JP2015070186A - Manufacturing method for double-sided wiring board, double-sided wiring board, and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a double-sided wiring board capable of providing a double-sided wiring board which is excellent in reliability and electric characteristic.SOLUTION: A wiring layer is formed by repeating a step for forming an insulating resin layer on a first wiring pattern by a number of times of required layers, the step including: manufacturing a core substrate by stacking two substrates with metal foil for bonding/fixing; forming a conductive electrode in a blind via that is formed at a base substrate; forming the first wiring pattern on the base substrate, at a position being conductive to the conductive electrode; forming a blind via for electrical conduction with the first wiring pattern on a first insulating resin layer that is formed on the first wiring pattern; forming a conductive electrode in the blind via; and forming a wiring pattern at a position being conductive to the conductive electrode formed in the blind via for electrical conduction to the first wiring pattern. By cutting an application region of an adhesive at a cutting position that is set on the core substrate, the two substrates with metal foil are separately manufactured.

Description

  The present invention is an interposer that is used as an intermediate medium when connecting a semiconductor element or the like to a printed circuit board, improves the workability and productivity of the process, suppresses the generation of voids, and has excellent reliability and electrical characteristics. The present invention relates to a double-sided wiring board with a conductive electrode using a thin substrate and a simple manufacturing method thereof.

Semiconductor devices such as various memories, CMOS, and CPU manufactured by the wafer process have terminals for electrical connection. The pitch of the electrical connection terminals of the semiconductor element and the pitch of the connection portion on the printed circuit board side to be electrically connected to the semiconductor element usually differ by several to several tens of times.
Therefore, when the semiconductor element and the printed board are to be electrically connected, an intermediary board (semiconductor element mounting board) for pitch conversion called an interposer is used. When the intermediary board is used, a semiconductor element is mounted on one side of the interposer, and connection with the printed board is made on the other side or the periphery of the board.

  Until now, organic substrates and organic build-up substrates have been used as interposers for mounting semiconductor elements on printed boards. However, due to the rapid performance enhancement of electronic devices such as recent smartphones, technology for stacking semiconductor elements vertically and three-dimensional mounting technology for mounting different semiconductor elements such as memory and logic on the same substrate. In addition, development of 2.5-dimensional mounting technology is becoming indispensable. These developments are expected to enable electronic devices to achieve higher speeds, larger capacities, lower power consumption, etc. However, with the increase in the density of semiconductor devices, finer wiring is also used for interposers. Therefore, it is required to form through electrodes having a narrow pitch.

However, in conventional substrates using organic materials, the expansion and contraction of the resin due to moisture absorption and coefficient of thermal expansion (CTE) is large. There was a problem that it was difficult.
In recent years, therefore, much attention has been paid to the development of interposers that use silicon or glass as a base material. Both of these interposers are advantageous for the formation of fine wiring because the effects of moisture absorption and CTE, which are problems when using an organic substrate, are reduced, and they are formed inside because they have high workability. A through electrode called TSV (Through-Silicon Via) or TGV (Through-Glass Via) can be formed by filling fine through holes with a conductive material.

In addition, as a technique regarding the interposer using glass as the base material, for example, as described in Patent Document 1, there is a technique for improving the strength of the glass substrate itself by defining the composition of the glass substrate for the interposer. .
In addition, as a technique related to the above TGV, for example, as described in Patent Document 2, there is a technique in which TGV is filled with a conductive paste and voids are avoided to form a conductive electrode.

  The above through electrode shortens the wiring length and enables the wiring on the front and back surfaces of the substrate to be connected at the shortest distance, so that it is possible to realize excellent electrical characteristics such as an increase in signal transmission speed. . Furthermore, due to the structure in which wiring is formed inside, it is an effective mounting method for downsizing and increasing the density of electronic devices, and through-electrodes enable multi-pin parallel connection, leading to various electronic devices. This has many advantages such as high speed and low power consumption.

  Comparing the two, the silicon interposer can be made finer than the glass interposer, and a wiring and TSV formation process has been established. On the other hand, since square chips are arranged on a round silicon wafer, there are problems that the peripheral portion of the wafer cannot be used and the wafer size entering the chamber of the vacuum apparatus is limited, so that the production cost per chip increases.

In addition, since TSV digs through holes by dry etching with reactive gas, it includes a long processing time and a process of making a through hole by scraping the wafer thinner than the back surface for holes that are not penetrated. This also increases the cost.
In addition, glass interposers can be produced in the process used in the production of organic substrates by using a glass substrate with a larger area than silicon wafers, and the production cost per chip can be kept low. It becomes possible.

TGV is advantageous in that through holes can be formed in a short time by electric discharge machining, laser machining, or the like.
Furthermore, in terms of electrical characteristics, the glass interposer is an insulator, unlike the silicon interposer, so that there is no fear of the occurrence of parasitic elements even in high-speed circuits, and the electrical characteristics are more excellent. In the first place, when glass is used for the substrate, the process itself for forming the insulating film is not necessary, so that the insulation reliability is high and the process can be shortened.

Japanese Patent No. 4803643 JP 2012-227253 A

  However, the above glass substrate is expected to be able to produce an interposer at a lower cost than a silicon wafer, but the problem is that the glass is easily damaged due to surface scratches and edge cracks, and handling is difficult. is there. In addition, the glass substrate as an interposer is thin, and further, through holes are formed on the entire surface of the substrate, so that the strength of the substrate is reduced and the glass substrate is easily damaged.

In addition, when performing through-hole via filling by electrolytic metal plating with the above TGV, if the ratio between the thickness of the substrate and the via diameter (aspect ratio) increases, voids are easily generated in the electrolytic metal plating, and the reliability is improved. It has a problem that the characteristics and electrical characteristics are lowered.
The present invention has been made to solve the above problems, and is a production of a wiring board, which improves workability and productivity of a process such as plating and washing / drying on a thin board, and To provide a manufacturing method capable of providing a double-sided wiring board excellent in reliability and electrical characteristics by forming a through electrode without voids, a double-sided wiring board manufactured by the manufacturing method, and a semiconductor device using the double-sided wiring board With the goal.

