JP2007043050A5 - - Google Patents

Claims (32)

A multilayer ceramic substrate having a plurality of ceramic layers laminated and having a cavity,
The opening area in the opening of the cavity is smaller than the opening area in the midway position in the depth direction of the cavity ,
An electronic device is sealed in the cavity with a resin .   The shape of the cavity is such that a midway part in the depth direction bulges out, and the opening area of the cavity gradually increases until reaching the midway position in the depth direction, and then gradually decreases. Item 11. A multilayer ceramic substrate according to Item 1.   3. The multilayer ceramic substrate according to claim 2, wherein the cross-sectional shape of the inner wall of the cavity is a substantially arc shape.   The cavity has a multi-stage shape in which the average opening area becomes smaller stepwise in the depth direction, and at least in the first-stage cavity portion, the opening area in the opening portion is smaller than the opening area in the midway position in the depth direction. The multilayer ceramic substrate according to claim 1, wherein the multilayer ceramic substrate is provided.   The shape of the cavity portion in the first stage is a shape in which a midway portion in the depth direction bulges, and the opening area of the cavity portion gradually increases until reaching the midway position in the depth direction, and then gradually decreases. The multilayer ceramic substrate according to claim 4, wherein:   6. The multilayer ceramic substrate according to claim 4, wherein in the second and subsequent cavities, the opening area in the opening is smaller than the opening area in the midway position in the depth direction.   6. The multilayer ceramic substrate according to claim 4, wherein the second and subsequent cavities are shaped so that the opening area gradually decreases with depth.   The multilayer ceramic substrate according to any one of claims 5 to 7, wherein a cross-sectional shape of an inner wall of each of the cavity portions is a substantially arc shape. A multilayer ceramic substrate having a cavity is formed by laminating a plurality of substrate green sheets including a cavity forming green sheet having through-holes corresponding to the cavities, and pressing and firing the laminate. A method for producing a multilayer ceramic substrate comprising:
A shrinkage-suppressing material green sheet piece is disposed on a green sheet for a substrate constituting the bottom surface of the cavity, and the embedding is separated from each cavity-forming green sheet in such a manner that the cavity is filled on the shrinkage-suppressing material green sheet piece. After performing the press in a state in which the shrinkage-suppressing material green sheet is laminated on the surface of the green sheet for the substrate, which is the outermost layer of the laminate,
Firing without suppressing the shrinkage of the surface of the green sheet for the substrate and the shrinkage of the cavity opening surface of the green sheet for embedding,
A method for producing a multilayer ceramic substrate, wherein the fired product of the green sheet for embedding is removed after firing. A multilayer ceramic substrate having a cavity is formed by laminating a plurality of substrate green sheets including a cavity forming green sheet having through-holes corresponding to the cavities, and pressing and firing the laminate. A method for producing a multilayer ceramic substrate comprising:
A shrinkage-suppressing material green sheet piece is disposed on a green sheet for a substrate constituting the bottom surface of the cavity, and the embedding is separated from each cavity-forming green sheet in such a manner that the cavity is filled on the shrinkage-suppressing material green sheet piece. After the pressing is performed in a state in which the green sheet for the shrinkage suppression material having the opening corresponding to the cavity is laminated on the surface of the green sheet for the outermost substrate on the cavity opening side of the laminate, And
A method for producing a multilayer ceramic substrate, wherein the fired product of the green sheet for embedding is removed after firing. A through hole is formed in the cavity forming green sheet laminated immediately above the substrate green sheet constituting the bottom surface of the cavity according to the cavity shape, and the shrinkage suppression material green sheet piece is fitted into the through hole. The method for producing a multilayer ceramic substrate according to claim 9 or 10, wherein:   12. The method for producing a multilayer ceramic substrate according to claim 11, wherein the thickness of the shrinkage-suppressing material green sheet piece is set so as to substantially match the thickness of the substrate green sheet. The cavity has a multi-stage shape in which the opening size is gradually reduced in the depth direction, and a shrinkage-suppressing material green sheet piece is disposed on each green sheet for a substrate constituting each bottom surface having a step. The method for producing a multilayer ceramic substrate according to any one of claims 9 to 12 . The method for producing a multilayer ceramic substrate according to claim 9 or 10 , wherein a burn-out sheet is interposed between the shrinkage-suppressing material green sheet piece and the embedding green sheet.   