JP2002170827A - Method for manufacturing semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To a semiconductor device which can be directly, electrically connected with a printed wiring board without interposing a lead component. SOLUTION: A transition layer 38 is placed on a die pad of IC chip 20 to be incorporated in a multi-layer printed wiring board 10. Thereby, an electrical connection between the IC chip 20 and the multi-layer printed wiring board 10 may be obtained without using any lead component and sealing resin. Additionally, a residual resin on a pad 24 can be avoided by locating the copper transition layer 38 on the die pad 24, and a connectivity between the die pad 24 and a via hole 60 and its reliability may be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device such as an IC chip.

[0002]

2. Description of the Related Art IC chips are manufactured by wire bonding,
The electrical connection with the printed wiring board has been established by a mounting method such as TAB or flip chip. Wire bonding is to bond the IC chip to the printed wiring board with an adhesive and connect the pad of the printed wiring board and the pad of the IC chip with a wire such as a gold wire, and then to protect the IC chip and the wire. To a sealing resin such as a thermosetting resin or a thermoplastic resin.

[0003] In TAB, bumps of an IC chip and pads of a printed wiring board are connected together by a wire called a lead by soldering or the like, and then sealed with a resin. The flip chip has been performed by connecting an IC chip and a pad portion of a printed wiring board via a bump, and filling a gap between the bump and the resin with a resin.

[0004] However, each mounting method is based on I
Electrical connection is made between the C chip and the printed wiring board via connection lead components (wires, leads, bumps). Each of these lead components is easily cut and corroded, which may cause the connection with the IC chip to be interrupted or a malfunction to occur. Also, in each mounting method, sealing is performed with a thermoplastic resin such as an epoxy resin to protect the IC chip, but if the resin is filled with air bubbles, the air bubbles become a starting point,
This leads to destruction of lead components, corrosion of IC pads, and a decrease in reliability. For sealing with thermoplastic resin, it is necessary to create a resin loading plunger and mold according to each part, and even for thermosetting resin, consider materials such as lead parts and solder resist Since it is necessary to select a suitable resin, the cost of each resin is also increased.

On the other hand, instead of mounting an IC chip on the outside of a printed wiring board (package substrate) as described above, a semiconductor element is embedded in a substrate and a build-up layer is formed thereon to provide electrical connection. Japanese Patent Laid-Open No. 9-321408 (USP5)
875100), JP-A-10-256429 and JP-A-11-126978.

Japanese Patent Application Laid-Open No. 9-321408 (USP 587)
No. 5100), a semiconductor element having a stud bump formed on a die pad is embedded in a printed wiring board, and a wiring is formed on the stud bump to make an electrical connection. However, since the stud bump has an onion shape and a large variation in height, when an interlayer insulating layer is formed, the smoothness is reduced, and even if a via hole is formed, the stud bump is easily disconnected. Further, the stud bumps are planted one by one by bonding, so that they cannot be arranged collectively, and there is a problem in terms of productivity.

Japanese Patent Laid-Open No. Hei 10-256429 discloses a structure in which a semiconductor element is housed in a ceramic substrate and is electrically connected in a flip-chip form. However, ceramic has poor external formability, and the semiconductor element is not easily accommodated. In addition, the bumps had large variations in height. Therefore, the smoothness of the interlayer insulating layer is impaired, and the connection is reduced.

Japanese Patent Application Laid-Open No. 11-126978 discloses a multilayer printed wiring board in which electronic components such as a semiconductor element are embedded in a space accommodating portion, connected to a conductor circuit, and stored through via holes. ing. However, since the accommodating portion is an air gap, it is easy to cause a positional shift and disconnection to a pad of the semiconductor element is apt to occur. Further, since the die pad and the conductor circuit are directly connected, there is a problem that an oxide film is easily formed on the die pad and the insulation resistance is increased.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to enable direct electrical connection to a printed wiring board without using lead components. An object of the present invention is to propose a method for manufacturing a semiconductor device.

[0010]

Means for Solving the Problems As a result of intensive studies, the present inventor has created a method of forming a transition layer on a die pad of a semiconductor device. The semiconductor element having the transition layer can be formed into a desired size and shape by embedding, storing, and housing in a printed wiring board, or by forming an interlayer insulating layer thereon and forming a via hole. Can be

The reason why the transition layer is provided on the die pad of the IC chip will be described. A die pad of an IC chip is generally made of aluminum or the like. When via holes in the interlayer insulating layer were formed by photoetching with the die pad having no transition layer formed thereon, the resin was likely to remain on the surface of the pad after exposure and development if the die pad was still formed. In addition, the adhesion of the developing solution caused discoloration of the pad. On the other hand, when a via hole is formed by a laser, there is a risk that the aluminum pad is burned. In addition, when performed under conditions that would not cause burnout, resin residue was left on the pad. Also, in the post-process, immersed in acid, oxidizing agent or etching solution,
After various annealing steps, discoloration and dissolution of the pads of the IC chip occurred. Further, the pads of the IC chip have 4
It is made with a diameter of about 0 μm, the via hole is larger than that, and a positional tolerance is required.

On the other hand, by providing a transition layer made of copper or the like on the die pad, the problem of via hole formation can be eliminated, and a solvent can be used, and resin residue on the pad can be prevented. In addition, the pads do not discolor or dissolve even after being immersed in an acid, an oxidizing agent, or an etching solution in a later step, or undergoing various annealing steps. This improves the connectivity and reliability between the pad and the via hole. Further, by interposing a transition layer having a diameter larger than that of the die pad of the IC chip, the via hole can be reliably connected. Desirably, the transition layer has a diameter equal to or larger than a via hole diameter and a position tolerance.

Further, since the transition layer is formed, the operation and electrical inspection of the semiconductor element can be easily performed before or after embedding, housing, or housing the IC chip as the semiconductor element in the printed wiring board. Became. This is because a transition layer that is larger than the die pad is formed, so that the inspection probe pins can easily come into contact. As a result, the availability of the product can be determined in advance, and productivity and cost can be improved. Further, no loss or damage of the pad due to the probe is generated.

Therefore, by forming the transition, the IC chip, which is a semiconductor element, can be suitably embedded, accommodated, and accommodated in the printed wiring. That is,
A semiconductor element having a transition layer can be said to be a semiconductor element for embedding, housing, and housing a printed wiring board. The transition layer is formed by forming a thin film layer on a die pad and forming a thick layer thereon. It can be formed of at least two layers.

Although each of them functions only by a multilayer printed wiring board, in some cases, a B board for connection to an external board, such as a mother board or a daughter board, is used to function as a package board as a semiconductor device.
GAs, solder bumps or PGAs (conductive connection pins) may be provided. In addition, with this configuration, the wiring length can be made shorter than in the case where the connection is made by the conventional mounting method, and the loop inductance can be reduced.

