JPH03108396A - Multilayer electronic circuit board - Google Patents

Abstract

PURPOSE:To improve resistance to high humidity, resistance to high temperature, and heat dissipative property by laminating porous electronic circuit boards and intervening inorganic or metallic porous intermediate layer between adjacent electronic circuit boards, and filling resinin interstices. CONSTITUTION:For a multi-layer electronic circuit board, electronic circuit boards 1, 1 are laminated on the upper and lower portions of a central electronic circuit board 2, and these members are integrally bonded intervening porous intermediate layers 6 therebetween. For the electronic circuit 12 board 1, a film-like conductive circuit 12 and a film-like resistor 13 are formed on te surface side of a board porous ceramic sintered structure 11 in close contact with the same, and the film-like conductive circuit 12 is likewise formed on the back side of the same. The close contact state is such that the lower surfaces of the film-like conductive circuit 12 and the film-like resistor 13 bite into uneven surface portions among many ceramic particles 10 constituting the sintered structure 11. Further, in the sinered structure 11, resin 14 impregnated after the lamination is filled in interstices formed among the ceramic particles 10. Further, the electronic circuit board 2 is likewise constructed, and the porous intermediate layer 6 is impregnated with resin.

Description

[Detailed description of the invention] [Industrial application field] In the present invention, a film element such as a conductive circuit is formed on one surface.

This invention relates to a multilayer electronic circuit board with excellent reliability.

[Prior art]

In recent years, various types of electronic circuit boards have become known and put into practical use.1 For example, electronic circuit boards using glass-epoxy composites, alumina sintered bodies, mullite sintered bodies, etc. as substrate materials have been proposed. has been used. and,
As one method for promoting higher integration, a mounting method in which silicon integrated circuits and the like are directly mounted on a substrate is being considered.

However, since the glass-epoxy composite has a significantly different coefficient of thermal expansion from that of silicon integrated circuits, the silicon integrated circuits that can be directly mounted on the substrate are limited to extremely small ones. In addition, the dimensions of a substrate made only of a glass-epoxy composite tend to change during the 9-circuit forming process, making it difficult to apply to substrates that require particularly fine and precise circuits.

Furthermore, alumina sintered bodies and mullite sintered bodies have high hardness and poor machinability. For this reason, if machining is required, for example to create through holes, etc., a method is used in which machining is performed at the stage of producing a formed body and then fired. However, it is difficult to cause uniform shrinkage during firing,
It has been difficult to manufacture products that require particularly high dimensional accuracy or have large dimensions.

Therefore, in order to deal with these problems,
No. 87190 or Japanese Patent Application Laid-Open No. 64-82689,
A substrate in which the pores of a porous ceramic sintered body are impregnated with resin has been proposed.

This substrate is made by varying the porosity of the ceramic to match the thermal expansion of the component 1 to be mounted, such as a silicon integrated circuit, and has low expansion and excellent dimensional stability.

Furthermore, it is easy to machine and can be made larger and lighter.

On the other hand, in recent years, in order to achieve high integration, it has become common to stack a plurality of child circuit boards 1 to form a multilayer electronic circuit board.

Moreover, instead of chip components such as chip resistors and capacitors, electronic circuit boards having film-like elements in which these elements are formed on circuits in the form of films have been developed.

In this way, by forming film-like conductive circuits, resistors, capacitors, and other film-like elements, the electronic circuit board can be made smaller and lighter.

[Problem to be solved]

However, the electronic circuit board in which film-like elements are formed on the porous ceramic resin-impregnated substrate described above.

Poor reliability in use.

That is, in the resin-impregnated porous ceramic substrate described above, since the film-like elements formed on the surface are formed on the resin, the film-like elements are significantly affected by the behavior of the resin. .

Initial characteristics 1 of the membrane element in contact with the above resin, for example,
A major drawback is that the resistance value and capacitance of the capacitor vary greatly.

Furthermore, in a multilayer electronic circuit board formed by laminating a plurality of electronic circuit boards, it is necessary to efficiently release heat generated from the electronic circuits of each electronic circuit board to the outside.

