JP2010080866A - Multilayer wiring board and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer wiring board which secures insulation property between members that are applied with voltage and have mutually different potentials, and substantially inhibits warpage and deflection. <P>SOLUTION: In order to achieve the objective, the multilayer wiring board 100 includes: a ceramic wiring board 110 having a first wiring layer 112 as an internal layer; a resin layer 120 laminated on the ceramic wiring layer 110; and a second wiring layer 130 laminated on the resin layer 120, wherein the first and second wiring layers 112, 130 are directly connected by a via 140. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a multilayer wiring board and a manufacturing method thereof.

  Conventionally, electronic devices such as active components of semiconductor devices, passive components such as filters, resistors and capacitors, and chip components thereof have been increasingly reduced in size and weight, and wiring boards on which these are mounted, Modules, package parts, and the like are also desired to be further reduced in size and weight by high-density mounting. In order to satisfy these requirements, various multilayer wiring boards that can not only realize high-density wiring but also can be further reduced in size and weight have been studied.

For example, in Patent Document 1, in a wiring board in which a resin insulating layer and a conductor layer are laminated on a core substrate, the core substrate is mainly composed of ceramic, and the linear expansion coefficient of the core substrate and the resin insulating layer is a predetermined condition. A wiring board that satisfies the above has been proposed. According to this patent document 1, when the linear expansion coefficients of the core substrate and the resin insulating layer satisfy a predetermined condition, it is difficult to cause separation between the core substrate and the resin insulating layer, and a highly reliable wiring board can be easily obtained. It can be manufactured.
JP 2005-191299 A

  In the wiring substrate described in Patent Document 1, as shown in FIG. 1 and the description in the corresponding specification, a conductor layer disposed on an inner layer of a core substrate 1 having a ceramic dielectric layer as an insulating layer. 61 and the conductor layer 8 disposed between the outer resin insulation layers 7 and 9 are connected to each other by connecting the via conductor 4 in the core substrate 2 and the via 34 provided in the resin insulation layer 7 to the conductor layer. It is secured by connecting via 63 (pad). Since the conductor layer 63 has a larger cross-sectional area in the in-plane direction than the via conductors 4 and 34, the conductor layer 63 and other wiring layers that are provided in the same layer of the conductor layer 8 and are not connected to the conductor layer 63. In other words, in order to ensure insulation between layers having different potentials when a voltage is applied (hereinafter also referred to as “different potential layers”), the resin insulating layer 7 existing between them is made thicker. There is a need. However, when the resin insulating layer 7 is thickened, the wiring board is warped or distorted due to shrinkage of the resin insulating layer 7 or the like. In particular, in recent years, as the pitch of the wiring substrate is reduced, the thickness of the wiring substrate has been further reduced, and it has been difficult to achieve both the above-described insulation between different potential layers and the suppression of warpage and distortion.

  Accordingly, the present invention has been made in view of the above circumstances, and while ensuring insulation between members having different potentials when a voltage is applied thereto, a multilayer wiring board in which warpage and distortion are sufficiently suppressed, and its An object is to provide a manufacturing method.

  In order to achieve the above object, the present inventors have focused on omitting pads connecting vias, and as a result of intensive research, they have completed the present invention. That is, the multilayer wiring board according to the present invention includes a ceramic wiring board having a first wiring layer as an inner layer, a resin layer laminated on the ceramic wiring board, and a second wiring layer laminated on the resin layer, A wiring board in which the first and second wiring layers are directly connected by vias. The multilayer wiring board preferably does not have a wiring layer connected to the via between the ceramic wiring board and the resin layer.

  In conventional multilayer wiring boards including those described in Patent Document 1, a wiring layer provided on the inner layer of the ceramic wiring board and a wiring layer formed on the surface of the resin layer laminated on the ceramic wiring board Are connected to each other through vias extending from the pads provided between the ceramic wiring board and the resin layer to the respective wiring layers. As described above, the conventional multilayer wiring board does not directly connect the respective wiring layers with vias, and passes through a pad having a larger cross-sectional area in the in-plane direction than the vias. Since the cross-sectional area of the pad is large, the distance between the pad and the other wiring layer laminated on the resin layer is shorter than the distance between the via and the other wiring layer, and dielectric breakdown is likely to occur. Therefore, in order to avoid such dielectric breakdown between different potential layers, the resin layer must be thickened. As a result, the thickness of the resin layer with respect to the ceramic wiring board increases, and the entire multilayer wiring board tends to be warped or distorted due to the shrinkage of the resin layer or the like. Moreover, if the resin layer is thinned to suppress warping and distortion of the multilayer wiring board, dielectric breakdown between different potential layers tends to occur.

  On the other hand, in the multilayer wiring board of the present invention, the first wiring layer in the inner layer of the ceramic wiring board and the second wiring layer laminated on the resin layer are directly connected by vias. This eliminates the need for a pad or the like for connecting these wiring layers. As a result, only vias having a small cross-sectional area in the in-plane direction exist between the wiring layers, and the distance between vias having different potentials and other wiring layers can be increased when a voltage is applied. However, dielectric breakdown between different potential layers is sufficiently suppressed. If the resin layer can be made thin, the ceramic wiring board becomes relatively thick. Therefore, warpage and distortion of the multilayer wiring board can be sufficiently prevented by the rigidity of the ceramic wiring board even when the resin layer contracts.

  Therefore, such an effect of the present invention is more effective when the multilayer wiring board of the present invention further includes a third wiring layer that is laminated on the resin layer and can have a potential different from that of the first wiring layer. To be played.

