JP2002337125A - Green sheet layer structure, laminate, and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a green sheet layer structure which can laminate a thin green sheet by surely releasing the green sheet from a base. SOLUTION: A method for manufacturing the green sheet layer structure comprises the steps of forming a first sheet 1 having an additive layer 3 which is solid at the ambient temperature and softened or molten by heating on a first base 2, and a second sheet 10 having the green sheet 11 formed on a second base 12 which has mold releasing properties or mold released; then forming an electrode part on the sheet 11 of the sheet 10 side; oppositely contacting the front surface of the sheet 11 with the layer 3 of the first sheet 1; passing the contacted sheets 11, 1 between two rolls 13A and 13B, one or both of which is heated while matching the sheet 11 with the sheet 1; cooling the sheets; and laminating the sheet 11 with the sheet 1. The method further comprises the steps of releasing the base 12 formed with the sheet 11, and transferring the sheet 11 to the base 2 with the layer 3 from the base 12 formed ith the sheet 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a green sheet layered structure and a laminate used for producing an electronic component by laminating and firing green sheets, and a method for producing the same.

[0002]

2. Description of the Related Art In order to manufacture a ceramic multilayer component such as a ceramic multilayer substrate and a multilayer chip component, a green sheet is formed from a ceramic paste (slurry) containing a ceramic powder of a magnetic substance or a dielectric, and then the green sheet is formed. Are known in the art.

A conventional green sheet laminating method has been carried out as follows. As shown in FIG. 5A, a substrate 32 such as a PET film subjected to a release treatment (one side is a release surface 32a
The green sheet 31 is formed on the green sheet 31, and an electrode portion is formed on the green sheet 31. A green sheet (with a base material) cut into a card shape or cut out from a roll and cut into a portion to be laminated is placed one by one on a press-type suction stage, and the base material is peeled off. Using the air permeability of the sheets, the next sheet surfaces are further stacked, and the sheets are fixed. Then, the sheets are hot-pressed to strengthen the adhesion between the sheets, the base material is peeled off, and the layers are sequentially laminated.

[0004]

The conventional green sheet laminating method has the following problems.

(1) A green sheet of 10 μm or less (particularly 5 μm or less) has a low strength and may not peel off from the substrate during lamination, or the green sheet may be torn and partially remain on the substrate. FIG. 5 (B) illustrates such a situation, in which 30 is a press-type suction stage, 31 is a green sheet which is sucked and sequentially laminated,
This shows a state in which when the green sheet 31 is peeled off from the base material 32 (one side of which is the release surface 32a) subjected to the release processing, a part of the green sheet 31 remains attached to the base material side.

(2) If the pressing pressure is increased in order to improve the lamination property of the green sheets (adhesion between the green sheets), the lamination misalignment or deformation may occur. FIG.
5 illustrates such a situation (the same parts as those in FIG. 5 are denoted by the same reference numerals), 30 is a press-type suction stage, and 31 is a green sheet that is suction-adsorbed and sequentially laminated. Due to the pressing pressure between the stage 30 and the pressing die 33, a shift occurs between the green sheets.

(3) There is a case where the laminating property of the green sheet is improved by heating at the time of pressing. However, when the temperature is increased, the base material expands, which may also cause laminating misalignment or deformation.

(4) Since the air permeability of the green sheet is used, there is a limit to the number of sheets that can be stacked without displacement.

(5) If the release treatment of the substrate is strengthened to facilitate the peeling, the slurry for forming the green sheet is repelled on the substrate (low wettability of the release material and surface tension of the slurry solvent). This makes it difficult to form a thin and uniform sheet (for example, 5 μm or less).

As a known technique, Japanese Patent Application Laid-Open No. 2000-2000
Japanese Patent Publication No. 252161 discloses a technique for avoiding damage to a green sheet by devising a method of peeling a carrier film as a base material from a green sheet. However, it is recognized that when the green sheet becomes thinner than a certain degree, the above-mentioned inconvenience may still occur.

