Method for manufacturing a component-embedded substrate

Abstract

The manufacturing method of the component-embedded substrate includes a cavity body forming step of forming a cavity (3) by temporarily curing and adhering a film (2) made of an insulating resin to one surface of a core material (1) to form a cavity body (10), a component mounting step of fixing an electronic component (7) on a first conductive layer (4) disposed on a support (5) to form a component mounting body (9), a layup step of overlapping the component mounting body (9), the cavity body (10), an insulating layer (11), and a second conductive layer (12), and a substrate forming step of performing a lamination press by fully curing the film (2) and the insulating layer (11).

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a component-embedded substrate.

Background Art

[0002] A component-embedded substrate having electronic components such as electronic devices embedded therein is known (see, for example, Patent Document 1). In Patent Document 1, it is intended to reduce the volume for embedding components and embed components with high reliability. In the method for manufacturing a component-embedded substrate represented by Patent Document 1, a cavity for accommodating components is provided only in a core material, and then this cavity is filled with resin by a lamination press. At this time, the position of the electronic component is fixed with an adhesive tape such as a resin film.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, during the lamination press, since the position of the electronic component is held only by the adhesiveness of the adhesive tape, when the resin flows into the cavity during the lamination press, even if the amount of this resin is reduced, it may be difficult to reliably hold the position of the electronic component.

[0005] If the electronic component is fixed on the support in advance, such displacement of the electronic component does not occur, but it is also necessary to form a cavity in the insulating resin for flowing into the cavity (especially under the electronic component) during the lamination press. However, it is not possible to drill holes in the insulating resin that becomes the insulating layer alone, and such a manufacturing method has not been realized.

[0006] The present invention is considered in view of the above prior art, and an object thereof is to provide a method for manufacturing a component-mounted substrate capable of reliably holding the position of an electronic component within a cavity during lamination pressing.

Means for Solving the Problems

[0007] To achieve the above object, in the present invention, a film made of an insulating resin is melted and temporarily cured to be adhered to one surface of a substantially flat core material, and a cavity which is a through hole in which an electronic component is to be accommodated is formed to form a cavity body in a cavity body forming step, an electronic component is fixed and mounted on a first conductive layer disposed on a support to form a component-mounted body in a component mounting step, after the cavity forming step and the component mounting step, a lay-up step of overlapping the component-mounted body, the cavity body, an insulating layer, and a second conductive layer, and a substrate forming step of fully curing the film and the insulating layer and performing lamination pressing are provided, and a method for manufacturing a component-mounted substrate is characterized by this.

Effects of the Invention

[0008] According to the present invention, since lamination pressing is performed with an electronic component pre-mounted on a support, even when resin flows into the cavity, the electronic component does not shift in position. Since the cavity through which the electronic component is inserted during the lay-up step is formed in the core material and the film integrated therewith, it is possible to perform drilling on the film that flows under the electronic component during lamination pressing. At this time, since the film is adhered to the core material by temporary curing, the film does not shift during drilling, and the film does not shift during lamination pressing either.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

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Figure 7

Embodiment for Carrying Out the Invention

[0010] The method for manufacturing a substrate with built-in components according to the present invention is carried out along a flowchart as shown in FIG. 1. First, a cavity body forming step is performed (step S1). In this step, a film 2 made of an insulating resin is melted and temporarily cured and adhered to one surface of a core material 1 having a substantially flat plate shape, and a cavity 3 which is a through hole for accommodating an electronic component 7 is formed to form a cavity body 10.

[0011] First, a core 1 as shown in FIG. 2 is prepared. The core material 1 has a certain degree of rigidity and may be an insulating resin or a metal. Then, as shown in FIG. 3, the film 2 is adhered to the core material 1. The film 2 does not contain a glass cloth and may be any insulating resin, for example, an epoxy resin, a cyanate resin, or a silicone resin can be used. These resins may contain alumina or aluminum nitride. The insulating resin composed of these has a high viscosity (high tackiness), and it is difficult to perform drilling processing on it alone.

[0012] At this time, the film 2 is adhered to the core material 1 by being temporarily cured. As shown in FIG. 4, when the insulating resin is heated to a certain extent, the melt viscosity becomes low and it melts (80°C to 150°C in FIG. 4). Then, by cooling, the melt viscosity becomes high, and at this time, adhesiveness is generated in the film 2 and it adheres to the core material 1, and by further cooling, it is cured again and adhered to the core material 1. In this way, heating the insulating resin to the melt viscosity and then cooling and curing it once is called temporary curing.

[0013] Then, as shown in FIG. 5, a cavity 3, which is a through-hole penetrating the core material 1 and the film 2, is formed. In this way, the cavity body 10 is formed.

[0014] Next, a component mounting process is performed (step S2). This process is a process of fixing and mounting an electronic component 7 on a first conductive layer 4 disposed on a support 5 to form a component mounting body 9.