  A method for manufacturing a multilayer wiring board according to the present invention includes a plurality of green sheets made of a base material of a ceramic substrate and laminated together, and a first layer made of a conductive paste disposed in an inner layer of the plurality of green sheets; And a step of preparing a structure including a non-sintered paste made of a material that does not sinter at the firing temperature of the base material filled in the hole communicating from the surface of the green sheet of the outermost layer to the first layer And firing the structure at the firing temperature of the base material to obtain a ceramic wiring board including a ceramic substrate that is a fired body of the green sheet and a wiring layer that is a fired body of the first layer; Removing the non-sintered paste from the ceramic wiring board; forming a resin layer made of a resin on the main surface of the ceramic wiring board; and vias connected to the wiring layer in the holes Forming a production method and a step of forming a wiring layer to be connected to the via on the surface of the resin layer. According to this manufacturing method, the multilayer wiring board of the present invention can be manufactured. That is, the method for manufacturing a multilayer wiring board according to the present invention is capable of manufacturing a multilayer wiring board in which warpage and distortion are sufficiently suppressed while ensuring insulation between members having different potentials when a voltage is applied. it can.

  ADVANTAGE OF THE INVENTION According to this invention, while ensuring the insulation between the members which have a potential different from each other by applying a voltage, the multilayer wiring board by which curvature and distortion were fully suppressed and its manufacturing method can be provided.

  Hereinafter, the best mode for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail with reference to the drawings as necessary. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the positional relationship such as up, down, left and right is based on the positional relationship shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios.

  FIG. 1 is a cross-sectional view schematically showing a main part of the multilayer wiring board of the present embodiment. The multilayer wiring board 100 of the present embodiment includes a ceramic wiring board 110 having a wiring layer 112 as an inner layer, a resin layer 120 laminated on the ceramic wiring board 110, and a wiring layer 130 laminated on the resin layer 120. The wiring layers 112 and 130 are directly connected between the layers by vias 140.

  The ceramic wiring board 110 includes a ceramic substrate 116 and wiring layers 112 and 114 provided in an inner layer of the ceramic substrate 116, and further connects the wiring layer 114 and a wiring layer (not shown) below the wiring layer 114 between the layers. Via 113, and via 111 connecting wiring layer 112 and wiring layer 114 between the layers.

  The ceramic substrate 116 is not particularly limited as long as it is insulating and contains a ceramic material (base material). The multilayer wiring board 100 provided with such a ceramic substrate 116 is preferable because it has excellent heat dissipation, wiring accuracy, and high-frequency characteristics as compared with a multilayer wiring board using only a conventional resin as an insulating layer. A ceramic material is a material obtained by baking the material contained in the green sheet which concerns on the below-mentioned embodiment, for example. The ceramic substrate 116 has insulating layers 116e, 116f, and 116f from above with the wiring layers 112 and 114 as boundaries. The thickness of these insulating layers 116e, 116f, and 116g may be, for example, 10 to 200 μm. The insulating layer 116e has a through hole 116a that communicates from the interface with the resin layer 120 to the upper surface of the wiring layer 112 in the thickness direction. The size of the through hole 116a is not particularly limited, and the inner diameter at the opening 116b is preferably 50 to 200 μm from the viewpoint of miniaturization and miniaturization (narrow pitch). Since the through hole 116a is formed by drilling from above, it has a tapered shape that tapers downward.

As the ceramic material, a low temperature co-fired ceramics (LTCC) material that can be fired simultaneously with a conductive material used for each wiring layer described later is preferable. Examples of the LTCC material include a glass composite material (glass composite material), a crystallized glass material, and a non-glass material (ceramics low-temperature fired material). The glass composite material is usually a mixed material of 50 to 70% by mass of amorphous glass powder and 50 to 30% by mass of ceramic powder (for example, alumina powder). A material in which a large number of fine crystals are precipitated in a glass component, and is also called glass ceramics. The non-glass-based material is a component that forms a liquid phase during firing of ZnO, CuO, B ₂ O ₃ or the like on a ceramic powder (for example, BaO-rare earth oxide-TiO ₂ -based material powder) as a main component (for example). It is a material that can be fired at a low temperature by adding a small amount (usually 10% or less) of a sintering aid.

Among these, the non-glass-based material is excellent in characteristics as a dielectric material for a high-frequency device such as a resonator. For example, the BaO-4TiO ₂ system and the BaO-rare earth oxide-TiO ₂ system are used. Materials, particularly BaO—Nd ₂ O ₃ —TiO ₂ materials, are particularly preferred because of their high dielectric constant and Q value (dielectric loss evaluation factor: defined by Q = 1 / tan δ).

  The wiring layers 112 and 114 are conductive and may be circuit wiring having a predetermined pattern shape, or may be in the form of a pad or a land. The materials constituting the wiring layers 112 and 114 will be described in detail in the description of the method for manufacturing a multilayer wiring board, which will be described later. For example, silver (Ag), palladium (Pd), gold (Au ), Copper (Cu) and nickel (Ni) and alloys of these metals. Among these, silver is preferable from the viewpoints of oxidation resistance and low temperature sintering. Moreover, copper is preferable from the viewpoint of migration resistance. The thickness of the wiring layers 112 and 114 may be, for example, 5 to 35 μm.