The transition layer defined in the present invention will be described. The transition layer means an intermediate layer provided for directly connecting an IC chip as a semiconductor element and a printed wiring board without using a conventional IC chip mounting technique. As a feature, it is formed of two or more metal layers. Alternatively, it is to be larger than a die pad of an IC chip which is a semiconductor element. Thereby, electrical connection and alignment are improved, and via holes can be formed by laser or photoetching without damaging the die pad. for that reason,
Embedding, storing, storing, and connecting the IC chip to the printed wiring board can be ensured. In addition, it is possible to directly form a metal which is a conductor layer of a printed wiring board on the transition layer. Examples of the conductor layer include via holes in an interlayer resin insulating layer and through holes on a substrate.

The resin substrate for incorporating electronic components such as an IC chip used in the present invention is a resin in which a reinforcing material such as a glass epoxy resin or a core material is impregnated with an epoxy resin, a BT resin, a phenol resin or the like, or an epoxy resin. A laminate of prepregs impregnated with is used, but those generally used for printed wiring boards can be used. In addition, a double-sided copper-clad laminate, a single-sided plate, a resin plate having no metal film, and a resin film can be used. However, if a temperature of 350 ° C. or more is applied, the resin will melt and carbonize.

A conductive metal film is formed on the entire surface of the IC chip by physical vapor deposition such as evaporation or sputtering. The metals include tin, chrome, titanium,
It is preferable to form one or more layers of a metal such as nickel, zinc, cobalt, gold, and copper. As the thickness, 0.001 to
It is preferable to form it between 2.0 μm. In particular, 0.01
~ 1.0 µm is desirable.

A metal film may be further provided on the metal film by electroless plating or the like. The upper metal film is preferably formed by forming one or more layers of a metal such as nickel, copper, gold, and silver. The thickness is preferably 0.01 to 5.0 μm,
0.1 to 3.0 μm is desirable.

The metal film is thickened by electroless or electrolytic plating. Types of plating to be formed include nickel, copper, gold, silver, zinc, and iron. It is preferable to use copper because the electrical characteristics, economy, and the conductor layer, which is a build-up formed later, are mainly copper. The thickness is preferably in the range of 1 to 20 μm.
If the thickness is larger than that, an undercut occurs at the time of etching, and a gap may be generated at the interface between the formed transition layer and the via hole. afterwards,
An etching resist is formed, exposed and developed to expose portions of the metal other than the transition layer, and etching is performed to form a transition layer on the pads of the IC chip.

In addition to the above-described method for manufacturing a transition layer, a dry film resist is formed on a metal film formed on an IC chip and a core substrate, and a portion corresponding to the transition layer is removed. After thickening, the resist can be peeled off, and a transition layer can be similarly formed on the pad of the IC chip using an etching solution.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. A. Semiconductor Device First, with respect to the configuration of the semiconductor device (IC chip) according to the first embodiment of the present invention, FIG.
This will be described with reference to FIG. 4A and FIG.

[First Embodiment] As shown in FIG. 3B, a die pad 22 and a wiring (not shown) are provided on the upper surface of the semiconductor element 20, and the die pad 22 and the wiring are provided on the die pad 22 and the wiring. , A protective film 24, and the die pad 22 includes
An opening in the protective film 24 is formed. On the die pad 22, a transition layer 38 mainly made of copper is formed. The transition layer 38 includes a thin film layer 33 and a thick layer 37. In other words, it is formed of two or more metal films.

Next, a method of manufacturing the semiconductor device described above with reference to FIG. 3B will be described with reference to FIGS.

(1) First, a wiring 21 and a die pad 2 are formed on a silicon wafer 20A shown in FIG.
2 (see FIG. 1A and FIG. 4A which shows a plan view of FIG. 1B, and FIG. 1B shows a cross section taken along line BB of FIG. 4A). There). (2) Next, a protective film 24 is formed on the die pad 22 and the wiring 21, and an opening 24a is provided on the die pad 22 (FIG. 1C).

(3) Physical vapor deposition such as vapor deposition and sputtering is performed on the silicon wafer 20A to form a conductive metal film (thin film layer) 33 on the entire surface (FIG. 2A).
The thickness is preferably in the range of 0.001 to 2.0 μm. If it is below the range, a thin film layer cannot be formed on the entire surface. If it is higher than this range, the thickness of the formed film will vary. The optimal range is from 0.01 to 1.0 μm. As a metal to be formed, a metal selected from tin, chromium, titanium, nickel, zinc, cobalt, gold, and copper is preferably used. These metals serve as a protective film for the die pad and do not degrade the electrical characteristics. In the first embodiment, the thin film layer 33 is formed of chromium by sputtering. Chromium has good adhesion to metal and can suppress moisture intrusion. Further, copper may be applied on the chromium layer by sputtering. Two layers of chromium and copper can be formed continuously in a vacuum chamber. At this time, the thickness is about 0.05-0.1 μm of chromium and about 0.5 μm of copper.

(4) Thereafter, a resist layer of any of a liquid resist, a photosensitive resist, and a dry film is formed on the thin film layer 33. A mask (not shown) on which a portion for forming the transition layer 38 is drawn is placed on the resist layer, and through exposure and development, a non-formed portion 35a is formed in the resist 35. Electroplating is performed to provide a thick layer (electrolytic plating film) 37 on the non-formed portion 35a of the resist layer (FIG. 2B). Examples of the type of plating formed include copper, nickel, gold, silver, zinc, and iron. Electrical properties, economics, and because the conductor layer that is a build-up formed later is mainly copper, it is better to use copper,
In the first embodiment, copper is used. Its thickness is 1-20 μm
It is better to perform within the range.

(5) After the plating resist 35 is removed with an alkaline solution or the like, the metal film 33 under the plating resist 35 is coated with sulfuric acid-hydrogen peroxide, ferric chloride, cupric chloride, cupric complex-organic. By removing with an etching solution such as an acid salt, the transition layer 38 is formed on the pad 22 of the IC chip.
Is formed (FIG. 2C).

(6) Next, a roughened surface 38α is formed by spraying an etching solution onto the substrate by spraying and etching the surface of the transition layer 38 (FIG. 3A).
reference). The roughened surface can be formed by using electroless plating or oxidation-reduction treatment.

(7) Finally, the silicon wafer 20A on which the transition layer 38 is formed is divided into individual pieces by dicing or the like to form the semiconductor elements 20 (FIG. 3).
(B) and FIG. 4 (B) which is a plan view of FIG. 3 (B)). Then, if necessary, the divided semiconductor elements 2
An operation check of 0 or an electrical inspection may be performed. Since the semiconductor element 20 has the transition layer 38 larger than the die pad 22, the probe pins can be easily applied to the semiconductor element 20, and the inspection accuracy is high.

[First Modification of First Embodiment] In the first embodiment described above, the thin film layer 33 is formed of chromium. On the other hand, in the first modification, the thin film layer 33 is formed of titanium. Titanium is applied by evaporation or sputtering.
Titanium has good adhesion to metal and can suppress moisture intrusion.

[Second Modification of First Embodiment] In the first embodiment described above, the thin film layer 33 is formed of chromium. On the other hand, in the second modification, the thin film layer is formed of tin. Chromium has good adhesion to metal and can suppress moisture intrusion.

[Third Modification of First Embodiment] In the first embodiment described above, the thin film layer 33 is formed of chromium. On the other hand, in the third modification, the thin film layer is formed of zinc.

