JP2000151112A - Wiring board and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase packaging density without reducing the sizes of electronic components by burying electronic components in the main body of a synthetic resin substrate. SOLUTION: Chip components 1 are put and positioned between inner faces of a pair of synthetic resin sheets 2. Next, a metal sheet 4 which is formed on one face with conical or pyramidal-bumps 3 are laid on an outer face of each of the synthetic resin sheets 2, with the face formed with the bumps facing the sheet 2. Then, this multilayer body is pressed in the direction shown by an arrow X under heat. By this pressing, the synthetic resin sheets 2 melt and enter spaces between the chip components 1, integrating the synthetic resin and the chip components 1. During this process, the bumps 3 are buried in the main body 5 of a substrate to be electrically connected to electrodes 1a. As a result, the synthetic resin sheets 2 and the metal sheets 4 are integrated into the main body 5 of a substrate. Thereafter, the metal sheets 4 are patterned into wiring patterns 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring board on which electronic components are mounted and a method for manufacturing the same.

[0002]

2. Description of the Related Art For example, capacitors and resistors have been used in digital devices such as personal computers as noise countermeasures. In recent years, with the development of mounting technology, most of electronic components such as resistors and capacitors have been replaced by chip components.

[0003] With the increase in the operating frequency of digital equipment, noise countermeasure components have been increasing, and the area of chip components occupying the wiring board has become a problem.

[0004] In a device having an analog circuit such as a mobile phone, individual resistors, capacitors, and inductors are required. In devices with remarkable miniaturization, such as mobile phones, it is not always sufficient to simply integrate the LSI and adopt a chip size package.

[0005] Although there is a tendency to reduce the size of chip components, it is difficult to secure connection reliability due to the reduction in size, and there is a problem in practical use.

[0006]

As described above, if the size of an electronic component is reduced in order to increase the mounting density of a wiring board, the connection reliability of the electronic component may decrease. Also, there is a limit to miniaturization of electronic components.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a wiring board and a method of manufacturing the same, which can improve the mounting density without reducing the size of the electronic component.

[0008]

According to a first aspect of the present invention, there is provided a wiring substrate having a wiring pattern formed on at least one surface thereof, wherein an electrically insulating substrate main body in which a first electronic component is built, and one end of which is provided. A conductive bump connected to the electrode of the first electronic component and having the other end electrically connected to the wiring pattern is provided.

According to the first aspect of the present invention, since the first electronic component built in the substrate does not reduce the mountable area of the substrate body, that is, only the area occupied by the first electronic component. The mounting density can be improved.

According to a second aspect of the present invention, in the first aspect, a second electronic component is mounted on the wiring pattern.

According to the second aspect of the present invention, since the second electronic component can be mounted on the surface of the substrate regardless of the first electronic component, the mounting density of the second electronic component can be improved.

According to a third aspect of the present invention, in the first aspect of the present invention, the surface of the substrate main body on which the wiring pattern is formed includes:
At least one insulating layer made of synthetic resin is joined, an upper wiring pattern is formed on the insulating layer, and the upper wiring pattern and the wiring pattern covered by the insulating layer penetrate the insulating layer. It is characterized by being electrically connected by the provided conductive interlayer bump.

According to the third aspect of the present invention, since the wiring pattern is formed on the substrate body and the insulating layer, the density of the wiring pattern can be increased.

According to a fourth aspect of the present invention, in the third aspect, the second electronic component is mounted on the wiring pattern of the outermost insulating layer.

According to the fourth aspect of the invention, not only the mounting density of electronic components can be improved, but also the wiring pattern can be increased in density, so that the outermost insulating layer wiring pattern has a large number of terminals. The second electronic component can be mounted.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a wiring board having a wiring pattern formed on at least one surface, the step of providing a first electronic component between a pair of synthetic resin sheets; The metal sheet is brought into contact with at least one of the resin sheets and the bumps formed on the plate surface are brought into contact and polymerized, and the polymer is heated and pressed to integrate a pair of synthetic resin sheets to form the substrate body and the bumps are formed. A step of embedding in the substrate body to connect to the electrode of the first electronic component; and a step of patterning the metal sheet to form a wiring pattern electrically connected to the bump. .

According to the fifth aspect of the present invention, since the first electronic component is embedded in the substrate main body, the substantial mounting density on the substrate main body can be improved.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the method further comprises the step of mounting a second electronic component on the wiring pattern.

According to the sixth aspect of the present invention, the mounting density of the electronic components on the substrate body can be improved.