  The columnar vias 111 and 113 are formed so as to penetrate the insulating layers 116f and 116g in the thickness direction, respectively. The vias 111 and 113 exhibit conductivity, and examples of constituent materials include silver, palladium, gold, copper, nickel, and alloys of these metals as conductive materials that impart conductivity. Among these, silver is preferable from the viewpoints of oxidation resistance and low temperature sintering. Moreover, copper is preferable from the viewpoint of migration resistance. The diameter of the vias 111 and 113 is preferably 50 to 200 μm from the viewpoint of connectivity although it depends on the interlayer thickness.

  When the ceramic wiring board 110 functions as a core substrate, the thickness is preferably 50 to 500 μm. When the thickness is equal to or more than the lower limit, the rigidity of the multilayer wiring board 100 can be increased and the high frequency characteristics can be further improved. Further, when the thickness is not more than the above upper limit value, the multilayer wiring board 100 can be further contributed to size reduction and height reduction.

  The resin layer 120 exhibits insulating properties and is composed of a resin composition. The resin contained in the resin composition may be either a thermoplastic resin or a thermosetting resin. Specifically, an epoxy resin, a phenol resin, a polyvinyl benzyl ether, a bismaleimide triazine resin, a cyanate ester resin, Examples include polyimide, polyolefin resin, polyester, polyphenylene oxide, liquid crystal polymer, silicone resin, and fluorine resin. These are used singly or in combination of two or more. In addition, the resin composition may contain a rubber component such as acrylic rubber or ethylene acrylic rubber, or may contain an inorganic filler such as ceramics, as long as the insulating property can be ensured. The thickness of the resin layer 120 is preferably 30 μm or less, and more preferably 2 to 20 μm. When the thickness of the resin layer 120 is 30 μm or less, even when the thickness of the resin layer 120 varies within the range, warping and distortion of the multilayer wiring board 100 can be further reliably suppressed. Further, by setting the thickness of the resin layer 120 to 2 μm or more, dielectric breakdown between different potential layers can be more effectively and reliably prevented, and adhesion to the ceramic wiring board 110 can be ensured.

  The ratio of the thickness of the resin layer 120 to the thickness of the portion above the wiring layer 112 of the insulating layer 116e in the ceramic wiring board 110 (resin layer / insulating layer) is such that the thickness of the insulating layer 116e and the resin layer 120 is within the above range. If set in, it can be set to any value.

  The multilayer wiring board 100 of the present embodiment may include not only the illustrated resin layer 120 but also other resin layers covering the ceramic wiring board.

  The wiring layer 130 exhibits conductivity, and may be circuit wiring having a predetermined pattern shape, or may be in the form of a pad, a land, or the like. The material constituting the wiring layer 130 will be described in detail in the description of the manufacturing method of the multilayer wiring board described later. Examples of the conductive material imparting conductivity include silver, palladium, gold, copper and nickel, and alloys of these metals. Is mentioned. Among these, copper is preferable from the viewpoint of migration resistance. The thickness of the wiring layer 130 may be, for example, 2 to 35 μm.

  The via 140 exhibits conductivity and has a tapered shape that tapers downward. The via 140 connects the wiring layer 112 and the wiring layer 130 between the layers through a through hole 116 a formed in the thickness direction of the insulating layer 116 e in the ceramic substrate 116. The diameter of the via 140 is preferably thinner from the viewpoint of more effectively preventing dielectric breakdown between different potential layers, but is 20 to 200 μm in both the portion joined to the wiring layer 112 and the portion joined to the wiring layer 130. It is preferable that it is 50-100 micrometers. When the diameter of the via 140 is equal to or larger than the lower limit value, the wiring layer 112 and the wiring layer 130 are more reliably connected to each other by the via 140, and disconnection thereof can be more effectively prevented. When the diameter of the via 140 is equal to or smaller than the upper limit value, it is possible to more effectively and reliably prevent dielectric breakdown between different potential layers.

  Examples of the constituent material of the via 140 include silver, palladium, gold, copper, nickel, and alloys of these metals as conductive materials that impart conductivity. Among these, copper is preferable from the viewpoint of migration resistance.

  A resin composition is filled around the via 140 in the through hole 116 a to form the resin filling portion 122. Since the resin filling portion 122 is bonded to the side surface of the via 140 together with the resin layer 120 and supported, an effect of protecting the ceramic wiring board from a chemical solution such as desmear treatment, alkali treatment, and acid treatment after laser processing can be obtained. The resin composition filled in the through holes 116 a only needs to have the same composition as the resin layer 120.

  The multilayer wiring board 100 of this embodiment further includes a wiring layer 150. Similar to the wiring layer 130, the wiring layer 150 is laminated on the resin layer 120, but is not connected to the wiring layer 112 or the wiring layer 130. That is, the wiring layer 150 is a layer having a potential different from that of the wiring layer 112 and the wiring layer 130 when a voltage is applied. The wiring layer 150 exhibits conductivity, and may be a circuit wiring having a predetermined pattern shape, or may be in the form of a pad, a land, or the like. The constituent material may be the same as that of the wiring layer 130.

