JP4061137B2 - Multilayer resin wiring board and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laminated resin wiring board and a manufacturing method thereof, and more particularly to a laminated resin wiring board using a metal plate as a core material or a base material and a manufacturing method thereof.
[0002]
[Prior art]
In recent years, with the miniaturization of electrical equipment, electronic equipment, etc., miniaturization and high density have been demanded for wiring boards and the like mounted on these equipments. In order to meet such market demand, multilayer circuit board technology has been studied. As a multilayering method, a so-called build-up method in which insulating layers and wiring layers are alternately laminated and integrated with a core material is generally employed. Conventionally, as a core material in this type of wiring board, a metal plate made of a copper alloy, an Fe—Ni alloy, or the like is often used in order to improve heat dissipation and reduce the thermal expansion coefficient of the entire board (special characteristics). (See Kai 2000-133913).
[0003]
[Problems to be solved by the invention]
However, in the case of the above conventional laminated resin wiring board, a metal having a relatively low thermal expansion coefficient is used as the material for the core material, while copper having a relatively high thermal expansion coefficient is currently used as the material for the wiring layer. Used. For this reason, although the said core material was used in order to acquire the effect of the reduction of the thermal expansion coefficient of the whole board | substrate, there existed a problem that the effect will be offset by use of copper. Therefore, it has been difficult in the past to obtain a laminated resin wiring board having excellent dimensional stability and reliability, since it is impossible to reliably reduce the thermal expansion coefficient of the entire board.
[0004]
If the build-up layer becomes more multilayered and denser than the current situation in the future, and the abundance ratio of the wiring layers in the board (that is, the usage ratio of copper) becomes even higher, this problem may become prominent. Fully expected.
[0005]
The present invention has been made in view of the above problems, and its purpose is to reliably achieve reduction in the thermal expansion coefficient of the entire substrate, and to provide a laminated resin wiring substrate excellent in dimensional stability and reliability, and its manufacture. It is to provide a method.
[0006]
[Means, actions and effects for solving the problems]
A solution for solving the above-mentioned problem is a conductive metal material having a first main surface and a second main surface and having a lower thermal expansion coefficient than copper. Metal plate made of rolled Fe-Ni alloy plate And a conductive metal material that is located on at least one of the first main surface and the second main surface and has a lower thermal expansion coefficient than copper Formed by etching a rolled Fe-Ni alloy foil A wiring layer, and a resin insulating layer interposed between the metal plate and the wiring layer; And a via-hole conductor having a via conductor made of electroless Fe—Ni alloy plating and connected to and conductive between the wiring layer and the metal plate, the metal plate can function as a ground layer or a power supply layer The gist of the laminated resin wiring board is characterized by this.
[0007]
Another solution is a conductive metal material having a first main surface and a second main surface and having a lower thermal expansion coefficient than copper. Rolled Fe-Ni alloy plate A conductive metal material which is located on the first main surface side and the second main surface side of the metal plate and has a lower thermal expansion coefficient than copper Formed by etching a rolled Fe-Ni alloy foil A plurality of wiring layers, and a plurality of resin insulation layers interposed between the metal plate and the wiring layer, or between the metal plate and the wiring layer and between the wiring layers; And a via-hole conductor having a via conductor made of electroless Fe—Ni alloy plating and connected to and conductive between the wiring layer and the metal plate, the metal plate can function as a ground layer or a power supply layer The gist of the laminated resin wiring board is characterized by this.
[0008]
And according to the said invention, the conductive metal material whose thermal expansion coefficient is lower than copper is used not only for the formation material of a metal plate but the formation material of a wiring layer. For this reason, the difference in thermal expansion coefficient between the metal plate and the wiring layer is smaller than that of the conventional laminated resin wiring board, and even if there is a wiring layer, the effect of reducing the thermal expansion coefficient of the entire board is hardly offset. . Therefore, it is possible to reliably reduce the thermal expansion coefficient of the entire substrate and to obtain a laminated resin wiring substrate excellent in dimensional stability and reliability.
[0009]
In the said invention, it is necessary to use the conductive metal material whose thermal expansion coefficient is lower than copper as a formation material of a metal plate and a formation layer of a wiring layer. Since the thermal expansion coefficient (30 ° C.-300 ° C.) of copper is about 17 ppm / ° C., a metal or an alloy of less than 17 ppm / ° C. needs to be used as the metal plate forming material and the wiring layer forming material. . In this case, it is desirable to use a metal or alloy of less than 14 ppm / ° C. (in other words, a metal or alloy having a thermal expansion coefficient lower than that of copper by 3 ppm / ° C. or more). Furthermore, it is desirable to use a metal or alloy of less than 11 ppm / ° C. (in other words, a metal or alloy having a thermal expansion coefficient lower than that of copper by 6 ppm / ° C. or more). In particular, it is desirable that a metal or alloy of less than 6 ppm / ° C. is used (in other words, a metal or alloy having a thermal expansion coefficient of 11 ppm / ° C. or more lower than that of copper is used). The reason is that the smaller the absolute value of the thermal expansion coefficient of the metal plate and the wiring layer, the higher the dimensional stability. In addition, the closer the thermal expansion coefficient of the metal plate and the wiring layer is to the thermal expansion coefficient (about 2.8 ppm / ° C., 30 ° C.-300 ° C.) of silicon that is usually used as an IC chip forming material, the connection to the chip This is because reliability is improved. Note that a metal material having a lower thermal expansion coefficient than copper needs to have conductivity. The reason is that the wiring layer is a layer formed mainly for the purpose of efficiently flowing electricity.
