ceramic substrate is made of a low temperature fired ceramic using a gold-based, silver-based or copper-based conductor as an internal wiring conductor will be described.

As shown in FIG. 3, the ceramic substrate of the present invention comprises insulating layers 10a to 10g, internal wiring 11, and via-hole conductors 12. An insulating base 13 is formed by the insulating layers 10a to 10g, and the surface thereof is formed. The surface wiring 3 is formed.

The insulating layers 10a to 10f are made of a glass ceramic material and have a thickness of 40 to 150 μm. The internal wiring 11 is arranged between the insulating layer 10a and the insulating layer 10b, the insulating layer 10c and the insulating layer 10d, and the insulating layer 10e and the insulating layer 10f. Internal wiring 11
Is made of a gold-based, silver-based, or copper-based metal material, for example, a silver-based conductor. Further, some of the internal wirings 11 are connected by a via-hole conductor 12 penetrating the thickness of the insulating layer 10g, and some of them are connected in a distributed constant manner by capacitive coupling or the like. Like the internal wiring 11, the via-hole conductor 12 is also made of a gold-based, silver-based, or copper-based metal material, for example, a silver-based conductor.

A surface wiring 3 connected to the via-hole conductor 12 of the insulating layer 10g is formed on the surface of the insulating substrate 13, and a thick film resistor film or a thick film is formed on the surface wiring 3 as needed. A film protective film is formed or plated, and as shown in FIG. 1, various electronic components including ICs are joined by solder or bonding fine wires.

Such a ceramic substrate of the present invention is manufactured through the intermediate structure shown in FIGS.

First, a slip material to be the insulating layers 10a to 10f is prepared.

Solvent-based slip materials are, for example, glass materials such as SiO ₂ , Al ₂ O ₃ , ZnO, MgO and B ₂ O.
_A glass-ceramic powder consisting of 50% by weight of a crystallized glass powder containing ₃ as a main component and 50% by weight of an alumina powder which is a ceramic material; and 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.

Although a solvent-based slip material is prepared in the above-mentioned embodiment, a photo-curable monomer having a hydrophilic functional group added thereto, for example, a polyfunctional methacrylate monomer, an organic binder, for example, is added as described above. A carboxyl-modified alkyl methacrylate may be used to prepare an aqueous slip material kneaded with ion-exchanged water.

In addition, the internal wiring 11 and the via-hole conductor 1
2. Prepare a conductive paste to be the end face electrode 2. The conductive paste is a metal material having a low melting point and a low resistance, such as silver powder, and a borosilicate low melting glass such as B ₂ O ₃
-SiO ₂ -BaO glass, CaO-B ₂ O ₃ -SiO
₂ glass, and _{CaO-Al 2 O 3 -B 2} O 3 -SiO 2 glass, an organic binder, such as ethyl cellulose,
It is prepared by mixing it with an organic solvent such as 2,2,4-trimethyl-1,3-pentadiol monoisobutyrate and uniformly kneading with a ball mill.

Then, first, as shown in FIG.
The above-mentioned slip material is applied onto the prepared support substrate 14 and dried to form the insulating layer molded body 20a which is the lowermost layer. Specifically, first, the above-mentioned slip material is applied onto the supporting substrate 14 by the doctor blade method and then dried to form the insulating layer 10a which is the lowermost layer of the insulating layers 10a to 10g after firing. Form body 20a. Here, as the support substrate 14, a Mylar film is used,
It is removed before the firing process. The drying condition after coating is 60
It is dried at -80 ° C for 20 minutes, and the thickness of the insulating layer molded body 20a that has been thinned and dried is 120 µm.

Since the conductor member 21 corresponding to the end surface electrode 2 is formed on the insulating layer molded body 20a, the annular end surface electrode through groove 23 is formed as shown in FIG. 4B. When viewed from the plane direction, the through-groove 23 for the end surface electrode is shown in FIG.
As shown in, a closed loop is formed. The end surface electrode through groove 23 is formed by performing an exposure process, a development process, and a cleaning / drying process.

In the exposure process, for example, a photo target is placed close to or placed on the insulating layer molded body 20a, and low-pressure, high-pressure, and ultra-high-pressure exposure light of a mercury lamp system is applied to a region other than the end face electrode through groove 23. Irradiate. As a result, the photocurable monomer causes a photopolymerization reaction in a region other than the end surface electrode through groove 23. Therefore, only the end surface electrode through groove 23 becomes a solubilized portion that can be removed by the developing process.

Specifically, the exposure process is performed by the insulating layer molding 2
A photo target is mounted on the surface 0a such that the region where the end surface electrode through groove 23 is formed is shielded from light, and exposure is performed using an ultrahigh pressure mercury lamp (10 mW / cm ² ) as a light source.

