JP2012169486A - Base material, wiring board, production method of base material and production method of wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base material ensuring strong bonding of vias and a wiring board when multilayered, and to provide a wiring board, a production method of a base material, and a production method of a wiring board.SOLUTION: The substrate includes a resin layer 100, wiring layers 101-107 buried in the upper surface of the resin layer 100, and semi-cured vias 108, 109 having a sintering temperature equal to or lower than the softening temperature of the resin layer 100, and having one end in contact with the wiring layers 102, 106 and the other end exposed from the lower surface of the resin layer 100.

Description

  The present invention relates to a base material for mounting electronic components, a wiring board, a manufacturing method of the base material, and a manufacturing method of the wiring board.

  As electronic devices become smaller, thinner, and more functional, electronic components built into electronic devices are also becoming smaller, and the wiring of printed circuit boards (printed wiring boards) on which electronic components are mounted has become finer. . At the same time, information-related equipment is required to reduce the distance between wirings that connect components in response to a wider band of signal frequencies. For this reason, multilayering of wiring boards to achieve high density and high performance is indispensable.

  For miniaturization of wiring, a substrate having grooves by injection molding of resin is obtained, and a single-sided substrate in which the grooves are filled with a conductive paste and a multilayer substrate in which double-sided substrates are laminated (for example, , See Patent Document 1).

  In addition, a technique is known in which a concave pattern is transferred to a resin using a mold, and the groove is filled with a conductive material and patterned to obtain a wiring pattern (see, for example, Patent Document 2).

  Also, a method of patterning by transferring a concave pattern to a resin using a mold having a two-stage shape in which a convex pattern for wiring formation and a convex pattern for via formation are stacked, and filling the groove with a conductive material Is known (for example, see Patent Document 3).

  Further, a technique is known in which a metal thin film is transferred to an insulating layer using a pattern forming plate, and then a via hole is formed by laser and filled by plating (for example, see Patent Document 4).

  In addition, a technique is known in which a conductor pattern is embedded on both surfaces of an insulating layer, and then a via hole is formed and filled by plating (see, for example, Patent Document 5).

JP 2001-244609 A JP 2001-320150 A JP 2005-108924 A JP 2006-196768 A JP 2008-277737 A

  However, when a plurality of base materials in which wiring layers are embedded are laminated to form a multilayer, there has been a problem that the vias and the wiring layers cannot be firmly bonded.

  In view of the above problems, the present invention provides a base material, a wiring board, a manufacturing method of the base material, and a manufacturing method of the wiring board that can firmly bond the via and the wiring layer when multilayered. Objective.

  According to one aspect of the present invention, the resin layer, the wiring layer embedded in the upper surface of the resin layer, and a sintering temperature that is equal to or lower than the softening temperature of the resin layer, one end of which is in contact with the wiring layer and the resin layer A base material is provided comprising a semi-cured via with the other end exposed from the lower surface.

  In the substrate according to one embodiment of the present invention, the wiring layer material and the via material may be different.

  The base material according to one embodiment of the present invention may further include an alloy layer formed between the wiring layer and the via.

  In the base material according to one embodiment of the present invention, the arithmetic average roughness of the surface bonded to the via of the wiring layer may be 1 μm or less.

  The base material according to one embodiment of the present invention may further include an adhesive layer disposed on the lower surface of the resin layer.

  According to another aspect of the present invention, a wiring board in which a plurality of base materials are laminated, wherein at least one of the plurality of base materials is a resin layer, a wiring layer embedded in an upper surface of the resin layer, and a resin A wiring board having a sintering temperature equal to or lower than the softening temperature of the layer, one end joined to the wiring layer, and a via joined to the wiring layer of another substrate laminated on the lower surface side of the resin layer Is provided.

  The wiring board according to another embodiment of the present invention may further include an adhesive layer disposed between each of the plurality of base materials.

  According to still another aspect of the present invention, a step of preparing a mold having a convex portion and a resin layer, a step of press-fitting the convex portion into the upper surface of the resin layer, and forming a concave portion in the resin layer, a mold, The step of releasing the resin layer from the resin layer, the step of embedding the wiring layer in the upper surface of the resin layer by filling and sintering the conductive material in the recesses, and a portion of the wiring layer exposed on the lower surface of the resin layer A method for manufacturing a base material is provided, which includes a step of forming an opening in the substrate, and a step of filling the opening with a conductive material having a sintering temperature equal to or lower than the softening temperature of the resin layer to form a semi-cured via. Is done.

  In the base material manufacturing method according to yet another aspect of the present invention, the step of filling the semi-cured conductive material may include projecting the tip of the conductive material from the lower surface of the resin layer.

  In the method for manufacturing a base material according to still another aspect of the present invention, when the surplus portion of the conductive material is formed in the step of embedding the wiring layer, the step of removing the surplus portion after the step of embedding the wiring layer. May further be included.