In order to achieve the above object, one aspect of the present invention is a method for manufacturing a double-sided wiring board formed by alternately laminating a plurality of insulating layers and wiring layers on a base substrate,
Two substrates with metal foil formed with a metal foil layer made of metal foil on one surface of the base substrate are laminated via a release layer having a smaller area than the metal foil in a state where the metal foils face each other. Then, an adhesive is applied between the two base substrates and on the outer peripheral side of the metal foil and the release layer to form an adhesive layer, and the two substrates with metal foil are bonded and fixed. A first step of producing a core substrate;
In the base substrate that forms the core substrate, a blind via that opens on the other surface of the base substrate and reaches the metal foil and does not penetrate the metal foil is formed, and a conductive electrode is formed in the blind via, A second step of forming a first wiring pattern at a position where the conductive electrode is electrically connected to the other surface of the base substrate;
A third step of forming a first insulating resin layer on the first wiring pattern;
A blind via is formed in the first insulating resin layer to be electrically connected to the first wiring pattern, a conductive electrode is formed in the blind via, and the first wiring pattern is electrically connected to the first insulating resin layer. Forming a wiring pattern at a position where it is electrically connected to the conductive electrode formed in the blind via, and forming a wiring layer by repeating the process of forming an insulating resin layer on the first wiring pattern as many times as necessary. 4 steps,
By cutting the adhesive coating region at the cutting position set on the core substrate, the fifth step of separating and creating two substrates with the metal foil,
A sixth step of forming a wiring pattern connected to the conductive electrode using the metal foil to form a substrate intermediate for the single-sided wiring substrate formed using the substrate with metal foil created in the fifth step;
A seventh step of forming an opening in the land portion of the insulating resin layer and the wiring pattern on the outermost surfaces of both surfaces of the substrate intermediate formed in the sixth step, and forming a connection pad in the opening. This is a featured double-sided wiring board.

One embodiment of the present invention is a method for manufacturing a double-sided wiring board formed by alternately laminating a plurality of insulating layers and wiring layers on a base substrate,
Two substrates with metal foil formed with a metal foil layer made of metal foil on one surface of the base substrate are laminated via a release layer having a smaller area than the metal foil in a state where the metal foils face each other. Then, an adhesive is applied between the two base substrates and on the outer peripheral side of the metal foil and the release layer to form an adhesive layer, and the two substrates with metal foil are bonded and fixed. A first step of producing a core substrate;
In the base substrate that forms the core substrate, a blind via that opens on the other surface of the base substrate and reaches the metal foil and does not penetrate the metal foil is formed, and a conductive electrode is formed in the blind via, A second step of forming a first wiring pattern at a position where the conductive electrode is electrically connected to the other surface of the base substrate;
A third step of forming a first insulating resin layer on the first wiring pattern;
A blind via is formed in the first insulating resin layer to be electrically connected to the first wiring pattern, a conductive electrode is formed in the blind via, and the first wiring pattern is electrically connected to the first insulating resin layer. Forming a wiring pattern at a position where it is electrically connected to the conductive electrode formed in the blind via, and forming a wiring layer by repeating the process of forming an insulating resin layer on the first wiring pattern as many times as necessary. 4 steps,
By cutting the adhesive coating region at the cutting position set on the core substrate, the fifth step of separating and creating two substrates with the metal foil,
A sixth step of forming a wiring board intermediate by forming a wiring pattern obtained by patterning the metal foil;
The insulating resin layers on both surfaces of the wiring board intermediate formed in the sixth step include an opening for forming a connection pad and a seventh step for forming a wiring pattern connected to the opening. It is a manufacturing method of a double-sided wiring board.

In one embodiment of the present invention, the surface of the wiring pattern of the opening that forms the connection pad has a single metal of nickel, gold, tin, tin silver, tin silver copper, tin copper, tin bismuth, tin lead, or A method for producing a double-sided wiring board, wherein a metal layer formed by laminating the single metals is formed.
One embodiment of the present invention is the method for manufacturing a double-sided wiring board, wherein the metal foil is made of metal and has a thickness of 10 μm or less.

In one embodiment of the present invention, the conductive material for forming the conductive electrode and the wiring pattern may be any of copper, silver, gold, nickel, platinum, palladium, ruthenium, iron, or a compound containing these metals. It is a manufacturing method of the double-sided wiring board characterized by these.
In one embodiment of the present invention, the base substrate is a glass substrate or an organic substrate,
In the method of manufacturing a double-sided wiring board, the thickness of the base substrate is in a range of 0.05 mm or more and 0.4 mm or less.

Another embodiment of the present invention is the method for manufacturing a double-sided wiring board, wherein the coefficient of thermal expansion (CTE) of the base substrate is 15 ppm / ° C. or less.
Another embodiment of the present invention is a double-sided wiring board manufactured using any one of the above-described double-sided wiring board manufacturing methods.
Another embodiment of the present invention is a double-sided wiring board comprising the above-described double-sided wiring board and a semiconductor element mounted on the uppermost layer portion of the surface of the wiring board.

  According to one embodiment of the present invention, it is a manufacturing of a wiring board, and it is possible to improve the handling of the manufacturing process in a thin board, and the workability and productivity are high, and the reliability is high. It is possible to easily provide a double-sided wiring board having a conductive electrode with excellent electrical characteristics.