[Fourth Modification of First Embodiment] In the first embodiment described above, the thin film layer 33 is formed of chromium. On the other hand, in the fourth modification, the thin film layer is formed of nickel. Nickel is formed by sputtering. Nickel has good adhesion to metal and can suppress moisture intrusion.

[Fifth Modification of First Embodiment] In the first embodiment described above, the thin film layer 33 is formed of chromium. On the other hand, in the fifth modification, the thin film layer is formed of cobalt. In each modification, copper may be further laminated on the thin film layer.

[Second Embodiment] A semiconductor device 20 according to a second embodiment will be described with reference to FIG. FIG.
In the semiconductor device according to the first embodiment described above with reference to FIG. 6B, the transition layer 38 has a two-layer structure including the thin film layer 33 and the thick layer 37. In contrast, the second
In the embodiment, as shown in FIG. 7B, the transition layer 38 is configured as a three-layer structure including a first thin film layer 33, a second thin film layer 36, and a thickening layer 37.

Next, the method of manufacturing the semiconductor device according to the second embodiment described above with reference to FIG.
This will be described with reference to FIGS.

(1) First, the wiring 21 and the die pad 22 are formed on the silicon wafer 20A shown in FIG. 5A (FIG. 5B). (2) Next, the protective film 2 is formed on the die pad 22 and the wiring.
4 is formed (FIG. 5C).

(3) By performing physical vapor deposition such as vapor deposition and sputtering on the silicon wafer 20A, a conductive metal film (first thin film layer) 33 is formed on the entire surface (FIG. 5).
(D)). The thickness is preferably in the range of 0.001 to 2.0 μm. If it is below the range, a thin film layer cannot be formed on the entire surface. If it is higher than this range, the thickness of the formed film will vary. The optimal range is from 0.01 to 1.0 μm. Metals to be formed include tin, chromium, titanium, nickel,
It is preferable to use one selected from zinc, cobalt, gold, and copper. These metals serve as a protective film for the die pad and do not degrade the electrical characteristics. Chromium, nickel, and titanium have good adhesion to metal and can suppress moisture intrusion. In the second embodiment, the first thin film layer 33 is formed of chromium.

(4) Sputtering on the first thin film layer 33
The second thin film layer 36 is laminated by any one of vapor deposition and electroless plating. In this case, the metal that can be laminated is preferably selected from nickel, copper, gold, and silver. In particular,
It is good to form with either copper or nickel. Copper is inexpensive and has good electrical conductivity. Nickel has good adhesion to a thin film and is unlikely to cause peeling or cracking. The thickness is preferably 0.01 to 5.0 μm,
In particular, the thickness is preferably 0.1 to 3.0 μm. In the second embodiment, the second thin film layer 36 is formed by electroless copper plating.
Desirable combinations of the first thin film layer and the second thin film layer are chromium-copper, chromium-nickel, titanium-copper, titanium-nickel, and the like. It is superior to other combinations in terms of bonding to metals and electrical conductivity.

(5) Thereafter, a resist layer is formed on the second thin film layer 3
6 is formed. A mask (not shown) is placed on the resist layer, and a non-formed portion 35a is formed on the resist 35 through exposure and development. Electroplating is performed to provide a thick layer (electrolytic plating film) 37 in the non-formed portion 35a of the resist layer (FIG. 6B). Examples of the type of plating formed include copper, nickel, gold, silver, zinc, and iron. Electrical properties, economics, and because the conductor layer that is a build-up formed later is mainly copper, it is better to use copper,
In the second embodiment, copper is used. The thickness is preferably in the range of 1 to 20 μm.

(6) After removing the plating resist 35 with an alkali solution or the like, the second thin film layer 3 under the plating resist 35 is removed.
6. By removing the metal film 33 with an etching solution such as sulfuric acid-hydrogen peroxide solution, ferric chloride, cupric chloride, cupric complex-organic acid salt, etc., a transition layer is formed on the pad 22 of the IC chip. 38 (FIG. 7C).

(7) Next, a roughened surface 38α is formed by spraying an etching solution on the substrate by spraying and etching the surface of the transition layer 38 (FIG. 7A).
reference). The roughened surface can be formed by using electroless plating or oxidation-reduction treatment.

(8) Finally, the silicon wafer 20A on which the transition layer 38 is formed is divided into individual pieces by dicing or the like to form the semiconductor elements 20 (FIG. 7).
(B)).

[First Modification of Second Embodiment] In the second embodiment described above, the first thin film layer 33 is made of chromium, the second thin film layer 36 is made of electroless plated copper, and the thick layer 37 is made of electrolytic copper. Formed by plating. On the other hand, in the first modification, the first thin film layer 33 is formed of chromium, the second thin film layer 36 is formed of sputtered copper, and the thickening layer 37 is formed of electrolytic copper plating. The thickness of each layer is chrome 0.07 μm, copper 0.5 μm, and electrolytic copper 15 μm.

[Second Modification of Second Embodiment] In a second modification, the first thin film layer 33 is formed of titanium, the second thin film layer 36 is formed of electroless copper, and the thickening layer 37 is formed of electrolytic copper plating. I do.
As the thickness of each layer, titanium 0.07 μm, plated copper 1.
0 μm and electrolytic copper 17 μm.

[Third Modification of Second Embodiment] In a third modification, the first thin film layer 33 is formed of titanium, the second thin film layer 36 is formed of sputtered copper, and the thickening layer 37 is formed of electrolytic copper plating. . As the thickness of each layer, titanium 0.06 μm, copper 0.5
μm and electrolytic copper 15 μm.

[Fourth Modification of Second Embodiment] In a fourth modification, the first thin film layer 33 is made of chromium, the second thin film layer 36 is made of electroless plated nickel, and the thickening layer 37 is made of electrolytic copper plating. Form. As the thickness of each layer, chrome 0.07 μm,
The plating copper is 1.0 μm and the electrolytic copper is 15 μm.

[Fifth Modification of the Second Embodiment] In a fifth modification, the first thin film layer 33 is made of titanium, the second thin film layer 36 is made of electroless plated nickel, and the thickening layer 37 is made of electrolytic copper plating. Form. As the thickness of each layer, titanium 0.05 μm,
The plating nickel is 1.2 μm and the electrolytic copper is 15 μm.

Third Embodiment A method of manufacturing a semiconductor device 20 according to a third embodiment will be described with reference to FIG. Third
The configuration of the semiconductor element of this embodiment is almost the same as that of the first embodiment described above with reference to FIG. However, in the first embodiment, the transition layer 38 was formed by forming the thickening layer 37 in the non-resist forming portion using a semi-additive process. On the other hand, in the third embodiment, a transition layer 38 is formed by forming a thick layer 37 uniformly using an additive process, providing a resist, and removing the non-resist-formed portion by etching.