  According to still another aspect of the present invention, a step of preparing a mold having a convex portion and a resin layer, a step of press-fitting the convex portion into the upper surface of the resin layer, and forming a concave portion in the resin layer, a mold, The step of releasing the resin layer from the resin layer, the step of embedding the wiring layer on the upper surface of the resin layer by filling and sintering the conductive material in the recesses, and a portion of the wiring layer exposed on the lower surface of the resin layer A step of forming a base material by the step of forming an opening in the step, and filling the opening with a conductive material having a sintering temperature equal to or lower than the softening temperature of the resin layer to form a semi-cured via; Laminating a plurality of substrates including at least one substrate, crimping the plurality of substrates while heating the plurality of substrates at a temperature equal to or higher than the softening temperature, curing the semi-cured via, and wiring There is provided a method of manufacturing a wiring board including a step of bonding to a layer.

  In the method for manufacturing a wiring board according to still another aspect of the present invention, the step of crimping the plurality of base materials may form an alloy layer between the wiring layer and the via.

  In the method for manufacturing a wiring board according to still another aspect of the present invention, the method further includes the step of forming an adhesive layer on the lower surface of the resin layer between the step of burying the wiring layer and the step of forming the opening. May be.

  According to the present invention, it is possible to provide a base material, a wiring board, a manufacturing method of the base material, and a manufacturing method of the wiring board that can firmly bond the via and the wiring layer when multilayered.

It is sectional drawing which shows an example of the base material which concerns on embodiment of this invention. It is process sectional drawing for demonstrating an example of the manufacturing method of the base material which concerns on embodiment of this invention. It is process sectional drawing following FIG. 2 for demonstrating an example of the manufacturing method of the base material which concerns on embodiment of this invention. It is process sectional drawing following FIG. 3 for demonstrating an example of the manufacturing method of the base material which concerns on embodiment of this invention. It is process sectional drawing following FIG. 4 for demonstrating an example of the manufacturing method of the base material which concerns on embodiment of this invention. It is process sectional drawing following FIG. 5 for demonstrating an example of the manufacturing method of the base material which concerns on embodiment of this invention. FIG. 7 is a process cross-sectional view subsequent to FIG. 6 for describing an example of a method for manufacturing a base material according to an embodiment of the present invention. It is sectional drawing which shows an example of the wiring board which concerns on embodiment of this invention. It is process sectional drawing for demonstrating an example of the manufacturing method of the wiring board which concerns on embodiment of this invention. It is process sectional drawing for demonstrating an example of the manufacturing method of the base material which concerns on the 1st modification of embodiment of this invention. It is process sectional drawing for demonstrating an example of the manufacturing method of the base material which concerns on the 1st modification of embodiment of this invention. It is process sectional drawing for demonstrating an example of the manufacturing method of the base material which concerns on the 1st modification of embodiment of this invention. It is sectional drawing which shows an example of the wiring board which concerns on the 2nd modification of embodiment of this invention. It is process sectional drawing for demonstrating an example of the manufacturing method of the wiring board which concerns on the 2nd modification of embodiment of this invention. It is sectional drawing which shows an example of the wiring board which concerns on the 3rd modification of embodiment of this invention. It is process sectional drawing for demonstrating an example of the manufacturing method of the wiring board which concerns on the 3rd modification of embodiment of this invention. It is sectional drawing which shows an example of the base material which concerns on the 4th modification of embodiment of this invention. It is process sectional drawing for demonstrating an example of the manufacturing method of the base material which concerns on the 4th modification of embodiment of this invention. It is process sectional drawing following FIG. 18 for demonstrating an example of the manufacturing method of the base material which concerns on the 4th modification of embodiment of this invention. It is process sectional drawing following FIG. 19 for demonstrating an example of the manufacturing method of the base material which concerns on the 4th modification of embodiment of this invention. It is sectional drawing which shows an example of the wiring board which concerns on the 5th modification of embodiment of this invention. It is process sectional drawing for demonstrating an example of the manufacturing method of the wiring board which concerns on the 5th modification of embodiment of this invention.

  Next, with reference to the drawings, embodiments of the present invention and first to fifth modifications will be described. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  The following embodiments and first to fifth modifications are examples of devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is as follows. The material, shape, structure, arrangement, etc. of the component parts are not specified as follows. The technical idea of the present invention can be variously modified within the scope of the claims.

(Base material structure)
As shown in FIG. 1, the base material according to the embodiment of the present invention includes a resin layer 100, wiring layers 101 to 107 embedded in the upper surface of the resin layer 100, and a sintering temperature equal to or lower than the softening temperature of the resin layer 100. Semi-cured vias 108 and 109 having a temperature and having one end in contact with the wiring layers 102 and 106 and the other end exposed from the lower surface of the resin layer 100 are provided.