It is a figure which shows schematic structure of the double-sided wiring board of embodiment of this invention. It is a figure which shows schematic structure of the semiconductor device of embodiment of this invention. It is a conceptual diagram of the manufacturing method of a double-sided wiring board, and is a figure which shows a 1st process. It is a conceptual diagram of the manufacturing method of a double-sided wiring board, and is a figure which shows the state which formed the blind via in the base substrate in the 2nd process. It is a conceptual diagram of the manufacturing method of a double-sided wiring board, and is a figure which shows the state which formed the photosensitive resist in the other surface of a base substrate in a 2nd process. It is a conceptual diagram of the manufacturing method of a double-sided wiring board, and is a figure which shows the state which formed the conduction electrode and the 1st wiring pattern in the 2nd process. It is a conceptual diagram of the manufacturing method of a double-sided wiring board, and is a figure which shows a 3rd process. It is a conceptual diagram of the manufacturing method of a double-sided wiring board, and is a figure which shows a 4th process. It is a conceptual diagram of the manufacturing method of a double-sided wiring board, and is a figure which shows a 5th process. It is a figure which shows the method of cut | disconnecting a core board | substrate, and is a conceptual diagram in the case of cut | disconnecting only a base board | substrate among a base board | substrate and metal foil. It is a figure which shows the method of cut | disconnecting a core board | substrate, and is a conceptual diagram in the case of cut | disconnecting a base substrate and metal foil. It is a conceptual diagram of the manufacturing method of a double-sided wiring board, and is a diagram showing a sixth step. It is a conceptual diagram of the manufacturing method of a double-sided wiring board, and is a diagram showing a sixth step. It is a conceptual diagram of the manufacturing method of a double-sided wiring board, and is a diagram showing a seventh step. It is a conceptual diagram of the manufacturing method of the double-sided wiring board of a comparative example. It is a conceptual diagram of the manufacturing method of the double-sided wiring board of a comparative example. It is a conceptual diagram of the manufacturing method of the double-sided wiring board of a comparative example. It is a conceptual diagram of the manufacturing method of the double-sided wiring board of a comparative example. It is a conceptual diagram of the manufacturing method of the double-sided wiring board of a comparative example.

Hereinafter, an embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described with reference to the drawings.
(Configuration of double-sided wiring board)
FIG. 1 is a diagram showing a schematic configuration of a double-sided wiring board according to the present embodiment, and is a schematic cross-sectional view of the double-sided wiring board as viewed from the side.

As shown in FIG. 1, the double-sided wiring board 100 has first wiring patterns 17 a formed using metal foil on both sides of the base board 11. The conduction is ensured by the first conduction electrode 15a formed in the first blind via 46a formed so as to penetrate 11.
An insulating resin layer 19 and a second wiring pattern 17b are stacked on the first wiring patterns 17a formed on both surfaces of the base substrate 11, respectively. The first wiring pattern 17a and the second wiring pattern 17b are formed of insulating resin. Conductivity is provided through the second conductive electrode 15b formed in the second blind via 46a formed in the layer 19.

  Further, in the double-sided wiring board 100, the wiring patterns 17 and the insulating resin layers 19 are laminated in a necessary number of layers as necessary, and connection pads made of the solder resist 111 are formed on the outermost surface. 1 shows an example of the double-sided wiring board 100, and the configuration of the double-sided wiring board 100 is not particularly defined by the configuration shown in FIG.

(Configuration of semiconductor device)
Next, the configuration of the semiconductor device formed using the double-sided wiring substrate 1 will be described with reference to FIG.
FIG. 2 is a diagram showing a schematic configuration of the semiconductor device of the present embodiment, and is a schematic cross-sectional view of the semiconductor device as viewed from the side.

As shown in FIG. 2, the semiconductor device 200 has a semiconductor element 215 mounted on one surface of the double-sided wiring substrate 100 (upper surface in FIG. 2) connected by a solder ball 212. The double-sided wiring board 100 is mounted on a printed board (not shown) by connecting the other side (the lower side in FIG. 2) with a solder ball 212.
2 illustrates an example of the semiconductor device 200. The configuration of the semiconductor device 200 (the shape of the semiconductor element 215, the connection method between the double-sided wiring board 100, the semiconductor element 215, and the printed board) is illustrated in FIG. The configuration shown in the figure is not particularly specified.

(Method for manufacturing double-sided wiring board 1)
Hereinafter, a method for manufacturing the double-sided wiring board 1 will be described with reference to FIGS. 1 and 2 and FIGS. 3 to 14.
The method for manufacturing the double-sided wiring board 1 includes first to seventh steps.
First Step In the first step, as shown in FIG. 3, two metal foil-coated substrates 418 each having a metal foil layer formed of a metal foil 32 on one surface of the base substrate 11 are used, and two metal foils are used. The attached substrate 418 is laminated through the peeling layer 33 having a smaller area than the metal foil 32 in a state where the metal foils 32 face each other. Further, an adhesive is applied between the two base substrates 11 and in a space on the outer peripheral side of the metal foil 32 and the release layer 33 to form an adhesive layer 34, and the two substrates 418 with metal foil are bonded. -The core substrate 300 is manufactured by fixing. FIG. 3 is a conceptual diagram of the method for manufacturing the double-sided wiring board 1 and shows the first step.

Here, the metal foil layer is formed using a method in which the metal foil 32 is bonded to the base substrate 11 via an adhesive or an organic resin, or a method in which the metal foil 32 is formed on the base substrate 11 by sputtering or plating.
By producing the core substrate 300 by the first step, the strength of the thin base substrate 11 can be increased and the handling property can be improved.

Further, the core substrate 300 manufactured by the first step is formed in a later step by forming a wiring layer in which a required number of wiring patterns and insulating resin layers are laminated on both surfaces of the core substrate 300, and then between the metal foil layers. It is necessary to easily separate the metal foil-fitted substrates 418 from each other to obtain a single metal foil-fitted substrate 418.
For this reason, when the adhesive layer 34 is formed, an adhesive is applied to the space between the two base substrates 11 and on the outer peripheral side of the metal foil 32 and the release layer 33, that is, the outer periphery of the metal foil 32. In this region, an adhesive is applied, and two substrates 418 with metal foil are laminated and bonded and fixed in a state where the metal foils 32 face each other, thereby producing the core substrate 300.