The manufacturing method of the third embodiment will be described with reference to FIG. (1) As described above with reference to FIG. 2B in the first embodiment, physical vapor deposition such as vapor deposition and sputtering is performed on the silicon wafer 20A to form a conductive metal film 33 on the entire surface ( FIG. 2 (A)). The thickness is 0.001
A range of 2.0 μm is preferable. If it is below that range,
A thin film layer cannot be formed on the entire surface. If it is higher than this range, the thickness of the formed film will vary. The optimum range is preferably formed in the range of 0.01 to 1.0 μm. Metals to be formed include tin, chromium,
From titanium, nickel, zinc, cobalt, gold and copper,
It is good to use what is chosen. These metals protect the die pad and do not degrade the electrical characteristics. In the third embodiment, the thin film layer 33 is formed by sputtering chromium. Chrome thickness is 0.05
μm.

(2) A thick layer (electrolytic plating film) 37 is uniformly provided on the thin film layer 33 by performing electrolytic plating (FIG. 8).
(B)). Examples of the type of plating formed include copper, nickel, gold, silver, zinc, and iron. Electrical properties, economics,
Further, since the conductor layer to be formed later is mainly made of copper, it is preferable to use copper. In the third embodiment, copper is used. The thickness is preferably in the range of 1.0 to 20 μm. If the thickness is larger than that, an undercut occurs during the etching described later, and a gap may be generated at the interface between the formed transition layer and the via hole.

(3) Thereafter, a resist layer 35 is formed on the thick layer 37 (FIG. 8C).

(4) The metal film 3 in the portion where the resist 35 is not formed
3 and the thickening layer 37 are removed with an etching solution such as sulfuric acid-hydrogen peroxide solution, ferric chloride, cupric chloride, cupric complex-organic acid salt, and the resist 35 is peeled off to remove the IC. A transition layer 38 on the chip pads 22
Is formed (FIG. 8D). Subsequent steps are the same as in the first embodiment, and a description thereof will not be repeated.

[First Modification of Third Embodiment] In the third embodiment described above, the thin film layer 33 is formed of chromium. On the other hand, in the first modification, the thin film layer 33 is formed of titanium.

[Fourth Embodiment] A method of manufacturing a semiconductor device 20 according to a fourth embodiment will be described with reference to FIG. In the semiconductor device according to the third embodiment described above with reference to FIG. 8, the transition layer 38 includes the thin film layer 33 and the thick layer 3.
7 was a two-layer structure. On the other hand, in the fourth embodiment, as shown in FIG. 9D, the transition layer 38 has a three-layer structure including a first thin film layer 33, a second thin film layer 36, and a thick layer 37. Is configured as

The manufacturing method of the fourth embodiment will be described with reference to FIG. (1) The second embodiment described above with reference to FIG.
Similarly to the embodiment, a second thin film layer 36 is laminated on the first thin film layer 33 by sputtering, vapor deposition, and electroless plating (FIG. 9A). In this case, the metal that can be laminated is preferably selected from nickel, copper, gold, and silver. In particular,
It is good to form with either copper or nickel. Copper is inexpensive and has good electrical conductivity. Nickel has good adhesion to a thin film and is unlikely to cause peeling or cracking. In the fourth embodiment, the second thin film layer 36 is formed by electroless copper plating. The thickness is 0.01 to 5.0
μm is good, and particularly preferably 0.1 to 3.0 μm. Desirable combinations of the first thin film layer and the second thin film layer are chromium-copper, chromium-nickel, titanium-copper, and titanium-nickel. It is superior to other combinations in terms of bonding to metals and electrical conductivity.

(2) The second thin film layer 36 is formed by electrolytic plating.
A thick film 37 made of nickel, copper, gold, silver, zinc, or iron is uniformly provided on the substrate (FIG. 9B). The thickness is
1 to 20 μm is desirable.

(3) Thereafter, a resist layer 35 is formed on the thick layer 37 (FIG. 9C).

(4) The first thin film layer 33, the second thin film layer 36, and the thickening layer 37 where the resist 35 is not formed are made of sulfuric acid-hydrogen peroxide solution, ferric chloride, cupric chloride, and copper cupper. After removal with an etchant such as a complex-organic acid salt, the resist 3
By peeling 5, a transition layer 38 is formed on the pads 22 of the IC chip (FIG. 9D). Subsequent steps are the same as in the first embodiment, and a description thereof will not be repeated.

[First Modification of Fourth Embodiment] In the fourth embodiment described above, the first thin film layer 33 is made of chromium, the second thin film layer 36 is made of electroless plated copper, and the thick layer 37 is made of electrolytic copper. Formed by plating. On the other hand, in the first modification, the first thin film layer 33 is formed of chromium, the second thin film layer 36 is formed of sputtered copper, and the thickening layer 37 is formed of electrolytic copper plating. The thickness of each layer is chromium 0.07 μm, copper 0.5 μm, electrolytic copper 15
μm.

[Second Modification of Fourth Embodiment] In a second modification, the first thin film layer 33 is formed of titanium, the second thin film layer 36 is formed of electroless copper, and the thickening layer 37 is formed of electrolytic copper plating. I do.
The thickness of each layer is 0.07 μm of titanium, 1.0 μm of copper, and 15 μm of electrolytic copper.

[Third Modification of Fourth Embodiment] In a third modification, the first thin film layer 33 is formed of titanium, the second thin film layer 36 is formed of sputtered copper, and the thickening layer 37 is formed of electrolytic copper plating. . The thickness of each layer is titanium 0.07 μm, copper 0.5 μm
m, electrolytic copper 18 μm.

[Fourth Modification of Fourth Embodiment] In a fourth modification, the first thin film layer 33 is made of chromium, the second thin film layer 36 is made of electroless nickel, and the thick layer 37 is made of electrolytic copper plating. Form. The thickness of each layer is 0.06 μm of chromium, 1.2 μm of nickel, and 16 μm of electrolytic copper.

[Fifth Modification of Fourth Embodiment] In a fifth modification, the first thin film layer 33 is made of titanium, the second thin film layer 36 is made of electroless nickel, and the thick layer 37 is made of electrolytic copper plating. Form. The thickness of each layer is 0.07 μm of titanium, 1.1 μm of nickel, and 15 μm of electrolytic copper.

B. Multilayer Printed Wiring Board Incorporating Semiconductor Element Subsequently, the semiconductor element (I
The configuration of a multilayer printed wiring board in which the C chip 20 is embedded, accommodated, and accommodated in the concave portion, void, or opening of the core substrate will be described. [First Embodiment] A multilayer printed wiring board 1 as shown in FIG.
0 denotes the IC of the first embodiment described above with reference to FIG.
It comprises a core substrate 30 for accommodating the chip 20, an interlayer resin insulation layer 50, and an interlayer resin insulation layer 150. Via holes 60 and conductive circuits 58 are formed in interlayer resin insulation layer 50, and via holes 16 and conductor circuits 58 are formed in interlayer resin insulation layer 150.
0 and a conductor circuit 158 are formed.

On the interlayer resin insulating layer 150, a solder resist layer 70 is provided. The conductor circuit 158 below the opening 71 of the solder resist layer 70 is provided with a solder bump 76 for connecting to an external board (not shown) such as a daughter board or a mother board.