In view of these conventional problems, the present invention takes advantage of the advantages of the resin-impregnated porous ceramic sintered substrate. Excellent high temperature resistance, high temperature resistance and heat dissipation. The present invention aims to provide a highly reliable multilayer electronic circuit board.

[Means for solving problems]

The present invention produces an electronic circuit board by directly forming a film-like conductive circuit, a film-like element such as a resistor, a capacitor, etc. on the surface of a porous ceramic sintered body, and then laminating the electronic circuit board. A multilayer electronic circuit board, characterized in that a porous intermediate layer of inorganic or metal is interposed between the electronic circuit boards and bonded together, and then resin is filled into the pores of the porous ceramic sintered body. be.

The most noteworthy feature of the present invention is that a plurality of electronic circuit boards each having a membrane element formed directly on the surface of a porous ceramic sintered body are used, and these are laminated and bonded with the porous intermediate layer interposed. Next, the pores of the sintered body were impregnated with resin.

That is, in the electronic circuit board of the present invention, a membrane element such as a conductive circuit is inserted into the pores and irregularities of the surface of the porous ceramic sintered body in a wedge shape and directly adheres thereto. On the other hand, the pores other than the part where the membrane element is formed are filled with resin after the electronic circuit boards are laminated.

To form film-like elements such as conductive circuits on the surface of a porous ceramic sintered body, first, a paste containing particles that form film-like elements is applied to the ceramic formed body by a method such as printing. First, there is a method in which the ceramic green body is fired at a temperature at which a sintered body is formed.

Another method is to first prepare a porous ceramic sintered body, then apply the paste on its surface and then bake it.

Furthermore, there is a method in which a film element such as a conductive circuit is formed by vapor deposition, sputtering, etc. by masking the surface of the porous ceramic sintered body except for the part that will become the circuit, and then removing the mask.

In either method, it is important that the porous ceramic sintered body and the membrane element are in direct contact with each other.

As described above, the direct contact between the porous ceramic and the membrane element makes the membrane element extremely stable against environmental changes such as temperature and humidity.

The term "membrane element" here refers to a conductive circuit as described above.

Electronic components such as film resistors and film capacitors that are formed in the form of a film on a substrate, and these film elements are formed on one or both sides of an electronic circuit board.

Further, the materials of the porous ceramic sintered body include cordierite, alumina, aluminum nitride, mullite magnesium titanate, aluminum titanate, silicon dioxide, lead oxide, zinc oxide, beryllium oxide, tin oxide,
There are ceramics whose main component is at least one of barium oxide, magnesium oxide, and calcium oxide. Among these, cordierite is a preferred material because its coefficient of thermal expansion is close to that of silicon integrated circuits.

In the present invention, the porous ceramic sintered body preferably has an average pore diameter of 0.2 to 15 μm. This is because if the average pore diameter is smaller than 0.2, the membrane element This is because the adhesion with the quality ceramic sintered body decreases. That is, this is because the wedge effect for improving adhesion is reduced.

On the other hand, if the average pore diameter is larger than 15 μm, the membrane element will penetrate considerably deeper than the surface of the porous ceramic sintered body, making it difficult to form a highly accurate electronic circuit board.

In addition, in the present invention, it is preferable that the porosity is 10% or more (volume ratio).9 This is because the porosity is 10% or more.
This is because if it is smaller, the wedge effect will be reduced.

Therefore, the electronic circuit board constructed as described above is made into a multilayer body by bonding a plurality of the electronic circuit boards in a laminated manner.

Thereafter, the porous portion of the porous ceramic sintered body is impregnated with resin to form a multilayer electronic circuit board (see FIG. 1).

The laminate is formed by interposing a porous intermediate layer between the electronic circuit boards and adhering them.

As the porous intermediate layer, an inorganic or metal porous body such as glass is used. Such a porous intermediate layer may be made of glass having a relatively low melting point, ceramic, aluminum, gold, l! , copper, tungsten, etc. Furthermore, in order to make the substrate porous as described above, powder particles are applied to the substrate surface.