[0010]
The conductive metal material constituting the metal plate can be appropriately selected from a copper alloy, a simple metal other than copper, and an alloy thereof as long as the condition that the coefficient of thermal expansion is lower than that of copper is satisfied. The same applies to the conductive metal material constituting the wiring layer. Preferable examples of alloys of metals other than copper include Fe-Ni alloys.
[0011]
The difference between the conductive metal material constituting the wiring layer and the conductive metal material constituting the metal plate is preferably 6 ppm / ° C. or less, more preferably 2 ppm / ° C. or less, particularly 1 ppm. / ° C. or less is desirable. The reason for this is that if the difference in thermal expansion coefficient between the two is small, it is difficult for thermal stress to occur inside the substrate, so the effect of reducing the thermal expansion coefficient of the entire substrate is not offset, and dimensional stability and reliability are reliably improved. Because it does.
[0012]
Here, both the wiring layer and the metal plate are preferably made of the same kind of metal, and in particular, both are preferably made of an Fe—Ni-based alloy.
[0013]
This is because, if the same kind of metal is used, the difference in thermal expansion coefficient is zero or very small, so that it is very convenient for achieving improvement in dimensional stability and reliability. In addition, since many of the Fe-Ni alloys have a property that the thermal expansion coefficient is lower than that of copper, the thermal expansion coefficient of the entire substrate can be reduced by using it as a metal plate and a wiring layer. This is because it can be achieved more reliably. In addition, Fe—Ni alloys are suitable as wiring layers because they are inferior to copper, but are suitable as wiring layers, and can function as a ground layer or a power supply layer by being conductively connected to the wiring layers. Because it can. Furthermore, although Fe—Ni-based alloy is inferior to copper, it has suitable thermal conductivity, so that it can achieve high heat dissipation by using it as a metal plate or the like.
[0014]
Specific examples of the Fe-Ni alloy include 42 alloy (Fe-42% Ni), 50 alloy (Fe-50% Ni), amber (Fe-36% Ni), superamber (Fe-31% Ni-). 5% Co) and Kovar (Fe-29% Ni-17% Co). However, as long as the condition that the thermal expansion coefficient is smaller than that of copper is satisfied, an Fe—Ni alloy other than the above composition may be used. For example, nickel containing 40%, 45%, 55% or 60% may be selected.
[0015]
Note that the Fe—Ni-based alloy mentioned here refers to an alloy containing iron and nickel (or iron, nickel, and cobalt) as main components in the alloy composition. Those containing a small amount of other elements (for example, carbon, silicon, manganese, etc.) are also included in the category of the Fe—Ni alloy.
[0016]
Although the thickness of the said metal plate is not specifically limited, If it says strongly, it is good that it is 150 micrometers or more, Furthermore, it is good that they are 150 micrometers-500 micrometers, especially 150 micrometers-300 micrometers. If the thickness of the metal plate is less than 150 μm, the rigidity of the metal plate itself is reduced. As a result, wrinkles and scratches are likely to occur during the manufacturing process, resulting in a decrease in handleability and a decrease in yield. is there. On the other hand, if the thickness is 500 μm, there is no problem with respect to rigidity, but the laminated resin wiring board is not only thickened, but hole processing becomes difficult. In addition, when it is a metal plate 150 micrometers or more in thickness, it is good to use a rolled metal plate.
[0017]
The wiring layer may be located on both sides of the first main surface and the second main surface of the metal plate, and may be located only on the first main surface side or only on the second main surface side. A method for forming such a wiring layer can be appropriately selected in consideration of conductivity, adhesion to the resin insulating layer, and the like. That is, it can be formed by a known method such as a subtractive method, a semi-additive method, or a full additive method. Specifically, for example, a technique such as etching of a metal layer, electroless plating, or electrolytic plating can be used. It is also possible to form a wiring layer by etching after forming a metal layer by a technique such as sputtering or CVD, or to form a wiring layer by printing a conductive paste or the like.