  In the multilayer wiring board 100 of the present embodiment, the wiring layer 112 in the inner layer of the ceramic wiring board 110 and the wiring layer 130 laminated on the resin layer 120 are directly connected by the vias 140. The pads and lands provided on the ceramic substrate 116 for connecting the wiring layers are not provided. Therefore, in the multilayer wiring board 100 of the present embodiment, dielectric breakdown between different potential members in the stacking direction is sufficiently suppressed as compared with the conventional case. As a result, the resin layer 120 can be made thinner than before, and the ceramic wiring board 110 can be made relatively thicker than before in a multilayer wiring board having the same thickness. The warp and distortion of the multilayer wiring board 100 can be sufficiently prevented due to the rigidity of the ceramic wiring board 110 due to shrinkage or the like. Although the distance between the wiring layer 112 and the wiring layer 150 is shortened by making the resin layer 120 thin, since the insulating layer 116e of the ceramic substrate 116 exists between these wiring layers, the occurrence of dielectric breakdown occurs. It can be sufficiently prevented. Further, by making the resin layer 120 thinner, the multilayer wiring board 100 can be further thinned.

  In particular, in recent years, both narrower pitch and thinner layers of wiring boards have been further demanded, and design rules within the same layer such as circuit wiring line / space width have been determined in detail, but between different layers. The design rules are not strictly determined. Under such circumstances, even if the wiring design based on the design rule is made in the same layer, the distance between the wiring layers existing in different layers becomes too short, and dielectric breakdown is likely to occur. The means for directly connecting the wiring layer 112 and the wiring layer 130 with the via 140 as in the multilayer wiring board 100 of the present embodiment is an effective means for suppressing the dielectric breakdown between the different layers.

  In the multilayer wiring board 100 of the present embodiment, the wiring layer 130 is the outermost wiring layer. The distance between the outermost wiring layers is usually shorter than the distance between the wiring layers inside the multilayer wiring board because there is no resin or ceramic between them and only a space (atmosphere with high dielectric constant) is interposed between them. can do. Then, even if the wiring layer 150 is further brought closer to the wiring layer 130, the insulating property in the outermost layer can be secured. In such a case, the multilayer wiring board 100 of the present embodiment is a particularly preferable aspect because it can sufficiently ensure insulation between different potential members.

  Furthermore, when LTCC material is used as the ceramic material constituting the ceramic substrate 116, the wiring specifications on the ceramic substrate 116 are compared with the wiring specifications (such as the pitch between the wirings) on the ceramic substrate 116 and the wiring specifications on the resin layer 120. Is much more severe. In order to connect the plurality of wiring layers 112 and the wiring layer 130 between the layers, if a pad or land provided between the ceramic substrate 116 and the resin layer 120 is passed, a distance between the plurality of pads or land is secured. Therefore, the interval between the plurality of interlayer connections becomes wide and it becomes difficult to realize a narrow pitch. On the other hand, in the multilayer wiring board 100 of this embodiment, since it is not necessary to provide such a pad or the like between the ceramic substrate 116 and the resin layer 120, the interval between a plurality of interlayer connections can be reduced, and dielectric breakdown is prevented. In a range that can be ensured, it is possible to further reduce the pitch.

  Further, depending on the composition of the resin composition constituting the resin layer 120, minute voids are likely to be generated on the surface of the resin layer 120. In this case, if the thickness of the resin layer 120 is reduced, the conductive material constituting the wiring layer 150 may enter a minute gap in the resin layer 120 and reach the vicinity of the interface between the resin layer 120 and the ceramic substrate 116. . Furthermore, the resin composition may contain a low resistivity inorganic filler. In these cases, if a land or a pad is provided between the resin layer 120 and the ceramic substrate 116, it is difficult to form the wiring layer 150 at a position near them in order to prevent dielectric breakdown. Since the multilayer wiring board 100 of the present embodiment does not need to provide lands or pads between the resin layer 120 and the ceramic substrate 116 as described above, the restriction on the position where the wiring layer 150 is formed is reduced, and the circuit design is reduced. The degree of freedom is further expanded.

  2, 3 and 4 are schematic process diagrams for explaining a method of manufacturing a multilayer wiring board according to another embodiment of the present invention, and each drawing shows a cross-section of a main part of the multilayer wiring board. In the manufacturing method of this embodiment, first, a plurality of green sheets 210, 211, 212, 213, and 214 (denoted as “green sheets 210 to 214”, which are made of a base material of a ceramic substrate; the same applies hereinafter). The conductive paste layers 215, 216, 217, and 218 made of the conductive paste disposed in the inner layers of the laminated green sheets 210 to 214 and the surface of the outermost green sheets 210 and 214 communicate with the conductive paste layers 215 and 218, respectively. A structure 200 including non-sintered bodies 220 and 224, which are non-sintered pastes made of a material that does not sinter at the firing temperature of the base material filled in the through-holes 210a and 214a, is prepared. In this structure 200, via precursors 221, 222, and 223 made of a conductive paste are filled in through holes 211 a, 212 a, and 213 a formed in the green sheets 211 to 213, respectively. The base material of the ceramic substrate may be the same as that described in the above embodiment.

The green sheets 210 to 214 included in the structure 200 are preferably those containing an LTCC material. For example, the green sheets 210 to 214 are obtained as follows. First, in order to prepare a base material of a non-glass material, for example, rare earth elements such as barium (Ba) and neodymium (Nd) as main components and titanium (Ti) oxides are prepared, and they have a predetermined composition. A predetermined amount is weighed so as to obtain a ratio, and mixed by, for example, wet mixing using water. Then, in order to synthesize a rare earth oxide-TiO ₂ compound such as BaO—Nd ₂ O ₃ , the mixture was calcined at a temperature of, for example, 1100 ° C. or higher, preferably about 1100 ° C. to 1400 ° C. for a predetermined time. Then, it grind | pulverizes so that it may become a predetermined particle size. The main component material does not need to be an oxide, and barium, rare earth elements, and titanium such as carbonates, hydroxides, sulfides, and the like that can be converted into oxides by heat treatment may be used. Good.

