JP3935456B2 - Wiring board manufacturing method - Google Patents

Description

[0001]
The present invention relates to a method for manufacturing a wiring substrate having no core substrate.
[0002]
[Prior art]
In recent years, due to the demand for higher functionality and lighter, thinner and smaller electronic devices, high-density integration has rapidly progressed in electronic components such as IC chips and LSIs. There is a demand for higher-density wiring and multi-terminals than ever before.
[0003]
As such a package substrate, a build-up multilayer wiring substrate is currently used. The build-up multilayer wiring board uses a rigid property of an insulating core substrate (glass epoxy substrate such as FR-4) in which a reinforcing fiber is impregnated with a resin, and is made of a polymer material on both main surfaces thereof. A build-up layer in which dielectric layers and conductor layers are alternately arranged is formed. In such a build-up multilayer wiring board, high-density wiring is realized in the build-up layer, while the core board plays a reinforcing role. For this reason, the core substrate is configured to be very thick compared to the buildup layer, and the wiring inside it (for example, referred to as a through-hole conductor) for establishing conduction between the buildup layers disposed on the respective main surfaces Are formed penetrating in the thickness direction. However, at the present time when the signal frequency to be used has become a high frequency band exceeding 1 GHz, there is a problem that the wiring penetrating such a thick core substrate contributes as a large inductance.
[0004]
Therefore, in order to solve such a problem, there has been proposed a wiring board mainly composed of a build-up layer that does not have a core board and can be formed with high density wiring, as shown in Patent Document 1. In such a wiring board, since the core board is omitted, the entire wiring length is short, which is suitable for high-frequency applications. In order to manufacture such a wiring board, as described in paragraphs 0012 to 0029 and FIGS. 1 to 4, a thin film is formed by forming a buildup layer on a metal plate and then etching the metal plate. Only get the build-up layer. This build-up layer is used as a wiring board.
[0005]
[Patent Document 1]
JP 2002-26171 A [0006]
[Problems to be solved by the invention]
However, in the case of the manufacturing method described in Patent Document 1, the metal plate on which the build-up layer is formed has a thickness that can play a reinforcing role at the time of manufacturing (for example, 0.8 mm in the case of a copper plate). However, it takes too much time (for example, about 30 minutes for a copper plate of 0.8 mm) to etch all of the build-up layer after forming it. there were.
[0007]
Therefore, the present invention has an object to provide a manufacturing method capable of easily obtaining a wiring substrate in which dielectric layers and conductor layers made of a polymer material are alternately laminated without having a core substrate. To do.
[0008]
[Means for solving the problems and functions / effects of the invention]
In order to solve the above problems, in the method for manufacturing a wiring board of the present invention,
In order to produce a wiring board in which dielectric layers and conductor layers made of a polymer material are alternately laminated so that both main surfaces are composed of dielectric layers without having a core substrate,
A metal foil adhesion body formed by adhering two metal foils so as to be included in the main surface on the main surface of the underlying dielectric sheet formed on the support substrate for reinforcement during manufacture; Forming a first dielectric sheet that wraps around the metal foil adhesion body and seals the metal foil adhesion body in close contact with the underlying dielectric sheet in a peripheral region of the metal foil adhesion body. ,
Forming a first conductor layer on the first dielectric sheet; forming a first via conductor connecting the first conductor layer and the metal foil adhesion body on the first dielectric sheet; A second dielectric sheet is formed on the dielectric sheet and the first conductor layer , a second via conductor is formed in the second dielectric sheet, and a second conductor layer is formed on the second dielectric sheet. Forming and repeating the same process to form a dielectric sheet, via conductor, conductor layer, forming a laminated sheet body,
A plurality of metal terminal pads connected to the metal foil adhesion body are formed on the exposed main surface of the laminated sheet body through a conductor layer provided between the dielectric sheets and via conductors provided in the dielectric sheet. Then, by supplying an electric current from any one of the plurality of metal terminal pads and performing an electroplating process, an electroplating surface layer is formed on each surface of the plurality of metal terminal pads,
Of the laminated sheet body, the region on the metal foil adhesion body is used as the wiring laminated portion to be the wiring substrate, and the peripheral portion is removed to expose the end surface of the wiring laminated portion, and then the wiring laminated portion. Is peeled off from the support substrate at the interface between the two metal foils in the metal foil adhesion body with one metal foil attached thereto.