According to a seventh aspect of the present invention, in the fifth aspect of the present invention, the step of bonding an insulating layer to the board surface of the substrate body on which the wiring pattern is formed, and the step of bonding an upper metal sheet to the insulating layer. The formed interlayer bump is brought into contact and polymerized,
Heating and pressurizing the insulating layer via the upper metal sheet to integrate the insulating layer with the substrate body and burying the interlayer bumps in the insulating layer to electrically connect to the wiring pattern of the substrate body. And patterning the metal sheet to form an upper wiring pattern electrically connected to the bumps.

According to the seventh aspect of the present invention, since the wiring patterns are formed on the substrate body and the insulating layer, respectively, the density of the wiring patterns can be increased.

According to an eighth aspect of the present invention, in the fifth aspect of the present invention, the step described in the seventh aspect is repeated a plurality of times.

According to the eighth aspect of the present invention, since the wiring patterns are formed on the substrate body and the plurality of insulating layers, the density of the wiring patterns can be increased.

According to a ninth aspect of the present invention, the method according to the seventh or eighth aspect further comprises the step of mounting the second electronic component on the upper wiring pattern formed on the outermost insulating layer. Features.

According to the ninth aspect of the present invention, not only the mounting density of electronic components can be improved, but also the density of the wiring pattern can be increased, and the wiring pattern of the outermost insulating layer has a large number of terminals. The second electronic component can be mounted.

[0026]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show a method of manufacturing a wiring board A according to a first embodiment of the present invention. First, as shown in FIG. 1A, a chip component 1 as a first electronic component is sandwiched between the inner surfaces of a pair of synthetic resin sheets 2, and as shown in FIG. Positioning is performed between the resin sheets 2.

The chip component 1 is a resistor, a capacitor, or the like.
0.5mm size) and 0603 and (0.6mm × 0.3
mm) are often used.

As the synthetic resin sheet 2, a thermosetting synthetic resin or a thermoplastic synthetic resin is used, for example, a BT resin or a PPE resin. Desirably, the synthetic resin sheet 2 has a thickness of one half or more of the thickness of the chip component 1. In this embodiment, the synthetic resin sheet 2 having substantially the same thickness as the chip component 1 is used. ing.

As a result, as described later, a pair of synthetic resin sheets 2 are softened by heating (in the case of a thermosetting resin) or melted by heating (in the case of a thermoplastic resin), and the chip component 1 is embedded in these synthetic resin sheets 2. Sometimes, the chip component 1 can be prevented from being exposed to the outside.

Next, as shown in FIG. 2A, a metal sheet 4 in which conical or pyramid-shaped bumps 3 are formed on one surface of each of the outer surfaces of a pair of synthetic resin sheets 2 is prepared.
After the surfaces on which the bumps 3 are formed are superposed and polymerized, the polymer is heated and pressed in the direction indicated by the arrow X in FIG.

When the polymer is pressurized, the synthetic resin sheet 2 melts and enters the gap between the chip components 1 shown in FIG. The bumps 3 formed on the metal sheet 4 are embedded in the substrate body 5 and
a. As a result, as shown in FIG. 2B, a substrate main body 5 in which the synthetic resin sheet 2 and the metal sheet 4 are integrated is formed.

The metal sheet 4 is made of a metal having a low electric resistance, such as copper or aluminum. In this embodiment, the metal sheet 4 has a thickness 18 which is used for a wiring pattern of a normal wiring board.
A μm electrolytic copper foil is used.

The bumps 3 are formed by printing a polymer type silver-based paste on the metal sheet 4. A mask is used for printing. The thickness is 10 as a mask
A metal mask having a hole having a diameter of several tens of μm or less at a predetermined position of a 0 μm stainless steel plate is used.

When the metal sheet 4 is integrated with the synthetic resin sheet 2 in this manner, the metal sheet 4 is patterned to form a wiring pattern 6 as shown in FIG. The patterning of the metal sheet 4 is performed by printing an etching resist on the metal sheet 4 and performing an etching process. Then, the resist is peeled off and removed with an alkaline aqueous solution, and as shown in FIG. The wiring board A on which the wiring pattern 6 is formed can be obtained.

FIGS. 3A to 3C show a process of manufacturing a multilayer wiring board B from the wiring board A shown in FIG. 2C, and FIG. An interlayer synthetic resin sheet 11 which is an insulating layer on both surfaces on which an is formed, and an upper metal sheet 13 having an interlayer bump 12 formed at a predetermined position on the plate surface are sequentially opposed.