[0018]
The resin insulating layer interposed between the metal plate and the wiring layer can be appropriately selected in consideration of insulation, heat resistance, moisture resistance, and the like. Preferable examples of the resin insulating layer forming material include EP resin (epoxy resin), PI resin (polyimide resin), BT resin (bismaleimide-triazine resin), PPE resin (polyphenylene ether resin) and the like. In addition, composite materials of these resins and organic fibers such as glass fibers (glass woven fabrics and glass nonwoven fabrics) and polyamide fibers, or three-dimensional network fluorine-based resin base materials such as continuous porous PTFE, epoxy resins, etc. A resin-resin composite material impregnated with a thermosetting resin may be used.
[0019]
Further, one or more resin insulation layers may be formed on the surface of the resin insulation layer formed on the main surface of the metal plate, and a wiring layer is formed on each resin insulation layer. It may be. In other words, the above laminated resin wiring board may be provided with only a resin insulating layer interposed between the metal plate and the wiring layer, or between the metal plate and the wiring layer and between different wiring layers. It may be provided with a plurality of resin insulation layers intervening.
[0020]
A via hole conductor (first via hole conductor) that connects and connects the wiring layer and the metal plate may be formed in the resin insulating layer. When there is such a via-hole conductor, the conductive metal plate can function as a ground layer or a power supply layer. In addition, not only via hole conductors that connect and connect between the wiring layer located on the innermost layer and the metal plate, but also via hole conductors that connect and connect between the wiring layer located on the outer layer side and the metal plate are formed. It may be. Also, a via-hole conductor that connects and connects different wiring layers may be formed.
[0021]
The via conductor constituting the via hole conductor is formed by, for example, electroless copper plating, electroless nickel plating, electroless Fe—Ni alloy plating, or the like. Among them, from the viewpoint of matching the thermal expansion coefficient with the wiring layer and the metal plate, it is preferable to use electroless plating of a metal having a lower thermal expansion coefficient than copper, as with the wiring layer and the metal plate. Is preferably electroless Fe—Ni alloy plating.
[0022]
When the wiring layer and the resin insulating layer are present on both sides of the first main surface and the second main surface of the metal plate, the metal plate is formed with a metal plate through hole that communicates the first main surface and the second main surface. In addition, it is preferable that the inside be filled with a resin filler.
[0023]
Here, the resin filler can be appropriately selected in consideration of insulation, heat resistance, moisture resistance, and the like. Preferable examples of the resin material forming the resin filler include EP resin, PI resin, BT resin, PPE resin, and the like. That is, as long as it can be used as the resin material for forming the resin insulating layer, it can be used without any problem as the resin material for forming the resin filler. In addition, it is preferable from a viewpoint of cost efficiency or productivity to use what was used as the resin material for resin insulation layer as it is as a resin material for resin filler formation.
[0024]
In the resin insulating layer and the resin filler, a via-hole conductor that connects and conducts connection between the wiring layer on the first main surface side and the wiring layer on the second main surface side while maintaining insulation with the metal plate (that is, A metal plate insulating via-hole conductor (second via-hole conductor) may be formed. Also, a via-hole conductor (that is, a metal plate conduction via-hole conductor) that connects and conducts wiring layers on both main surfaces while maintaining a connection conduction state with the metal plate may be formed.
[0025]
The method for forming the metal plate through hole is not particularly limited, and various conventionally known hole forming methods can be employed. Examples of such methods include etching, laser processing, punching and the like, but it is desirable to employ etching (especially double-sided simultaneous etching) for a metal plate having a large plate thickness. Furthermore, it is desirable to employ photo-etching. In this case, the positional accuracy of the formed through-hole can be increased, and the yield can be improved.
[0026]
Next, another solution is a conductive metal material having a first main surface and a second main surface and having a lower thermal expansion coefficient than copper. Metal plate made of rolled Fe-Ni alloy plate And a conductive metal material that is located on at least one of the first main surface and the second main surface and has a lower thermal expansion coefficient than copper Formed by etching a rolled Fe-Ni alloy foil A wiring layer, and a resin insulating layer interposed between the metal plate and the wiring layer; And a via-hole conductor having a via conductor made of electroless Fe—Ni alloy plating and connected to and conductive between the wiring layer and the metal plate, the metal plate can function as a ground layer or a power supply layer A method for producing a laminated resin wiring board, comprising: Rolled Fe-Ni alloy plate In at least one of the first main surface and the second main surface in the above, via a resin insulating layer forming material, Rolled Fe-Ni alloy foil Laminating and laminating said Rolled Fe-Ni alloy foil Forming the wiring layer by etching And forming the via conductor in the via hole forming hole formed in the resin insulating layer by the electroless Fe—Ni alloy plating. The gist of the manufacturing method of the laminated resin wiring board characterized in that it is included.
