WO2014041628A1

WO2014041628A1 - Component-embedded substrate and method for producing same

Info

Publication number: WO2014041628A1
Application number: PCT/JP2012/073297
Authority: WO
Inventors: 琢哉長谷川; 知之長田; 光昭戸田
Original assignee: 株式会社メイコー
Priority date: 2012-09-12
Filing date: 2012-09-12
Publication date: 2014-03-20

Abstract

This component-embedded substrate (15) comprises: a conductor pattern formed on the surface of a substrate; an adhesive layer (10) formed on the inner side of the conductor pattern; an electric or electronic component (3) that adheres to the adhesive layer (10); an electrode (3a) of the component (3); an insulating layer (2) made of an insulating material in which the component (3) is embedded; and a conduction section that penetrates the adhesive layer (10) and electrically connects the conductor pattern and the electrode (3a). A component group (16-20) including a plurality of types of said components (3) is embedded in the insulating layer (2). Each said electrode (3a) is covered with a metal-made metal film. Each said conduction section is formed so as to enter the metal film. The metal films on the respective electrodes (3a) of the respective components (3) included in the component group (16-20) all have the same etching rate or each have an etching rate of from 1 µm/minute to 2 µm/minute.

Description

Component built-in substrate and manufacturing method thereof

The present invention relates to a component-embedded substrate and a manufacturing method thereof.

There are various methods for manufacturing a component-embedded substrate (see, for example, Patent Document 1). In this method, an adhesive layer is formed on a copper foil by a dispenser or a printing method, a component to be incorporated is mounted thereon, the adhesive layer is cured, and the component is fixed. Then, by laminating press, the component is embedded in the insulating material, and a via that reaches the terminal of the component from the outside is formed by laser processing. Then, the via is plated to form a conductive via so as to be electrically connected to the terminal.

In recent years, diversification of built-in parts has progressed, and various types of electrical or electronic parts have been used. The electrode of the terminal which these components have is formed with the copper electrode by which the copper plating was given. After the via is formed, the copper portion is melted by slightly soft-etching the copper electrode.

However, when various parts are built in, the manufacturers of these parts are different, or even the same manufacturer manufactures different offices. Therefore, the copper electrode is formed by a different manufacturing process for each part. Yes. As a result, the etching rate differs for each copper electrode of the component, and even if the board manufacturer performs soft etching processing under the same conditions, the dissolved thickness of the copper electrode will differ, so the connection reliability between the board wiring and the copper electrode will be defective It is feared that this will occur.

JP 2010-27917 A

The present invention takes the above-mentioned conventional technology into consideration, and even when a plurality of types of electrical or electronic components are incorporated, a component-embedded substrate that can align the melt thickness of the copper electrode by the soft etching process And it aims at providing the manufacturing method.

In order to achieve the object, in the present invention, a conductor pattern formed on a substrate surface, an adhesive layer formed inside the conductor pattern, an electrical or electronic component that adheres to the adhesive layer, and the component In the component-embedded substrate, comprising: an electrode comprising: an insulating layer made of an insulating material that embeds the component; and a conductive portion that penetrates the adhesive layer and electrically connects the conductor pattern and the electrode. A part group consisting of a plurality of types of parts is embedded in the insulating layer, the electrode is coated with a metal metal film, and the conductive portion is formed so as to penetrate into the metal film. Provided is a component-embedded substrate in which all of the metal films of the electrodes of the component included have the same or an etching rate of 1 μm / min to 2 μm / min.

Preferably, the components forming the component group are capacitors, resistors, inductors, and active components.

In the present invention, an adhesive layer forming step of forming a plurality of adhesive layers made of an insulating material corresponding to the components on a metal layer formed on a support plate, and a component on which the component group is mounted on the adhesive layer A group mounting step, a stacking step of stacking the insulating material on the component group and embedding the component in the insulating layer, removing the support plate, penetrating the metal layer and the adhesive layer, A via forming step of forming a plurality of vias reaching each of the electrodes included in the component forming a component group; and melting the metal film exposed to the via and extending the via into the metal film Built-in component comprising: a soft etching step for forming, a plating step for depositing plating on the surface of the via to form the conductive portion, and a pattern forming step for forming a conductor pattern including the metal layer substrate The manufacturing method for providing.

According to the present invention, the built-in component group includes a plurality of types of components. When such a part has an electrode coated with a metal film such as copper by plating, for example, the metal film is partly soft etched to improve the connection reliability with the conductor pattern by the conductive part. Dissolve by processing. Since this soft etching process is performed on the metal film of each component by the substrate manufacturer under the same conditions, the dissolved thickness of the metal film differs if the etching rate of each metal film is different. For this reason, there is a concern that the connection reliability between the substrate wiring and the electrode may cause a problem. However, since all the metal films of the electrodes of the components included in the component group have the same etching rate, all the metal films In this case, grooves having the same depth can be formed. For this reason, the connection reliability of the conductor pattern and the component as the whole substrate is improved.