Note that the size of the metal foil 32 with respect to the base substrate 11 is not particularly limited, and may be set in accordance with the size of the base substrate 11 and the application region of the adhesive forming the adhesive layer 34.
Further, the adhesive coating area for forming the adhesive layer 34 may be provided in an area outside the area left by cutting in the fifth step. In this method, after forming wiring layers on both surfaces of the core substrate 300, the substrate 418 with two metal foils can be easily formed by cutting inside the region of the core substrate 300 where the adhesive is applied. This is because it becomes possible.

  Also, the size of the release layer 33 is larger than the region left to be cut in the fifth step, and corresponds to the region inside the adhesive application region. In addition, the material of the release layer 33 may be a material that has adhesiveness to hold the metal foils 32 in the state of the core substrate 300 and can be easily peeled after the core substrate 300 is cut. The material of the release layer 33 is not particularly specified, but a material that is not denatured at the process temperature of the wiring layer is desirable, and a silicone-based release material, a fluorine release material, or the like can be used.

Second Step In the second step, as shown in FIGS. 4 to 6, the base substrate 11 forming the core substrate 300 is opened on the other surface of the base substrate 11 to reach the metal foil 32 and the metal foil. After forming the blind via 46 that does not penetrate 32, the conductive electrode 15 is formed in the blind via 46. Further, a first wiring pattern 17 a is formed on the other surface of the base substrate 11 at a position where the conductive electrode 15 is electrically connected. FIG. 4 is a conceptual diagram of the method for manufacturing the double-sided wiring board 1 and shows a state in which the blind vias 46 are formed in the base substrate 11 in the second step.

Although the method for forming the blind via 46 on the base substrate 11 is not particularly defined, electric discharge machining, laser machining such as carbon dioxide, YAG, or excimer, sandblasting, dry etching, wet etching, or the like can be used.
In addition, after forming the blind via 46 on the base substrate 11, in order to remove the adhesive component at the via bottom and obtain electrical connection with the conductive electrode, dry cleaning using plasma or a wet method using an alkaline solution is used. Thus, it is preferable to perform desmearing of the via bottom portion.

  Further, as shown in FIG. 5, after forming the blind via 46 on the base substrate 11, a photosensitive resist 48 is formed on the other surface of the base substrate 11. FIG. 5 is a conceptual diagram of a method for manufacturing the double-sided wiring board 1, and shows a state in which a photosensitive resist 48 is formed on the other surface of the base substrate 11 in the second step.

After the photosensitive resist 48 is formed on the other surface of the base substrate 11, the conductive electrode 15 and the first wiring pattern 17a are formed as shown in FIG. FIG. 6 is a conceptual diagram of the method for manufacturing the double-sided wiring board 1 and shows a state in which the conductive electrode 15 and the first wiring pattern 17a are formed in the second step.
Here, a method for forming the first wiring pattern 17a is not particularly defined, but a semi-additive method, a printing method using conductive ink, or the like can be used.

Third Step In the third step, as shown in FIG. 7, a first insulating resin layer 19a is formed on the first wiring pattern 17a. In addition, FIG. 7 is a conceptual diagram of the manufacturing method of the double-sided wiring board 1, and is a figure which shows a 3rd process.
In the third step, the second insulating pattern 19b is formed on the surface of the first insulating resin layer 19a in the fourth step by forming the first insulating resin layer 19a on the conductive electrode 15 and the first wiring pattern 17a. It is possible to ensure insulation.

-4th process In a 4th process, as shown in FIG. 8, the blind via which connects with the 1st wiring pattern 17a is formed in the 1st insulating resin layer 19a, and a conduction electrode is formed in this blind via. . Further, a wiring pattern is formed on the first insulating resin layer 19a at a position where it is electrically connected to the conductive electrode formed in the blind via that is electrically connected to the first wiring pattern 17a. Then, an insulating resin layer is formed on these layers by repeating the necessary number of layers to form a wiring layer. In addition, FIG. 8 is a conceptual diagram of the manufacturing method of the double-sided wiring board 1, and is a figure which shows a 4th process.

In the fourth step, since it is necessary to ensure conduction between the first wiring pattern 17a and the wiring pattern formed on the first insulating resin layer 19a, the first wiring pattern 17a on the first insulating resin layer 19a A blind via is formed at the position.
In the fourth step, as shown in FIG. 8, the outermost surface of the core substrate 300 is covered with an insulating resin layer. Here, in this embodiment, as shown in FIG. 8, the solder resist 111 is used as the outermost resin layer, and the same resin as the first insulating resin layer 19a is used as the outermost resin layer. You may choose according to.

Further, the number of layers including the blind via, the conductive electrode, the wiring pattern, and the insulating resin layer is repeatedly formed according to the required number of layers according to the product.
In FIG. 8, the conductive electrodes are offset, but it is also possible to fill the blind vias and connect the wiring patterns directly above.

-5th process In a 5th process, as shown in FIG. 9, two metal foils are cut | disconnected by cut | disconnecting the application area | region of the adhesive agent which forms the contact bonding layer 34 in the cutting position set to the core board | substrate 300. FIG. The attached substrate 418 is separated and formed. In addition, FIG. 9 is a conceptual diagram of the manufacturing method of the double-sided wiring board 1, and is a figure which shows a 5th process. Moreover, in FIG. 9, the protective film arrange | positioned on the outermost surface is shown with code | symbol "414."