[0027]
Therefore, according to the above manufacturing method, the wiring layer pattern is formed by etching the laminated metal foil, that is, by a subtractive method. Therefore, it is possible to manufacture the laminated resin wiring board having the above configuration in a short time and at a low cost compared to the case where pattern formation is performed by the additive method.
[0028]
As the metal foil, any of a foil formed by an electrolytic method (electrolytic metal foil) and a foil formed by a rolling method (rolled metal foil) may be used, but speakingly, a rolled metal foil is used. It is preferable. The reason is that the rolled metal foil has a dense crystal structure as compared with the electrolytic metal foil, and is considered to be more advantageous than the electrolytic metal foil from the viewpoint of rigidity and conductivity.
[0029]
In particular, when the metal plate is a rolled metal plate, selecting a metal foil made of the same kind of metal (for example, selecting a rolled Fe—Ni alloy plate as the metal plate and a rolled Fe—Ni alloy foil as the metal foil) It is desirable to select it. The reason is that, if the metals are both formed by a rolling method, the properties are basically the same, so that the difference in coefficient of thermal expansion can be made almost zero.
[0030]
The thickness of the metal foil used is preferably 5 μm to 70 μm, more preferably 5 μm to 35 μm, and particularly preferably 10 μm to 18 μm. This is because, if the thickness of the metal foil is less than 5 μm, the handleability may be significantly lowered and the foil itself may be difficult to manufacture. Conversely, if the thickness of the metal plate exceeds 70 μm, it is no longer a foil and the properties are close to those of the plate.
[0031]
In the step of forming the wiring layer by etching the laminated metal foil, the metal foil is chemically etched using, for example, an etchant capable of dissolving and removing the metal foil. The etchant in this case is not particularly limited, and a conventionally known one can be used. For example, ferric chloride is used.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a laminated resin wiring board (so-called metal core board) according to an embodiment of the present invention will be described in detail with reference to FIGS.
[0033]
FIG. 1 schematically shows the laminated resin wiring board 11 of the present embodiment. The laminated resin wiring board 11 includes a metal plate 12 made of a Fe—Ni rolled alloy as a core material. In FIG. 1, buildup layers are formed on the upper surface (that is, the first main surface) 13 and the lower surface (that is, the second main surface) 14 of the metal plate 12.
[0034]
The thickness of the metal plate 12 is set to 0.25 mm, and a large number of 0.30 mmφ metal plate through-holes 15 that allow the upper surface 13 and the lower surface 14 to communicate with each other are provided at predetermined positions.
[0035]
The buildup layer on the upper surface 13 side has a structure in which the resin insulating layers 21, 41, 61 and the wiring layers 31, 51 are alternately stacked. The build-up layer on the lower surface 14 side has a structure in which resin insulating layers 22, 42, 62 and wiring layers 32, 52 are alternately laminated. That is, in this embodiment, the number of wiring layers 31, 32, 51, 52 is equal on both sides of the laminated resin wiring board 11.
[0036]
The first resin insulation layers 21 and 22 and the second resin insulation layers 41 and 42 have a thickness of 30 μm, and a resin-resin composite material in which continuous porous PTFE is impregnated with an epoxy resin. Consists of. The first resin insulation layers 21 and 22 are formed on the upper surface 13 and the lower surface 14 of the metal plate 12. The second resin insulation layers 41 and 42 are respectively formed on the first resin insulation layers 21 and 22. The metal plate through-hole 15 is filled with an epoxy resin derived from the resin-resin composite material, thereby forming a resin filler 23.
[0037]
The first wiring layers 31 and 32 are both made of an Fe—Ni alloy having a thickness of about 15 μm, and are formed on the first resin insulation layers 21 and 22, respectively. A via hole forming hole 33 having a diameter of 70 μm is formed in the first resin insulating layers 21 and 22. A via conductor 35 is formed inside the via hole forming hole 33 by electroless Fe—Ni alloy plating, thereby forming a blind via hole conductor 34. The metal plate 12 and the wiring layer 31 and the metal plate 12 and the wiring layer 32 are connected and connected through the blind via-hole conductor 34, respectively.
[0038]
The second wiring layers 51 and 52 are both made of an Fe—Ni alloy having a thickness of about 15 μm, and are formed on the second resin insulating layers 41 and 42, respectively. A via hole forming hole 53 having a diameter of 70 μm is formed in the second resin insulating layers 41 and 42. A via conductor 55 is formed in the via hole forming hole 53 by electroless Fe—Ni alloy plating, thereby forming a blind via hole conductor 54. The wiring layer 31 and the wiring layer 51 and the wiring layer 32 and the wiring layer 52 are connected and connected through the blind via-hole conductor 54.