It is the schematic for demonstrating in order the manufacturing method of the component built-in board which concerns on this invention. It is the schematic for demonstrating in order the manufacturing method of the component built-in board which concerns on this invention. It is the schematic for demonstrating in order the manufacturing method of the component built-in board which concerns on this invention. It is the schematic for demonstrating in order the manufacturing method of the component built-in board which concerns on this invention. It is the schematic for demonstrating in order the manufacturing method of the component built-in board which concerns on this invention. It is the schematic for demonstrating in order the manufacturing method of the component built-in board which concerns on this invention. It is the schematic for demonstrating in order the manufacturing method of the component built-in board which concerns on this invention. 1 is a schematic view of a component built-in substrate according to the present invention. It is a graph which shows an etching rate.

A basic configuration to which the method for manufacturing a component-embedded substrate according to the present invention is applied will be described with reference to FIGS.

First, as shown in FIGS. 1 and 2, an adhesive layer forming step is performed. In this step, first, as shown in FIG. 1, for example, a substrate in which a metal layer 12 is formed on a support plate 11 is prepared. The support plate 11 has a degree of rigidity required for process conditions. The support plate 11 is formed of a rigid SUS (stainless steel) plate or aluminum plate as a support device. For example, when the support plate 11 is a SUS plate, the metal layer 12 is formed by depositing a copper plating foil having a predetermined thickness. Alternatively, the metal layer 12 is formed by attaching a copper foil if the support plate 11 is an aluminum plate. Then, as shown in FIG. 2, the adhesive layer 10 is applied onto the metal layer 12 with an adhesive made of an insulating material, for example, by a dispenser or printing. That is, the adhesive layer 10 is bonded to the metal layer 12.

Next, as shown in FIG. 3, a component group mounting process is performed. In the present invention, a component-embedded substrate in which a plurality of types of electrical or electronic components 3 are built is used as a reference. However, in FIG. This component mounting step is a step of mounting the electronic or electrical component 3 on the adhesive layer 10. The mounted component 3 includes an active component and a passive component. The component 3 has a component main body 3a and an electrode 3b. The electrode 3b is bonded to an adhesive that forms the adhesive layer 10. That is, in the component mounting process, the component 3 is mounted with the electrode 3 b aligned with the position of the adhesive layer 10.

Then, as shown in FIG. 4, a lamination process is performed. The laminating step is for laminating an insulating material to be the insulating layer 2 on the component 3 and embedding the component 3 in the insulating material. This step is performed by laying up an insulating material such as a prepreg on the side opposite to the side on which the metal layer 12 is disposed with respect to the component 3 and pressing it while heating under vacuum. This press is performed using, for example, a vacuum press machine. Note that it is preferable to use an insulating material having a thermal expansion coefficient close to that of the component 3. Another metal layer 4 is formed on the surface opposite to the metal layer 12 with the insulating layer 2 interposed therebetween.

Thereafter, as shown in FIG. 5, a via formation process is performed. In this step, first, the support plate 11 is removed. Thereby, the metal layer 12 is exposed on one surface of the insulating layer 2. Then, drilling is performed using a laser or the like to form the via 13. Specifically, the via 13 is formed so as to reach the surface of the electrode 3 b from the metal layer 12 through the adhesive layer 10. Also, depending on the structure, through conduction holes or other conduction vias may be formed at this point in order to obtain electrical connection between each layer or front and back. After the via is formed, a desmear process is performed to remove the resin remaining during the via formation.

Thereafter, a soft etching process is performed as shown in FIG. Here, the electrode 3b described above is formed of a central portion 8 serving as a base and a metal film 9 covering the central portion 8. Specifically, the metal film 9 made of copper is formed by plating the central portion 8 formed of nickel, silver, sintered copper, or the like. The thickness of the metal film 9 is 5 μm to 15 μm, but most is 5 μm to 10 μm. In the soft etching process, the metal film 9 exposed at the bottom of the via 13 is dissolved to extend the via 13 into the metal film 9. When the metal film 9 is copper, the soft etching process is performed by using a chemical solution such as sodium persulfate or potassium persulfate and slightly dissolving the metal film 9. As a result, oxides and organic substances on the surface of the metal film 9 are removed, and a fresh metal surface is exposed. Accordingly, the adhesion with the metal deposited in the subsequent plating process is increased, and as a result, the electrical connection reliability is improved.

Thereafter, as shown in FIG. 7, a plating process and a pattern forming process are performed. In the plating process, a plating process (conducting process) is performed, and copper is deposited in the via 13 to form the conductive via 7. In the pattern forming step, the conductor pattern 6 is formed on both surfaces of the insulating layer 2 using etching or the like. As shown in FIG. 7, the component-embedded substrate 1 obtained through such a process includes an insulating layer 2, a component 3, a conductor pattern 6, an adhesive layer 10, and a conductive via 7. The insulating layer 2 is obtained by curing the above-described insulating material (such as a prepreg), and the component 3 is connected to the conductor pattern 6 via the adhesive layer 10. The conductor pattern 6 is formed on the surface of the insulating layer 2.