When the core substrate 300 is cut at the cutting position 316, the adhesive layer 34 and the metal foil 32 are cut and separated from the release layer 33 between the metal foils 32, so that a wiring layer is formed on one surface of the base substrate 11. The two metal foil-fitted substrates 418 formed with the above are manufactured.
As a cutting method of the core substrate 300, a method capable of cutting the base substrate 11 and the metal foil 32, such as a punching machine, a laser processing machine, or a dicing machine, may be selected.

In this case, for example, if the base substrate 11 is a glass substrate, the combination of the punching method and the glass substrate breaks the glass substrate, so that the area of the metal foil 32 is larger than the glass substrate, Just cut it.
In addition, as the cutting position 316 of the core substrate 300, the cutting method and the base substrate 11 include a position where only the base substrate 11 is cut out of the base substrate 11 and the metal foil 32 and a position where the base substrate 11 and the metal foil 32 are cut. What is necessary is just to set according to the workability of.

  The case where the cutting position 316 of the core substrate 300 is set to a position where only the base substrate 11 is cut out of the base substrate 11 and the metal foil 32 is, for example, a product of the substrate 418 with a metal foil as shown in FIG. This is a case where the core substrate 300 is formed using the base substrate 11 larger than the outer shape, and the core substrate 300 is cut to the size of the product outer shape. In this case, the release layer 33 larger than the product outer shape is used, and the core substrate 300 is cut with the adhesive layer 34 surrounding the region outside the release layer 33 in a square shape. FIG. 10 is a diagram illustrating a method of cutting the core substrate 300, and is a conceptual diagram when only the base substrate 11 is cut out of the base substrate 11 and the metal foil 32.

  On the other hand, when the cutting position 316 of the core substrate 300 is set to a position where the base substrate 11 and the metal foil 32 are cut, for example, as shown in FIG. 11, the size of the base substrate 11 is a substrate with metal foil. This corresponds to the case of 418 product outline. In this case, the core substrate 300 is formed using the metal foil 32 larger than the base substrate 11, the release layer 33 larger than the base substrate 11 is used, and the region outside the release layer 33 of the metal foil 32. The core substrate 300 is cut in a state where the adhesive layer 34 is enclosed in a square shape. That is, the cutting position 316 of the core substrate 300 is a portion on the release layer 33 of the metal foil 32. FIG. 11 is a diagram showing a method of cutting the core substrate 300, and is a conceptual diagram when cutting the base substrate 11 and the metal foil 32. FIG.

-6th process In 6th process, as shown in FIG.12 and FIG.13, metal foil 32 is used with respect to the single-sided wiring board 417 formed using the board | substrate 418 with metal foil manufactured at the 5th process. A wiring pattern 17 connected to the conductive electrode is formed to form a substrate intermediate.
In the sixth step, although not particularly illustrated, the wiring substrate intermediate may be formed by forming the wiring pattern 17 obtained by patterning the metal foil 32.

  Specifically, after manufacturing a substrate 418 with a metal foil having a wiring layer formed on one surface of the base substrate 11 in the fifth step, the other surface of the base substrate 11 is photosensitive on the other surface as shown in FIG. A resist 48 is formed. Then, as shown in FIG. 13, the wiring pattern 17 is formed on the other surface of the base substrate 11 in the fifth step using the metal foil 32. At this time, by forming the wiring pattern 17 that is electrically connected to the conductive electrode 15 in the blind via 46 of the base substrate 11, it is possible to form a wiring substrate intermediate that is conductive on both sides of the base substrate 11. It becomes. 12 and 13 are conceptual diagrams of the method for manufacturing the double-sided wiring board 1 and show the sixth step.

Here, as a method of forming the wiring pattern 17 using the metal foil 32, a subtractive method, a semi-additive method, or the like can be used.
The metal foil 32 can be made of a metal such as copper, tin copper, nickel, or a laminate thereof depending on conductivity, workability, and availability. In this case, as a method for forming the wiring pattern 17 using the metal foil 32, dry film formation such as rolling of a metal material, sputtering, vapor deposition or the like can be used.

Further, the thickness of the wiring pattern 17 using the metal foil 32 is desirably 10 μm or less, which enables formation of a thin line by the subtractive method, and about 1 μm for the semi-additive method. It is also possible to use a thicker metal foil by etching to a thickness of about 1 μm by the semi-additive method.
As the wiring layer on the surface of the metal foil 32, the required number of layers, the insulating resin layer, the blind via, the conductive electrode, and the wiring pattern may be formed in the same manner as the back surface.

-7th process In the 7th process, as shown in FIG. 14, in the outermost surface of both surfaces of the board | substrate intermediate body formed at the 6th process, an opening part is formed in the land part of an insulating resin layer and a wiring pattern, and this A connection pad is formed in the opening.
In the seventh step, when the wiring board intermediate is formed in the sixth step, although not particularly shown, the connection pad opening and the connection pad opening are connected to the insulating resin layers on both sides of the wiring board intermediate. A wiring pattern may be formed. In addition, FIG. 14 is a conceptual diagram of the manufacturing method of the double-sided wiring board 1, and is a figure which shows a 7th process.

Further, the outermost surface of the wiring board on the surface of the metal foil 32 is covered with an insulating resin layer, and the outermost resin layer may be the same as the insulating resin or may be selected according to the product, such as a solder resist. FIG. 14 shows an example where the solder resist 111 is selected as the outermost resin layer.
In the seventh step, a conductive pad 413 that is an opening for establishing conduction with a lower wiring electrode and a semiconductor element connection pad are formed in the insulating resin of the double-sided wiring board.
In this case, a single layer of nickel, gold, tin, tin silver, tin silver copper, tin copper, tin bismuth, tin lead, or a metal layer obtained by laminating a single metal on the surface of the wiring pattern of the connection pad opening Form. Here, as the metal forming the metal layer, a material having high electrical connection stability may be selected in accordance with the connection pad and the connection method on the bonded material side.