[0011] A first object of the present invention is to solve the above problems,
It is an object of the present invention to provide a green sheet layered structure which ensures separation of a green sheet from a base material and enables lamination of a thin green sheet, and a method for manufacturing the same.

A second object of the present invention is to provide a green sheet laminate having no breakage of the green sheets even when the thickness is reduced, and having no misalignment even when many sheets are laminated, and a method of manufacturing the same. It is in.

Other objects and novel features of the present invention will be clarified in embodiments described later.

[0014]

In order to achieve the above object, a green sheet layered structure according to the first aspect of the present invention is provided on a substrate via an additional layer which is solid at room temperature and is softened or melted by heating. A green sheet having a predetermined thickness.

The green sheet layered structure according to the second aspect of the present invention is characterized in that, in the first aspect, the additional layer is formed thinner than the green sheet.

The green sheet laminate according to the third aspect of the present invention is characterized in that a plurality of green sheets having a predetermined thickness are laminated via an additional layer which is solid at room temperature and softens or melts by heating.

According to a fourth aspect of the present invention, there is provided a method for manufacturing a green sheet layered structure, comprising: a first sheet having an additional layer formed on a first substrate, which is solid at room temperature and softened or melted by heating; Using a second sheet having a green sheet formed on a second substrate having moldability or a release treatment,
The additional layer of the first sheet and the green sheet of the second sheet are heated in contact with each other, then cooled and bonded, and then the second base material is peeled off to remove the first base material. The green sheet is transferred to the side.

According to a fifth aspect of the present invention, there is provided a method for manufacturing a green sheet laminate comprising a green sheet having a predetermined thickness provided on a substrate via an additional layer which is solid at room temperature and softened or melted by heating. A first step of producing a green sheet with an additional layer by exposing the base material from the structure to expose the additional layer; and forming a green sheet having a green sheet layered structure next to the additional layer of the green sheet with the additional layer. A second step of heating the sheet in a contact state, cooling the sheet, bonding the sheet, and peeling the substrate.

The method for producing a green sheet laminate according to the invention of claim 6 of the present invention is a method for manufacturing a green sheet laminate comprising a green sheet having a predetermined thickness provided on a substrate via an additional layer which is solid at room temperature and softened or melted by heating. A first step of producing a green sheet with an additional layer by exposing the base material from the structure to expose the additional layer, and laminating the green sheet with the additional layer produced in the first step via an additional layer; And a second step of cooling after heating and pressurizing.

According to a seventh aspect of the present invention, in the method for manufacturing a green sheet laminate according to the fifth or sixth aspect, the substrate is peeled off in a state where the additional layer is softened or melted by heating. And

[0021] The method for manufacturing a green sheet laminate according to the invention of claim 8 of the present application is the method according to claim 5, 6 or 7, wherein the green sheets are laminated one by one without utilizing the air permeability of the green sheets. It is characterized by cooling after heating and pressing.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a green sheet layered structure and a laminate according to the present invention and a method for producing the same will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention, which shows a step of producing a green sheet layered structure by transfer. In this case, in order to produce a green sheet layered structure, the first sheet 1 shown in FIG.
The second sheet 10 is used, but the first sheet 1 is
An additional layer 3 which is solid at normal temperature and softens or melts by heating is formed on the first base material 2, and the second sheet 10
Is a second substrate 12 having a release property or having been subjected to a release treatment.
A green sheet 11 is formed thereon. The fabrication itself of the second sheet 10 belongs to the prior art.

The first and second substrates 2 and 12 are, for example, a resin film or plate such as PET, a metal plate such as stainless steel, or a glass plate. The first base material 2 has at least heat resistance enough to withstand the temperature at which the additional layer 3 is softened or melted. These substrates 2,
For example, when a PET film is used, the thickness of 12 is 7
It is about 5 μm.