[0039]
The third resin insulation layers 61 and 62 located at the outermost layer have a thickness of 20 μm and are formed on the second resin insulation layers 41 and 42 using a photosensitive epoxy resin. Yes. Via hole forming holes 63 and 64 are formed through the third resin insulating layers 61 and 62. In the via hole forming holes 63 and 64, mortar-shaped pads 71 and 72 made of three layers of conductors, that is, an Fe—Ni alloy plating layer, a nickel plating layer, and a gold flash plating layer (all not shown) are formed. Yes. The bottom of the pad 71 is connected and connected to the second wiring layer 51, and the bottom of the pad 72 is connected and connected to the second wiring layer 52. These pads 71 and 72 are connected to connection terminals such as an IC chip and a mother board (not shown) by soldering or the like. The third resin insulation layers 61 and 62 also serve as solder resist layers.
[0040]
The first resin insulation layers 21 and 22 and the resin filler 23 are formed with via hole forming holes 25 having a diameter of 0.15 mm that pass through them. A via conductor 27 is formed inside the via hole forming hole 25 by electroless Fe—Ni alloy plating, and as a result, a metal plate insulating via hole conductor 26 is formed. The metal plate insulating via-hole conductor 26 is electrically insulated from the inner wall surface of the metal plate through-hole 15 of the metal plate 12 and between the wiring layers 31 and 51 on the upper surface side and the wiring layers 32 and 52 on the lower surface side. Connection is connected. The metal plate insulating via-hole conductor 26 penetrates not only the first resin insulating layers 21 and 22 and the resin filler 23 but also the second resin insulating layers 41 and 42. May be.
[0041]
A so-called metal core package can be obtained by mounting an IC chip or the like (not shown) on such a laminated resin wiring substrate 11. When power is supplied to such a package, the metal plate 12 has a predetermined potential (such as a ground potential or a power supply potential) through the blind via-hole conductor 34, and functions as a ground layer or a power supply layer.
[0042]
Next, a procedure for manufacturing the laminated resin wiring board 11 having the above configuration will be described.
[0043]
First, a metal plate 12 having a thickness of 0.25 mm is prepared (see FIG. 2). In this embodiment, specifically, as shown in the table of FIG. 13, as an example, five types of metal plates 12 (that is, rolled 42 alloy plate, rolled 50 alloy plate, rolled amber plate, rolled superamber plate, rolled) Kovar plate) was used. Then, a photosensitive resist is formed on the upper surface 13 and the lower surface 14 of the metal plate 12, and a mask 81 having a predetermined pattern is formed by performing exposure and development. An opening 82 is provided at a location where the metal plate through hole 15 is to be formed in the mask 81 (see FIG. 3).
[0044]
In this state, when the metal plate 12 is etched with an etchant (specifically, ferric chloride) that can dissolve the Fe—Ni-based alloy, the metal plate 12 is eroded from both the upper surface 13 and the lower surface 14, resulting in opening. The metal plate through-hole 15 is formed at a position where the portion 82 is present (see FIG. 4). Thereafter, the mask 81 that has become unnecessary is dissolved and removed with a special stripping solution (see FIG. 5).
[0045]
Subsequently, first resin insulation layers 21 and 22 and a resin filler 23 are formed on the metal plate 12. Here, first, the upper surface 13 and the lower surface 14 of the metal plate 12 are each made of a Fe—Ni-based rolled alloy through a prepreg (not shown) in which continuous porous PTFE is impregnated with a semi-cured epoxy resin. The metal foils 83 and 84 having a thickness of 12 μm are overlapped. Then, such a laminate is subjected to vacuum thermocompression bonding with a vacuum hot press machine (not shown) to fully cure the semi-cured prepreg, whereby the resin insulating layers 21 and 22 having a thickness of 30 μm are respectively formed. Form. In the metal plate through-hole 15 indicated by a broken line in FIG. 6, as a result of being filled with the epoxy resin exuded from the prepreg, a resin filler 23 is formed.
[0046]
Specifically, as shown in the table of FIG. 13, for the examples, metal foils 83 and 84 (namely, rolled 42 alloy foil, rolled 50 alloy foil, rolled amber) made of five types of Fe—Ni-based rolled alloys. Foil, rolled superamber foil, rolled Kovar foil). On the other hand, copper foil was used about the comparative example (namely, conventional example).
[0047]
Next, by carrying out laser drilling using a YAG laser or a carbon dioxide gas laser, the first resin insulation layers 21 and 22, the resin filler 23, and the metal foils 83 and 84 are perforated, and the diameter is 70 μm. Via hole forming holes 25 and 33 are formed (see FIG. 7). In the present embodiment, it is necessary to set the laser output and the like under such conditions that the metal plate 12 is not perforated.