[0009]
According to the present invention, the method for manufacturing a wiring board according to the present invention will be briefly described with reference to FIG. 1. (a) A base formed on a support substrate 20 (corresponding to a metal plate in Patent Document 1). On the dielectric sheet 21, a laminated sheet body 10 containing a wiring laminated portion 100 (see FIG. 2) to be a wiring substrate is formed, and (b) a peripheral portion of the wiring laminated portion 100 (see FIG. 2). The end surface 103 of the wiring laminated portion 100 is exposed by removing the inner broken line portion), and (c) the wiring laminated portion 100 is peeled from the support substrate 20 (and the underlying dielectric sheet 21). As described above, the wiring substrate can be easily obtained by separating the wiring laminated portion and the supporting substrate by peeling. In addition, since the wiring laminated portion and the support substrate are not separated by etching, a laminated sheet body can be formed on both main surfaces of the support substrate, which enables mass production of the wiring substrate.
[0010]
Hereinafter, detailed description will be given with respect to each step of FIG. In FIG. 1A, a laminated sheet body 10 containing a wiring laminated portion 100 (see FIG. 2; details will be described later) to be a wiring board is formed on a base dielectric sheet 21 formed on a support substrate 20. Has been. In the laminated sheet body 10, a metal foil adhesion body 5 formed by adhering two metal foils 5 a and 5 b is disposed so as to be included in the main surface of the base dielectric sheet 21, and the metal foil adhesion body 5 is wrapped around. The first dielectric sheet 11 is arranged so as to be uneven. In addition to this, the laminated sheet body 10 has conductor layers 31 and 32 provided between the dielectric sheets, via conductors 41 and 43 provided in the dielectric sheet, and the metal foil adhesion body 5 by these. The metal terminal pads 33 are connected to each other, which will be described later. The first dielectric sheet 11 formed so as to wrap the metal foil adhesion body 5 is in close contact with the metal foil adhesion body 5 (upper metal foil 5b) and is grounded in the peripheral region 21c of the metal foil adhesion body 5. It is in close contact with the dielectric sheet 21, whereby the metal foil contact body 5 is sealed with the first dielectric sheet 11.
[0011]
Thus, the metal foil adhesion body 5 is sealed by the first dielectric sheet 11, so that the interface between the metal foil adhesion body 5 (lower metal foil 5 a) and the base dielectric sheet 21 swells or peels off. The laminated sheet body 10 can be formed without the occurrence of. Then, in FIG. 1B, since the peripheral region 21c where the first dielectric sheet 11 and the base dielectric sheet 21 are in close contact with each other is removed, in FIG. It becomes possible to easily peel off the wiring laminated portion 100 at the interface. That is, with this configuration, formation of a laminated sheet body that requires adhesion (FIG. 1 (a)) and separation of a wiring laminate portion that requires ease of peeling (FIG. 1 (c)). Both can be performed satisfactorily.
[0012]
As shown in FIG. 2, a region on the metal foil adhesion body 5 in the laminated sheet body 10 is a wiring laminated portion 100. The wiring laminated portion 100 is obtained in a state where the upper metal foil 5b is adhered by the peeling of FIG. In other words, it has a structure in which dielectric layers and conductor layers made of a polymer material are alternately laminated so as not to have a core substrate and both main surfaces are composed of dielectric layers (detailed structure) Will be described later).
[0013]
Moreover, the form of the lamination sheet body 10 should just have the wiring lamination | stacking part 100 (area | region on the metal foil contact | adherence body 5), and is not limited to the form of Fig.1 (a). For example, as shown in FIG. 3A, a configuration in which the dielectric sheets 111 and 112 are arranged on the metal foil adhesion body 5 and the first dielectric sheet 11 is sealed together may be employed. Further, as shown in FIG. 3B, another dielectric sheet formed on the first dielectric sheet 11 may be configured only by a portion that becomes the wiring laminated portion 100.