A method is used in which the substrates are laminated and then heated and sintered at a temperature below the melting point.

Moreover, such a porous intermediate layer can be obtained by laminating formed bodies of electronic circuit boards and firing them at a high temperature.

It can also be formed. In other words, since each electronic circuit board is made of ceramic, the firing causes the two electronic circuit boards to sinter together, form a porous intermediate layer, and bond them together (see the first embodiment).

Note that when metal is used as the porous intermediate layer, if the membrane element is on the substrate surface facing the intermediate layer, there is no electrical insulation between the membrane element and the porous intermediate layer. Provide layers. Furthermore, the pores of the porous intermediate layer are also impregnated with resin as described below.

The resins to be impregnated into the sintered body include epoxy resin, polyimide resin, triazine resin, polyparabanic acid resin, polyamideimide resin, silicone resin, epoxy silicone resin, acrylic acid resin, methacrylic acid resin, anilic acid resin, and phenol resin. , urethane resins, furan resins, fluororesins, etc.

Further, as a method of impregnating these resins into a porous sintered body, there is a method of heating and melting the resin and immersing a laminate of electronic circuit boards in the resin.

Other methods include a method of dissolving a resin in a solvent and impregnating it, and a method of impregnating a resin in a monomer state and then turning it into a polymer. During this impregnation, the resin is impregnated into the porous sintered body directly or through the porous intermediate layer. As a result, the pores of the porous intermediate layer are also impregnated with the resin.

In addition, the adhesion of the laminate was as shown in Examples.

Pressure firing, baking of the intermediate layer, etc. are performed.

Further, an insulating layer may be provided on the surface of the multilayer electronic circuit board obtained as described above, and a conductive layer may be further formed thereon (see FIG. 4).

As the insulating layer, a resin or a composite material of a resin and an inorganic material is used. As the resin, epoxy resin, phenol resin, polyimide resin, etc. are used. As the composite material of resin and inorganic material, glass fiber and epoxy resin, glass fiber and polyimide resin, etc. are used.

The above-mentioned conductor layer refers to a conductor for electronic circuits. Methods for forming the conductor layer include 1, for example, a method of laminating metal foil;
Methods include vapor deposition and sputtering.

Note that in the multilayer electronic circuit board formed as described above, through holes can be formed after filling with resin, and conduction between circuits can be established by electroless copper plating or the like.

[Action and effect]

In the multilayer electronic circuit board of the present invention, since each electronic circuit board has a membrane element in direct contact with the surface of the porous ceramic sintered body, the membrane element is wedged between the particles of the sintered body. It is strongly connected to the shape.

The membrane element does not peel off, and since the pores of the part where the membrane element is not formed are filled with resin, it has excellent high temperature resistance and high temperature resistance.

In addition, filling the board with resin increases the strength of the entire board, making it less likely to crack, and at the same time making machining easier and preventing processing defects such as chips and chipping. Also,
It is effective in preventing gas permeation and reducing the influence from the usage environment.

Further, the porous intermediate layer is interposed between the stacked electronic circuit boards. And, the porous intermediate layer is
Since it is made of an inorganic or metal material, it has good heat conductivity. Therefore, the heat generated in each electronic circuit board is efficiently radiated to the outside through the porous intermediate layer.

Therefore, according to the present invention, it has excellent high temperature resistance, high temperature resistance, heat dissipation property, and machinability. A highly reliable multilayer electronic circuit board can be provided.

〔Example〕

First Embodiment Regarding the multilayer electronic circuit board according to the embodiment of the present invention, the first embodiment
This will be explained using FIGS.

The multilayer electronic circuit board is as shown in FIG.