Next, a main component (base material powder) obtained by weighing a predetermined amount of each of the oxides of copper (Cu), zinc (Zn), and boron (B), which are sintering aid components, and calcining first. And the BaO-rare earth oxide-TiO ₂ compound, for example, by wet mixing using water or the like. The mixing ratio of the main component and the sintering aid at this time is not particularly limited, and can be appropriately adjusted, for example, so that the sintering aid is about 0.1 to 10% by mass with respect to the main component powder. Note that the sintering aid need not be an oxide as in the case of the main component material. For example, a sintering aid that becomes an oxide by heat treatment, such as carbonate, hydroxide, sulfide, etc., is used. Also good.

  Next, in order to obtain a powder having a narrow particle size distribution in order to improve the uniform dispersibility of the main component and the sintering aid component and to improve the workability such as molding in a subsequent process, Then, after re-calcining at a temperature equal to or lower than the sintering temperature for a predetermined time, the calcined powder is pulverized to a predetermined particle size.

  Then, the obtained powder is made into, for example, acrylic (acrylic acid, methacrylic acid or a homopolymer or copolymer thereof, more specifically, an acrylic ester copolymer, a methacrylic ester copolymer. , Acrylic acid ester-methacrylic acid ester copolymer, etc.), polyvinyl butyral, polyvinyl alcohol, acrylic-styrene, polypropylene carbonate, cellulose, ethyl cellulose, and other homopolymers or copolymers with an appropriate solvent. A dissolved organic binder such as a vehicle, or an inorganic binder, and a plasticizer such as ester and an organic solvent such as terpineol as necessary are mixed to obtain a slurry. Next, the slurry is formed into a sheet by an appropriate method such as a doctor blade method, a slurry casting method, a screen printing method, a rolling method, or a pressing method, and a plurality of the slurry sheets of the dielectric are laminated as desired to obtain a green sheet. 210 to 214 are obtained.

  Next, through holes 210a, 211a, 212a, 213a, and 214a are provided in the thickness direction of the obtained green sheets 210 to 214 by punching, laser irradiation, drilling, and the like, respectively.

  Next, a conductive paste is prepared, and this conductive paste is filled into the through holes 211a to 213a of the green sheets 211 to 213 to form via precursors 221 to 223. As the conductive paste, a metal paste showing good conductivity is preferable. As the metal paste, one containing the constituent material of the wiring layer according to the above-described embodiment is preferable, and silver (Ag), copper (Cu), silver-palladium (Ag-Pd), gold (Au), platinum (Pt) Add an organic binder such as polyvinyl alcohol, acrylic or ethyl cellulose to a powder such as nickel (Ni) (for example, having an average particle size of the order of several μm), and mix appropriately to obtain a viscosity suitable for coating. Can be used. Also, the metal contained in the metal paste need not be a metal from the beginning, and for example, a metal that becomes a metal by heat treatment such as nitrate, oxide, chloride, etc. can be used.

Furthermore, it is preferable to add an appropriate sintering aid to the metal paste. As the sintering aid, amorphous SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ , ZnO, PbO, Bi ₂ O ₃ , ZrO ₂ , TiO ₂ , alkali metal oxide, alkaline earth metal oxidation objects, or glass powder such as rare earth oxides, crystalline SiO _2, Al ₂ O _{3 of, ZrO 2, TiO 2, ZnO} , MgO, MnO 2, MgAl 2 O 4, ZnAl 2 O 4, MgSiO 3, Zn 2 Ceramic powders such as SiO ₄ , Zn ₂ TiO ₄ , SrTiO ₃ , CaTiO ₃ , MgTiO ₃ , BaTiO ₃ , AlN, Si ₃ N ₄ , and SiC can be appropriately selected and used alone or in combination.

  At this time, the compound or composition of the sintering aid contained in the metal paste is more preferably the same kind as the sintering aid contained in the green sheets 210 to 214 of the base material. Further, the mixing ratio of the metal component and the sintering aid component in the metal paste can be appropriately set according to the electrical properties and functions required for the via formed by subsequent firing.

  Subsequently, a non-sintered paste is prepared, and this non-sintered paste is filled into the through holes 210a and 214a of the green sheets 210 and 214 to obtain non-sintered bodies 220 and 224. The non-sintered bodies 220 and 224 can be easily removed from the through holes 210a and 214a even after firing at the firing temperature of the green sheets 210 and 214 (sintering temperature of the base material powder of the green sheets 210 and 214). It is easy to remove. The non-sintered paste for obtaining the non-sintered bodies 220 and 224 includes a binder, an inorganic powder capable of imparting easy removal to the non-sintered bodies 220 and 224, and an organic solvent (for example, organic Vehicle). Examples of such inorganic powder include calcium carbonate, zirconium oxide, and aluminum oxide. Among these, calcium carbonate is preferable. Although calcium carbonate is not as much as tridymite, which will be described later, it is difficult to shrink even if it is fired at the firing temperature of green sheets 210 and 214, and through holes filled with non-sintered bodies 220 and 224 including this Even if a load is applied to 210a and 214a from the outside, deformation of the through holes 210a and 214a is suppressed. Combined with this and the easier removal of the fired product after firing, calcium carbonate is suitable as a material for the non-sintered paste.

  Although any resin can be used as the binder, a resin that can be rapidly thermally decomposed during firing is preferable.