  Here, the softening temperature of the resin layer 100 means a heat deformation temperature or a glass transition temperature which is a temperature at which the resin layer 100 starts to soften. The heat distortion temperature is a temperature at which the magnitude of the deflection becomes a constant value by raising the temperature of the sample in a state where a load specified by the test method standard is applied. The glass transition temperature refers to the temperature at which a substance rapidly changes its viscosity due to a decrease in temperature and almost loses its fluidity and changes to an amorphous solid. It is possible to appropriately select which of the heat distortion temperature and the glass transition temperature is used as the softening temperature.

  The vias 108 and 109 have a diameter of about 30 μm and a height of about 15 μm. The line width of the line pattern portion of the wiring layers 101 to 107 is about 1 μm to 10 μm, and the height is about 3 μm to 10 μm. The thickness of the resin layer 100 is about 10 μm to 25 μm.

  As a material of the resin layer 100, a semi-cured thermosetting resin such as an epoxy resin, or a thermoplastic resin such as thermoplastic polyimide, polyolefin, or liquid crystal polymer can be used. The softening temperature of the resin layer 100 is, for example, about 240 ° C to 300 ° C.

  As the material of the vias 108 and 109, a conductive material such as a conductive paste or a conductive ink can be used. The conductive paste is selected from, for example, nickel (Ni), gold (Au), silver (Ag), copper (Cu), zinc (Zn), aluminum (Al), iron (Fe), tungsten (W), etc. At least one kind of low electric resistance metal particles, and at least one kind of low melting point metal particles selected from bismuth (Bi), indium (In), and lead (Pb), and tin (Sn) as a component. A paste (metallized paste) containing a binder component containing epoxy, acrylic or urethane as a main component can be used. This conductive paste is in a soft state that is semi-cured (including uncured) at room temperature, and is completely cured by a heat treatment or the like and performs an adhesive function. In this conductive paste, tin (Sn) and a low melting point metal can be melted at 200 ° C. or less to form an alloy. In particular, copper (Cu), silver (Ag), and the like form an intermetallic compound.

  Furthermore, as a material for the vias 108 and 109, a filler such as gold (Au), silver (Ag), copper (Cu), or nickel (Ni) having a particle size of nano level is mainly composed of epoxy, acrylic, urethane, or the like. Nanopaste mixed with the binder component to be used can be used.

  Furthermore, as a material for the vias 108 and 109, a paste (powder) in which particles such as silver (Ag), copper (Cu), or nickel (Ni) are mixed with a binder component mainly composed of epoxy, acrylic, urethane, or the like. A contact-type paste) can also be used. This paste is electrically connected by contacting metal particles.

  The vias 108 and 109 have a semi-cured state that is not sintered. The sintering temperature of the vias 108 and 109 is equal to or lower than the softening temperature of the resin layer 100, for example, about 180 ° C. to 240 ° C.

  As the material of the wiring layers 101 to 107, the same material as that of the vias 108 and 109 described above can be used. The sintering temperature of the wiring layers 101 to 107 is not higher than the softening temperature of the resin layer 100, and is, for example, about 180 ° C to 240 ° C. The arithmetic average roughness Ra of the lower surfaces of the wiring layers 102 and 106 in contact with the vias 108 and 109 is preferably about 1.0 μm or less, and more preferably about 0.1 μm or less.

The vias 108 and 109 and the wiring layers 101 to 107 may use the same material or different materials. For example, when a nano paste containing copper (Cu) is used as the vias 108 and 109 and a paste containing tin (Sn) is used as the wiring layers 101 to 107, the vias 108 and 109 and the wiring layers 102 and 106 In between, an alloy layer (intermetallic compound layer) having a composition such as Cu ₃ Sn or Cu ₆ Sn is formed. As a result, the vias 108 and 109 and the wiring layers 102 and 106 can be firmly bonded to each other.

  According to the base material according to the embodiment of the present invention, when a plurality of base materials including at least one base material shown in FIG. 1 are laminated and multilayered, the wiring layers 102 and 106 and the vias 108 and 109 And between the vias 108 and 109 and the wiring layer of the underlying substrate can be firmly bonded.

  Furthermore, since the height of the upper surface of the wiring layers 101 to 107 is substantially the same as the height of the upper surface of the resin layer 100, the wiring layers 101 to 107 can be laminated flatly when being multilayered.

(Manufacturing method of substrate)
Next, an example of the manufacturing method of the base material which concerns on embodiment of this invention is demonstrated using FIGS. In addition, the manufacturing method shown below is an example, and it is not specifically limited, It can manufacture with various manufacturing methods.