In the multilayer printed wiring board 10 of this embodiment,
The IC chip 20 is built in the core substrate 30, and a transition layer 38 is provided on the pad 22 of the IC chip 20. Therefore, the electrical connection between the IC chip and the multilayer printed wiring board (package substrate) can be established without using a lead component or a sealing resin. Further, since the transition layer 38 is formed in the IC chip portion, the IC chip portion is flattened, so that the upper interlayer insulating layer 50 is also flattened and the film thickness becomes uniform. Further, the transition layer allows the upper via hole 6 to be formed.
Even when 0 is formed, the stability of the shape can be maintained.

Further, by providing a copper transition layer 38 on the die pad 22, resin residue on the pad 22 can be prevented, and it can be immersed in an acid, an oxidizing agent, or an etching solution in a later step. Discoloration and dissolution of the pad 22 do not occur even after various annealing processes. This improves the connectivity and reliability between the pads of the IC chip and the via holes. Further, by interposing the transition layer 38 having a diameter of 60 μm or more on the pad 22 having a diameter of 40 μm, a via hole having a diameter of 60 μm can be reliably connected.

Next, a method of manufacturing the multilayer printed wiring board described above with reference to FIG. 14 will be described with reference to FIGS.

(1) First, an insulating resin substrate (core substrate) 30 in which a prepreg in which a core material such as glass cloth is impregnated with a resin such as epoxy is laminated is used as a starting material (FIG. 10).
(A)). Next, a recess 32 for accommodating an IC chip is formed on one surface of the core substrate 30 by counterboring.
(B)). Here, the concave portion is formed by counterboring, but a core substrate having an accommodating portion can be formed by laminating an insulating resin substrate having an opening and a resin insulating substrate having no opening.

(2) Thereafter, an adhesive material 34 is applied to the recess 32 using a printing machine. At this time, besides coating,
Potting may be performed. Next, the IC chip 20
Is placed on the adhesive material 34 (see FIG. 10C).

(3) Then, the upper surface of the IC chip 20 is pushed or hit and completely accommodated in the concave portion 32 (see FIG. 10D). Thereby, the core substrate 30 can be smoothed. At this time, the adhesive material 34 may be applied to the upper surface of the IC chip 20. However, since a resin layer is provided on the upper surface of the IC chip 20 and an opening for via holes is provided by a laser as described later, the transition layer 3
The connection between the via hole 8 and the via hole is not affected.

(4) A substrate having a thickness of 50 μm
The thermosetting resin sheet is vacuum-press-laminated at a pressure of 5 kg / cm ² while the temperature is raised to 50 to 150 ° C. to provide an interlayer resin insulating layer 50 (see FIG. 11A). The degree of vacuum during vacuum compression is 10 mmHg.

(5) Next, using a CO ² gas laser having a wavelength of 10.4 μm, a beam diameter of 5 mm, a top hat mode,
Under the conditions of a pulse width of 5.0 μsec, a mask hole diameter of 0.5 mm, and one shot, a via hole opening 48 having a diameter of 60 μm is provided in the interlayer resin insulating layer 50 (see FIG. 11B).
The resin residue in the opening 48 is removed using permanganic acid at 60 ° C. By providing the copper transition layer 38 on the die pad 22, resin residue on the pad 22 can be prevented, thereby improving the connectivity and reliability between the pad 22 and via holes 60 described later. Furthermore, 4
By interposing the transition layer 38 having a diameter of 60 μm or more on the pad 22 having a diameter of 0 μm, the via hole opening 48 having a diameter of 60 μm can be reliably connected. Here, the resin residue is removed using an oxidizing agent such as permanganic acid, but desmearing can be performed using oxygen plasma or corona treatment.

(6) Next, a roughened surface 50α of the interlayer resin insulating layer 50 is provided by dipping in an oxidizing agent such as chromic acid or permanganate (see FIG. 11C).
The roughened surface 50α is preferably formed in a range of 0.1 to 5 μm. As an example, a roughened surface 50α of 2 to 3 μm is provided by immersing in a sodium permanganate solution 50 g / l at a temperature of 60 ° C. for 5 to 25 minutes.
Other than the above, SV-454 manufactured by Japan Vacuum Engineering Co., Ltd.
By performing a plasma treatment using 0, a roughened surface 50α can be formed on the surface of the interlayer resin insulating layer 50. On this occasion,
Argon gas is used as the inert gas, and power 200
Plasma treatment is performed for 2 minutes under the conditions of W, gas pressure of 0.6 Pa, and temperature of 70 ° C.

(9) A metal layer 52 is provided on the interlayer resin insulation layer 50 on which the roughened surface 50α is formed (see FIG. 12A). The metal layer 52 is formed by electroless plating. By applying a catalyst such as palladium to the surface layer of the interlayer resin insulating layer 50 in advance, and immersing it in the electroless plating solution for 5 to 60 minutes, the metal layer 52 as a plating film is provided in a range of 0.1 to 5 μm. As an example, [aqueous electroless plating solution] NiSO4 0.003 mol / l tartaric acid 0.200 mol / l copper sulfate 0.030 mol / l HCHO 0.050 mol / l NaOH 0.100 mol / l α, α ' -Bipyridyl 100 mg / l polyethylene glycol (PEG) 0.10 g / l immersed at a liquid temperature of 34 ° C for 40 minutes.

Instead of plating, SV-4540 manufactured by Japan Vacuum Engineering Co., Ltd. was used, and sputtering was performed using a Ni—Cu alloy as a target at a pressure of 0.6 Pa, a temperature of 80 ° C., a power of 200 W, and a time of 5 minutes. Under the conditions, N
The i-Cu alloy 52 can also be formed on the surface of the epoxy-based interlayer resin insulation layer 50. At this time, the formed Ni
-The thickness of the Cu alloy layer 52 is 0.2 µm.

(8) A commercially available photosensitive dry film is adhered to the substrate 30 that has been subjected to the above processing, a photomask film is placed, and after exposure at 100 mJ / cm ² ,
Develop with 0.8% sodium carbonate to provide a plating resist 54 having a thickness of 15 μm. Next, electrolytic plating is performed under the following conditions to form an electrolytic plating film 56 having a thickness of 15 μm (see FIG. 12B). The additive in the electrolytic plating aqueous solution was Capparaside H manufactured by Atotech Japan.
L.

[Aqueous electrolytic plating solution] Sulfuric acid 2.24 mol / l Copper sulfate 0.26 mol / l Additive (Capparaside HL, manufactured by Atotech Japan) 19.5 ml / l [Electroplating conditions] Current density 1 A / dm ² Time 65 minutes Temperature 22 ± 2 ℃

(9) Plating resist 54 is made of 5% NaOH
And then remove the metal layer 52 under the plating resist.
Is dissolved and removed by etching using a mixed solution of nitric acid, sulfuric acid and hydrogen peroxide, a 16 μm-thick conductor circuit 58 composed of a metal layer 52 and an electrolytic plating film 56 and a via hole 6 are formed.
0, and roughened surfaces 58α and 60α are formed by an etching solution containing a cupric complex and an organic acid (FIG. 1).
2 (C)).

(10) Next, the above steps (4) to (9) are repeated to form a further upper interlayer resin insulation layer 150 and a conductor circuit 158 (including via holes 160) (FIG. 13 ( A)).