  Next, the conductive paste, preferably the metal paste, is screen-printed, for example, on one main surface of the green sheets 211 to 214 in which the via precursor or the non-sintered body is provided in the through hole as described above. It apply | coats to a predetermined pattern by the method etc., it dries and forms the electrically conductive paste layers 215-218, respectively.

  On the other hand, a shrinkage suppression sheet (not shown) is prepared separately from the structure. The shrinkage-suppressing sheet is a sheet that does not easily shrink in the in-plane direction even when fired at the firing temperature of the green sheets 210 to 214, and functions to suppress shrinkage that is directly or indirectly supported by the shrinkage-suppressing sheet. Have The shrinkage-suppressing sheet is obtained by adding an organic binder to a hardly sinterable ceramic material powder that does not sinter at the firing temperature of the green sheets 210 to 214, and mixing the slurry in the same manner as the paste preparation for the green sheets 210 to 214. The slurry is prepared, applied to a sheet on a flat support by, for example, a doctor blade method, a slurry cast method, a screen printing method, a rolling method, or a press method, and dried. The thickness of the shrinkage suppression sheet may be, for example, 20 to 150 μm.

  Examples of the hardly sinterable ceramic material constituting the shrinkage suppression sheet include zirconia, alumina, tridymite, tridymite, α quartz, tridymite-α quartz, cristobalite, β quartz and the like. Moreover, in order to remove the organic binder efficiently and reliably (debye treatment) while increasing the binding force of the structure 200 by the shrinkage suppression sheet at the time of firing, the green sheet 210 to the non-sinterable ceramic material powder. A predetermined amount of glass powder having a softening point lower than the sintering temperature of 214 and higher than the decomposition temperature of the organic components contained in the green sheets 210 to 214 may be added.

  Next, as shown in FIG. 2, the prepared members are green sheet 214, conductive paste layer 218, green sheet 213, conductive paste layer 217, green sheet 212, conductive paste layer 216, green sheet 211, conductive material from the bottom. The structure 200 is obtained by stacking the paste layer 215 and the green sheet 210 in this order, and the structure 200 is sandwiched in the stacking direction by two shrinkage suppression sheets and thermocompression bonded. During the stacking, the non-sintered bodies 220 and 224 are bonded to predetermined portions of the conductive paste layer 215 and the conductive paste layer 218, respectively, and the via precursor 221 includes the conductive paste layer 215 and the conductive paste layer 216. The via precursor 222 aligns the conductive paste layer 216 and the conductive paste layer 217, and the via precursor 223 aligns the conductive paste layer 217 and the conductive paste layer 218 at predetermined positions, respectively. .

  In addition, you may pinch | shrink the shrinkage | contraction suppression sheet | seat which shows a further easy removal between the shrinkage | contraction suppression sheet | seat and the structure 200 in the said lamination | stacking. The shrinkage-suppressing sheet exhibiting easy removability is particularly in the in-plane direction even when fired at the firing temperature of the green sheets 210 to 214 (sintering temperature of the base material powder of the green sheets 210 to 214) as in the case of the shrinkage-suppressing sheet The sheet is difficult to shrink, and has a function of suppressing the shrinkage of the sheet directly or indirectly supported by the easily removable shrinkage suppression sheet. Furthermore, the easily removable shrinkage suppression sheet can be easily removed even after firing at the firing temperature of the green sheets 210 to 214.

  The easy-removable shrinkage suppression sheet is a non-sintered paste having a shrinkage suppression effect on a flat support, for example, a doctor blade method, a slurry cast method, a screen printing method, a rolling method, It is obtained by applying it into a sheet by a pressing method or the like and drying it. The thickness of the easily removable shrinkage suppression sheet may be, for example, 20 to 150 μm.

  Then, after placing the structure 200 sandwiched between the shrinkage suppression sheet and an easily removable shrinkage suppression sheet as necessary, for example, on a support such as an alumina setter, and performing a debye treatment at an appropriate temperature, For example, baking is performed at a temperature of about 850 ° C. to 1050 ° C. for a predetermined time. This firing temperature is more preferably 950 ° C. or lower. At this time, in order to assist / promote sintering shrinkage in the thickness direction of the structure 200, pressurization in the thickness direction may be performed using an appropriate method such as placing a ceramic plate on the shrink sheet. Thus, the ceramic substrate 310 that is a fired body of the green sheets 210 to 214, the wiring layers 315, 316, 317, and 318 that are fired bodies of the conductive paste layers 215 to 218, and the fired bodies of the via precursors 221 to 223. A ceramic wiring board 300 (see FIG. 3) including the vias 321, 322, and 323 is obtained.

  Next, the shrinkage suppression sheet remaining as an unsintered body on both main surface sides of the fired ceramic wiring board 300 and an easily removable shrinkage suppression sheet in some cases, and the unsintered body in the through holes 210a and 214a. The remaining non-sintered bodies 220 and 224 are subjected to, for example, dry blasting such as sand blasting, bead blasting and dry ice blasting, wet blasting such as water jet, ice blasting and slurry blasting, desmearing, plasma ( It removes using appropriate methods, such as an ashing process, a jet scrub process, an ultrasonic process, and a brush process. At this time, if an easily removable shrinkage suppression sheet is used, even if the shrinkage suppression sheet is not easily removed, it is easily removed together with the easily removable shrinkage suppression sheet.