  (A) As shown in FIG. 2, a mold (mold) 5 and a resin layer 100 are prepared. The mold 5 includes a support portion 50 and convex portions 51 to 57 provided on the support portion 50 for forming the wiring layers 101 to 107. The pitch and material of the pattern of the convex portions 51 to 57 can be appropriately changed as necessary. As a material for the mold 5, silicon (Si), nickel (Ni), copper (Cu), diamond-like carbon (DLC), or the like can be used. Further, the surface of the mold 5 may be subjected to a release treatment with a release agent such as a commercially available fluorine-based silane coupling agent. In the embodiment of the present invention, a mold 5 made of silicon (Si) having a pattern with a minimum line / space of 5 μm / 5 μm and a height of 5 μm was prepared. On the other hand, as the material of the resin layer 100, a semi-cured thermosetting resin such as an epoxy resin, or a thermoplastic resin such as thermoplastic polyimide, polyolefin, or liquid crystal polymer can be used. In the embodiment of the present invention, a resin film made of thermoplastic polyimide having a thickness of 25 μm was prepared.

  (B) As shown in FIG. 3, the resin layer 100 is heated at a temperature equal to or higher than the softening temperature of the resin layer 100 (for example, about 240 ° C. to 300 ° C.) to press-fit the mold 5 into the resin layer 100. Thereby, the convex parts 51-57 are transcribe | transferred on the upper surface of the resin layer 100, and the recessed parts 61-67 are formed. Thereafter, the resin layer 100 is cooled below the softening temperature, and the mold 5 is released from the resin layer 100 as shown in FIG.

  (C) As shown in FIG. 5, a wiring layer is formed by forming a seed layer in the recesses 61 to 67 by sputtering or electroless plating, supplying power to the seed layer, and filling the recesses 61 to 67 with a conductive material by electrolytic plating. Layers 101-107 are formed. The wiring layers 101 to 107 may be formed by filling a conductive material by printing a conductive paste and sintering at a temperature higher than the sintering temperature of the conductive material (for example, about 180 ° C. to 240 ° C.). Good.

  (D) As shown in FIG. 5, when there is an excess portion 110 of the conductive material that protrudes from the recesses 61 to 67 and covers the surface of the resin layer 100, the excess portion 110 is removed by polishing or etching. As a result, the resin layer 100 in which the wiring layers 101 to 107 are embedded as shown in FIG. 6 is obtained. Note that this step can be omitted when the surplus portion 110 is not formed, for example, by optimizing the filling conditions of the conductive material.

(E) As shown in FIG. 7, openings (via holes) 68 and 69 are formed by laser at predetermined positions on the lower surface of the resin layer 100. As the laser, an excimer laser, a carbonic acid (CO ₂ ) laser, a UV laser, or the like can be used. In the embodiment of the present invention, the openings 68 and 69 having a diameter of 30 μm are formed by an ultraviolet (UV) laser. When smear is generated by laser processing, wet desmear with a chemical solution or dry desmear with CF ₄ plasma or the like may be performed. The openings 68 and 69 may be formed by drilling or etching instead of laser processing.

  (F) Opening a semi-cured conductive material having a sintering temperature (for example, about 180 ° C. to 240 ° C.) below the softening temperature (for example, about 240 ° C. to 300 ° C.) of the resin layer 100 by screen printing or an inkjet method. By filling 68 and 69, semi-cured vias 108 and 109 that respectively contact the wiring layers 102 and 106 are formed as shown in FIG. 1. As a result, the base material shown in FIG. 1 is obtained.

  According to the base material manufacturing method according to the embodiment of the present invention, when a plurality of base materials are stacked to form a multilayer, the vias 108 and 109 and the wiring layers 102 and 106 and the vias 108 and 109 It becomes possible to manufacture a base material that can be firmly bonded to the wiring layer of the lower base material.

(Structure of wiring board)
The wiring board which concerns on embodiment of this invention is equipped with the 1st-4th base materials 1-4 as shown in FIG.

  The first substrate 1 includes a first resin layer 10 and first wiring layers 11 to 17 embedded in the upper surface of the first resin layer 10.

  The second substrate 2 includes a second resin layer 20 disposed on the first resin layer 10, second wiring layers 21 to 27 embedded in the upper surface of the second resin layer 20, The first vias 28 and 29 penetrate through the two resin layers 20 and are joined to the first wiring layers 12 and 16 and the second wiring layers 22 and 26, respectively.

  The third substrate 3 includes a third resin layer 30 disposed on the second resin layer 20, third wiring layers 31 to 37 embedded in the upper surface of the third resin layer 30, 3 via the third resin layer 30 and having second vias 38 and 39 joined to the second wiring layers 22 and 26 and the third wiring layers 32 and 36, respectively.

  The fourth substrate 4 includes a fourth resin layer 40 disposed on the third resin layer 30, fourth wiring layers 41 to 47 embedded in the upper surface of the fourth resin layer 40, 4 via the fourth resin layer 40, and third vias 48 and 49 joined to the fourth wiring layers 42 and 46 and the third wiring layers 32 and 36, respectively.