The additional layer 3 which functions as a softened or melted layer upon heating is a so-called wax or the like, which is a kind of paraffin (saturated chain hydrocarbon) or synthetic wax and has a melting onset temperature of 50 to 120 ° C. Very low substances are preferred.
The first sheet 1 is obtained by applying the additional layer 3 on one surface of the first base material 2 with a constant thickness of about several μm. A preferred example of the additional layer 3 has a thickness of 2 μm, a melting point of 80 ° C., and a melt viscosity of 100 cps of paraffin, synthetic wax, or the like.

In order to obtain the second sheet 10, a second sheet
The green sheet 11 is formed by applying a ceramic paste (slurry) containing a ceramic powder of a magnetic substance or a dielectric substance at a constant thickness to a release surface 12a having a release property of the base material 12 or subjected to a release treatment. The green sheet is formed to have a constant thickness. At this time, the compounding ratio of the binder (organic substance) contained in the green sheet is 5 to 50% by weight, and the thickness of the green sheet is 1%.
0 μm or less (more preferably 5 μm or less). If the binder compounding ratio is less than 5% by weight, sheet formation becomes difficult due to insufficient binder, and the binder compounding ratio is 50% by weight.
Exceeding the range is not preferable because voids are generated in the ceramic layer obtained after firing, and problems such as poor insulation occur. When the thickness of the green sheet exceeds 10 μm, the necessity of employing the manufacturing method described in the present invention is reduced. The lower limit of the thickness of the green sheet is limited by the particle size of the magnetic or dielectric ceramic powder, but the limit is about 1 μm. An example of a preferable green sheet has a binder compounding ratio of 15% by weight and a thickness of about 4 μm.

FIG. 1B shows the first sheet 1 shown in FIG.
After forming the second sheet 10, an electrode portion of a predetermined shape is formed on the green sheet 11 containing the magnetic substance and the dielectric powder on the second sheet 10 side, and as shown in FIG. The surface of the green sheet 11 and the additional layer 3 (the layer softened or melted by heating) of the first sheet 1 are brought into contact with each other, and the two sheets are heated while heating one or both of them, such as a laminator. Through the gap (additional layer 3
Is softened or melted and adheres to the surface of the green sheet), and cooled and bonded by cooling means 14 (for example, contact of a cooling plate, blowing of cooling air, etc.) (the additional layer which has been softened or melted is solidified). . Then, the green sheet 11 is transferred from the base 12 on which the green sheet 11 is formed to the base 2 with the additional layer 3 by first peeling off the base 12 on which the green sheet 11 is formed. Here, the transfer temperature, that is, the temperature set value of the heat roll constituted by at least one of the rolls 13A and 13B is set higher than the softening or melting start temperature of the additional layer 3, but the thermal expansion of the base materials 2 and 12 is performed. In consideration of the above, it is preferable that the temperature is not higher than necessary, and 130 ° C. or lower is preferable. For example, if the melting point of the additional layer 3 is 80 ° C., the transfer temperature (heat roll set value) is set to about 95 ° C.

As a result, as shown in FIG. 1 (D), the base material 2 is formed through the additional layer 3 which is solid at room temperature and softened or melted by heating.
A green sheet layered structure 20 having the green sheet 11 provided thereon with a predetermined thickness is obtained. Here, additional layer 3
Has a thickness of about 0.1 μm to several μm, and is formed sufficiently thinner than the green sheet 11. The green sheet layered structure 20 may be manufactured as a long roll, or may be manufactured in a rectangular card shape.

The green sheet layered structure 20 according to the first embodiment utilizes the property of the additional layer 3 which is softened or melted by heating, and determines the softening point and melting point of the additional layer 3 by using a green sheet or a base material. Is set to a value that does not affect the deformation of the green sheet 11 and the stacking deviation, so that even when the green sheet 11 is formed thin, the green sheet 11 can be easily removed from the base material without damaging the green sheet 11 (breakage, crack, partial remaining, etc.). Can be peeled. In particular, green sheet thickness 1 with low sheet strength
The effectiveness is remarkable with a green sheet of 0 μm or less (particularly 5 μm or less). As will be described later, by using the green sheet layered structure 20, by controlling the heating and cooling temperatures during the lamination of the sheets, there is no need for air permeability for fixing the green sheets, and there is no need to apply excessive heat and pressure. The green sheets can be laminated and the base material can be peeled off with high precision, and the green sheets can be easily laminated as many as the number of equipments permits.