The conductive material for forming the conductive electrode 15 and the wiring pattern 17 in the blind via 46 is, for example, any one of copper, silver, gold, nickel, platinum, palladium, ruthenium, iron, or a compound containing these metals. It is possible to select.
The conductive electrode 15 and the wiring pattern 17 can be formed by a dry method such as sputtering, a wet method such as chemical plating or electrolytic plating, or a printing method using conductive ink. What is necessary is just to use the electrically-conductive material according to a construction method.

In the electroplating method, when plating is formed on the through-hole portion of the substrate, if the aspect ratio is high, both ends of the through-hole are closed first and voids are generated.
In the case of the blind via 46 of the present invention, it is possible to perform plating up while suppressing the generation of voids with respect to a high aspect ratio hole, and it is possible to obtain a conductive electrode 15 without voids. Here, voids cause deterioration of electrical characteristics due to an increase in resistance, disconnection, and the like, and formation of the conductive electrode 15 without voids is important.

Moreover, as a material of the base substrate 11, for example, a glass substrate, an organic substrate such as an acrylic resin, a polyimide resin, or a prepreg can be used.
The thickness of the base substrate 11 is preferably in the range of 0.05 mm or more and 0.45 mm or less. The reason is shown below.
If the thickness of the base substrate 11 is greater than 0.45 mm, the rigidity of the double-sided wiring substrate 100 is increased, so that handling at the time of manufacture of the substrate alone becomes easy and there is no need to develop the technique of the present invention. is there. Further, when the thickness of the base substrate 11 is 0.4 mm or less, the base substrate 11 is greatly bent, so that it is difficult to handle the substrate alone. In addition, by bonding the two metal foil-attached substrates 418, the core substrate 300 has high rigidity and can be easily handled during manufacture.

Further, when the end portion of the core substrate 300 is cut and separated, it is necessary to gradually peel the end portions of the two single-sided wiring formation substrates outwardly with the release layer 33 as a boundary. At this time, if the thickness of the base substrate 11 is larger than 0.45 mm, the rigidity is high and it is difficult to warp. From this viewpoint, the thickness of the base substrate 11 is desirably 0.4 mm or less.
In addition, the distance between the conductive electrodes 15 in the blind vias 46 formed in the core substrate 300 of the double-sided wiring substrate 100 is required to be short. In this respect, the base substrate 11 must be thin. is there.

  Further, until the substrate 418 with the metal foil is formed, the core substrate 300 needs to be handled alone, and the thickness of the substrate capable of obtaining rigidity is required. Further, when the metal foil 32 is bonded through the adhesive layer 34, the thickness of the adhesive layer 34 and the organic resin is about 0.005 mm, and the thermal expansion coefficient of the adhesive layer 34 and the organic resin is about 10 times that of the base substrate 11. In order to avoid deformation of the base substrate 11 due to curing shrinkage of the adhesive layer 34 or the organic resin, the thickness of the base substrate 11 needs to be 0.05 mm or more, which is 10 times the thickness of the adhesive layer 34.

In addition, the present invention assumes development on a double-sided wiring board 100 having low rigidity and a small thickness.
As described above, the thickness of the base substrate 11 is preferably in the range of 0.05 mm or more and 0.45 mm or less. Note that the thickness of the base substrate 11 is measured by, for example, a micrometer.

  Further, it is assumed that the double-sided wiring board 100 of this embodiment is used by being connected to a semiconductor element made of a silicon substrate or a printed board. The thermal expansion coefficients of the semiconductor element and the printed circuit board are 2-3 ppm / ° C. and 10-15 ppm / ° C., respectively, and in order to avoid conduction breakdown due to warpage due to thermal expansion during mounting, The expansion coefficient is preferably between the semiconductor element and the printed board. This is because the upper limit of the thermal expansion coefficient of the printed circuit board is 15 ppm / ° C., and therefore, the thermal expansion coefficient of the base substrate 11 is 15 ppm / ° C. or less, and preferably lower than that of the printed circuit board to be connected. . The lower limit of the coefficient of thermal expansion of the base substrate 11 only needs to be higher than the upper limit of 3 ppm / ° C. of the semiconductor element. The thermal expansion coefficient of the base substrate 11 is measured by TMA according to JIS R3102 when the base substrate 11 is a glass substrate, for example. On the other hand, when the base substrate 11 is an organic substrate, it is measured by TMA according to JIS K7197.

The double-sided wiring board 100 manufactured in the above steps (first to seventh steps) can achieve high conduction reliability between the wiring patterns on both sides.
In addition, the semiconductor device 200 formed by mounting the semiconductor element 215 on the double-sided wiring board 100 obtains high connection strength by optimizing the metal material between the semiconductor element and the printed circuit board to be connected, High connection reliability can be achieved by optimizing thermal deformation during mounting.

  Hereinafter, examples of the present invention will be described using FIGS. 15 to 19 and comparison results based on comparative examples with reference to FIGS. 1 to 14. In addition, although the Example and comparative example of this invention are shown below, this invention is not limited to this. 15 to 19 are conceptual diagrams of a method for manufacturing the double-sided wiring board 1 of the comparative example.

(Example)
The base substrate 11 was designed with low expansion glass having a thickness of 0.2 mmt, a size of 300 × 400 mm, and a thermal expansion coefficient of 4 ppm / ° C.
The metal foil 32 is formed by laminating a Ti film and a Cu film with a thickness of 0.1 μm and 0.2 μm, respectively, by sputtering, and designed in a region 3 mm inside from the periphery of the base substrate 11. did.
The product outer shape of the single-sided wiring board 417 was 270 × 370 mm, and this position was designed as the cutting position 316 of the core board 300. And after laminating | stacking both surfaces of the core board | substrate 300 with the protective film 414, the cutting position 316 of the core board | substrate 300 was cut with the dicing apparatus, and the two single-sided wiring board 417 was obtained. Thereafter, a Ti / Cu sputtered film of the metal foil layer of the single-sided wiring board 417 is used as a seed layer, and a positive photosensitive resist 48 is applied, exposed and developed, and a resist pattern in which the wiring pattern 17 portion is opened. Formed.