[0048]
Next, a via conductor 35 is formed in the via hole forming hole 33 and a via conductor 27 is formed in the via hole forming hole 25 by a conventionally known method. As a result, the blind via hole conductor 34 and the metal plate insulating via hole conductor 26 are formed (see FIG. 8). Further, according to a conventionally known method, first wiring layers 31 and 32 are formed on the first resin insulating layer 21 and the lower surface of the resin insulating layer 22, respectively. Specifically, after electroless Fe—Ni alloy plating, exposure / development is performed to form a predetermined pattern of plating resist. In this state, after electroless Fe—Ni alloy plating is performed using the electroless Fe—Ni alloy plating layer as a common electrode, the resist is first dissolved and removed, and further, an unnecessary electroless Fe—Ni alloy plating layer is formed by, for example, second chloride. It is removed by etching using iron or the like.
[0049]
Next, an epoxy resin is filled in the blind via-hole conductor 34 and the metal plate insulating via-hole conductor 26, and the plug body 28 is formed by curing the epoxy resin. Further, the metal foils 83 and 84 are superposed on the first resin insulating layers 21 and 22 via the prepreg, and are pressure-bonded and cured by vacuum hot pressing. As a result, the second resin insulation layers 41 and 42 and the metal foils 83 and 84 are laminated (see FIG. 9).
[0050]
Next, by performing laser drilling using a YAG laser or a carbon dioxide laser, the first resin insulation layers 21 and 22, the second resin insulation layers 41 and 42, the resin filler 23, Metal foils 83 and 84 are perforated to form via hole forming holes 25 and 53 having a diameter of 70 μm (see FIG. 10).
[0051]
Next, the via conductor 55 is formed in the via hole forming hole 53 and the via conductor 27 is formed in the via hole forming hole 25 by a conventionally known method. As a result, the blind via hole conductor 54 and the metal plate insulating via hole conductor 26 are formed (see FIG. 11). Also, second wiring layers 51 and 52 are respectively formed on the second resin insulation layer 41 and the lower surface of the resin insulation layer 42 by a conventionally known method. The specific formation method is the same as the formation method of the blind via-hole conductor 34, the metal plate insulating via-hole conductor 26, and the first wiring layers 31 and 32.
[0052]
Next, the plug body 28 is formed by filling the blind via hole conductor 54 and the metal plate insulating via hole conductor 26 with epoxy resin and curing it. Thereafter, a photosensitive epoxy resin is deposited on the second resin insulation layers 41 and 42, and exposure / development is performed, whereby a third resin insulation layer having via hole forming holes 63 and 64 is formed. 61, 62 are formed. At this time, the second wiring layers 51 and 52 are exposed at the bottoms of the via hole forming holes 63 and 64, respectively (see FIG. 12).
[0053]
Next, on the third resin insulation layers 61 and 62, using an electroless Fe—Ni alloy plating, an etching process, an electroless nickel plating, and an electroless gold plating are sequentially performed using a conventionally known method. By applying, pads 71 and 72 are formed. As a result, the laminated resin wiring substrate 11 shown in FIG. 1 is completed.
[0054]
Therefore, according to the present embodiment, the following effects can be obtained.
[0055]
(1) In this laminated resin wiring board 11, not only the forming material of the metal plate 12 but also the forming materials of all the wiring layers 31, 32, 51, 52 are Fe—Ni alloys having a lower thermal expansion coefficient than copper. Is used. For this reason, the difference in thermal expansion coefficient between the metal plate 12 and the wiring layers 31, 32, 51, 52 is extremely small as compared with the conventional laminated resin wiring board (see Table 1 in FIG. 13). Specifically, in the comparative example, the difference in thermal expansion coefficient is 12.9 ppm / ° C. (30 ° C.-300 ° C.), whereas in Examples 1-14, the difference in thermal expansion coefficient is 0-5.8 ppm / ° C. (30 ° C-300 ° C). Therefore, even if there are a plurality of wiring layers 31, 32, 51, 52, the effect of reducing the thermal expansion coefficient of the entire substrate is hardly offset. Therefore, the reduction of the thermal expansion coefficient of the entire substrate is reliably achieved, and the laminated resin wiring substrate 11 having excellent dimensional stability and reliability can be obtained relatively easily and reliably.
[0056]
In the case of this laminated resin wiring board 11, the build-up layer will be further multilayered and densified in the future, and the existing ratio of the wiring layers 31, 32, 51, 52 in the board (that is, the usage ratio of copper) will be increased. Even if it becomes higher, it is possible to reliably achieve a reduction in the coefficient of thermal expansion of the entire substrate. That is, it can be said that the structure of the laminated resin wiring board 11 of this embodiment is suitable for multilayering and high density.
[0057]
(2) Moreover, in the manufacturing method of this embodiment, laminated metal foils 83,84 The wiring layers 31, 32, 51, and 52 are formed by etching (that is, the subtractive method). Therefore, it is possible to manufacture the multilayer resin wiring substrate 11 having the above-described configuration in a shorter time and at a lower cost than when pattern formation is performed by the additive method.