Electronic circuit boards 1°1 are laminated above and below a central electronic circuit board 2, and these are integrally bonded with a porous intermediate layer 6 interposed. As shown in FIG. 2, the electronic circuit board l has a film-like conductive circuit 12 and a film-like resistor 13 on the front side of a porous ceramic sintered body 11 as a substrate, and a film-like conductive circuit 12 and a film-like resistor 13 on the back side. A conductive circuit 12 is formed in close contact with each other.

Further, the above-mentioned close contact state is as shown in FIG.

A film-like conductive circuit 12 is formed on the uneven surface portion between the large number of ceramic particles IO constituting the porous ceramic sintered body 11.
．． The lower surface of the film resistor 13 is wedge-shaped. Furthermore, inside the porous ceramic sintered body 11, in the pores formed between the ceramic particles 10,
After lamination, the impregnated resin 14 is filled.

Also, in the electronic circuit board 2, the electronic circuit board 1
It is similar to Note that the resin is also impregnated into the pores of the porous intermediate layer.

As mentioned above (the multilayer electronic circuit board of this example is one in which the electronic circuit board 2 is placed between the electronic circuit boards 1 and 1, and they are bonded to each other by the porous intermediate layer 6).

Each electronic circuit board 1 1.2 has film elements on both its front and back surfaces. One example therefore is a multilayer electronic circuit board with six layer circuits. As the above porous intermediate layer.

Glass was used.

Moreover, since the multilayer electronic circuit board is formed into a laminate, the entire board is immersed in a molten resin to be impregnated with the resin, so that its surface is coated with the resin.

Second Embodiment This example is a multilayer electronic circuit board with eight layer circuits as shown in FIG. & Provide an insulating layer on the back surface.

A conductor layer is formed thereon.

That is, the two examples of multilayer electronic circuit boards include the electronic circuit board 51,
52 and 53 are laminated and bonded together, and an insulating layer 3 is provided on the upper and lower outermost surfaces, and a conductor layer 40 is provided on the surface thereof.

Each of the above-mentioned electronic circuit boards 51, 52.53 includes film-like conductive circuits 512, 522, 532. Film resistor 513, 52
3,533. is formed on its surface. Further, between the film-like conductive circuits and film-like resistors on the electronic circuit boards 51, 52, and 53, and further between the outermost conductor layer 40, there are board-to-substrate conductive through holes 55. Through hole 5 in the board
7 are provided respectively.

Further, a porous intermediate layer 6 is interposed between each electronic circuit board 51, 52, 53, and these are bonded together.

The porous intermediate layer is made of a ceramic material.

These film-like conductive circuits 12. and a film resistor 13.

The state of close contact with the porous ceramic sintered body as a substrate, the porous ceramic sintered body, the resin filling state in the porous intermediate layer, etc. are the same as those of the electronic circuit board 1 shown in the first embodiment.

Therefore, in the multilayer electronic circuit boards according to the first and second embodiments, each of the electronic circuit boards constituting the multilayer electronic circuit boards has the above-described structure, and porous holes with good heat conductivity are provided between the electronic circuit boards. There is a middle layer of quality. Furthermore, the pores of the porous ceramic sintered body are impregnated with resin. Therefore, the multilayer electronic circuit board has excellent high temperature resistance, high temperature resistance, heat dissipation property, and machinability, and has high reliability.

Third Embodiment As shown in the second embodiment above. A multilayer electronic circuit board (see FIG. 4) with an 8-layer circuit was manufactured and tested.

The multilayer electronic circuit board was manufactured by first preparing an electronic circuit board A and an electronic circuit board B, and then laminating the electronic circuit board B between the electronic circuit boards A and A.

That is, in order to produce the electronic circuit board A, the average particle size is 1.
2 parts by weight of polyvinyl alcohol, 1 part by weight of polyethylene glycol, 0.5 parts by weight of stearic acid, and 100 parts by weight of water were mixed with 100 parts by weight of 8 μm cordierite powder, mixed in a ball mill for 3 hours, and then sprayed. Dry.

Collect an appropriate amount of this dried material and use a metal press to perform 1. O
Molded with a pressure of L/cd, size 220m x 250cm
×1.2 cabinets, density 1. 5 g/cd (6Qvo 1
%) ceramic-produced bodies were obtained.

