JP2003347722A - Multilayer electronic parts mounting substrate and its fabricating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer electronic parts mounting substrate with high reliability in electrical connection between the substrates. <P>SOLUTION: A fabricating method of a multilayer electronic parts mounting substrate having at least two substrates 11 to 15 and arranged with the electronic parts 3 between both of the substrates, comprises a process where a plurality of the substrates 11 to 15 are prepared in which conductor circuits 4 are provided on insulation substrates 5, and a process where substrates 12 to 15 are mounted with the electronic parts 3 to be arranged between the substrates 12 to 15 when laminating the substrates. A plurality of the substrates 11 to 15 are laminated and then the electronic parts are arranged between the substrates 11 to 15 and each of conductor circuits 4 provided on the substrates 11 to 15 that are adjacent to one another are mutually connected electrically by solder balls 2 serving as connecting terminals and thereafter the gaps between the substrates are sealed with resin 6. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate for mounting a multilayer electronic component in which electronic components are accommodated between substrates, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as a substrate for mounting multilayer electronic components,
As shown in FIG. 10, an electronic component 93 is mounted between an upper substrate 91 and a lower substrate 92 and sealed with a resin 94. The upper substrate 91 and the lower substrate 92 are electrically connected by solder balls 95. The electronic component 93 is a flip chip type and is mounted on the lower substrate 92.

In manufacturing the above-mentioned substrate for mounting a multilayer electronic component, a conductor circuit 900 is formed on an insulating substrate 905 as shown in FIG.

A conductor circuit 90 is provided on another insulating substrate 906.
2 is formed and used as a lower substrate 92. The electronic component 93 is joined to the conductor circuit 902 on the upper surface by solder 904.
The conductor circuit 902 on the periphery of the substrate includes solder balls 9
5 are joined. Next, the electronic component 93 and the conductor circuit 902 on the upper surface are sealed with the resin 94.

[0005] Thereafter, the upper substrate 91 is laminated on the lower substrate 92 and heat-pressed. At this time, the solder balls 95 joined to the lower substrate 92 are joined to the conductor circuit 900 of the upper substrate 91. Thus, the multilayer electronic component mounting board 96 shown in FIG. 10 is obtained.

[0006]

However, in the above-mentioned conventional method for manufacturing a substrate for mounting a multilayer electronic component, the upper substrate 9 is not provided.
Before laminating the substrate 1 and the lower substrate 92, the electronic component 93 is sealed with a resin 94. Therefore, the solder balls 95 of the lower substrate 92 may be covered with the resin 94 and may not be joined to the conductor circuit 900 of the upper substrate 91, and an electrical connection failure may occur between the upper substrate 91 and the lower substrate 92. May be.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a substrate for mounting a multilayer electronic component having high reliability of electrical connection between the substrates and a method of manufacturing the same.

[0008]

A first invention relates to a method for manufacturing a multilayer electronic component mounting substrate comprising at least two substrates, wherein electronic components are arranged between the two substrates. And a step of mounting electronic components to be arranged between the substrates upon lamination on the substrate, and then laminating the substrates,
The electronic component is disposed between the substrates, the conductor circuits provided on the adjacent substrates are electrically connected to each other by connection terminals, and then the gap between the substrates is sealed with a resin. (Claim 1).

In the first invention, after a plurality of substrates are stacked and conductive circuits of adjacent substrates are electrically connected to each other by connection terminals, a gap between the substrates is sealed with a resin. For this reason, the conductor circuits of the adjacent boards are reliably connected by the connection terminals without being disturbed by the resin.

A second invention is a multilayer electronic component mounting board in which at least two boards each having a conductor circuit are laminated and electronic components are arranged between the two boards, and is provided on the adjacent board. The conductor circuits are electrically connected to each other by connection terminals, the gap between the substrates is sealed with resin, and the height of the interval between the substrates is 10 to 15
It is a multilayer electronic component mounting substrate characterized by having a thickness of 0 μm.

In the second aspect, since the gap between the substrates is narrow as described above, a capillary phenomenon is likely to occur when the resin is sealed during the gap. Therefore, resin sealing can be easily performed.

A third aspect of the present invention is a multilayer electronic component mounting board in which at least two boards having conductive circuits are stacked and electronic components are arranged between the two boards. The conductor circuits are electrically connected to each other by connection terminals, the gap between the substrates is sealed with a resin, and the protruding amount of the electronic component from the substrate surface is 150 μm or less. A multilayer electronic component mounting board characterized by the following (claim 7).

In the third aspect of the present invention, since the amount of protrusion of the electronic component from the substrate surface is low as described above, the gap between the substrates can be narrowed to cause a capillary phenomenon of the resin.
Therefore, the resin can be easily sealed between the two substrates.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the first invention, a conductor circuit provided on a substrate has a joint portion for joining a connection terminal. These joints are pads, through holes, and the like.