As a result, the photopolymerization reaction of the photo-curable monomer does not occur in the insulating layer molding 20a in the region where the end face electrode through groove 23 is formed, and the end face electrode through groove 2 is formed.
In the insulating layer molded body 20a other than the region where 3 is formed, a photopolymerization reaction occurs. The portion where the photopolymerization reaction has occurred is called the insolubilized portion, and the portion where the photopolymerization reaction does not occur is called the solubilized portion. In addition, the insulating layer molded body of about 120 μm is
Exposure can be performed by irradiating an ultrahigh pressure mercury lamp (10 mW / cm ² ) for about 20 to 30 seconds.

The developing treatment is carried out by bringing a solvent such as chlorocene into contact with the exposed and solubilized portion which is the insulating layer molded body 20a by, for example, a spray developing method or a puddle developing method. Then, if necessary, washing and drying are performed. The development process is
The solubilized portion of the insulating layer molded body 20a is removed by a developing solution, and specifically, 1,1,1-trichloroethane is developed by a spray method.

By this development processing, the insulating layer molding 20a is formed.
An annular through hole 23 for an end face electrode having a width of 100 to 200 μm
Can be formed. Then, the insulating layer molded body 20a
Unnecessary dust and the like caused by development are completely removed by washing and drying steps. Incidentally, the end surface electrode through groove 23,
Needless to say, it may have an oval shape, a square shape, or any other shape as long as it has a closed loop shape (annular shape) in plan view.

Next, a conductor paste is filled in the end face electrode through-grooves 23 and dried to form a conductor member 21 for forming the end face electrode 2 as shown in FIG. 4C. Specifically, the above-mentioned conductive paste is filled in the end surface electrode through-grooves 23 formed in the above-described process and dried. The conductor member 21 to be an end face electrode is formed by printing using a screen that can be printed only on the portion corresponding to the end face electrode through groove 23, and then dried at 50 ° C. for 10 minutes.

Next, after firing, a pattern to be the internal wiring 11 is printed and dried. Specifically, as shown in FIG. 4C, an internal wiring pattern 26, which is the internal wiring 11 arranged between the insulating layer 10a and the insulating layer 10b, is formed by a screen printing method and dried. .

Then, the steps from the formation of the insulating layer molded body 20a to the formation of the internal wiring pattern 26 are repeated. In this way, as shown in FIG. 5, the uppermost insulating layer molded body 10g is formed, and through holes for forming the end face electrode through-grooves 23 and via holes are formed by the exposure / development process. A conductive paste to be the through-holes 23 and the via-hole conductors 13 is printed and filled to form a seven-layer laminated compact 27. When the internal wiring pattern 26 is unnecessary, the above-mentioned manufacturing process of the internal wiring pattern 26 is omitted.

Subsequently, a conductor film to be the surface wiring 4 is printed and
Formed by drying. This is for each insulator molded body layer 20a.
˜20 g, the wiring pattern 26 to be the internal wiring 11, the via hole conductor 13 and the conductor member 21 to be the end face electrode 2 are collectively fired, and the conductor film to be the surface wiring 3 is also to be collectively fired.

Next, if necessary, the laminated molded body 27 is shaped by a press to form the dividing grooves 7, and the supporting substrate 14 is removed. The division groove is formed in the laminated molded body 27 so that the division groove 7 for dividing each divided circuit board 1 passes through the columnar body 29 inside the annular end surface electrode through groove 23. The division groove is formed by using a dicing saw.

Next, a cylindrical conductor member 21 to be the end surface electrode 2 is formed.
The cylindrical columnar body 29 surrounded by is removed. The removal is performed by punching with a mold. At this time, the inner surface of the cylindrical conductor member 21 as well as the columnar body 29 is removed by a slight thickness in consideration of the mold clearance. Although it is not limited in the present invention that this step is carried out in a non-fired state as described above, it is preferable to remove it after forming the laminated compact 27 for ease of processing. As a method, as described above, a punching method using a die is preferable, but a construction method using a drill is also practical.

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 lower, and the insulating layer molded body 20a
.About.20 g, the internal wiring pattern 26, the organic binder contained in the conductor member 21, and the photocurable monomer are lost, and the main firing step is performed at a peak temperature of 850 to 10.
It is a firing process at a peak of 50 ° C., for example, 900 ° C. for 30 minutes.
The conductor member 21 to be the same is collectively fired.

As a result, as shown in FIG. 3, the internal wiring 11 and the via-hole conductor 12 are formed between the seven insulating layers 10a to 10g at predetermined intervals, and the surface wiring 3 is further formed on the ceramic of the present invention. A substrate is produced.