After making holes in this formed body, it was calcined at 5300″C to remove the organic binder, and then a gold pattern with a thickness of 0.5 μm was wired on the surface of the formed body by sputtering.

Through the above steps, electronic circuit board A was manufactured.

Next, in order to produce electronic circuit board B, the average particle size is 0.
50 parts by weight of alumina powder having an average particle size of 0.32 μm and 12 parts by weight of polyacrylic acid ester for 50 parts by weight of alumina powder having an average particle size of 68 μm.

1 part by weight of a polyester dispersant, 2 parts by weight of dibutyl phthalate and 50 parts by weight of ethyl acetate were blended.

After mixing in a ball mill for 3 hours, it was formed into a sheet.

After making holes in this formed body, it was calcined at 300°C to remove the organic binder, and then a gold pattern with a thickness of 0.5 μm was wired on the surface of the formed body by sputtering.

Through the above steps, electronic circuit board B was manufactured.

Next, as shown in FIG. Laminated in 3 layers. Then, it was fired at 1350°C in air while pressurizing at 10 kg/cj. This results in
It was made into a sintered body.

Here, the physical properties of the obtained sintered substrate were measured.

As a result, the average pore size and density of each layer.

The porosity is 3.0 layer m and 1°8 in the cordierite layer.
g/d, 32% (vol), while for the alumina layer, 0.52 μm, 2. 54 g/c4. 3
It was 5%.

Moreover, between the cordierite layer and the alumina layer,
A 0.5 μm thick AltOsSiOxMgO-based intermediate layer was formed. The average pore diameter and porosity of this porous intermediate layer were 1.5 μm, and the porous layer was 42%. Also, the adhesion between the eyebrows is 1. It had good adhesion at 8 kg/mum''.

Next, on the front and back surfaces of this laminate, a material with a viscosity of 170 Pa-s containing 38% of ruthenium oxide particles with an average particle size of 16 μm was applied.
The paste was printed using a 325 mesh screen to form a thin film resistor on the conductor. After drying,
Baked at 850°C in air. The resistance value at this time is 59Ω
/It was a mouth.

At this stage, this board was subjected to a high temperature and high temperature life test for 1000 hours at 85°C and 85% RH (relative humidity), and the rate of change in resistance was 0.12%, indicating excellent stability. It had

Next, the laminate is impregnated with a two-component epoxy resin.

After curing, a multilayer electronic circuit board was obtained. This impregnation was carried out by placing the substrate under vacuum, impregnating the defoamed epoxy resin under vacuum, and then thermally curing it.

Next, on the front and back sides of this resin-impregnated laminate, 0.05 μm thick BT resin prepreg is placed as an insulating layer, and 18 μm copper foil is further placed on top of that, and conductor layers are formed on each of the two front and back sides by vacuum pressing. was formed.

Next, holes were drilled in the laminate using a diamond drill with a diameter of 0.40 mm to the front, back, and intermediate layers, and 15 μm electroless copper plating was applied to ensure continuity.

A circuit was formed by etching the conductor layers on the front and back surfaces.

The thus obtained multilayer electronic circuit board was an 8-layer circuit, and had a total thickness of 0.86 g*, which was extremely thin.

Moreover, this multilayer electronic circuit board.

It had an extremely high packaging density, with 26 film-like resistors and 14 capacitor elements built-in per 14.

30 seconds at 20°C for this multilayer electronic circuit board.

A heat resistance test was conducted by repeatedly dipping in oil for 30 seconds at 260°C. As a result, no defects such as wire breakage or separation between substrates occurred even after 500 cycles.

Further, when this multilayer electronic circuit board was subjected to a high temperature and high temperature life test for 100 hours at 85° C. and 85% RH, the rate of change in resistance value was extremely stable at 0.18%.