(11) Next, a cresol novolak type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.) dissolved in diethylene glycol dimethyl ether (DMDG) so as to have a concentration of 60% by weight was sensitized by acrylizing 50% of epoxy groups. Oligomer for imparting properties (molecular weight 4000) 46.67
15 parts by weight of a bisphenol A type epoxy resin (trade name: Epicoat 1001 manufactured by Yuka Shell Co., Ltd.) of 80% by weight dissolved in methyl ethyl ketone, imidazole hardener (trade name: 2E4MZ-CN)
1.6 parts by weight, 3 parts by weight of a polyfunctional acrylic monomer (manufactured by Kyoei Chemical Co., trade name: R604) as a photosensitive monomer,
Similarly, polyvalent acrylic monomer (manufactured by Kyoei Chemical Co., Ltd., trade name:
1.5 parts by weight of DPE6A) and 0.71 part by weight of a dispersant antifoaming agent (manufactured by San Nopco, trade name: S-65) are placed in a container, stirred and mixed to prepare a mixed composition. Of benzophenone (manufactured by Kanto Kagaku) and 0.2 parts by weight of Michler's ketone (manufactured by Kanto Kagaku) as a photosensitizer were added to give a viscosity of 25.
A solder resist composition (organic resin insulating material) adjusted to 2.0 Pa · s at ° C is obtained. The viscosity was measured using a B-type viscometer (DVL-B type, manufactured by Tokyo Keiki Co., Ltd.) at 60 rpm and rotor No. 4 at 6 rpm.
According to

(12) Next, the above-mentioned solder resist composition is applied to the substrate 30 at a thickness of 20 μm,
After performing a drying process at 70 ° C. for 30 minutes for 0 minute, a 5 mm-thick photomask on which a pattern of the opening of the solder resist resist is drawn is brought into close contact with the solder resist layer 70, and an ultraviolet ray of 1000 mJ / cm ² is applied. And developing with a DMTG solution to form an opening 71 having a diameter of 200 μm (see FIG. 13B). Further, a commercially available solder resist may be used.

(13) Next, the substrate on which the solder resist layer (organic resin insulating layer) 70 was formed was replaced with nickel chloride (2.3 × 10 ⁻¹ mol / l) and sodium hypophosphite (2.8 × 10 ¹ mol / l). 10 ^-1 mol / l) and an electroless nickel plating solution having a pH of 4.5 containing sodium citrate (1.6 × 10 ^-1 mol / l) for 20 minutes.
Then, a nickel plating layer 72 having a thickness of 5 μm is formed. Further, the substrate was subjected to potassium gold cyanide (7.6 × 10 ^−3).
mol / l), ammonium chloride (1.9 × 10 ^-1 mo)
1 / l), sodium citrate (1.2 × 10 ^-1 mol)
/ L), sodium hypophosphite (1.7 × 10 ^-1 mol)
/ L) is immersed for 7.5 minutes at 80 ° C. in an electroless plating solution containing
By forming the gold plating layer 74 of the length m, the conductor circuit 158 can be formed.
Then, a solder pad 75 is formed (see FIG. 13C).

(14) Thereafter, the solder resist layer 70
The solder paste is printed on the opening 71 of
To form the solder bumps 76. Thereby, the multilayer printed wiring board 10 having the IC chip 20 built-in and having the solder bumps 76 can be obtained (see FIG. 14).

For the solder paste, Sn / Pb, Sn / S
b, Sn / Ag, Sn / Ag / Cu, etc. can be used. Of course, a solder paste of a low α-ray type of radiation may be used.

In the above embodiment, the interlayer resin insulating layer 5
Thermosetting resin sheets were used for Nos. 0 and 150. This resin sheet contains a poorly soluble resin, soluble particles, a curing agent, and other components. Each is described below.

The resin used in the production method of the present invention is obtained by dispersing particles soluble in an acid or an oxidizing agent (hereinafter referred to as “soluble particles”) in a resin which is hardly soluble in an acid or an oxidizing agent (hereinafter referred to as a “slightly soluble resin”). It was done. Note that the terms "sparingly soluble" and "soluble" used in the present invention mean that when immersed in the same acid or oxidizing agent for the same time,
Those with a relatively fast dissolution rate are called "soluble" for convenience, and those with a relatively slow dissolution rate are called "poorly soluble" for convenience.

Examples of the soluble particles include resin particles soluble in an acid or an oxidizing agent (hereinafter referred to as “soluble resin particles”), inorganic particles soluble in an acid or an oxidizing agent (hereinafter referred to as “soluble inorganic particles”), and acid or oxidizing agents. Soluble metal particles (hereinafter referred to as “soluble metal particles”) and the like. These soluble particles may be used alone or in combination of two or more.

The shape of the soluble particles is not particularly limited.
Spherical, crushed and the like. The shape of the soluble particles is desirably a uniform shape. This is because a roughened surface having unevenness with a uniform roughness can be formed.

The average particle size of the above-mentioned soluble particles is 0.1.
1 to 10 μm is desirable. Within this particle size range, 2
More than one kind of particles having different particle sizes may be contained. That is, it contains soluble particles having an average particle size of 0.1 to 0.5 μm and soluble particles having an average particle size of 1 to 3 μm.
Thereby, a more complicated roughened surface can be formed,
Excellent adhesion to conductor circuits. In the present invention, the particle size of the soluble particles is the length of the longest portion of the soluble particles.

Examples of the soluble resin particles include those made of a thermosetting resin, a thermoplastic resin, and the like. When immersed in a solution containing an acid or an oxidizing agent, the soluble resin particles have a higher dissolution rate than the hardly soluble resin. If it is, there is no particular limitation. Specific examples of the soluble resin particles include, for example, those made of epoxy resin, phenol resin, polyimide resin, polyphenylene resin, polyolefin resin, fluororesin, and the like, and may be made of one of these resins. Alternatively, it may be composed of a mixture of two or more resins.

Further, as the soluble resin particles, resin particles made of rubber can be used. Examples of the rubber include polybutadiene rubber, various modified polybutadiene rubbers such as epoxy-modified, urethane-modified, (meth) acrylonitrile-modified, and (meth) acrylonitrile-butadiene rubber containing a carboxyl group. By using these rubbers, the soluble resin particles are easily dissolved in an acid or an oxidizing agent. In other words, when dissolving the soluble resin particles using an acid, an acid other than a strong acid can be dissolved, and when dissolving the soluble resin particles using an oxidizing agent, permanganese having a relatively weak oxidizing power is used. Acid salts can also be dissolved. Even when chromic acid is used, it can be dissolved at a low concentration. Therefore, the acid or the oxidizing agent does not remain on the resin surface, and as described later, when a catalyst such as palladium chloride is applied after forming the roughened surface, the catalyst is not applied or the catalyst is oxidized. Or not.

Examples of the above-mentioned soluble inorganic particles include particles made of at least one selected from the group consisting of aluminum compounds, calcium compounds, potassium compounds, magnesium compounds and silicon compounds.