[0015] As shown in FIG. 6, first, a support 5 having a first conductive layer 4 on one surface is prepared. For example, a copper-clad laminate or a metal plate with a pattern formed in advance can be used. Terminals 8 of the electronic component 7 are mounted on the first conductive layer 4 via an adhesive 6. Thereby, the position of the electronic component 7 is surely fixed on the first conductive layer 4. In this way, the component mounting body 9 is formed. Note that there is no limitation on the order of performing the cavity body forming process and the component mounting process, and they may be performed separately or simultaneously.

[0016] Next, a layup process is performed (step S3). This process is a process of overlapping the component mounting body 9, the cavity body 10, the insulating layer 11, and the second conductive layer 12 after the cavity forming process and the component mounting process.

[0017] As shown in FIG. 6, the cavity body 10 is laid up on the component mounting body 9, the insulating layer 11 is laid up on the cavity body 10, and the second conductive layer 12 is laid up on the insulating layer 11. As the insulating layer 11, a material similar to the film 2 or a prepreg may be used.

[0018] Next, a substrate forming process is performed (step S4). This process is a process of fully curing the film 2 and the insulating layer 11 and performing a lamination press.

[0019] When performing the lamination press, the film 2 and the insulating layer 11 melt and flow into the cavity 3, and the component-embedded substrate 13 as shown in FIG. 7 is formed. In this component-embedded substrate 13, the film 2 is flowed so as to cover the lower side of the electronic component 7. At this time, the film 2 and the insulating layer 11 are further heated and fully cured. Full curing means heating the insulating resin to the melt viscosity once and then further heating it to completely cure it. Therefore, full curing is performed by heating to at least 180°C as shown in FIG. 4. This is because if it is heated to 180°C or higher, the insulating resin starts to cure again. At this time, the insulating resin is completely cured. The component-embedded substrate 13 is then formed with vias (not shown) as necessary to achieve electrical connection with the first conductive layer 4. Note that the support 5 has been removed.

[0020] According to the present invention, since the lamination press is performed with the electronic component 7 pre-mounted on the support 5, even when the resin flows into the cavity 3, the electronic component 7 does not shift. Since the cavity 3 through which the electronic component 7 is inserted during the layup process is formed with respect to the core material 1 and the film 2 integrated therewith, the film 2 that flows under the electronic component 7 during the lamination press can also be subjected to drilling. At this time, since the film 2 is adhesively bonded to the core material 1 by semi-curing, the film 2 does not shift during the drilling process, nor does the film 2 shift during the lamination press.

[0021] This can prevent the displacement of the electronic component 7 during the lamination press, and can also achieve the perforation process for the film 2, which was a problem associated with this. In particular, since this film 2 is adhered to the core material 1 by semi-curing, it can be made more fluid during the lamination press and can flow into the cavity 3. More specifically, during the lamination press, in order to uniformly flow the resin in the cavity 3, it is necessary to dispose an insulating resin layer in the vertical direction of the cavity 3. When the electronic component 7 is fixed on the support 5, it is necessary to perform a perforation process on the insulating resin layer disposed on the lower side of the cavity 3. Since the insulating resin layer is viscous, it was difficult to perform a perforation process on it alone, but by adhering it to the core material 1, it is possible to perform a perforation process together with the core material 1. At the time of this adhesion, by using adhesion by semi-curing, the film 2 will melt even during heating in the next lamination press process, and it can also be used as an insulating resin for substrate formation. As described above, the present invention not only enables the film 2 to be adhered to the core material 1 and perforated, but also adopts semi-curing as the adhesion method, thereby solving the problems unique to the substrate manufacturing process in which it is also used as a fluid insulating resin during subsequent lamination press.

[0022] Note that, although the above shows that the electronic component 7 is fixed on the support 5 by the adhesive 6, it is also applicable to the flip chip bonding structure as the component mounting body 9. In this case, the electronic component 7 is connected to the support 5 using solder paste or an alloy paste such as silver or copper as a bonding material.

Explanation of symbols

[0023] 1: Core material, 2: Film, 3: Cavity, 4: First conductive layer, 5: Support, 6: Adhesive, 7: Electronic component, 8: Terminal, 9: Component mounting body, 10: Cavity body, 11: Insulating layer, 12: Second conductive layer, 13: Substrate with built-in components

Claims

【Claim 1】 Temporary curing is performed by heating, melting, and then cooling a film made of an insulating resin on one surface of a substantially flat plate-shaped core material to cure it, and then bonding is carried out. A cavity body forming step of forming a cavity, which is a through hole in which an electronic component is to be accommodated, to form a cavity body; A component mounting step of fixing and mounting the electronic component on a first conductive layer disposed on a support to form a component mounting body; After the cavity forming step and the component mounting step, a layup step of overlapping the component mounting body, the cavity body, an insulating layer, and a second conductive layer; A method for manufacturing a substrate with built-in components, comprising a substrate forming step of heating and melting the film and the insulating layer, and further heating to cure them by full curing and performing a lamination press.

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