Further, the thermal conductivity of the multilayer electronic circuit board was measured by a laser flash test under vacuum. As a result, the heat dissipation was as high as 3.6 W/m-. In addition,
When the porous intermediate layer was not provided and the adhesive film was bonded with an organic adhesive film, the strength was 0°9 W/m-.

Note that the electronic circuit boards @A and B are shown in FIG. 2 above.

As shown in FIG. 3, a film-like conductive circuit 12 and a film-like resistor 13 are firmly adhered to both the front and back surfaces of a porous ceramic sintered body 11 (see the first embodiment for details). ).

On the other hand, for comparison, after producing a porous cordierite sintered body in the same manner, it was immediately impregnated with the same two-component epoxy resin, and at the same time a copper foil was laminated to obtain a substrate. A circuit was formed by etching. The beer strength at this time was 1.8 kg/l, which was low.

In addition, in the multilayer electronic circuit boards described above, it was possible to drill more than 120,006 holes in each board with a length of 350 mm and a radius of 250 mm. in this way.

The electronic circuit board of the present invention has high strength and excellent machinability.

Fourth Example Using the same cordierite molded body (substrate A) and alumina molded body (substrate B) as in the third example, a paste made of tungsten powder was formed on the surface by screen printing to form a conductor circuit. . That is, a tungsten pattern was formed instead of the gold pattern in the third example. The rest is the same as the third embodiment.

As a result, in FIG. 4, the tungsten particles in the through holes were electrically conductive even though they were not sintered, and the connection reliability, resistance stability, etc. were good.

Fifth example The same ceramic molded body as in the third example was used.

A multilayer electronic circuit board was fabricated.

That is, the cordierite molded body shown in the third example was fired at 1400° C. in air to form a porous cordierite sintered body. This sintered body has a thickness of 0.25 m,
The sintered body had a density of 1.8 g/ej, a porosity of 30%, and an average pore diameter of 3.2 μm.

Next, a paste with a viscosity of 80 Pa-s containing 48% silver-palladium particles with an average particle diameter of II μm was printed on the surface of the porous cordierite sintered body using a 325 mesh screen to form a conductor circuit. Then, viscosity 1 containing 38% ruthenium oxide particles with an average particle size of 16 μm
A 70 Pa-s paste was printed using a 325 mesh screen to form a film-like resistor on the conductor.

On the other hand, an alumina molded body similar to the third example.

It was fired in the air at 1550°C for 1 hour to obtain a porous alumina sintered body. The sintered body has a thickness of 0.25 mm and a density of 2
．． gg/c+1. Porosity 25%, average pore diameter 0.29μ
It was m.

Silver-palladium particles similar to those printed on the surface of the porous cordierite sintered body were applied to the surface of this porous alumina sintered body to form two circuits.

Next, 38 ruthenium oxide particles with an average particle size of 16 μm were
% and a viscosity of 170 Pa-s.

A film-like resistor was formed on the conductor by printing with a 325 mesh screen.

Next, as shown in FIG. 1, the first and third layers were made of a porous cordierite sintered body, and the second layer was made of a porous alumina sintered body. At this time, in order to form a porous intermediate layer, A1, O, -3in, -TiO with an average particle size of 13 μm was inserted between each layer.
Approximately 100 μm of ceramic powder was applied and the pieces were bonded together. after that.

These were baked at 850°C in air.

The typical resistance value at this point was 350Ω/mouth.

In addition, the average pore diameter and porosity of the intermediate layer are 5°5 μm, 33
% porous layer. Also, the adhesion between the 9 layers is 4. 5
kg/sm" and had good adhesion.

Next, in the same manner as in the third example, a two-component epoxy resin was impregnated and cured to obtain a multilayer electronic circuit board.

The thus obtained multilayer electronic circuit board had six layers and had a total thickness of 0.93 mm, which was extremely thin. Moreover,
There are 56 film-like resistors per 1 cii.

It had an extremely high packaging density with 11 built-in capacitor elements.

For this board, 30 seconds at 20°C and 30 seconds at 260°C.
A heat resistance test was conducted with repeated oil dips for seconds. As a result, no defects such as wire breakage or separation between substrates occurred even after 500 cycles.