The connection terminals include solder balls and pins. For example, when the connection terminal is a solder ball, the bonding portion of the conductor circuit is a pad. When the connection terminal is a pin, the joint is the inner wall of the through hole.

At least one of the substrates adjacent at the time of lamination has an electronic component to be accommodated between the substrates.
In sealing the gap between the substrates with the resin, the resin is filled between the two substrates so that the electronic components and the conductor circuits disposed between the two substrates are shielded from the outside air. For example, the entire gap between the two substrates is filled with resin, or the entire periphery of the gap between the substrates is surrounded by resin. In the latter case, when the entire periphery of the gap between the substrates is surrounded by the resin, it is preferable that the resin is filled at least to such an extent that the connection terminals are filled. This is because if the enclosing width of the resin is small, the effect of blocking moisture is weakened, and the electronic component may not be able to be protected from moisture.

The resin for sealing between the substrates includes a thermoplastic resin such as a polyolefin resin and a UV-curable resin such as an acrylate resin. Among them, epoxy resin is preferable from the viewpoint of adhesion reliability and the like.

In sealing the gap between the substrates with a resin, the stacked substrates are set upright in the direction perpendicular to the resin bath surface, and the open end side between the substrates is melted with a resin in a molten state. It is preferable to immerse in a bath (claim 2). As a result, the resin can be sealed in the gap between the two substrates without contaminating the conductor circuits formed on the two substrates with the resin. In this case, it is preferable that the opening end portion is in contact with the bath surface of the resin bath or soaked up to a maximum of 1.0 mm from the bath surface. This is because, if immersed more than 1.0 mm, the conductor circuit formed on the substrate may be stained by the resin bath.

It is preferable that the height of the interval between the adjacent substrates at the time of lamination is 10 to 150 μm.
When the gap between the two substrates is narrow as described above, the molten resin naturally enters the gap between the two substrates due to a capillary phenomenon. Therefore, it is easy to seal the resin between the two substrates.
If the gap between the substrates is less than 10 μm, there is a risk of occurrence. If it exceeds 150 μm, there is a possibility that the capillary phenomenon is unlikely to occur.

It is preferable that an amount of the mounted electronic component protruding from the surface of the substrate is not more than 150 μm. The protruding amount of the electronic component from the substrate surface is low as described above. For this reason, the gap between the substrates can be narrowed to 150 μm or less, and the molten resin can naturally enter between the two substrates by the capillary phenomenon as in the third aspect of the present invention. Therefore, it is easy to seal the resin between the two substrates. Here, the protruding amount of the electronic component from the substrate surface refers to the height of the electronic component measured from the surface of the substrate. Therefore, when the electronic component is mounted in the concave portion of the substrate, the height of the portion buried in the concave portion is excluded from the total height of the electronic component. When the projection amount of the electronic component from the substrate surface exceeds 150 μm, there is a possibility that the capillary phenomenon hardly occurs.

When electrically connecting the conductor circuits provided on the adjacent substrates with connection terminals,
It is preferable that the connection between the conductor circuit of the substrate and the connection terminal is performed by using solder. Even if there is a slight misalignment between the joints of the opposing conductor circuits at the time of lamination, the connection terminals can move the board by the surface tension of the molten solder to move the connection terminals and the conductor circuits to the correct position. An alignment effect occurs. In particular,
In the present invention, when the connection terminal is joined to the conductor circuit, no sealing resin is interposed between the two. For this reason,
The self-alignment effect is easily generated without being hindered by the resin. Therefore, alignment between the substrates is easy.

The substrate for mounting a multilayer electronic component according to the second invention is obtained by carrying out the invention of the third invention of the first invention. The multilayer electronic component mounting board of the third invention is obtained by performing the invention of claim 4 of the first invention.

[0023]

(Example 1) A substrate for mounting a multilayer electronic component and a method of manufacturing the same according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the multilayer electronic component mounting board of the present embodiment includes five boards 11 to 15, and an electronic component 3 is arranged between these boards. The uppermost substrate 11 has the conductive circuit 4, but has no electronic components mounted on either the upper surface or the lower surface thereof.
Substrates 12 to 15 stacked on the lower side of the uppermost stage have conductor circuits 4 and have electronic components 3 mounted thereon.

The substrates 11 to 15 are stacked so as to accommodate the electronic components 3. The conductor circuits 4 provided on each of the substrates 11 to 15 are electrically connected by solder balls 2 as connection terminals. The height H of the gap between the substrates 11 to 15 is 200 μm, and this gap is sealed with the resin 6. The protruding amount t of the electronic component 3 from the substrate surface is 50 μm.