Thereafter, as surface treatment, printing / baking of a thick film resistance film or a thick film protective film, plating treatment, and joining of electronic parts including an IC chip are further performed. Then, after that, by dividing along the dividing groove 7, the divided circuit board 1 as shown in FIG. 1 is obtained.

According to the method for manufacturing a ceramic substrate of the present invention, since the through holes and the through grooves are formed by the exposure and development processing using the photo target, the complicated shape and various sizes can be obtained depending on the pattern of the photo target. The end surface electrode is formed, and it can have a shape and size corresponding to the mating member to be connected.

In addition, the conventional manufacturing method, that is, the mold and NC
It is possible to form a through groove or a through hole having a large diameter or a small diameter which cannot be obtained by punching a punch, and it is possible to form a through hole with high relative positional accuracy.

Further, since the insulating layer molded body is formed by applying the slip material to be the insulating layer, the surface of the insulating layer molded body is irrespective of the laminated state of the wiring patterns of the internal wiring.
The planar state can be maintained at all times, and the precision becomes extremely high when forming the wiring pattern on the insulating layer molded body.

In the above embodiment, the internal wiring 11 is
The method of manufacturing a low-temperature fired ceramic substrate using a Au-based, Ag-based, or Cu-based low-melting-point metal material has been described. The manufacturing method of the present invention may be applied to the ceramic substrate that is fired in.
In this case, it is necessary to set the composition of the glass material of the slip material as a predetermined component and set the mixing ratio with the ceramic material to a predetermined value.

[0074]

As described above, according to the present invention, end face electrodes of various shapes and sizes can be formed, the connection reliability between the internal wiring and the end face electrode is good, the number of manufacturing steps is small, and It is possible to realize a ceramic circuit board that can be individually taken. Furthermore, since it is possible to take a large number of chips, there is an advantage that mounting efficiency becomes high when components are mounted on the surface of the ceramic circuit board.

[Brief description of drawings]

FIG. 1 is a perspective view of a divided circuit board obtained by dividing a ceramic substrate manufactured by a manufacturing method of the present invention.

FIG. 2 is a perspective view showing a ceramic substrate obtained by the manufacturing method of the present invention.

3 is a cross-sectional view taken along the line A of FIG.

FIG. 4 is a process drawing for explaining the manufacturing method of the present invention.

FIG. 5 is a cross-sectional view showing a laminated molded body before firing.

FIG. 6 is a perspective view showing a state in which an end surface electrode through groove is formed.

[Explanation of symbols]

1-divided circuit board 2 ... Edge electrode 4 ... Electronic components 7: Dividing groove 10a to 10g ... Insulating layer 11 ... Internal wiring 12 ... Via hole conductor 13 ... Insulating substrate 14 ... Support substrate 20a to 20g ... Insulating layer molded body 21 ... Conductor member 23 ... Penetration groove for end face electrode 26 ... Wiring pattern 27 ... Laminated body 29: Columnar body

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-148553 (JP, A) JP-A-8-18235 (JP, A) JP-A-9-186458 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H05K 1/02 H05K 1/11 H05K 3/40 H05K 3/46 H01L 23/12 H01L 23/13 H01L 25/00

Claims (2)

(57) [Claims] 1. An insulating substrate comprising a plurality of insulating layers made of ceramics and an internal wiring formed between the insulating layers, each of which is divided by a dividing groove formed in the insulating substrate. In a method for manufacturing a ceramic substrate, which is a divided circuit substrate having a plurality of end face electrodes, an insulating layer material is formed by thinning and drying an insulating layer material made of ceramics, a photocurable monomer, and a slip material containing an organic binder. And a step of curing by exposing the surface of the insulating layer formed body except at least the position where the end face electrode is formed, and curing the insulating layer formed body after the exposure treatment. A step of forming an annular end surface electrode through groove at a position where an electrode is formed; a step of filling a conductive paste into the end surface electrode through groove; Of a conductive paste to form an internal wiring pattern, a step of laminating an insulating layer molded body before exposure processing on the insulating layer molded body filled with a conductive paste in the end face electrode through groove, and an exposure step A division groove for dividing each divided circuit board is formed so as to pass through the columnar body inside the annular end surface electrode through groove in a laminated molded body formed by repeating the steps from processing to lamination. A method of manufacturing a ceramic substrate, comprising: a step; and a step of firing a laminated compact having the dividing groove formed therein. 2. The surface of the end face electrode is plated with a metal having a good solder wettability after firing.
A method for manufacturing the ceramic substrate described above.