Next, as shown in FIG. 2B, the interlayer synthetic resin sheet 13 and the upper metal sheet 13 are polymerized on the substrate body 5 and the polymer is heated while heating the polymer. To the direction indicated by the arrow Y.

As a result, the interlayer synthetic resin sheet 13 is melted and integrated with the substrate main body 5, and the interlayer bumps 12 enter the interlayer synthetic resin sheet 13 and electrically connect with the wiring patterns 6 of the substrate main body 5. Connected.

When the interlayer bump 12 is electrically connected to the wiring pattern 6, the upper metal sheet 13 is etched to form the upper wiring pattern 14, so that the wiring patterns 6, 14 have a four-layer structure. Multilayer wiring board B
Can be configured.

Then, for example, a ball grid array package 15 is mounted as a second electronic component on the upper wiring pattern 14 of the multilayer wiring board B as shown by a chain line in FIG. 3C.

The interlayer bumps 1 are formed on the upper metal sheet 13.
2 and the method of patterning the upper metal sheet 13 may be performed in the same manner as when the wiring board A is formed.

As described above, since the chip component 1 as the first electronic component is embedded in the substrate body 5, the chip component 1 is formed on the surface of the multilayer wiring board B on which the upper wiring pattern 14 is formed. Need not be implemented. for that reason,
Since the entire board surface of the multilayer wiring board B can be used for mounting the second electronic component, the mounting density of the entire multilayer wiring board B can be improved.

Moreover, the electrodes 1 a of the chip component 1 and the wiring patterns 6 can be electrically connected by the bumps 3 formed on the metal sheet 4 when forming the substrate body 5. That is, the electrode 1a of the chip component 1 and the wiring pattern 6 can be connected in the process of manufacturing the substrate body 5, and it is not necessary to perform a dedicated operation for connection. The efficiency can be improved.

The wiring density can be improved by forming the wiring patterns 6 and 14 as a multilayer wiring board B having a four-layer structure. Thus, even if the second electronic component is a ball grid array package 15 having a large number of terminals, it can be mounted on the multilayer wiring board B.

FIG. 4 shows a multilayer wiring board C according to a second embodiment of the present invention. In the multilayer wiring board C of this embodiment, the chip component 1 embedded in the substrate main body 5 is, for example, a decoupling capacitor, and the wiring pattern 6 a formed on one surface of the substrate main body 5 is a ground layer 31. Wiring pattern 6a formed on the other surface
Are used as the power supply layer 32.

The first and second surfaces of the substrate body 5 are respectively
The upper synthetic resin sheet 21, the first upper metal sheet (not shown), the second synthetic resin sheet 23, and the second upper metal sheet (not shown) are sequentially laminated. The first and second upper metal sheets are formed into wiring patterns 6b and 6c by etching.

Thus, the multilayer wiring board C has a six-layer structure in which three wiring patterns 6a, 6b, and 6c are formed on the upper and lower sides, respectively, and the lower wiring pattern 6c in the drawing has the second wiring pattern 6a. A flat package 25 as an electronic component is mounted, and a chip component 1 as a first electronic component and a ball grid array package 15 as a second electronic component are mounted on the upper surface.

The above-mentioned interlayer metal sheets are provided with interlayer bumps 22, 24, and these interlayer bumps 22, 24 are provided.
Thus, the three-layer wiring patterns 6a, 6b, and 6c are electrically connected to each other.

According to the wiring board C having such a configuration, the chip component 1 which is a decoupling capacitor embedded in the substrate body 5 is replaced with the wiring pattern 6a serving as the ground layer 31 and the wiring pattern 6a serving as the power supply layer 32. , The inductance between them can be reduced, and the function of the chip component 1 as a decoupling capacitor can be effectively exhibited.

FIG. 5 shows a multilayer wiring board D according to a third embodiment of the present invention. As in the second embodiment, the multilayer wiring board D of this embodiment has a six-layer structure in which three upper and lower wiring patterns are formed, and the wiring pattern 6a on the upper surface of the substrate body 5 is a ground pattern 33. Similarly, the wiring pattern 6 c of the third layer on the upper surface side is used as the signal line 34.

One of the plurality of chip components 1 embedded in the substrate main body 5 is a terminating resistor, and the terminating resistor 1 includes a wiring pattern 6 c serving as the ground pattern 33,
It is connected between the signal line 34 and the wiring pattern 6c.