The present invention is premised on being applied to a component-embedded substrate 15 in which a component group 14 composed of a plurality of types of components 3 is embedded in an insulating layer 2 as shown in FIG. The components 3 constituting the component group 14 here are a capacitor 16, a resistor 17, an inductor 18, and an active component 19. FIG. 8 shows a state after the end of the soft etching process when such a component group 14 is embedded. As described above, vias are formed with a laser and soft etching is performed after desmearing. If multiple types of parts 16 to 19 are embedded in this way, the manufacturer that manufactures each part. The etching rate is often different for each metal film 9 of the electrode film, such as different from each other, or even from the same manufacturer with different establishments. For this reason, even if the substrate manufacturer performs the soft etching process under the same conditions, the dissolved thickness of the metal film 9 is different, and there is a concern that the connection reliability between the conductor pattern 6 and the electrode 3b may be defective. However, since the etching rates of the components 16 to 19 forming the component group 14 embedded in the component-embedded substrate 15 according to the present invention are all the same, even if the substrate manufacturer performs the soft etching process under the same conditions, The metal film 9 is similarly dissolved by the electrode 3b.

For example, if the metal film 9 is 8 μm, if the etching rate of the metal film 9 of the parts 16 to 19 is made uniform at 2 μm / min, then 5 μm will be dissolved if the substrate manufacturer performs the soft etching process for 2.5 minutes. As a result, the metal film 9 is exposed to a fresh surface. That is, the via 13 is formed so as to enter the metal film 9. Thereby, the metal film 9 in the same dissolved state can be efficiently obtained without exposing the central portion 8.

In order to obtain such a component-embedded substrate 15, for example, the substrate maker can achieve the standardization so that the etching rates are uniform for each of the component manufacturers of the components 16-19.

FIG. 9 shows the relationship between the etching time and the etching amount depending on the etching rate. A solid line A indicates a case where the etching rate is 2 μm, and a broken line B indicates a case where the etching rate is 4 μm. The soft etching time needs to be at least 1.5 minutes considering the entry of the chemical into the via bottom. Usually it takes 2.5 minutes. Since the metal film is often 8 μm, if the etching rate is 4 μm, it will dissolve 10 μm in 2.5 minutes, and this will expose the central part of nickel or the like. On the other hand, if the etching rate is 2 μm, the etching amount is 5 μm even after 2.5 minutes, so that the metal film with a thickness of 8 μm remains 3 μm. Therefore, adjusting the etching rate according to the thickness of the metal film is very useful for the substrate manufacturing process when a large number of components are incorporated. The applicant has confirmed that an etching rate of 1 μm / min or more is sufficiently practical.

DESCRIPTION OF SYMBOLS 1 Component built-in board 2 Insulation layer 3 Electrical or electronic component 3a Component main body 3b Electrode 4 Metal layer 6 Conductive pattern 7 Conductive via 8 Central part 9 Metal film 10 Adhesive layer 11 Support plate 12 Metal layer 13 Via 14 Component group 15 Component Built-in substrate 16 Capacitor 17 Resistor 18 Inductor 19 Active component

Claims

A conductor pattern formed on the substrate surface;
An adhesive layer formed inside the conductor pattern;
An electrical or electronic component that adheres to the adhesive layer;
An electrode of the component;
An insulating layer made of an insulating material for embedding the component;
In the component-embedded substrate that includes a conductive portion that penetrates the adhesive layer and electrically connects the conductor pattern and the electrode,
In the insulating layer, a component group consisting of a plurality of types of the components is embedded,
The electrode is coated with a metallic metal film,
The conduction part is formed so as to enter the metal film,
The component-embedded substrate, wherein all of the metal films of the electrodes of the component included in the component group have the same or an etching rate of 1 μm / min to 2 μm / min.
2. The component built-in board according to claim 1, wherein the components forming the component group are a capacitor, a resistor, an inductor, and an active component.
An adhesive layer forming step of forming a plurality of the adhesive layers made of an insulating material on the metal layer formed on the support plate corresponding to the component;
A component group mounting step of mounting the component group on the adhesive layer;
A stacking step of stacking the insulating material on the component group and embedding the component in the insulating layer;
A via forming step of removing the support plate and forming a plurality of vias that reach each of the electrodes of the component that penetrates the metal layer and the adhesive layer to form the component group;
A soft etching step of dissolving the metal film exposed in the via and extending the via into the metal film;
A plating step of depositing plating on the surface of the via to form the conductive portion;
The method for manufacturing a component-embedded board according to claim 1, further comprising a pattern forming step of forming a conductor pattern including the metal layer.