A through hole is formed in the cavity forming green sheet laminated immediately above the substrate green sheet constituting the bottom surface of the cavity according to the cavity shape, and the shrinkage-suppressing material green sheet piece and the burnout property are formed in the through hole. The method for producing a multilayer ceramic substrate according to claim 14, wherein the sheet is fitted.   16. The method for producing a multilayer ceramic substrate according to claim 15, wherein the total thickness of the shrinkage-suppressing material green sheet piece and the burnable sheet is set so as to substantially match the thickness of the substrate green sheet.   The cavity has a multi-stage shape in which the opening size is gradually reduced in the depth direction, and the shrinkage-suppressing material green sheet piece and the burnable sheet are arranged on the green sheet for the substrate constituting each bottom surface having a step. The method for producing a multilayer ceramic substrate according to any one of claims 14 to 16, wherein:   The method for producing a multilayer ceramic substrate according to any one of claims 14 to 17, wherein the burnout sheet is formed of a resin material.   The method of manufacturing a multilayer ceramic substrate according to claim 18, wherein the resin material is the same as the resin material contained in the cavity forming green sheet. The multi-layer ceramic substrate according to any one of claims 9 to 19, wherein a cut portion corresponding to a cavity shape is formed in the green sheet for cavity formation, and a portion separated by the cut is used as the green sheet for embedding. Production method. The through-hole corresponding to a cavity shape is formed in the green sheet for cavity formation, The green sheet for embedding separately stamped and formed in this through-hole is fitted , The any one of Claim 9 to 19 characterized by the above-mentioned. A method for producing a multilayer ceramic substrate. A through hole corresponding to the shape of the cavity opening is formed in the shrinkage-suppressing material green sheet disposed on the surface of the outermost substrate green sheet on the opening side of the cavity, and the embedding green sheet is fitted therein. The method for producing a multilayer ceramic substrate according to any one of claims 9 to 21 . The method of manufacturing a multilayer ceramic substrate according to any one of claims 9 to 22, wherein the thickness of the green sheet piece of the shrinkage suppression material in the cavity portion is corrected.   The thickness of the green sheet for forming the cavity is made different from the thickness of the other green sheet for forming the cavity by making the thickness of the green sheet for forming the cavity directly above the green sheet for forming the substrate constituting the bottom surface of the cavity. 24. The method for manufacturing a multilayer ceramic substrate according to claim 23, wherein the thickness is set to be different from the thickness of the sheet for suppressing shrinkage.   The shrinkage-suppressing material green sheet disposed on the surface of the outermost substrate green sheet on the side opposite to the opening side of the cavity should be set so that the thickness is different between the part facing the cavity and the other part. The method for producing a multilayer ceramic substrate according to claim 23 or 24.   The shrinkage-suppressing material green sheet is formed by laminating a first shrinkage-suppressing material green sheet having a predetermined thickness and a second shrinkage-suppressing material green sheet having a through hole formed in a portion facing the cavity. The method of manufacturing a multilayer ceramic substrate according to claim 25, comprising: 27. The shrinkage suppression material green sheet and the shrinkage suppression material green sheet piece contain at least one selected from quartz, cristobalite, and tridymite as a shrinkage suppression material . A method for producing a multilayer ceramic substrate.   28. The method for producing a multilayer ceramic substrate according to claim 27, wherein the shrinkage suppression material green sheet and the shrinkage suppression material green sheet piece are formed of a composition containing tridymite and a hardly sinterable oxide. The method for producing a multilayer ceramic substrate according to any one of claims 9 to 28, wherein a firing temperature during the firing is 1000 ° C or lower. 30. The method for producing a multilayer ceramic substrate according to claim 9 , wherein a washing step of washing the residue is performed after the firing.   31. The method of manufacturing a multilayer ceramic substrate according to claim 30, wherein the cleaning step is performed by ultrasonic cleaning in a solvent.   The method of manufacturing a multilayer ceramic substrate according to claim 30, wherein the cleaning step is performed by wet blasting.