  The ceramic wiring board 300 obtained in this way is fine in order to maintain its shape and dimensions satisfactorily without the through holes 210a and 214a contracting or deforming even after firing. It is possible to provide a simple via. As a result, it is possible to more effectively and reliably prevent dielectric breakdown between different potential layers of the finally obtained multilayer wiring board. Moreover, since the structure 200 is sandwiched and fired between the shrinkage suppression sheets, the shrinkage particularly in the in-plane direction is suppressed, and the ceramic wiring board 300 with high dimensional accuracy and shape accuracy can be manufactured. This can effectively contribute to further miniaturization and higher density of the ceramic wiring board 300, the multilayer wiring board containing the ceramic wiring board 300, and the electronic component including the multilayer wiring board.

  Next, resin layers 330 and 332 are formed so as to cover both main surfaces of the ceramic wiring board 300, and the resin composition is filled into the through holes 210a and 214a. The method for forming the resin layers 330 and 332 and filling the resin composition is not particularly limited. For example, a resin paste containing the resin composition constituting the resin layers 330 and 32 is directly applied to both main surfaces of the ceramic wiring board 300. Examples thereof include a method in which coating is performed by a known coating method such as screen printing, and the through holes 210a and 214a are filled, dried and cured. Alternatively, a resin sheet formed by forming the resin paste into a sheet shape is bonded to both main surfaces of the ceramic wiring board 300 by vacuum lamination or the like, and at least a part of the resin sheet is flowed to fill the through holes 210a and 214a. And a curing method.

  The resin composition should just be the same as what was demonstrated in the above-mentioned embodiment. The resin paste is obtained by dissolving and dispersing the powdered resin composition in an organic vehicle. The bonded resin sheet preferably has sufficient fluidity so that it can be filled in the through holes 210a and 214a. For example, the resin sheet is preferably in a semi-cured state (B stage state). When the resin sheet contains a thermosetting resin, the resin sheet becomes semi-cured by heat treatment.

  Specifically, the lamination by the vacuum laminating is performed by placing the ceramic wiring board 300 and the resin sheet between the heating flat plate and the film of the vacuum laminator apparatus, and then depressurizing the space formed by the heating flat plate and the film. The film expanded in the direction of the heating flat plate with the heating gas is pressed against the ceramic wiring board 300 and the resin sheet. Since the vacuum lamination can be heated and pressurized isotropically at a low pressure, the resin sheet can be bonded together while preventing the ceramic wiring board 300 from being damaged.

  In order to cure the resin paste after application or the resin sheet after lamination, when the resin layers 330 and 332 contain a thermosetting resin, they may be heated, and if necessary, the ceramic wiring board 300 and the resin sheet. What is necessary is just to pressurize the laminated bodies, such as the lamination direction. The conditions for heating and pressurization can be set as appropriate depending on the type of resin and the like.

  Next, the resin composition filled in the resin layers 330 and 332 and the through holes 210a and 214a is punched to form holes 334 and 336. At this time, holes 334 and 336 are formed so that a part of the surface of the wiring layers 315 and 318 is exposed. Examples of the drilling method for forming the holes 334 and 336 include drilling using various lasers, drilling using a drill, and drilling by blasting using a mask, but it is possible to form finer holes. In addition, from the viewpoint of suppressing perforation of the wiring layers 315 and 318, perforation using a laser is preferable.

In the case of drilling with a laser, from the viewpoint of further preventing the perforation of the wiring layers 315 and 318 and selectively removing only the resin composition filled in the resin layers 330 and 332 and the through holes 210a and 214a, preferably, CO The surface of the resin layers 330 and 332 is irradiated with _two lasers or UV-YAG laser. By using these lasers, finer holes can be formed. The CO ₂ laser usually has an oscillation wavelength of about 10 μm, and in this embodiment, the output may be 150 W or less. In addition, the UV-YAG laser usually has an oscillation wavelength of about 0.355 μm, and in this embodiment, the output may be 5 W or less. Moreover, the laser beam may be continuously irradiated to the site to be perforated, or may be irradiated with a pulse. Furthermore, the output may or may not be changed during laser irradiation.

  When the holes 334 and 336 are formed by the perforation, all of the resin composition filled in the through holes 210a and 214a may be removed, but the inner walls of the through holes 210a and 214a of the ceramic substrate 310 are covered. It is preferable to perforate the resin composition with a part remaining. Thereby, since the ceramic substrate 310 is bonded to the resin portion not only on the main surface but also in the through holes 210a and 214a, the bonding area thereof becomes larger and the mutual adhesion is further strengthened.

  Next, as shown in FIG. 3, vias 340 and 342 are formed in the holes 334 and 336 by deposition of metal plating by an electroless plating method, and the conductive layer 344 and the surfaces of the resin layers 330 and 332 are covered. 346 is formed. The material of the metal plating that constitutes each filled via and each plating layer is not particularly limited, and may be the same as the via 140 and the wiring layer 130 in the above-described embodiment, and examples thereof include copper plating. Examples of the method for applying the electroless plating solution include a dipping method and a spray method.

  Then, as shown in FIG. 4, the conductive layers 344 and 346 are patterned into a desired shape to obtain wiring layers 345 and 347. At this time, the wiring layers 345a and 347a in which the wiring layers 345 and 347 are connected to the vias 340 and 342 are not connected to the vias 340 and 342, and as a result, the wiring layers 345b and 347b are not connected to the wiring layers 315 and 318, and It may be patterned so as to constitute This patterning method is not particularly limited, and may be a known method such as photolithography and etching. In this way, the multilayer wiring board 400 is obtained.