As shown in FIGS. 1 and 2, the uppermost substrate 1
1 is provided with a conductor circuit 4 including pads 41 and 43, a conductor filling hole 42, and a wiring portion (not shown). The pad 41 formed on the lower surface of the substrate 11 is a bonding portion for bonding with the solder ball 2. The pad 43 formed on the upper surface of the substrate 11 is a part for bonding to an external motherboard. Between the pad 43 on the upper surface and the pad 41 on the lower surface,
It is electrically connected through the conductor filling hole 42 and the wiring portion.

As shown in FIGS. 1 and 3, the uppermost substrate 1
The conductor circuits 4 are also provided on the substrates 12 to 15 stacked on the lower side of 1. This conductor circuit 4 is composed of
A pad 44, a wiring portion 45, and a bonding pad 46 provided on the upper surface of the substrate 15, a pad 48 provided on the lower surface of the substrates 12 to 15, and a conductor filling hole 47 for electrically connecting the pads 44, 48 are provided. The electronic component 3 is joined to the bonding pad 46 by the solder 23. This electronic component 3 is a flip chip.

Next, a method of manufacturing the substrate for mounting a multilayer electronic component according to the present embodiment will be described. In manufacturing the uppermost substrate 11, as shown in FIG. 4, a conductor circuit 4 including conductor filling holes, pads, wiring portions, and the like is formed on an insulating substrate 5 by using a technique such as drilling, plating, exposure, and etching. Form. The insulating substrate 5 is a glass epoxy resin substrate. When fabricating the lower substrates 12 to 15 of the substrate 11, the conductor circuit 4 is formed on the insulating substrate 5 in the same manner as described above. As shown in FIGS. 4 and 3, on the upper surfaces of the substrates 12 to 15, the solder balls 2 are bonded to the pads 44 which are a part of the conductor circuit 4.

Next, the obtained substrates 11 to 15 are laminated in order from top to bottom. The solder balls 2 bonded to the upper surfaces of the substrates 12 to 15 are brought into contact with pads 41 and 48 formed on the lower surfaces of the substrates 11 to 14 thereon. As shown in FIG. 5, the solder ball 2 is partially melted by heating in this state, and the solder ball 2 is joined to the pads 41 and 48 that are in contact. Thus, the conductor circuits of the adjacent boards are electrically connected by the solder balls 2.

Next, as shown in FIG.
The substrates 11 to 15 joined together by the bath 6
0 in the vertical direction with respect to
The 0 side is immersed in a resin bath 61 in a molten state. At this time,
The gap opening end 10 is 1.0 mm from the bath surface 60 of the resin bath 61.
mm. If you leave this state for a while,
Due to the capillary action, the resin in the resin bath 61 is filled with the gap opening end 10.
From the inside, and eventually fills the entire gap between the substrates. Thereby, the space between the substrates 11 to 15 is sealed with the resin 6. Thus, the multilayer electronic component mounting board shown in FIG. 1 is obtained.

In this embodiment, after the conductor circuits 4 provided on the respective substrates 11 to 15 are connected by the solder balls 2, the substrates are sealed with the resin 6, so that the conductor circuits 4 are obstructed by the resin. Without fail, the connection is reliably made by the solder ball 2. Since the height T of the gap between the substrates 11 to 15 is narrow as described above, when the resin 6 is sealed in this gap,
Capillary phenomenon easily occurs. Therefore, resin sealing can be easily performed.

Each of the substrates 11 to 15 is connected by a solder ball 2. A part of the solder ball 2 is melted at the time of lamination heating and is joined to the mating pads 41 and 48. Therefore, the solder ball 2 has a self-alignment effect of being moved to a correct position by the surface tension of the molten solder even if there is a slight displacement between the solder ball 2 and the pads 41 and 48 on the other side. Further, at the time of solder ball bonding, since the sealing resin has not been interposed yet, the movement of the substrate is not hindered by the resin, and the self-alignment effect is easily generated. Therefore, alignment between the substrates is easy. When sealing the substrates with resin, the substrates 11 to 15 are
Only the gap opening end 10 is slightly immersed in the resin bath 61 while standing vertically to zero. Therefore, the resin sealing operation can be performed without soiling the conductor circuit 4.

In this embodiment, the portion where the solder balls 2 are bonded in advance is the substrate surface on which the electronic component 3 is mounted as shown in FIG. 4, but the surface on which the electronic component 3 is not mounted. There may be. The electronic components 3 mounted only on the lower substrate are disposed in the gaps between the substrates 11 to 15, but the electronic components mounted on both the upper and lower substrates may be disposed. Good.