Examples of the aluminum compound include alumina and aluminum hydroxide. Examples of the calcium compound include calcium carbonate and
Examples of the potassium compound include potassium carbonate.Examples of the magnesium compound include magnesia, dolomite, and basic magnesium carbonate.Examples of the silicon compound include silica and zeolite. Is mentioned. These may be used alone or in combination of two or more.

Examples of the soluble metal particles include, for example,
Copper, nickel, iron, zinc, lead, gold, silver, aluminum,
Examples include particles made of at least one selected from the group consisting of magnesium, calcium, and silicon. These soluble metal particles may have a surface layer coated with a resin or the like in order to ensure insulation.

When two or more of the above-mentioned soluble particles are used in combination, the combination of the two types of soluble particles to be mixed is preferably a combination of resin particles and inorganic particles. Both have low conductivity, so that the insulation of the resin film can be ensured, and thermal expansion can be easily adjusted with the poorly soluble resin, and no crack occurs in the interlayer resin insulation layer made of the resin film. This is because peeling does not occur between the interlayer resin insulating layer and the conductor circuit.

The hardly soluble resin is not particularly limited as long as it can maintain the shape of the roughened surface when the roughened surface is formed by using an acid or an oxidizing agent in the interlayer resin insulating layer. Examples thereof include thermosetting resins, thermoplastic resins, and composites thereof. Further, a photosensitive resin obtained by imparting photosensitivity to these resins may be used. By using a photosensitive resin, an opening for a via hole can be formed in an interlayer resin insulating layer by using exposure and development processes. Among these, those containing a thermosetting resin are desirable. Thereby, the shape of the roughened surface can be maintained even by the plating solution or various heat treatments.

Specific examples of the hardly soluble resin include, for example, epoxy resin, phenol resin, phenoxy resin,
Examples thereof include a polyimide resin, a polyphenylene resin, a polyolefin resin, a polyether sulfone, and a fluororesin. These resins may be used alone or in combination of two or more. Further, an epoxy resin having two or more epoxy groups in one molecule is more desirable. Not only can the above-described roughened surface be formed, but also excellent in heat resistance, etc., even under heat cycle conditions, stress concentration does not occur in the metal layer, and peeling of the metal layer does not easily occur. Because.

Examples of the epoxy resin include cresol novolak type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolak type epoxy resin, alkylphenol novolak type epoxy resin, biphenol F type epoxy resin, and naphthalene type epoxy resin. Resin, dicyclopentadiene type epoxy resin, epoxidized product of condensate of phenols and aromatic aldehyde having phenolic hydroxyl group,
Triglycidyl isocyanurate, alicyclic epoxy resin and the like. These may be used alone or in combination of two or more. Thereby, it becomes excellent in heat resistance and the like.

In the resin film used in the present invention, the soluble particles are desirably substantially uniformly dispersed in the hardly-soluble resin. It is possible to form a roughened surface with unevenness of uniform roughness, and even if via holes and through holes are formed in the resin film, it is possible to secure the adhesion of the metal layer of the conductor circuit formed thereon. Because you can. Alternatively, a resin film containing soluble particles only in the surface layer forming the roughened surface may be used. Thereby,
Since the portions other than the surface layer of the resin film are not exposed to the acid or the oxidizing agent, the insulation between the conductor circuits via the interlayer resin insulating layer is reliably maintained.

In the above resin film, the amount of the soluble particles dispersed in the poorly soluble resin is preferably 3 to 40% by weight based on the resin film. If the amount of the soluble particles is less than 3% by weight, it may not be possible to form a roughened surface having desired irregularities. If the amount exceeds 40% by weight, the soluble particles may be dissolved using an acid or an oxidizing agent. In addition, there is a case where the resin film is melted to a deep portion of the resin film and the insulation between the conductor circuits via the interlayer resin insulating layer made of the resin film cannot be maintained, which may cause a short circuit.

The resin film desirably contains a curing agent and other components in addition to the soluble particles and the hardly-soluble resin. As the curing agent, for example,
Imidazole-based curing agents, amine-based curing agents, guanidine-based curing agents, epoxy adducts of these curing agents and microcapsules of these curing agents, and organic materials such as triphenylphosphine, tetraphenylphosphonium, and tetraphenylborate. Phosphine compounds and the like can be mentioned.

The content of the curing agent is desirably 0.05 to 10% by weight based on the resin film. 0.
If the amount is less than 05% by weight, the resin film is insufficiently cured, so that the degree of penetration of the acid or the oxidizing agent into the resin film is increased, and the insulating property of the resin film may be impaired. On the other hand, when the content exceeds 10% by weight, an excessive curing agent component may modify the composition of the resin, which may cause a decrease in reliability.

Examples of the other components include fillers such as inorganic compounds and resins which do not affect the formation of the roughened surface. As the inorganic compound, for example,
Examples of the resin include silica, alumina, and dolomite. Examples of the resin include a polyimide resin, a polyacryl resin, a polyamideimide resin, a polyphenylene resin, a melanin resin, and an olefin resin. By incorporating these fillers, the performance of the multilayer printed wiring board can be improved by matching thermal expansion coefficients, improving heat resistance and chemical resistance, and the like.

Further, the resin film may contain a solvent. As the solvent, for example, acetone,
Ketones such as methyl ethyl ketone and cyclohexanone,
Ethyl acetate, butyl acetate, cellosolve acetate, and aromatic hydrocarbons such as toluene and xylene. These may be used alone or in combination of two or more. However, these interlayer resin insulation layers are dissolved and carbonized when a temperature of 350 ° C. or more is applied.

[Second Embodiment] Next, a multilayer printed wiring board according to a second embodiment of the present invention will be described with reference to FIG. In the first embodiment described above, the case where the BGA is provided has been described. The second embodiment is almost the same as the first embodiment, but is configured as a PGA system in which connection is made via conductive connection pins 96 as shown in FIG. In the first embodiment described above, the via holes are formed by laser, but in the second embodiment, the via holes are formed by photoetching.

A method for manufacturing a multilayer printed wiring board according to the second embodiment will be described with reference to FIG. (4) As in the first embodiment, (1)-(3) a 50 μm thick thermosetting epoxy resin 5
0 (see FIG. 15A).

(5) Next, the photomask film 49 on which the black circle 49a corresponding to the via hole formation position is drawn is placed on the interlayer resin insulation layer 50 and exposed (FIG. 15).
(B)).

(6) Spray development with a DMTG solution and heat treatment are performed to obtain a via hole opening 4 having a diameter of 85 μm.
8 is provided (FIG. 15C).
reference).

(7) The surface of the interlayer resin insulating layer 50 is roughened with permanganic acid or chromic acid to form a roughened surface 50α (see FIG. 15D). Subsequent steps are the same as those in the above-described first embodiment, and a description thereof will not be repeated. The roughened surface is preferably between 0.05 and 5 μm.

FIGS. 17 and 18 show the results of housing the semiconductor element of the above-described embodiment and the semiconductor element of the comparative example in the multilayer printed wiring boards of the first and second embodiments and evaluating the results. Comparative Example 1 The comparative example is the same as the semiconductor device of the first embodiment. However, in Comparative Example 1, the transition layer was not formed, and the die pad was directly embedded in the multilayer printed wiring board. Comparative Example 2 In Comparative Example 2, a stud bump disclosed in JP-A-9-321408 was formed and embedded in a multilayer printed wiring board.