[0014]
Next, in FIG.1 (b), the surrounding part (dashed line part in a figure) of the wiring lamination | stacking part 100 is removed among the lamination sheet bodies 10, and the end surface 103 of this wiring lamination | stacking part 100 is exposed. That is, the peripheral region 21c where the first dielectric sheet 11 and the base dielectric sheet 21 are in close contact with each other is removed, and the end face of the metal foil adhesive body 5 is exposed. As a result, as shown in FIG. 1C, the wiring laminated portion 100 can be easily removed from the support substrate 20 at the interface of the metal foil adhesion body 5 (that is, the interface between the lower metal foil 5a and the upper metal foil 5b). Can be peeled off. When removing the peripheral portion (broken line portion in the drawing) of the wiring laminated portion 100 in the laminated sheet body 10, the region under the peripheral portion of the support substrate 20 and the base dielectric sheet 21 is also removed together with the peripheral portion. By doing so, the end surface 103 of the wiring laminated portion 100 can be easily exposed.
[0015]
Further, in FIG. 1B, when the peripheral portion of the wiring laminated portion 100 is removed, the peripheral region 21c where the first dielectric sheet 11 and the base dielectric sheet 21 are in close contact is removed, and the metal foil adhesive body 5 is removed. As shown in FIGS. 4 (a) and 4 (b), it is possible to peel the wiring laminated portion 100 by exposing the end portion of the metal foil. The wiring laminated portion 100 is constituted by a portion excluding the vicinity of the outer edge of the metal foil adhesion body 5 and a region on the portion, and the peripheral area is removed, that is, the vicinity of the outer edge of the metal foil adhesion body 5 is also removed. Can be.
[0016]
Next, the laminated sheet body 10 includes the conductor layers 31 and 32 provided between the dielectric sheets, the via conductors 41 and 43 provided in the dielectric sheet, and the metal foil adhesion body 5 by these. And a plurality of metal terminal pads 33 which are connected and exposed on the main surface of the laminated sheet body 10. That is, since the plurality of metal terminal pads 33 are electrically connected to each other, as shown in FIG. 16, by supplying an electric current from any one of the plurality of metal terminal pads 33 and performing an electrolytic plating process. (In the figure, current is supplied from the plating bar 70 to one metal terminal pad 33), and the electrolytic plating surface layer 7 can be formed on the surface of each of the plurality of metal terminal pads 33. Further, since the electroplating process can be performed in a state where the laminated sheet body 10 (or the wiring laminated body 100) is held on the support substrate 20, the thin and soft wiring laminated portion 100 after peeling shown in FIG. Work can be reduced.
[0017]
On the metal terminal pad 33, for example, a bonding member with an external substrate such as a solder ball is installed. However, when the electrolytic plating surface layer 7 is formed by electrolytic plating, a reducing agent is not used in the plating bath. There is an advantage that a plated surface layer having good wettability and adhesion to solder can be obtained. Thereby, the connection reliability of a metal terminal pad and a joining member (solder ball etc.) improves. In general, in order to perform the electrolytic plating process, it is necessary to insert a plating tie bar between the dielectric layers together with the wiring. However, if the above method is used, it is not necessary to arrange the plating bar between the dielectric layers. There are also advantages. The plating tie bar not only hinders high-density wiring, but also remains on the wiring board as an unnecessary conductive path with electrically open ends, so this part becomes a noise collection source and noise resistance deteriorates. Or there is a problem of causing impedance mismatching of the transmission path including the pad.
[0018]
Next, in the laminated sheet body 10, a first via conductor 41 that connects the first conductor layer 31 and the metal foil adhesion body 5 is formed in the first dielectric sheet 11. Therefore, in the wiring laminated body 100 to which the metal foil 5b shown in FIG. 1C is attached, for example, as shown in FIG. 10, when the metal foil 5b is removed to form the metal terminal 8, the first conductor is formed on the surface. An opening 11a having a first via conductor 41 connected to the layer 31 appears, and the metal terminal 8 can be directly formed there. As a result, the metal terminals can be formed without performing operations such as perforating the first dielectric sheet 11 ′ and filling the holes with a conductor (for example, spare solder) in the thin and soft wiring laminated portion 100 after peeling. 8 can be formed.