(Embodiment 2) In this embodiment, when performing resin sealing between the substrates, the entirety of the substrates 11 to 15 connected by the solder balls 2 is placed in a resin bath 61 as shown in FIG. I'm soaking. The substrates 11 to 15 are arranged slightly inclined with respect to the bath surface 60, and gently dipped in the resin bath 61 in this state. Then, the air remaining between the substrates escapes from the gap opening end portion 10 and is filled with the resin. By providing a cutting area on one side of the outer shape in advance and deleting the cutting area after filling with the resin, it is possible to prevent the conductive circuit on the substrate surface from being contaminated by the resin. Also in this example, resin sealing between the substrates and alignment between the substrates can be easily performed.

Embodiment 3 In this embodiment, as shown in FIGS. 8 and 9, only the peripheral portion 71 between the substrates 11 to 15 is filled with the resin 6, and the central portion 72 is not filled with the resin. Resin 6
As shown in FIGS. 8 and 9, the solder balls 2 are filled until the solder balls 2 disposed on the substrates 12 to 15 are filled. In this example, as described above, the resin 6 is filled in the peripheral portion 71 between the substrates. Therefore, as in the case where the entire space between the substrates is filled with the resin, the resin at the peripheral portion 71 can suppress the invasion of moisture, and the electronic components 3 accommodated in the central portion 72
Can be protected from moisture.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a multilayer electronic component mounting board according to a first embodiment.

FIG. 2 is a plan view of an uppermost substrate according to the first embodiment.

FIG. 3 is a plan view of a substrate other than the uppermost substrate in the first embodiment.

FIG. 4 is a cross-sectional view of each substrate before lamination in Example 1.

FIG. 5 is a cross-sectional view of the boards connected by solder balls in the first embodiment.

FIG. 6 is an explanatory diagram of a resin sealing method between substrates in the first embodiment.

FIG. 7 is an explanatory view of a method of sealing a resin between substrates in Embodiment 2.

FIG. 8 is a sectional view of a multilayer electronic component mounting board according to a third embodiment.

FIG. 9 is an explanatory view showing a resin-sealed state between substrates in Example 3.

FIG. 10 is a cross-sectional view of a conventional multilayer electronic component mounting substrate.

FIG. 11 is an explanatory view showing a method of manufacturing a multilayer electronic component mounting board in a conventional example.

[Explanation of symbols]

11-15. . . substrate, 2. . . Solder balls, 3. . . Electronic components, 4. . . Conductor circuit, 41, 43, 44, 48. . . pad, 5. . . Insulating substrate, 6. . . resin,

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H05K 1/18 H05K 3/46 N 3/28 Q 3/46 H01L 25/08 Z F term (reference) 5E314 AA24 BB02 BB13 CC04 FF05 FF21 GG01 5E336 AA04 AA13 AA16 BB03 BB15 BC31 CC32. GG25 GG28 GG40 HH07

Claims (7)

[Claims] 1. A method for manufacturing a multilayer electronic component mounting substrate comprising at least two substrates, wherein electronic components are arranged between the two substrates, comprising the steps of: preparing a plurality of substrates having conductive circuits provided on an insulating substrate; Mounting electronic components to be arranged between the substrates on the substrate, and then laminating the plurality of substrates, disposing the electronic components between the substrates, and The conductor circuits provided on the substrate are electrically connected to each other by connection terminals,
Thereafter, the gap between the substrates is sealed with a resin. 2. The method according to claim 1, wherein, when the gap between the substrates is sealed with a resin, the stacked substrates are set upright in a direction perpendicular to a resin bath surface, and an opening end side between the substrates is provided. Immersing the substrate in a molten resin bath. 3. The method for manufacturing a multilayer electronic component mounting board according to claim 1, wherein a height of an interval between the adjacent substrates at the time of lamination is 10 to 150 μm. 4. The electronic device according to claim 1, wherein the mounted electronic component has a protrusion amount of 150 μm from the substrate surface.
A method for manufacturing a multilayer electronic component mounting board, characterized by the following. 5. The method according to claim 1, wherein:
When electrically connecting the conductor circuits provided on the adjacent substrates with connection terminals, the conductor circuits of the substrate and the connection terminals are bonded using solder. Of manufacturing a multilayer electronic component mounting substrate. 6. A multilayer electronic component mounting board in which at least two boards each having a conductor circuit are stacked and an electronic component is arranged between both boards, wherein said conductor circuits provided on adjacent boards are connected to each other. Are electrically connected by connection terminals, and the gap between the substrates is sealed with resin.
A multilayer electronic component mounting substrate, wherein the height of the interval between the substrates is 10 to 150 μm. 7. A multilayer electronic component mounting board in which at least two boards each having a conductor circuit are stacked and an electronic component is arranged between both boards, wherein said conductor circuits provided on adjacent boards are connected to each other. Are electrically connected by connection terminals, and the gap between the substrates is sealed with resin.
The amount of protrusion of the electronic component from the surface of the substrate is 150
A multilayer electronic component mounting substrate having a thickness of not more than μm.