  Between the first vias 28 and 29 and the first wiring layers 12 and 16 and the second wiring layers 22 and 26, the second vias 38 and 39, the second wiring layers 22 and 26, and the third wiring An alloy layer (intermetallic compound layer) is formed between the layers 32 and 36 and between the third vias 48 and 49 and the third wiring layers 32 and 36 and the fourth wiring layers 42 and 46, respectively. They are firmly joined together.

  As the first to fourth resin layers 10, 20, 30, and 40, the same material as that of the resin layer 100 shown in FIG. 1 can be used. The first to fourth resin layers 10, 20, 30, and 40 may be made of the same material or different materials.

  The first to third vias 28, 29, 38, 39, 48, 49 are made of a conductive material that is completely cured by sintering. As materials for the first to third vias 28, 29, 38, 39, 48, and 49, the same materials as those for the vias 108 and 109 shown in FIG. 1 can be used. The first to third vias 28, 29, 38, 39, 48, and 49 may use the same material for each layer, or may use different materials. Further, the first to third vias 28, 29, 38, 39, 48, and 49 may be made of the same material or different materials in the same layer.

  As the first to fourth wiring layers 11 to 17, 21 to 27, 31 to 37, and 41 to 47, the same material as the wiring layers 101 to 107 shown in FIG. 1 can be used. The first to fourth wiring layers 11 to 17, 21 to 27, 31 to 37, and 41 to 47 may use the same material for each layer or may use different materials. Further, the first to fourth wiring layers 11 to 17, 21 to 27, 31 to 37, and 41 to 47 may be made of the same material or different materials in the same layer.

  The first to third vias 28, 29, 38, 39, 48, 49 and the first to fourth wiring layers 11-17, 21-27, 31-37, 41-47 are made of the same material. Alternatively, different materials may be used.

  According to the wiring board which concerns on embodiment of this invention, the 1st-4th wiring layers 11-17, 21-27, 31-37, 41-47 are the 1st-4th resin layers 10, 20, Since it is embed | buried under the upper surface of 30,40, favorable flatness can be maintained.

(Manufacturing method of wiring board)
Next, an example of a method for manufacturing a wiring board according to an embodiment of the present invention will be described. In addition, the manufacturing method shown below is an example, and it is not specifically limited, It can manufacture with various manufacturing methods.

  (A) As shown in FIG. 9, the 1st-4th base materials 1-4 are prepared. The 1st base material 1 can be produced by passing through the process similar to the process shown in FIGS. The 2nd-4th base materials 2-4 can be produced by passing through the process similar to the process shown in FIGS. The first to fourth base materials 1 to 4 are aligned and stacked by an alignment device with an image recognition function or the like.

  (B) Using a vacuum thermocompression bonding apparatus or the like, the first to fourth resin layers 10, 20, 30, 40 are heated at a temperature equal to or higher than the softening temperature (for example, about 240 ° C. to 300 ° C.). 4 resin layers 10, 20, 30, and 40 are softened, and the first to fourth base materials 1 to 4 are laminated using the adhesive force of the first to fourth resin layers 10, 20, 30, and 40. The first to third vias 28, 29, 38, 39, 48, 49 in a semi-cured state are cured while being pressed in the direction. When the first to fourth resin layers 10, 20, 30, 40 are made of a thermosetting resin, the thermosetting resin and the semi-cured conductive material may be continuously heat-bonded until completely cured, or When the thermosetting resin is softened and the first to fourth base materials 1 to 4 are bonded to each other, they are cooled, and the thermosetting resin and the semi-cured conductive material are completely cured in a separate oven. May be. On the other hand, when the first to fourth resin layers 10, 20, 30, and 40 are made of a thermoplastic resin, they may be continuously heat-bonded until the semi-cured conductive material is completely cured, or the thermoplastic resin It may be cooled when softened and the first to fourth substrates 1 to 4 are bonded to each other, and the semi-cured conductive material may be completely cured separately in an oven. As a result, the wiring board shown in FIG. 8 is obtained.

  According to the method for manufacturing a wiring board according to the embodiment of the present invention, the first vias 28 and 29, the second vias 38 and 39, and the third vias 48 and 49 in a semi-cured state are connected to the first wiring. Since the layers 12, 16, the second wiring layers 22, 26, the third wiring layers 32, 36, and the fourth wiring layers 42, 46 are brought into contact with each other and cured, the first vias 28, 29 and the first wiring layers Between the second wiring layers 22, 16 and the second wiring layers 22, 26, between the second vias 38, 39 and the second wiring layers 22, 26, the third wiring layers 32, 36, and the third. The vias 48 and 49 and the third wiring layers 32 and 36 and the fourth wiring layers 42 and 46 can be firmly bonded to each other.