FIG. 2 shows a second embodiment of the present invention, which shows another step of manufacturing a green sheet layered structure. In this case, instead of using a conventional release-treated product as a substrate, as shown in FIG. 2A, a resin film or plate such as PET, a metal plate such as stainless steel, or a substrate 2 such as a glass plate.
And an additional layer 3 which is solid at room temperature and softens or melts by heating.
Is used. Then, a ceramic paste (slurry) containing a ceramic powder of a magnetic substance or a dielectric substance is applied on the additional layer forming surface of the base material 2 at a constant thickness to form the green sheet 11 at a constant thickness as shown in FIG. I do.

As a result, as shown in FIG. 2 (B), a green sheet layered structure in which the green sheet 11 is provided on the base material 2 with a predetermined thickness via the additional layer 3 which is solid at room temperature and softened or melted by heating. 20 is obtained. The conditions such as the thickness of the additional layer 3 and the green sheet 11 are the same as in the first embodiment.

FIG. 3 shows a third embodiment of the present invention, which shows a step of manufacturing a green sheet laminate using the green sheet layered structure 20 described with reference to FIG. 1 or FIG.

First, as shown in FIG. 3B, the green sheet layered structure 20 shown in FIG. 3A is placed on a press-type suction stage 21 for applying heat and pressure with the green sheet 11 facing downward (facing the suction stage). Then, the green sheet 11 side is sucked and held by the suction stage 21 so that the substrate 2
Is peeled off. At this time, preferably, the upper side of the green sheet layered structure 20 is heated to soften or melt the additional layer 3 so that the substrate 2 is peeled off. Thereby, the first step of manufacturing the green sheet with the additional layer in which the base material 2 is peeled off from the green sheet layered structure 20 to expose the additional layer 3 is executed.

After the lowermost green sheet 11 is held on the suction stage 21, the next green sheet layered structure 20 is moved downward by the suction plate 22 as shown in FIG. Then, the green sheets 11 are opposed to each other and aligned with each other, and are heated and pressed. The heating condition at this time is higher than the softening or melting start temperature of the additional layer 3, but preferably not higher than necessary in consideration of the thermal expansion of the base material 2;
The following is preferred. As a preferred example of the laminating conditions, when the melting point of the additional layer 3 is 80 ° C., the laminating temperature (set value of hot press) is set to about 85 ° C., and the pressure is 0.5 kgf /
cm ² . Thereafter, the additional layer 3 interposed between the softened or melted green sheets 11 is solidified by cooling with cooling means, and then the base material 2 is peeled off as shown in FIG. That is, the second step of heating the next green sheet 11 of the green sheet layered structure 20 to the additional layer 3 of the green sheet with the additional layer in a state of being in contact with each other, and then cooling and bonding the green sheet 11 is executed. Usually, since the surface of the green sheet 11 has fine irregularities, the additional layer 3
Are adhered to each other after melting, whereas the adhesion between the additional layer 3 and the substrate 2 is not so strong because the surface of the substrate 2 is formed smoothly. The substrate 2 can be easily peeled from the substrate. If necessary, the additional layer 3 on the side of the base material 2 may be heated and melted to peel the base material 2.

Thereafter, by repeating the laminating operation shown in FIGS. 3C and 3D, a green sheet laminate 23 in which the required number of green sheets 11 are laminated and integrated as shown in FIG. 3E is obtained. be able to.

According to the third embodiment, the following effects can be obtained.

(1) The green sheet 11 can be easily peeled off without damaging the green sheet 11 (breakage, cracks, remaining portions, etc.), has a low sheet strength, and has a green sheet thickness of 10 μm.
Particularly remarkable effects can be obtained with a sheet having a thickness of 5 μm or less.