For the release layer 33, a 50 μm thick silicone resin film was used. In addition, the design was designed to be 5 mm wider than the product outer shape of the single-sided wiring board 417.
The adhesive layer 34 was designed with an acrylic adhesive.
For the insulating resin layer 19, ABF made of epoxy resin was used and designed to have a thickness of 10 μm on the copper wiring.

The wiring pattern 17 was designed by a semi-additive method using a Ti / Cu sputtered film or electroless copper plating for the seed layer, and electrolytic copper plating for thickening the wiring pattern 17. At this time, the conductive electrode 15 in the blind via 46 was designed by conformal plating.
The wiring pattern 17 was formed by forming electrolytic copper plating on the base substrate 11 with a thickness of 9 μm, dissolving and removing the photosensitive resist 48, and etching away the Ti / Cu sputtered film.

The LS value of the wiring pattern 17 was designed to be 10 μm and the thickness of the copper wiring was 8 μm.
The photosensitive resist 48 was a positive type and was coated, exposed and developed to form a resist pattern having an opening corresponding to the wiring pattern 17.
A UV-YAG laser was used to form the blind via 46, and a picosecond laser was used for the glass substrate (base substrate 11). The top diameter of the blind via 46 was designed to be 50 μmφ. The dust in the blind via 46 generated by laser processing was cleaned by desmearing with an alkaline aqueous processing solution.

The conductive pad part 413 was designed by Ni / Au plating, and the semiconductor element 215 was assumed to be connected by solder. The conductive pad portion 413 is formed by forming a seed layer on the base substrate 11 by electroless copper plating, forming a wiring pattern 17 by a semi-additive method, laminating a photosensitive solder resist 11, and performing exposure and development. Formed. In the embodiment, the number of layers of the wiring pattern 17 on one side is two, but it is not particularly limited.
Further, Ni / Au surface treatment was performed on the surfaces of the conductive pads 413 on both sides to manufacture the double-sided wiring board 100 of the example.

(Evaluation of Examples)
In the double-sided wiring substrate 100 of the embodiment, a glass substrate having a thickness of 0.2 mmt is used as the base substrate 11, the conduction reliability between the double-sided wiring patterns 17 is high, and the semi-additive method or cleaning drying of the double-sided wiring substrate 100 is performed. It has been confirmed that it is possible to obtain the double-sided wiring board 100 and the method for manufacturing the double-sided wiring board 100 that enables processing in a process in which the board is easily damaged.

(Comparative example)
As the base substrate 11, low expansion glass having a thickness of 0.5 mm, a size of 300 × 400 mm, and a thermal expansion coefficient of 4 ppm / ° C. was used.
For the insulating resin layer 19, ABF made of epoxy resin was used and designed to have a thickness of 10 μm on the copper wiring.
A picosecond laser was used to form a through hole in the glass substrate, and a UV-YAG laser was used to form the blind via 46. The top hole diameter of the through hole and the blind via 46 was designed to be 80 μmφ and 50 μmφ, respectively.

The wiring pattern 17 was formed by using a Ti / Cu sputtered film or electroless copper plating as a seed layer, and by performing electrolytic copper plating to thicken the wiring pattern 17 by a semi-additive method.
As the sputtered film, a Ti film and a Cu film were designed with a thickness of 0.1 μm and a thickness of 0.2 μm, respectively. At this time, the conductive electrode 15 in the blind via 46 was formed by TH conformal plating.
The wiring pattern 17 was designed with an LS value of 10 μm and a copper wiring thickness of 8 μm.

(Manufacturing method of comparative example)
When manufacturing the double-sided wiring board 100 of the comparative example, first, as shown in FIG. 15, through holes were formed in the glass substrate (base substrate 11). At this time, the glass substrate is lifted by 3 mm and held by a special jig that is held at multiple points so that the laser processing surface plate 518 is not processed by laser light. An area that cannot be placed was created. Moreover, since the glass substrate was thick, the processing time was long.

Next, as shown in FIG. 16, a Ti / Cu sputtered film is formed as a seed layer on both surfaces of the base substrate 11, and a positive photosensitive resist 48 is applied, exposed and developed to form a wiring pattern. A resist pattern having an opening corresponding to the corresponding portion was formed.
Then, as shown in FIG. 17, electrolytic copper plating is formed on both surfaces of the base substrate 11 to a thickness of 9 μm, and the photosensitive resist 48 is dissolved and removed, and the Ti / Cu sputtered film is removed by etching. Formed.

Next, as shown in FIG. 18, insulating resin layers 19 are laminated on both surfaces of the base substrate 11, blind vias 46 are formed on the formed insulating resin layers 19 by UV-YAG, and laser processing is performed. The generated dust in the blind via 46 was cleaned by desmearing with an alkaline aqueous processing solution.
Finally, as shown in FIG. 19, a seed layer is formed on both surfaces of the base substrate 11 by electroless copper plating, a wiring pattern 17 is formed by a semi-additive method, and then a photosensitive solder resist 11 is laminated. Then, exposure and development were performed, and a conductive pad portion 413 was formed. In addition, the surface of the conductive pads 413 on both sides was subjected to Ni / Au surface treatment to manufacture a double-sided wiring board 100 of a comparative example.

(Evaluation of comparative example)
In the manufacturing method of the comparative example, it was possible to obtain a wiring pattern 17 in which conduction was established between the wiring patterns 17 on both sides. However, in order to obtain the rigidity of the glass substrate that does not damage the base substrate 11 such as a semi-additive method or cleaning / drying of the double-sided wiring board, the base substrate 11 becomes thicker and the hole diameter of the through hole becomes larger. It was confirmed that high definition could not be realized. In addition, it was confirmed that there was a problem that an area where the wiring pattern 17 could not be arranged was generated, and the area ratio of the product that could be taken from one core substrate 300 was lowered.