  Furthermore, since a plurality of (first to fourth) base materials 1 to 4 are laminated by the collective laminating method, only one heat history is required. For this reason, the deformation of the lower layer can be suppressed as compared with the case where the layers are laminated one by one by the buildup method. In particular, when the first to fourth resin layers 10, 20, 30, and 40 are thermoplastic resins, it is effective because they can be prevented from being sequentially distorted from the lower layer.

  Furthermore, since materials having an adhesive function such as a thermoplastic resin or a semi-cured thermosetting resin are used as the first to fourth resin layers 10, 20, 30, and 40, multiple layers without using an adhesive separately. Can be realized.

  Furthermore, the first to fourth wiring layers 11 to 17, 21 to 27, 31 to 37, and 41 to 47, the first vias 28 and 29, the second vias 38 and 39, and the third vias 48 and 49, Are separately formed, and can be sintered and cured at heating temperatures independent of each other according to the respective materials. For example, when the first to fourth wiring layers 11 to 17, 21 to 27, 31 to 37, and 41 to 47 are sintered and cured, the temperatures of the first vias 28 and 29, the second vias 38, The temperature may be higher or lower than the temperature at which the 39 and the third vias 48 and 49 are sintered and cured.

(First modification)
As a first modification of the embodiment of the present invention, another example of the substrate manufacturing method will be described.

  (A) A substrate that is the single-sided circuit shown in FIG. 7 is prepared through the same steps as those shown in FIGS. Subsequently, as shown in FIG. 10, a mask layer 60 is formed on the surface opposite to the surface on which the wiring layers 101 to 107 of the substrate are provided. As the mask layer 60, for example, a polyethylene terephthalate (PET) film can be used, and this is attached by thermal lamination.

  (B) The mask layer 60 and a part of the resin layer 100 are removed by a laser. As a result, openings 68 and 69 that penetrate the mask layer 60 and the resin layer 100 and reach the wiring layers 102 and 106 are formed.

  (C) Thereafter, screen printing is performed, and the openings 68 and 69 are filled with a conductive material 58 such as a conductive paste using a squeegee 59 using the mask layer 60 as a mask. As a result, semi-cured vias 108 and 109 are formed as shown in FIG. The exposed upper surfaces of the vias 108 and 109 substantially coincide with the height of the upper surface of the mask layer 60.

  (D) Thereafter, the mask layer 60 shown in FIG. 11 is removed as shown in FIG. As a result, the tips of the vias 108 and 109 protrude from the upper surface of the resin layer 100.

  According to the manufacturing method of the base material according to the first modification of the embodiment of the present invention, the vias 108 and 109 are formed from the upper surface of the resin layer 100 by performing screen printing instead of direct printing of the conductive paste. A base material with a protruding tip can be produced. Since the tips of the vias 108 and 109 protrude, the contact between the vias 108 and 109 and the wiring layer of the lower base material is ensured at the time of thermocompression bonding of a plurality of base materials, and the connection reliability of the vias 108 and 109 is improved. be able to.

  Furthermore, as shown in FIG. 10, the upper surface of the resin layer 100 is masked with the mask layer 60 and filled with the conductive paste, so that the upper surface of the resin layer 100 can be prevented from being contaminated by the conductive paste.

  In the ink jet method, the vias 108 and 109 can be directly formed without using a mask as in screen printing.

(Second modification)
Another example of the wiring board will be described as a second modification of the embodiment of the present invention. As shown in FIG. 13, the wiring board according to the second modification of the embodiment of the present invention uses a single-sided substrate of a flexible printed circuit board (FPC) as the first base material 7. Different from the wiring board shown in FIG. The first substrate 7 is disposed on the first resin layer 70, the first wiring layers 71 to 74 disposed on the upper surface of the first resin layer 70, and the lower surface of the first resin layer 70. Lower wiring layers 75 to 77 are provided. The first wiring layers 71 and 74 are joined to the first vias 28 and 29, respectively. The lower wiring layers 75 and 77 extend through the opening of the first resin layer 70 and are joined to the first wiring layers 71 and 74, respectively. Other configurations are substantially the same as those of the wiring board shown in FIG.

  According to the wiring board according to the second modification of the embodiment of the present invention, one side of the first base material 7 that is an FPC can be multilayered.

  As shown in FIG. 14, the wiring board according to the second modification of the embodiment of the present invention prepares a first base material 7 and second to fourth base materials 2 to 4. The first substrate 7 can be manufactured by a normal FPC manufacturing method. The 2nd-4th base materials 2-4 can be produced by passing through the process similar to the process shown in FIGS. The first base material 7 and the second to fourth base materials 2 to 4 are aligned by an alignment device with an image recognition function, etc., and manufactured by batch stacking in the same manner as the process shown in FIG. Is possible.