[0019]
Further, in the wiring laminate 100 to which the metal foil 5b shown in FIG. 1C is attached, the metal foil 5b is connected to the first conductor layer 31 through the first via conductor 41. As shown, a metal terminal 8 having part of the metal foil 5b can be formed.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 5 is a diagram showing an outline of a cross-sectional structure of the wiring board 1 obtained by the method for manufacturing a wiring board of the present invention. The wiring substrate 1 has a structure in which dielectric layers (B1 to B3, SR) made of a polymer material and conductor layers (M1, M2, PD) are alternately stacked. The first main surface MP1 is a mounting surface for mounting an electronic component, and the first dielectric layer B1 forming the main surface has a protruding shape made of a well-known solder for connecting to the electronic component. Metal terminals (solder bumps) FB are formed. The second main surface MP2 is a connection surface for connecting to an external substrate, and an opening is formed in the dielectric layer (solder resist layer) SR forming the main surface, and the external substrate is in the opening. A metal terminal (metal terminal pad) PD for installing a solder ball (described later) that bears the connection to is exposed.
[0021]
A wiring CL is formed in the metal layers M1 and M2, and a via conductor VA connected to the wiring CL is embedded in the dielectric layers B1 to B3. An electrical conduction path (for example, from the solder bump FB to the metal terminal pad PD) is formed by the wiring CL and the via conductor VA. The dielectric layers B1 to B3, SR can be made of, for example, a material mainly composed of an epoxy resin, and the wiring CL, the via conductor VA, and the metal terminal pad PD are mainly composed of, for example, copper. It can be composed of materials. Further, the metal terminal pad PD is provided with an electrolytic plating surface layer, for example, by Ni—Au plating, which is obtained by electrolytic plating treatment on the surface thereof. In addition, the electrolytic plating surface layer can be configured by, for example, Sn (solder) plating.
[0022]
As shown in FIG. 6, the wiring board 1 as described above is provided with solder balls SB for connection to an external substrate on the metal terminal pads PD of the second main surface MP2, while the first main surface MP1 has The reinforcing frame (stiffener) ST is installed, the electronic component IC is flip-chip connected to the solder bump FB, and the gap under the electronic component IC is filled with the underfill material UF, so that the semiconductor device 300 is obtained. .
[0023]
FIG. 12 is a diagram showing an outline of a cross-sectional structure of the second embodiment of the wiring board 1 obtained by the method for manufacturing a wiring board of the present invention. Here, only different points from the wiring substrate 1 of the first embodiment will be described, and the same points are denoted by the same reference numerals in the drawing, and the description thereof is omitted. In the second embodiment, a metal terminal TB composed of a metal foil CF is formed on a first main surface MP1 that is a mounting surface for mounting an electronic component. The metal terminal TB is composed of a metal foil CF with a via conductor VA connected to the back surface and a plating layer NM formed on the surface of the metal foil CF. The plating layer NM protects the surface of the metal foil CF, and for example, electroless Ni—Au plating or the like can be used.
[0024]
Such a metal terminal 8 can be formed as a terminal for wire bonding or a terminal for TAB (Tape Automated Bonding), for example. Then, as shown in FIG. 13, the electronic component IC is mounted on the first main surface MP1 serving as the mounting surface, and the electronic component IC and the metal terminal 8 are connected by the bonding wire YB or the like. It becomes.
[0025]
Hereinafter, an example of the manufacturing method of the wiring board which is embodiment of this invention is demonstrated. 7-10 is a figure showing a manufacturing process. The step of forming the laminated sheet body 10 on the support substrate 20 shown in steps 1 to 5 can be performed by a known build-up method or the like. First, as shown in Step 1 of FIG. 7, a base dielectric sheet 21 is formed on a support substrate 20 for reinforcement during manufacturing. The support substrate 20 is not particularly limited as long as the underlying dielectric sheet 21 is in close contact with each other. For example, the support substrate 20 is composed of a glass epoxy substrate such as FR-4 (which is a material used for the core substrate as described above). be able to. Also, the base dielectric sheet 21 is not particularly limited, but can be made of, for example, the same material as the first dielectric sheet 11 described later, that is, a material mainly composed of epoxy.