[0058]
In addition, you may change embodiment of this invention as follows.
[0059]
In the above-described embodiment, all of the plurality of wiring layers 31, 32, 51, 52 are formed using the same metal material (Fe—Ni alloy). However, the present invention is not limited to this. For example, an Fe—Ni alloy may be used only for the wiring layers 31 and 32, and a metal material other than the Fe—Ni alloy having a lower thermal expansion coefficient than copper may be used for the wiring layers 51 and 52.
[0060]
The via-hole conductors 26, 34, 53 may be formed by electroless Fe—Ni alloy plating as in the above embodiment, or may be formed by, for example, electroless copper plating. Further, the via-hole conductors 26, 34, 53 may be formed by a method other than electroless plating (for example, filling with a conductive paste).
[0061]
The present invention may be embodied in a form in which the via-hole conductor 34 (first via-hole conductor) that connects and conducts between the metal plate 12 and the wiring layer 31 or between the metal plate 12 and the wiring layer 32 is omitted. Further, the present invention omits the via-hole conductor 26 (second via-hole conductor) that connects and connects the upper and lower wiring layers 31, 32, 51, 52 of the metal plate 12 while maintaining insulation with the metal plate 12. May be embodied in
[0062]
In the above embodiment, a specific example of the laminated resin wiring board 11 using only one metal plate 12 as a core material is shown. Of course, the present invention is not limited to such an embodiment. For example, it can be embodied as a laminated resin wiring board using two or more metal plates 12.
[0063]
In the above embodiment, the same number of resin insulating layers 21, 22, 41, 42, 61, 62 and wiring layers 31, 32, 51, 52 are formed above and below the metal plate 12 that is the core material. Of course, the number is not limited, and may be a different number in the upper and lower sides.
[0064]
In the above embodiment, the specific example of the laminated resin wiring substrate 11 using the metal plate 12 as a core material and having build-up layers on the upper and lower sides thereof is shown. Of course, the present invention is not limited to such an embodiment. For example, the metal plate 12 may be used as a base material, and may be embodied as a laminated resin wiring board (so-called metal base board) having a buildup layer on only one of the upper and lower sides.
[0065]
Next, in addition to the technical ideas described in the claims, the technical ideas grasped by the embodiment described above are listed below.
[0066]
(1) The difference between the thermal expansion coefficient of the conductive metal material constituting the wiring layer and the thermal expansion coefficient of the conductive metal material constituting the metal plate is 6 ppm / ° C. or less (preferably 2 ppm / ° C. or less, particularly 3. The laminated resin wiring board according to claim 1 or 2, which is preferably 1 ppm / ° C. or less.
[0067]
(2) The coefficient of thermal expansion of the conductive metal material constituting the wiring layer and the coefficient of thermal expansion of the conductive metal material constituting the metal plate are both less than 14 ppm / ° C. (preferably less than 11 ppm / ° C., particularly 3. The laminated resin wiring board according to claim 1 or 2, which is preferably less than 6 ppm / ° C.
[0068]
(3) The laminated resin wiring board according to claim 1 or 2, wherein the wiring layer and the metal plate are made of the same kind of metal.
[0069]
(4) The multilayer resin wiring board according to any one of claims 1 to 3, wherein the wiring layer is formed by etching a metal foil.
[0070]
(5) The laminated resin according to any one of claims 1 to 3, wherein the metal plate is a rolled metal plate, and the wiring layer is formed by etching a rolled metal foil. Wiring board.
[0071]
(6) The multilayer resin wiring board according to claim 2 or 3, wherein all of the plurality of wiring layers are made of an Fe-Ni alloy.
[0072]
(7) A via-hole conductor that connects and connects between the wiring layer and the metal plate or between the wiring layers is provided, and the via-hole conductor is formed by electroless plating of a conductive metal having a lower thermal expansion coefficient than copper. The laminated resin wiring board according to claim 1, wherein the laminated resin wiring board is formed.
[0073]
(8) A via hole conductor for connecting and connecting the wiring layer and the metal plate or between the wiring layers is provided, and the via hole conductor is formed by electroless Fe—Ni alloy plating. The laminated resin wiring board according to any one of claims 1 to 3.
[0074]
(9) A metal plate made of a rolled Fe—Ni alloy material having a first main surface and a second main surface and having a thickness of 150 μm or more, and a first main surface side and a second main surface side of the metal plate. , A plurality of wiring layers formed by etching a rolled Fe-Ni alloy foil, and a plurality of layers interposed between the metal plate and the wiring layer, or between the metal plate and the wiring layer and between the wiring layers. A resin insulating layer, a first via-hole conductor formed in the resin insulating layer and connected and connected between the wiring layer and the metal plate, and the first main surface and the second main surface of the metal plate A resin filler filled in a metal plate through-hole communicating with the metal plate, and a via hole forming hole penetrating the resin filler, and the first main surface side while maintaining insulation between the metal plate And a second via for connecting and connecting between the wiring layer and the wiring layer on the second main surface side Laminating resin wiring board, characterized in that a Lumpur conductor.