(Third Modification)
Another example of the wiring board will be described as a third modification of the embodiment of the present invention. In the wiring board according to the third modification of the embodiment of the present invention, as shown in FIG. 15, a fifth base material 8 is further arranged on the lower surface of the first base material 7 which is an FPC. However, it is different from the wiring board shown in FIG. The fifth substrate 8 includes a fifth resin layer 80, fifth wiring layers 81 to 85 embedded in the lower surface of the fifth resin layer 80, a lower wiring layer 76, and a fifth wiring layer 83. A fourth via 86 joined is provided. Other configurations are substantially the same as those of the wiring board shown in FIG.

  According to the wiring board according to the third modification of the embodiment of the present invention, both surfaces of the first base material 7 that is an FPC can be multilayered.

  As shown in FIG. 16, the wiring board according to the third modification of the embodiment of the present invention includes a first base material 7, second to fourth base materials 2 to 4, and a fifth base material 8. Prepare. The first substrate 7 can be manufactured by a normal FPC manufacturing method. The 2nd-4th base materials 2-4 and the 5th base material 8 are producible by passing through the process similar to the process shown in FIGS. The first base material 7, the second to fourth base materials 2 to 4 and the fifth base material 8 are aligned by an alignment apparatus with an image recognition function or the like, and the same process as shown in FIG. It can be manufactured by stacking.

(Fourth modification)
Another example of the base material will be described as a fourth modification of the embodiment of the present invention. The base material according to the fourth modification of the embodiment of the present invention is that the base material shown in FIG. 1 is further provided with an adhesive layer 90 arranged on the lower surface of the resin layer 100 as shown in FIG. And different. As a material for the adhesive layer 90, a thermoplastic resin such as an epoxy resin, or a film or varnish made of a thermosetting resin can be used. The temperature at which the adhesive layer 90 can exhibit the adhesive function (adhesive temperature) is equal to or higher than the sintering temperature of the vias 108 and 109, and is, for example, about 100 ° C. to 240 ° C.

  As a material of the resin layer 100, a semi-cured thermosetting resin such as an epoxy resin or a thermoplastic resin such as a polyolefin or a liquid crystal polymer, or a completely cured thermosetting resin that does not have an adhesive function. A cured thermosetting resin can also be used. Other configurations are substantially the same as those of the substrate shown in FIG.

  According to the base material according to the fourth modification of the embodiment of the present invention, when a plurality of base materials are laminated, the base materials are bonded together via the adhesive layer 90, and the wiring layers 102 and 106 It is possible to firmly bond between the vias 108 and 109 and between the vias 108 and 109 and the underlying wiring layer.

  Next, an example of the manufacturing method of the base material which concerns on the 4th modification of embodiment of this invention is demonstrated. A base material which is a single-sided circuit is produced by performing the same steps as those shown in FIGS. 2 to 5 as shown in FIG. As shown in FIG. 19, an adhesive layer 90 is formed on the lower surface of the resin layer 100. As shown in FIG. 20, openings 68 and 69 that penetrate through the adhesive layer 90 and the resin layer 100 and reach the wiring layers 102 and 106 are formed by laser processing. Thereafter, by filling the openings 68 and 69 with a conductive paste, semi-cured vias 108 and 109 can be formed, and the substrate shown in FIG. 17 is completed.

(Fifth modification)
Another example of the wiring board will be described as a fifth modification of the embodiment of the present invention. In the wiring board according to the embodiment of the present invention, as shown in FIG. 21, each of the second to fourth substrates 2 to 4 further includes each of first to third adhesive layers 91 to 93. This is different from the wiring board shown in FIG. The first base 1 is substantially the same as the base shown in FIG. 1, and the second to fourth bases 2 to 4 are substantially the same as the base shown in FIG. Therefore, a duplicate description is omitted.

  Next, a method for manufacturing a wiring board according to a fifth modification of the embodiment of the present invention will be described. As shown in FIG. 22, the 1st base material 1 is formed through the process similar to the process shown in FIGS. Moreover, the 2nd-4th base materials 2-4 similar to the base material shown in FIG. 17 are produced. The first to fourth base materials 1 to 4 are aligned and laminated. The first to fourth substrates 1 to 4 are bonded to the first to third substrates while being heated at a temperature equal to or higher than the bonding possible temperature of the first to third bonding layers 91 to 93 (for example, about 100 ° C. to 240 ° C.). The first to third vias 28, 29, 38, 39, 48, and 49 in a semi-cured state are cured while being bonded through the layers 91 to 93, respectively.

  According to the fifth modification of the embodiment of the present invention, when the bonding possible temperature of the first to third adhesive layers 91 to 93 is lower than the temperature at which the resin layers 100 are bonded to each other, the resin The bonding can be performed at a temperature lower than the temperature at which the layers 100 are bonded to each other. Therefore, compared with the case where the resin layers 100 are bonded to each other without using an adhesive layer, the layers can be laminated at a lower temperature, and distortion can be suppressed.