[0026]
Next, as shown in Step 2, the metal foil adhesion body 5 is arranged on the main surface of the base dielectric sheet 21 so as to be included in the main surface, and the two metal foils 5a and 5b are in close contact with each other. Arrange. In addition, the metal foil adhesion body 5 can be arranged on the base dielectric sheet 21 in a semi-cured state. Thereby, it becomes easy to obtain adhesiveness to such an extent that the metal foil adhesion body 5 (lower metal foil 5a) does not peel from the base dielectric sheet 21 in the subsequent steps. In addition, as the metal foil adhesion body 5, for example, two copper foils adhered through metal plating (for example, Cr) can be used. Such a metal foil adhesion body 5 can be peeled off.
[0027]
Next, as shown in step 3, the first dielectric sheet 11 is formed so as to wrap the metal foil adhesion body 5. The first dielectric sheet 11 is in close contact with the base dielectric sheet 21 in the peripheral region of the metal foil adhesion body 5 together with the metal foil adhesion body 5 (upper metal foil 5b) to seal the metal foil adhesion body 5. Stop. The dielectric sheet can be formed using, for example, a well-known vacuum lamination method.
[0028]
Next, as shown in Step 4 of FIG. 8, the first conductor layer 31 is patterned on the first dielectric sheet 11, and the first conductor layer 31 and the metal foil are in close contact with the first dielectric sheet 11. A first via conductor 41 connecting the body 5 is formed. The conductor layer can be formed by, for example, a known semi-additive method. The via conductor can be obtained, for example, by forming a via hole by a well-known photo via process and filling the via hole by electroless plating in the semi-additive method.
[0029]
Next, the second dielectric sheet 12 is formed on the first dielectric sheet 11 (and the first conductor layer 31), the via conductors 42 are formed in the second dielectric sheet 12, and the second dielectric sheet 12 is formed. The second conductor layer 32 is formed on the body sheet 12. And the same process is repeated and the dielectric sheets 13 and 14, the via conductor 43, and the conductor layer 33 are formed, and the lamination sheet body 10 as shown to the process 5 is formed. In addition, in this embodiment, although the lamination sheet body 10 is comprised by the metal foil adhesion body 5 and the dielectric sheet 11-14 of 4 layers, the number of layers of a dielectric sheet is not restricted to this. . As described above, the metal foil adhesion body 5 disposed so as to be included in the main surface on the main surface of the base dielectric sheet 21, and the metal foil adhesion body formed so as to wrap around the metal foil adhesion body 5. 5, a laminated sheet body 10 having a first dielectric sheet 11 that is in close contact with the base dielectric sheet 21 and seals the metal foil adhesion body 5 is formed.
[0030]
The dielectric sheets 11 to 14 can be made of a material mainly composed of epoxy. Further, the conductor layers 31 to 33 and the via conductors 41 to 43 can be composed mainly of copper.
[0031]
In the present embodiment, the exposed main surface on the upper side of the laminated sheet body 10 is formed to be the second main surface MP2 of the wiring board 1 shown in FIGS. Therefore, the dielectric sheet 14 forming the upper main surface of the laminated sheet 10 corresponds to the solder resist layer SR of the wiring board 1 of FIG. 5, and the conductor layer 33 exposed in the opening 14a is shown in FIGS. This corresponds to the metal terminal pad PD of the 12 wiring boards 1.
[0032]
After the above step 5 and before proceeding to the next step 6, as shown in FIG. 16, a plurality of metal terminals are connected to the plurality of metal terminal pads 33 electrically connected to each other through the metal foil adhesion body 5. By supplying an electric current from one of the pads 33 and performing an electroplating process (in the figure, an electric current is supplied from the plating bar 70 to one metal terminal pad 33), each surface of the plurality of metal terminal pads 33 is obtained. Then, the electrolytic plating surface layer 7 is formed. For example, electrolytic Ni—Au plating or electrolytic Sn (solder) plating can be used for the electrolytic plating treatment. In addition, since the electrolytic plating surface layer 7 functions as a resist for the alkaline etchant, it is not necessary to protect the metal terminal pad 33 with a dry film in the subsequent steps.