(2) Without utilizing the air permeability of the green sheets 11, the green sheets can be fixed to each other by a change in state of the additional layer 3 which is solid at room temperature such as wax and is softened or melted by heating. Therefore, it is possible to stack green sheets to the limit or more when the air permeability of the green sheets is used.

(3) The green sheets can be fixed to each other due to the change in the state of the additional layer 3 and can be laminated without applying a high pressing pressure, thereby preventing a lateral shift of the green sheets generated at a high pressure. .

(4) By appropriately setting the melting point of the additional layer 3 to a temperature at which the base material does not expand, it is possible to prevent lamination displacement due to expansion.

FIG. 4 shows a fourth embodiment of the present invention, which shows another step of producing a green sheet laminate using the green sheet layered structure 20 described with reference to FIG. 1 or FIG. In this case, a plurality of suction plates 25 are prepared as shown in FIG.
The green sheet 11 is disposed on each suction plate 25 downward (facing the suction plate), and the surface on the green sheet 11 side is sucked and held by the suction plate 25 to peel the base material 2. At this time, preferably, the upper side of the green sheet layered structure 20 is heated to soften or melt the additional layer 3 so that the substrate 2 is peeled off. Thereby, the green sheet layered structure 20
The first step of manufacturing the green sheet 26 with the additional layer in which the base material 2 is peeled off from the substrate to expose the additional layer 3 is executed.

Next, as shown in FIG.
Is reversed and the green sheet 2 with the additional layer from which the substrate has been peeled off
6 is transferred to a press-type suction stage 21 for applying heat and pressure (the green sheet becomes an upper layer). Thereafter, the green sheet 26 with an additional layer held by another suction plate 25 is
The adsorbing plate 25 is turned over, the additional layer 3 is laminated so as to be a lower layer, the green sheets 11 are overlapped with the additional layer 3 interposed therebetween, aligned, and pressed under heat and pressure. After that, the additional layer 3 interposed between the green sheets 11 once softened or melted is cooled by cooling means. As a result, a second step of laminating the green sheet 26 with the additional layer produced in the first step via the additional layer 3, heating and pressing, and then cooling is performed. Then, the second step is repeated every time one green sheet 26 with an additional layer is laminated, whereby a green sheet laminate of a required number of layers is obtained.

The heating / pressing conditions and the like during the lamination may be the same as in the third embodiment.

When manufacturing a ceramic multilayer component such as a ceramic multilayer substrate or a multilayer chip component, the green sheet laminate obtained in the third or fourth embodiment is fired, and if necessary, externally. Form electrodes. During firing,
Since the additional layer such as waxes interposed between the green sheets disappears, the function of sintering and integrating the multilayer green sheets during firing is not hindered.

Although the embodiments of the present invention have been described above, it is obvious to those skilled in the art that the present invention is not limited to the embodiments and that various modifications and changes can be made within the scope of the claims. There will be.

[0046]

As described above, according to the green sheet layered structure and the method of manufacturing the same according to the present invention, by utilizing the properties of the additional layer formed on the base material, which is softened or melted by heating, Even when the green sheet is formed thin, the green sheet can be easily peeled from the substrate without damaging the green sheet (breakage, cracks, partial remaining, etc.). In particular, the effectiveness is remarkable for a green sheet having a weak sheet strength and a green sheet thickness of 10 μm or less (particularly 5 μm or less).

Further, according to the green sheet laminate and the method for producing the same according to the present invention, by using the green sheet layered structure, a solid such as wax at room temperature can be used without utilizing the air permeability of the green sheet. The green sheets can be fixed to each other by a change in the state of the additional layer which is softened or melted by heating. Therefore, it is possible to stack green sheets to the limit or more when the air permeability of the green sheets is used. In addition, the green sheets can be fixed to each other by the change in the state of the additional layer, and the lamination can be performed without applying a high pressing pressure, so that the green sheets generated by the high pressure can be prevented from shifting in the horizontal direction. Furthermore, by appropriately setting the melting point of the additional layer to a temperature at which the base material does not expand, it is possible to prevent lamination displacement due to expansion.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a step of producing a green sheet layered structure by transfer according to a first embodiment of the present invention.