(Other embodiments)
As described above, the present invention has been described by the embodiment and the first to fifth modifications. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. . From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, when multilayering a plurality of substrates, at least one of the plurality of substrates may have the structure of the substrate according to the embodiment of the present invention.

  In addition, the structures, materials, arrangements, manufacturing methods, and the like according to the embodiments of the present invention and the first to fifth modifications can be mutually applied or combined.

  As described above, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 1,7 ... 1st base material 2 ... 2nd base material 3 ... 3rd base material 4 ... 4th base material 5 ... Mold 8 ... 5th base material 10,70 ... 1st resin layer 11-17, 71-74 ... 1st wiring layer 20 ... 2nd resin layer 21-27 ... 2nd wiring layer 28, 29 ... 1st via 30 ... 3rd resin layer 31-37 ... 3rd Wiring layer 38, 39 ... second via 40 ... fourth resin layer 41-47 ... fourth wiring layer 48, 49 ... third via 50 ... support portion 51-57 ... convex portion 58 ... conductive material 59 ... Squeegee 60 ... Mask layer 61-67 ... Recess 68, 69 ... Opening 75-77 ... Lower layer wiring layer 80 ... Fifth resin layer 81-85 ... Fifth wiring layer 86 ... Fourth via 90 ... Adhesive layer DESCRIPTION OF SYMBOLS 91 ... 1st contact bonding layer 92 ... 2nd contact bonding layer 93 ... 3rd contact bonding layer 100 ... Resin layer 101-107 ... Wiring layer 108,109 ... Via 1 0 ... the excess portion

Claims (13)

A resin layer;
A wiring layer embedded in the upper surface of the resin layer;
A semi-cured via having a sintering temperature equal to or lower than a softening temperature of the resin layer, one end contacting the wiring layer and the other end exposed from the lower surface of the resin layer .   The base material according to claim 1, wherein a material of the wiring layer is different from a material of the via.   The base material according to claim 1, further comprising an alloy layer formed between the wiring layer and the via.   The base material according to any one of claims 1 to 3, wherein an arithmetic average roughness of a surface of the wiring layer to be joined to the via is 1 µm or less.   The base material according to claim 1, further comprising an adhesive layer disposed on a lower surface of the resin layer. A wiring board in which a plurality of base materials are laminated,
At least one of the plurality of substrates is
A resin layer;
A wiring layer embedded in the upper surface of the resin layer;
A via having a sintering temperature equal to or lower than the softening temperature of the resin layer, one end bonded to the wiring layer, and the other end bonded to a wiring layer of another substrate laminated on the lower surface side of the resin layer; A wiring board comprising:   The wiring board according to claim 6, further comprising an adhesive layer disposed between the plurality of base materials. Preparing a mold having a convex portion and a resin layer;
Press-fitting the convex portion into the upper surface of the resin layer, and forming a concave portion in the resin layer;
Releasing the mold from the resin layer;
Burying a wiring layer on the upper surface of the resin layer by filling and sintering the recess with a conductive material;
Forming an opening on the lower surface of the resin layer so that a part of the wiring layer is exposed;
Filling the opening with a conductive material having a sintering temperature equal to or lower than the softening temperature of the resin layer, and forming a semi-cured via.   The method of manufacturing a base material according to claim 8, wherein the step of filling the semi-cured conductive material includes projecting a tip of the conductive material from a lower surface of the resin layer.   10. The method according to claim 8, further comprising the step of removing the surplus portion after the step of embedding the wiring layer when the surplus portion of the conductive material is formed in the step of embedding the wiring layer. The manufacturing method of the base material as described in any one of. Providing a mold having a convex portion and a resin layer, pressing the convex portion into an upper surface of the resin layer, forming a concave portion in the resin layer, and releasing the mold from the resin layer; Burying a wiring layer on the upper surface of the resin layer by filling and sintering the conductive material in the concave portion, and opening portions so that a part of the wiring layer is exposed on the lower surface of the resin layer Forming a base material by filling the opening with a conductive material having a sintering temperature equal to or lower than the softening temperature of the resin layer and forming a semi-cured via; and
Laminating a plurality of substrates including at least one of the substrates;
A step of crimping the plurality of base materials while heating the plurality of base materials at a temperature equal to or higher than the softening temperature, curing the semi-cured via, and bonding the wiring layer to the wiring layer. A method for manufacturing a wiring board.   The method for manufacturing a wiring board according to claim 11, wherein the step of pressure bonding the plurality of base materials includes forming an alloy layer between the wiring layer and the via.   The wiring board according to claim 11, further comprising a step of forming an adhesive layer on a lower surface of the resin layer between the step of burying the wiring layer and the step of forming the opening. Manufacturing method.

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