[0033]
Next, the laminated sheet body 10 is formed so that the region on the metal foil adhesion body 5 becomes the wiring laminated portion 100 to be the wiring substrate 1 (see FIG. 5). Therefore, as shown in Step 6, the peripheral region of the wiring laminated portion 100 is removed to expose the end face 103 (Step 7 in FIG. 9). At that time, at the boundary between the wiring laminated portion 100 and the peripheral portion, the underlying dielectric sheet 21 and the supporting substrate 20 thereunder are cut by, for example, a blade blade. In this manner, when the region under the peripheral portion of the support substrate 20 and the base dielectric sheet 21 is removed together with the peripheral region of the wiring laminated portion 100, the end face 103 is easily exposed.
[0034]
Next, as shown in step 8, the two metal foils 5 a and 5 b in the metal foil adhesion body 5 are attached to the wiring laminated portion 100 from the support substrate 20 with one metal foil (upper metal foil 5 b) attached thereto. Peel at the interface.
[0035]
And after peeling the wiring laminated part 100 from the support substrate 20, as shown in FIG. 10, the metal foil 5b adhering to the main surface which the 1st dielectric sheet 11 of this wiring laminated part 100 comprises is removed (process). 9) Metal terminals 5 (solder bumps FB in the wiring board 1 of FIG. 5) connected to the first via conductors 4 are formed (step 10). Thereby, the wiring board 1 shown in FIG. 5 is obtained.
[0036]
In step 9, the metal foil 5b can be removed by etching, for example. A via hole 11a in which the first via conductor 41 is exposed appears on the main surface of the first dielectric sheet 1 ′ from which the metal foil 5b has been removed. Since the first via conductor 41 is slightly etched by etching the metal foil 5b, the end face thereof is located in the via hole (for example, in the vicinity of the opening 11a). That is, the completed wiring board does not have a core board, and the dielectric layers 11 ′ to 14 ′ made of a polymer material and the conductor layers 31 to 33 so that both main surfaces are constituted by dielectric layers. Are alternately stacked and connected to the first conductor layer 31 ′ directly below the first dielectric layer 11 ′ in the via hole 11 a formed through the first dielectric layer 11 ′ forming the first main surface. The via conductor 41 is formed, and the via conductor 41 is configured such that the end surface on the first main surface side is located in the via hole 11a, and the metal terminal 8 is connected to the end surface. Thus, if the end face of the via conductor 41 is located in the via hole 11a, the metal terminals (solder bumps) 8 made of, for example, solder can be easily formed, and connection reliability can be ensured.
[0037]
As shown in FIG. 14, when the depth position from the first main surface of the end face of the via conductor 41 is D and the maximum diameter of the via hole is W, the ratio D / W is greater than 0 and 0.5 or less. It is preferable to set so that. If the ratio D / W exceeds 0.5, the connection reliability between the via conductor 41 and the metal terminal 8 to be connected may be somewhat lowered.
[0038]
On the other hand, as shown in steps 9 ′ and 10 ′ of FIG. 15, the metal terminal 8 using a part 5 b ′ of the metal foil 5 b can be formed. That is, after peeling the wiring laminated portion 100 from the support substrate 20, the metal foil 5b attached to the main surface of the wiring laminated portion 100 on which the first dielectric sheet 11 is formed is selectively removed (step 9 '). Then, the metal terminal 8 connected to the first via conductor 41 and including a part of the remaining metal foil 5b ′ is formed (step 10 ′). That is, in the completed wiring board, the dielectric layers 11 ′ to 14 ′ made of a polymer material and the conductor layers 31 to 3 do not have a core board and both main surfaces are constituted by dielectric layers. Are alternately laminated, and a metal terminal 8 composed of a metal foil 5b ′ is formed on the first main surface.