[Brief description of the drawings]
FIG. 1 is a schematic partial cross-sectional view showing a laminated resin wiring board according to an embodiment of the present invention.
FIG. 2 is a partial cross-sectional schematic view showing a metal plate that is a constituent member of the wiring board.
FIG. 3 is a partial cross-sectional schematic view showing a state in which a photoetching mask is formed on a metal plate.
FIG. 4 is a partial cross-sectional schematic view showing a state where metal plate through holes are formed by photoetching.
FIG. 5 is a partial cross-sectional schematic view showing a state in which a photoetching mask is removed.
FIG. 6 is a partial cross-sectional schematic view showing a state in which a first resin insulating layer and a metal foil are laminated.
FIG. 7 is a partial cross-sectional schematic view showing a state in which a hole for forming a via hole is formed in the first resin insulating layer.
FIG. 8 is a partial cross-sectional schematic view showing a state where a blind via-hole conductor is formed.
FIG. 9 is a partial cross-sectional schematic view showing a state in which a second resin insulating layer and a metal foil are laminated.
FIG. 10 is a partial cross-sectional schematic view showing a state in which a hole for forming a via hole is formed in a second resin insulating layer or the like.
FIG. 11 is a partial cross-sectional schematic view showing a state in which a blind via hole conductor and a metal plate insulating via hole conductor are formed.
FIG. 12 is a partial cross-sectional schematic view showing a state in which a third resin insulating layer is formed.
FIG. 13 is a table showing combinations of metal materials used for metal foils constituting a metal plate and a wiring layer for each example and comparative example.
[Explanation of symbols]
11 ... Laminated resin wiring board
12 ... Metal plate
13 ... Upper surface as the first main surface
14 ... lower surface which is the second main surface
21, 22, 41, 42, 61, 62 ... resin insulation layer
31, 32, 51, 52 ... wiring layer
83,84 ... metal foil

Claims (4)

A metal plate made of a rolled Fe-Ni alloy plate, which is a conductive metal material having a first main surface and a second main surface and having a lower thermal expansion coefficient than copper, the first main surface and the second main surface A wiring layer formed by etching a rolled Fe—Ni alloy foil, which is a conductive metal material having a thermal expansion coefficient lower than that of copper, located on at least one side of the metal plate, the metal plate, and the wiring A resin insulating layer interposed between the wiring layer and a via-hole conductor having a via conductor made of electroless Fe-Ni alloy plating and connected and conductive between the wiring layer and the metal plate; A laminated resin wiring board, which can function as a ground layer or a power supply layer . A metal plate made of a rolled Fe-Ni alloy plate, which is a conductive metal material having a first main surface and a second main surface and having a lower thermal expansion coefficient than copper, and the first main surface side and the first of the metal plate A plurality of wiring layers formed by etching a rolled Fe-Ni alloy foil, which is a conductive metal material having a lower thermal expansion coefficient than copper, located on the two principal surface sides, the metal plate and the wiring layer, Or a plurality of resin insulation layers interposed between the metal plate and the wiring layer and between the wiring layers, and between the wiring layer and the metal plate, and electroless Fe-Ni alloy plating A laminated resin wiring board , wherein the metal plate can function as a ground layer or a power supply layer . 3. The laminated resin wiring board according to claim 1 , wherein a thickness of the rolled Fe—Ni alloy plate is 150 μm to 500 μm, and a thickness of the rolled Fe—Ni alloy foil is 5 μm to 70 μm . A metal plate made of a rolled Fe-Ni alloy plate, which is a conductive metal material having a first main surface and a second main surface and having a lower thermal expansion coefficient than copper, the first main surface and the second main surface A wiring layer formed by etching a rolled Fe—Ni alloy foil, which is a conductive metal material having a thermal expansion coefficient lower than that of copper, located on at least one side of the metal plate, the metal plate, and the wiring A resin insulating layer interposed between the wiring layer and a via-hole conductor having a via conductor made of electroless Fe-Ni alloy plating and connected and conductive between the wiring layer and the metal plate; A method of manufacturing a laminated resin wiring substrate that can function as a ground layer or a power supply layer ,
The rolled Fe—Ni alloy foil is laminated on at least one of the first main surface and the second main surface of the rolled Fe—Ni alloy plate with a resin insulating layer forming material interposed therebetween. Process,
Etching the laminated rolled Fe-Ni alloy foil to form the wiring layer ;
Forming the via conductor in a hole for forming a via hole formed in the resin insulation layer by the electroless Fe-Ni alloy plating;
The manufacturing method of the laminated resin wiring board characterized by including.

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