As the evaluation items, the presence / absence of discoloration / dissolution of the die pad was visually determined. Whether a via hole opening can be formed is determined by using a laser with a diameter of 60 μm using the method for manufacturing a multilayer printed wiring board of the first embodiment.
m can be formed using the method for manufacturing a multilayer printed wiring board according to the second embodiment.
It was examined whether an opening of 5 μm could be formed. The contact resistance between the die pad and the via hole was measured.
In the semiconductor devices of the first to fourth embodiments, favorable results were obtained, but in Comparative Examples 1 and 2, problems such as poor formation of via holes, poor connection, or an increase in resistance value occurred.

[0115]

According to the structure of the present invention, the connection between the IC chip and the printed wiring board can be established without the intervention of a lead component. Therefore, resin sealing is not required. Furthermore, since there is no problem caused by lead components or sealing resin,
Connectivity and reliability are improved. Also, since the pad of the IC chip and the conductive layer of the printed wiring board are directly connected,
Electrical characteristics can also be improved. Furthermore, conventional IC
Compared with the chip mounting method, the wiring length from the IC chip to the substrate to the external substrate can be shortened, and the loop inductance can be reduced. In addition, the degree of freedom in wiring formation has increased as BGA, PGA, and the like can be provided.

[Brief description of the drawings]

FIGS. 1A, 1B, and 1C are manufacturing process diagrams of a semiconductor device according to a first embodiment of the present invention.

FIGS. 2A, 2B, and 2C are manufacturing process diagrams of a semiconductor device according to a first embodiment of the present invention.

FIGS. 3A and 3B are manufacturing process diagrams of the semiconductor device according to the first embodiment of the present invention.

FIG. 4A is a plan view of a silicon wafer 20A according to the first embodiment of the present invention, and FIG. 4B is a plan view of a singulated semiconductor element.

FIGS. 5A, 5B, 5C, and 5D are manufacturing process diagrams of a semiconductor device according to a second embodiment of the present invention.

FIGS. 6A, 6B, and 6C are manufacturing process diagrams of a semiconductor device according to a second embodiment of the present invention.

FIGS. 7A and 7B are manufacturing process diagrams of a semiconductor device according to a second embodiment of the present invention.

FIGS. 8A, 8B, 8C, and 8D are manufacturing process diagrams of a semiconductor device according to a third embodiment of the present invention.

FIGS. 9A, 9B, 9C, and 9D are manufacturing process diagrams of a semiconductor device according to a second embodiment of the present invention.

FIGS. 10A, 10B, 10C, and 10D are manufacturing process diagrams of the multilayer printed wiring board according to the first embodiment of the present invention.

FIGS. 11A, 11B, and 11C are manufacturing process diagrams of the multilayer printed wiring board according to the first embodiment of the present invention.

FIGS. 12A, 12B, and 12C are manufacturing process diagrams of the multilayer printed wiring board according to the first embodiment of the present invention.

FIGS. 13A, 13B, and 13C are manufacturing process diagrams of the multilayer printed wiring board according to the first embodiment of the present invention.

FIG. 14 is a sectional view of the multilayer printed wiring board according to the first embodiment of the present invention.

FIGS. 15A, 15B, 15C, and 15D are manufacturing process diagrams of the multilayer printed wiring board according to the second embodiment of the present invention.

FIG. 16 is a sectional view of a multilayer printed wiring board according to a second embodiment of the present invention.

FIG. 17 is a table showing the results of evaluating the semiconductor devices of the first and second examples.

FIG. 18 is a table showing the results of evaluating the semiconductor elements of the third and fourth examples as comparative examples.

[Explanation of symbols]

 Reference Signs List 20 IC chip (semiconductor element) 22 die pad 24 protective film 30 core substrate 32 concave portion 36 resin layer 38 transition layer 50 interlayer resin insulating layer 58 conductive circuit 60 via hole 70 solder resist layer 76 solder bump 90 daughter board 96 conductive connecting pin 97 conductive Adhesive 120 IC chip 150 Interlayer resin insulation layer 158 Conductor circuit 160 Via hole

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5F033 HH07 HH11 HH13 HH14 HH15 HH17 HH18 MM08 MM25 PP15 PP19 PP27 QQ08 QQ10 QQ19 VV07

Claims (10)

[Claims] 1. A method of manufacturing a semiconductor device in which a transition layer is formed through at least (a) to (f): (a) forming a wiring and a die pad on a wafer; Forming a thin layer on the entire surface of the obtained wafer; (c) forming a resist layer on the thin film layer and forming a thick layer on a non-formed portion of the resist layer; (d) resist layer (E) removing the thin film layer by etching; and (f) dividing the wafer to form semiconductor elements. 2. A method of manufacturing a semiconductor device in which a transition layer is formed through at least (a) to (f): (a) a step of forming wiring and a die pad on a wafer; (b) the step of (a) Forming a first thin film layer and a second thin film layer on the entire surface of the obtained wafer; (c) forming a resist layer on the thin film layer, and forming a thick layer on a non-formed portion of the resist layer. (D) removing the resist layer; (e) removing the first and second thin film layers by etching; (f) dividing the wafer to form semiconductor elements. 3. A method of manufacturing a semiconductor device in which a transition layer is formed through at least (a) to (f): (a) forming a wiring and a die pad on a wafer; Forming a thin film layer on the entire surface of the obtained wafer; (c) forming a thick layer on the entire thin film layer and forming a resist on the thick layer; (d) etching (E) removing the resist layer; (f) dividing the wafer to form semiconductor elements. 4. A method of manufacturing a semiconductor device in which a transition layer is formed through at least (a) to (f): (a) forming a wiring and a die pad on a wafer; Forming a first thin film layer and a second thin film layer on the whole surface of the obtained wafer; (c) forming a thick layer on the whole thin film layer, and forming a resist on the thick layer Step (d): First of the non-formed portions of the resist by etching,
Removing the second thin film layer and the thickened layer; (e) removing the resist layer; and (f) dividing the wafer to form semiconductor elements. 5. The method according to claim 1, wherein the thin film layer is formed by sputtering or vapor deposition. 6. The method according to claim 2, wherein the first thin film layer is formed by sputtering or vapor deposition. 7. The method according to claim 2, wherein the second thin film layer is formed by sputtering, vapor deposition, or plating. 8. The thickening layer may be formed of nickel, copper, gold,
The method for manufacturing a semiconductor device according to claim 1, wherein the method is selected from silver, zinc, and iron. 9. The thin film layer is made of tin, chromium, titanium,
4. The method according to claim 1, wherein at least one selected from nickel, zinc, cobalt, gold, and copper is stacked. 10. The first thin film layer is laminated with at least one selected from the group consisting of tin, chromium, titanium, nickel, zinc, cobalt, gold, and copper. The semiconductor device according to claim 2, wherein the semiconductor device is selected from the group consisting of copper, gold, and silver.