  The present invention can be used as a method for manufacturing a double-sided wiring board that can cope with higher functionality and higher speed of electronic devices in three-dimensional mounting and 2.5-dimensional mounting.

DESCRIPTION OF SYMBOLS 11 Base substrate 15 Conductive electrode 17 Wiring pattern 19 Insulating resin layer 32 Metal foil 33 Peeling layer 34 Adhesion layer 46 Blind via 48 Photosensitive resist 100 Double-sided wiring substrate 111 Solder resist 200 Semiconductor device 212 Solder ball 215 Semiconductor element 300 Core substrate 316 Cutting Position 413 Conductive pad 414 Protective film 417 Single-sided wiring board 418 Board with metal foil

Claims (9)

A method of manufacturing a double-sided wiring board formed by alternately laminating a plurality of insulating layers and wiring layers on a base substrate,
Two substrates with metal foil formed with a metal foil layer made of metal foil on one surface of the base substrate are laminated via a release layer having a smaller area than the metal foil in a state where the metal foils face each other. Then, an adhesive is applied between the two base substrates and on the outer peripheral side of the metal foil and the release layer to form an adhesive layer, and the two substrates with metal foil are bonded and fixed. A first step of producing a core substrate;
In the base substrate that forms the core substrate, a blind via that opens on the other surface of the base substrate and reaches the metal foil and does not penetrate the metal foil is formed, and a conductive electrode is formed in the blind via, A second step of forming a first wiring pattern at a position where the conductive electrode is electrically connected to the other surface of the base substrate;
A third step of forming a first insulating resin layer on the first wiring pattern;
A blind via is formed in the first insulating resin layer to be electrically connected to the first wiring pattern, a conductive electrode is formed in the blind via, and the first wiring pattern is electrically connected to the first insulating resin layer. Forming a wiring pattern at a position where it is electrically connected to the conductive electrode formed in the blind via, and forming a wiring layer by repeating the process of forming an insulating resin layer on the first wiring pattern as many times as necessary. 4 steps,
By cutting the adhesive coating region at the cutting position set on the core substrate, the fifth step of separating and creating two substrates with the metal foil,
A sixth step of forming a wiring pattern connected to the conductive electrode using the metal foil to form a substrate intermediate for the single-sided wiring substrate formed using the substrate with metal foil created in the fifth step;
A seventh step of forming an opening in the land portion of the insulating resin layer and the wiring pattern on the outermost surfaces of both surfaces of the substrate intermediate formed in the sixth step, and forming a connection pad in the opening. A method for manufacturing a double-sided wiring board, which is characterized. A method of manufacturing a double-sided wiring board formed by alternately laminating a plurality of insulating layers and wiring layers on a base substrate,
Two substrates with metal foil formed with a metal foil layer made of metal foil on one surface of the base substrate are laminated via a release layer having a smaller area than the metal foil in a state where the metal foils face each other. Then, an adhesive is applied between the two base substrates and on the outer peripheral side of the metal foil and the release layer to form an adhesive layer, and the two substrates with metal foil are bonded and fixed. A first step of producing a core substrate;
In the base substrate that forms the core substrate, a blind via that opens on the other surface of the base substrate and reaches the metal foil and does not penetrate the metal foil is formed, and a conductive electrode is formed in the blind via, A second step of forming a first wiring pattern at a position where the conductive electrode is electrically connected to the other surface of the base substrate;
A third step of forming a first insulating resin layer on the first wiring pattern;
A blind via is formed in the first insulating resin layer to be electrically connected to the first wiring pattern, a conductive electrode is formed in the blind via, and the first wiring pattern is electrically connected to the first insulating resin layer. Forming a wiring pattern at a position where it is electrically connected to the conductive electrode formed in the blind via, and forming a wiring layer by repeating the process of forming an insulating resin layer on the first wiring pattern as many times as necessary. 4 steps,
By cutting the adhesive coating region at the cutting position set on the core substrate, the fifth step of separating and creating two substrates with the metal foil,
A sixth step of forming a wiring board intermediate by forming a wiring pattern obtained by patterning the metal foil;
The insulating resin layers on both surfaces of the wiring board intermediate formed in the sixth step include an opening for forming a connection pad and a seventh step for forming a wiring pattern connected to the opening. Manufacturing method of a double-sided wiring board.   A single metal of nickel, gold, tin, tin silver, tin silver copper, tin copper, tin bismuth, tin lead, or the single metal is laminated on the surface of the wiring pattern of the opening that forms the connection pad. The method for producing a double-sided wiring board according to claim 2, wherein a metal layer is formed.   The method for manufacturing a double-sided wiring board according to any one of claims 1 to 3, wherein the metal foil is made of metal and has a thickness of 10 µm or less.   The conductive material forming the conductive electrode and the wiring pattern is any one of copper, silver, gold, nickel, platinum, palladium, ruthenium, iron, or a compound containing these metals. The manufacturing method of the double-sided wiring board described in any one of Claim 1 to Claim 4 to do. The base substrate is made of a glass substrate or an organic substrate,
The thickness of the said base substrate exists in the range of 0.05 mm or more and 0.4 mm or less, The manufacturing method of the double-sided wiring board described in any one of Claims 1-5 characterized by the above-mentioned.   7. The method for manufacturing a double-sided wiring board according to claim 1, wherein the base substrate has a coefficient of thermal expansion of 15 ppm / ° C. or less.   A double-sided wiring board manufactured using the method for manufacturing a double-sided wiring board according to any one of claims 1 to 7.   A semiconductor device comprising: the double-sided wiring board according to claim 8; and a semiconductor element mounted on an uppermost layer portion on the surface of the wiring board.

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