FIG. 2 is an explanatory view showing another process for producing a green sheet layered structure according to the second embodiment of the present invention.

FIG. 3 is an explanatory view showing a step of producing a green sheet laminate using a green sheet layered structure according to a third embodiment of the present invention.

FIG. 4 is a fourth embodiment of the present invention and is an explanatory view showing another step of producing a green sheet laminate using a green sheet layered structure.

FIG. 5 is an explanatory diagram showing a situation in which a green sheet is damaged in a conventional technique.

FIG. 6 is an explanatory view showing a situation in which the stacked green sheets are shifted in the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st sheet 2 1st base material 3 additional layer 10 2nd sheet 11, 31 green sheet 12 2nd base material 12a mold release surface 13A, 13B roll 14 cooling means 20 green sheet layered structure 21, 30 adsorption Stage 22 Suction plate 23 Green sheet laminate 25 Suction plate 26 Green sheet with additional layer 32 Substrate

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tomoyuki Sasaki 1-13-1 Nihonbashi, Chuo-ku, Tokyo Inside TDK Corporation (72) Inventor Genichi Watanabe 1-13-1 Nihonbashi, Chuo-ku, Tokyo Inside DK Corporation (72) Inventor Junichi Sudo 1-13-1 Nihonbashi, Chuo-ku, Tokyo Tee DK Corporation F term (reference) 4F100 AA17C AB01A AD00C AJ11B AK02B AK42A AR00B AT00A BA03 BA07 BA10A BA10C EC032 GB41 JA04B JL00 JM02 4G030 BA09 CA03 CA07 CA08 GA19 4G052 DA02 DB01 DC01 DC06 4G055 AA08 AC01 AC09 BA24

Claims (8)

[Claims] 1. A green sheet layered structure wherein a green sheet is provided on a substrate at a predetermined thickness via an additional layer which is solid at room temperature and softened or melted by heating. 2. The green sheet layered structure according to claim 1, wherein the additional layer is formed thinner than the green sheet. 3. A green sheet laminate comprising a plurality of green sheets having a predetermined thickness laminated through an additional layer which is solid at room temperature and softens or melts by heating. 4. A first sheet having an additional layer which is solid at room temperature and which is softened or melted by heating on a first substrate, and a second substrate having a releasing property or having been subjected to a releasing treatment. Using a second sheet having a green sheet formed thereon, the additional layer of the first sheet and the green sheet of the second sheet are heated in contact with each other, then cooled and bonded, and then the A method for manufacturing a green sheet layered structure, comprising: separating a second base material and transferring the green sheet to the first base material side. 5. A green sheet layered structure in which a green sheet is provided with a predetermined thickness on a substrate through an additional layer which is solid at room temperature and softens or melts by heating, exposing the substrate to expose the additional layer. A first step of producing a green sheet with an additional layer, wherein the green sheet of the next green sheet layered structure is heated in contact with the additional layer of the green sheet with the additional layer, and then cooled and bonded. And a second step of peeling the substrate. 6. A green sheet layered structure having a green sheet provided on a substrate with a predetermined thickness through an additional layer which is solid at room temperature and softens or melts by heating, exposing the substrate to expose the additional layer. A first step of producing a green sheet with an additional layer that has been made, and a second step of laminating the green sheet with an additional layer produced in the first step via an additional layer, heating and pressing, and then cooling. A method for producing a green sheet laminate, comprising: 7. The method for manufacturing a green sheet laminate according to claim 5, wherein the base material is peeled off in a state where the additional layer is softened or melted by heating. 8. The method for producing a green sheet laminate according to claim 5, wherein the green sheets are laminated one by one without utilizing the air permeability of the green sheets, and cooled after heating and pressing. .