  In the obtained multilayer wiring board 400, the wiring layers 345a and 347a and the vias 340 and 342 are formed in the same electroless plating process, and the resin layers 330 and 332 and the through holes 210a and 214a formed in the same process are formed. Since it is formed on the surface of the resin composition, there is an advantage that the ceramic wiring board is protected from a chemical solution such as desmear treatment, laser treatment or acid treatment after laser processing.

  The multilayer wiring board 400 has the same effect as the multilayer wiring board 100 of the above embodiment. For example, dielectric breakdown between different potential members, for example, between the wiring layer 345b and the wiring layer 315, or between the wiring layer 347b and the wiring layer 318, is sufficiently suppressed as compared with the related art. In addition, since the resin layers 330 and 332 can be made thinner than before and the ceramic wiring board 300 can be made relatively thicker in the multilayer wiring board having the same thickness, the multilayer wiring can be obtained. Warpage and distortion of the plate 400 can be sufficiently prevented.

  Although the best mode for carrying out the present invention has been described above, the present invention is not limited to the present embodiment. The present invention can be variously modified without departing from the gist thereof.

  For example, in the multilayer wiring board of the present invention, an IC chip may be incorporated in a ceramic wiring board. Since there are more vias around the IC chip, there is a tendency that more pads and lands connect between the vias. Therefore, as in the present invention, if the wiring between each layer is directly connected via vias without going through bumps or lands, the bumps and lands that existed in the past can be largely omitted. The advantage of widening the degree of freedom can be effectively utilized.

  In the above-described embodiment, the inner wall of the via and the surrounding hole directly connecting the uppermost wiring layer and the lower wiring layer have a tapered shape, but the shape is limited to the tapered shape. For example, it may be a columnar shape. Furthermore, in the above embodiment, the vias 340 and 342 and the conductive layers 344 and 346 are formed by electroless plating. However, these forming methods are not limited to electroless plating. For example, the conductive paste described above is applied and filled. Then, it may be obtained through drying and / or firing. In the above-described embodiment, an insulating layer and a wiring layer may be stacked further above the wiring layer (for example, the wiring layers 130 and 150) which is the outermost layer. Further, the resin composition may not be filled in the hole (for example, the through hole 116a), and the via may be directly bonded to the inner wall of the hole.

  Alternatively, in the method for manufacturing a multilayer wiring board according to the above embodiment, the vias 340 and 342 and the conductive layers 344 and 346 are formed in one step. However, after the vias 340 and 342 are formed, the conductive layers 344 and 346 are formed. May be formed. In this case, the vias 340 and 342 may be formed using a conductive paste, and the conductive layers 344 and 346 may be formed by electroless plating.

  As described above, according to the multilayer wiring board and the method of manufacturing the same according to the present invention, insulation between members having different potentials when a voltage is applied is ensured, and warping and distortion of the multilayer wiring board are sufficiently suppressed. can do. Therefore, it can be widely and effectively used for various electronic devices, apparatuses, systems, devices, and the like that include a semiconductor-embedded substrate and other printed wiring boards, especially those that require miniaturization, thinning, and high performance. .

It is a schematic sectional drawing which shows the multilayer wiring board which concerns on embodiment of this invention. It is a schematic process drawing which shows the manufacturing method of the multilayer wiring board which concerns on another embodiment of this invention. It is a schematic process drawing which shows the manufacturing method of the multilayer wiring board which concerns on another embodiment of this invention. It is a schematic process drawing which shows the manufacturing method of the multilayer wiring board which concerns on another embodiment of this invention.

Explanation of symbols

  100, 400 ... multilayer wiring board, 110, 300 ... ceramic wiring board, 111, 113, 140, 321, 322, 323, 340, 342 ... via, 112, 114, 130, 150, 315, 316, 317, 318, 345, 347 ... wiring layer, 116, 310 ... ceramic substrate, 116a, 210a, 211a, 212a, 213a, 214a ... through hole, 120, 330, 332 ... resin layer, 200 ... structure, 210, 211, 212, 213 ... green sheets, 215, 216, 217, 218 ... conductive paste layers, 220, 222 ... non-sintered bodies, 221, 222, 223 ... via precursors, 344, 346 ... conductive layers.

Claims (4)

  The first and second wirings include a ceramic wiring board having a first wiring layer as an inner layer, a resin layer laminated on the ceramic wiring board, and a second wiring layer laminated on the resin layer. A multilayer wiring board in which layers are directly connected by vias.   The multilayer wiring board according to claim 1, wherein a wiring layer connected to the via is not provided between the ceramic wiring board and the resin layer.   The multilayer wiring board according to claim 1, further comprising a third wiring layer laminated on the resin layer and having a potential different from that of the first wiring layer. A plurality of green sheets made of a base material of a ceramic substrate and laminated to each other, a first layer made of a conductive paste disposed in an inner layer of the plurality of green sheets, and the surface of the green sheet as the outermost layer Preparing a structure including a non-sintered paste made of a material that does not sinter at the firing temperature of the base material filled in the holes communicating to the first layer;
Firing the structure at a firing temperature of the base material to obtain a ceramic wiring board including the ceramic substrate that is a fired body of the green sheet and a wiring layer that is a fired body of the first layer;
Removing the non-sintered paste from the ceramic wiring board;
Forming a resin layer made of resin on the main surface of the ceramic wiring board;
Forming a via connected to the wiring layer in the hole;
Forming a wiring layer connected to the via on the surface of the resin layer;
The manufacturing method of the multilayer wiring board which has this.

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