By embedding the chip component 1 as an end point resistor in the substrate body 5, one electrode 1a of the chip component 1 is directly connected to the wiring pattern 6a serving as the ground pattern 33 via the bump 3. be able to.

Therefore, it is only necessary to connect the wiring pattern 6c to be the signal line 34 to the chip component 1, so that the connection to the chip component 1 becomes easy and the chip component 1 and the ground pattern 33 are connected. Since the connection length with the wiring pattern 6a can be almost eliminated, the electrical characteristics can be improved.

In the third embodiment, the same parts as those of the second embodiment shown in FIG.

The present invention is not limited to the above embodiments, but can be variously modified. For example, in each of the above embodiments, the wiring patterns were formed on both the upper and lower surfaces of the substrate body.
A configuration in which the wiring pattern is formed only on one of the surfaces may be used. When a multilayer wiring board is formed on the basis of such a substrate body, it goes without saying that the next insulating layer and the wiring pattern may be sequentially formed on one surface on which the wiring pattern is formed.

[0056]

As described above, according to the present invention, the electronic components are embedded in the substrate body made of synthetic resin, so that the mounting density of the electronic components is lower than when the electronic components are mounted only on the surface of the substrate. Can be improved.

Moreover, in the process of manufacturing the substrate main body, the wiring pattern can be electrically connected to the electronic components embedded in the substrate main body, so that the productivity can be improved.

[Brief description of the drawings]

FIGS. 1A and 1B are explanatory views showing a manufacturing process of a substrate main body according to a first embodiment of the present invention.

FIGS. 2A to 2C are explanatory views showing a manufacturing process of the substrate main body according to the first embodiment of the present invention.

FIGS. 3A to 3C are explanatory views showing the steps of manufacturing the multilayer wiring board according to the first embodiment of the present invention;

FIG. 4 is a sectional view showing a multilayer wiring board according to a second embodiment of the present invention;

FIG. 5 is a sectional view showing a multilayer wiring board according to a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Chip component (1st electronic component) 1a ... Electrode 2 ... Synthetic resin sheet 3 ... Bump 4 ... Metal sheet 5 ... Substrate body 6 ... Wiring pattern 11 ... Interlayer synthetic resin sheet 12 ... Interlayer bump 13 ... Upper layer metal sheet 15 ... Ball grid array package (second electronic component)

Claims (9)

[Claims] 1. A wiring board having a wiring pattern formed on at least one surface thereof, comprising: an electrically insulating substrate main body containing a first electronic component; and one end connected to an electrode of the first electronic component. A wiring board, comprising: a conductive bump electrically connected to the wiring pattern at the other end. 2. The wiring board according to claim 1, wherein a second electronic component is mounted on the wiring pattern. 3. At least one insulating layer made of synthetic resin is bonded to the surface of the substrate body on which the wiring pattern is formed, and an upper wiring pattern is formed on the insulating layer. 2. The wiring board according to claim 1, wherein the wiring pattern and the wiring pattern covered by the insulating layer are electrically connected by a conductive interlayer bump provided through the insulating layer. 4. The wiring board according to claim 3, wherein the second electronic component is mounted on the wiring pattern of the insulating layer located on the outermost side. 5. A method of manufacturing a wiring board in which a wiring pattern is formed on at least one surface, a step of providing a first electronic component between a pair of synthetic resin sheets, and at least one of the pair of synthetic resin sheets. The metal sheet is brought into contact with the bumps formed on the plate surface and polymerized,
Heating and pressurizing the polymer to integrate a pair of synthetic resin sheets to form a substrate body, embedding the bumps in the substrate body and connecting to the electrodes of the first electronic component, and patterning the metal sheet Forming a wiring pattern electrically connected to the bumps. 6. The method according to claim 5, further comprising a step of mounting a second electronic component on the wiring pattern. 7. A step of bonding an insulating layer to the board surface of the substrate main body on which the wiring pattern is formed, and contacting the upper metal sheet with the insulating layer by contacting an interlayer bump formed on the board surface to polymerize; Heating and pressurizing the insulating layer via the upper metal sheet to integrate the insulating layer with the substrate body and burying the interlayer bumps in the insulating layer to electrically connect to the wiring pattern of the substrate body. 6. The method according to claim 5, further comprising the steps of: patterning the metal sheet to form an upper wiring pattern electrically connected to the bumps. 8. The method according to claim 5, wherein the step according to claim 7 is repeated a plurality of times. 9. The method according to claim 7, further comprising the step of mounting the second electronic component on the upper wiring pattern formed on the outermost insulating layer. Method.