[0039]
In the above manufacturing process, as shown in FIG. 11, the wiring laminated portion 100 included in the laminated sheet body 10 is formed by connecting a plurality of individual 100 ′ corresponding to one wiring board, that is, the wiring board 1. It can be configured as a multi-piece work substrate.
[Brief description of the drawings]
FIG. 1 is a diagram schematically illustrating the steps of a method for manufacturing a wiring board according to the present invention. FIG. 2 is a diagram showing a wiring laminated sheet body 100 included in the laminated sheet body. FIG. FIG. 4 is a diagram showing a modified example of a region to be a wiring laminated portion 100 in the laminated sheet body. FIG. 5 is a diagram showing an outline of a cross-sectional structure of a wiring board according to an embodiment of the present invention. FIG. 7 is a diagram showing the steps of a method of manufacturing a wiring substrate according to an embodiment of the present invention. FIG. 8 is a diagram following FIG. 7. FIG. 9 is a diagram following FIG. FIG. 10 is a view subsequent to FIG. 9; FIG. 11 is a top view of the wiring laminated portion 100 that is a multi-piece work substrate. FIG. 12 is a schematic cross-sectional structure of the wiring substrate according to the second embodiment of the invention. FIG. 13 is a semiconductor device using the wiring substrate 1 of FIG. 12. FIG. 14 is exposed in a via hole. FIG. 15 is a view showing the end face position of the first via conductor 41. FIG. 15 is a view showing a process for manufacturing the wiring board of the second embodiment. FIG. Diagram showing formation 【Explanation of symbols】
DESCRIPTION OF SYMBOLS 1 Wiring board 5 Metal foil adhesion body 10 Laminated sheet body 11 First dielectric sheet 20 Support substrate 21 Base dielectric sheet 100 Wiring laminated sheet body

Claims (3)

In order to produce a wiring board in which dielectric layers and conductor layers made of a polymer material are alternately laminated so that both main surfaces are composed of dielectric layers without having a core substrate,
A metal foil adhesion body formed by adhering two metal foils so as to be included in the main surface on the main surface of the underlying dielectric sheet formed on the support substrate for reinforcement during manufacture; Forming a first dielectric sheet that wraps around the metal foil adhesion body and seals the metal foil adhesion body in close contact with the underlying dielectric sheet in a peripheral region of the metal foil adhesion body. ,
Forming a first conductor layer on the first dielectric sheet; forming a first via conductor connecting the first conductor layer and the metal foil adhesion body on the first dielectric sheet; A second dielectric sheet is formed on the dielectric sheet and the first conductor layer , a second via conductor is formed in the second dielectric sheet, and a second conductor layer is formed on the second dielectric sheet. Forming and repeating the same process to form a dielectric sheet, via conductor, conductor layer, forming a laminated sheet body,
A plurality of metal terminal pads connected to the metal foil adhesion body are formed on the exposed main surface of the laminated sheet body through a conductor layer provided between the dielectric sheets and via conductors provided in the dielectric sheet. Then, by supplying an electric current from any one of the plurality of metal terminal pads and performing an electroplating process, an electroplating surface layer is formed on each surface of the plurality of metal terminal pads,
Of the laminated sheet body, the region on the metal foil adhesion body is used as the wiring laminated portion to be the wiring substrate, and the peripheral portion is removed to expose the end surface of the wiring laminated portion, and then the wiring laminated portion. Is peeled off from the support substrate at the interface between the two metal foils in the metal foil adhesion body, with one metal foil attached thereto. After peeling off the wiring laminated portion from the support substrate, the metal foil attached to the main surface of the wiring laminated portion formed by the first dielectric sheet is removed, and the metal terminal connected to the first via conductor The method of manufacturing a wiring board according to claim 1, wherein: is formed on the main surface. After peeling off the wiring laminated part from the support substrate, the metal foil attached to the main surface of the wiring laminated part on which the first dielectric sheet is formed is selectively removed and connected to the first via conductor. 2. The method of manufacturing a wiring board according to claim 1, wherein a metal terminal including a part of the remaining metal foil is formed.

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