Further, when this multilayer electronic circuit board was subjected to a high temperature and high temperature life test for 1000 hours at 85° C. and 85% RH, the rate of change in resistance value was extremely stable at 0.25%.

Moreover, regarding heat dissipation, it was 2.9 W/m-.

Sixth Example Similar to the fifth example, a porous cordierite sintered body on which two circuits and a film resistance element were formed was heated to 850°C in air.
It was baked in.

The adhesion strength of the obtained circuit was 3 kg, and the typical resistance value at this point was 300 Ω/port.

On the other hand, a porous alumina sintered body was formed in the same manner as in the fifth example, and lanthanum poride with an average particle size of 18 μm was coated on the surface of the porous alumina sintered body.
A paste containing 41% tin oxide particles and a viscosity of 110 Pa-s was printed with a 250 mesh screen. After drying, it was baked at 900°C in nitrogen to form a film-like resistor.

Next, a paste with a viscosity of 120 Pa-s containing 50% copper particles with an average particle size of 8 μm was applied onto this resistor at 250 Pa-s.
Printing was performed using a mesh screen to form a conductor circuit.

Further, the porous cordierite sintered body is used as a second layer, and the porous alumina sintered body is used as a first layer. Laminated as the third layer. At this time, due to the formation of a porous intermediate layer.

BzOs SiO□-Z with an average grain size of 18 μm between each layer
Approximately 5011 ml of nO-based glass powder was applied to the cloth, and then baked at 600°C in nitrogen.

The average pore system and porosity of the intermediate layer thus obtained was 7.1.
It was a porous layer of 21% in μm. Also.

The tightness between the eyebrows is 6. It had good adhesion at 9 kg/ma''.

Next, as in the third example, a two-component epoxy resin was impregnated and cured to obtain a multilayer electronic circuit board.

The multilayer electronic circuit board is a 6-layer circuit, and the total thickness is 0.8
It was thin at 3 mm. Moreover.

It had extremely high packaging density, with 61 film-like resistors and 26 capacitor elements built-in per No. 11.

For this board, 30 seconds at 20°C and 30 seconds at 260°C.
When a heat resistance test was conducted with repeated oil dips for 500 seconds, no defects such as wire breakage or separation between substrates occurred even after 500 cycles.

Further, this multilayer electronic circuit board was subjected to a high-temperature life test at 85° C. and 85% RH for 100 hours. As a result, the rate of change in resistance value was 0.41% for the ruthenium oxide system.
The lanthanumolide-tin oxide system was extremely stable at 1.18%. Moreover, the heat dissipation property was 2.3 W/m·k.

[Brief explanation of drawings]

1 to 3 show the multilayer electronic circuit board of the first embodiment, FIG. 1 is a sectional view thereof, FIG. 2 is a sectional view of one electronic circuit board, and FIG. 3 is an enlarged sectional view of main parts. . FIG. 4 is a sectional view of the multilayer electronic circuit board of the second embodiment. 1, 2゜l Oo. 11. l 2. . 13. 14. 3. 40. 6. 51, 52. 53 Electronic circuit board. ceramic particles. Porous ceramic sintered body. Membrane conductive circuit. Film resistor element. resin. insulation layer. conductor layer. Porous intermediate layer.

Claims (2)

[Claims] (1) An electronic circuit board is produced by directly forming a film-like conductive circuit, a film-like element such as a resistor, a capacitor, etc. on the surface of a porous ceramic sintered body, and then the electronic circuit board is laminated and 1. A multilayer electronic circuit board, characterized in that the electronic circuit boards are bonded together with a porous intermediate layer of inorganic or metal interposed between them, and then the pores of the porous ceramic sintered body are filled with resin. (2) In the first claim, the multilayer electronic circuit board is characterized in that a conductor layer is formed on the surface of the multilayer electronic circuit board through an insulating layer made of resin or a composite material of resin and inorganic material. circuit board.