JP2002009231A - Semiconductor device - Google Patents

Abstract

(57) [Problem] To use a flexible circuit board with a short delivery time, low cost, and high reliability, which has a high degree of freedom in the types, combinations, and wirings of ICs and is excellent in ease of assembling into three dimensions. Provided is a semiconductor device having a three-dimensional mounting module configuration. A flexible circuit board has a first region including a mounting portion and a second region including only a wiring portion, and the first region on which electronic components are mounted.
First, the second region 112 is folded. The opening 13 is
When bending in the direction of arrow B, it contributes to stress relaxation.
The insertion bar 15 is inserted so that the second region 112 has a gentle curve in the bent shape of the flexible circuit board 11 in the direction of arrow B. The flexible circuit board 11 is folded and laminated and fixed together with a laminated support 14 for protecting the electronic components 121 and 122.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device using a flexible circuit board, and more particularly to a semiconductor device constituting a three-dimensional mounting module which is required to be inexpensive, small, thin, and lightweight.

[0002]

2. Description of the Related Art Unlike a rigid circuit board, a flexible circuit board has the advantage of being soft and deformable. This is advantageous for high-density mounting of ICs and downsizing of modules. That is, the flexible circuit board has a TC
P (Tape Carrier Package) and COF (Chip On Flexib)
le or Film), and is particularly indispensable for miniaturization of various media devices.

[0003] In addition, the technology of the system LSI is also important in realizing the miniaturization, thinning, and weight reduction of media devices.
The system LSI has steadily advanced the technology for one chip while taking in the LSI of the peripheral circuit. But,
In the development of a system LSI, a long development period and an increase in chip cost due to a mixture of heterogeneous processes are caused. As a result, the current situation is that short delivery times and low costs required by media devices cannot be satisfied.

[0004]

For the above-mentioned reasons, 3
There has been an increasing demand for implementation of system functions mainly in three-dimensional implementation, and integration of system LSI and implementation technology has become important. In the media equipment industry, the degree of growth is determined by frequency (higher speed) and delivery time (short delivery time). For this reason, the connection length and the wiring length of the built-in LSI must be reduced as much as possible by mounting and package technology. For these reasons, various ideas have been devised for the three-dimensional mounting module and the three-dimensional mounting module has entered the stage of practical use.

For example, conventionally, a three-dimensional mounting module is
The following configuration is in practical use or in practical use.
First, as (A), TCP (Tape Carrier Package)
And connection between chip stacks is achieved by outer leads of TCP. Also, as (B), a wiring frame is provided between the stacks of TCPs to achieve connection between the chip stacks. In addition, as (C), there are various techniques such as stacking at a chip level and connecting the chip stacks with a conductive material.

According to such a conventional technique, it is necessary to electrically connect the chip stacks via some kind of interposer. The connection configuration between the interposers includes an external connection configuration as in the above (A) and (C) and an internal connection configuration as in the above (B).
In any case, there are various restrictions such as the size of the IC to be combined, the position of the IC terminal, and the wiring design. Therefore, as a three-dimensional mounting module, the degree of freedom of the types and combinations of ICs is narrow, and a lot of design time is required due to restrictions, and short delivery time and low cost required by media devices cannot be satisfied.

The present invention has been made in view of the above circumstances, and has a high degree of freedom in the type, combination, and wiring of ICs, and is excellent in ease of assembling into three dimensions, and has a short delivery time.
3 using a low cost, highly reliable flexible circuit board
An object of the present invention is to provide a semiconductor device having a three-dimensional mounting module configuration.

[0008]

According to the present invention, there is provided a semiconductor device comprising:
A flexible circuit board having a first area and a second area and formed so that at least the first area and the second area are folded; an external terminal provided on the flexible circuit board; and the flexible circuit board. An opening provided at a position corresponding to the bending, a plurality of electronic components mounted corresponding to the mounting portion of the flexible circuit board, and a predetermined outer frame provided to protect the electronic component, respectively. Comprising a laminated support, wherein the first region is outside the flexible circuit board,
The electronic component is laminated and fixed together with the laminated support with the second region being bent inward.

According to the semiconductor device of the present invention, the flexible circuit board has a form in which the second region is folded over the first region, and the effective area of the wiring region is increased. In addition, the form in which the first region and the second region are folded over has a configuration in which the wiring region is hidden by the mounting portion. Thereby, the laminated form of the electronic component with the laminated support is made compact.

[0010]

1A to 1C are schematic views showing the structure of a semiconductor device according to a first embodiment of the present invention in the order of assembly. As shown in FIG. 1A, the flexible circuit board 11 has a first region 111 mainly including a mounting portion and a second region 112 mainly including a wiring portion. The flexible circuit board 11 is formed of a soft base material such as polyimide that can be freely bent.
Although not shown, the first region 111 and the second region 112 have a predetermined conductive pattern formed under the protective film.

Also, a flexible circuit board 1 (not shown)
External terminals for mounting on the main substrate are provided on the back side of the device 1. For example, an array type electrode such as a BGA (Ball Grid Array) can be considered.

In the flexible circuit board 11, the first
In the area 111, electronic components 121 and 122 are mainly mounted face-down. Electronic components 121, 12
2 is a memory chip, a system LSI chip, a control unit, and various other types.

As such face-down mounting of the electronic components 121 and 122, for example, soldering between the bump electrodes of the electronic components and a predetermined conductive pattern of the flexible circuit board 11 can be considered. A connection using an ACF (anisotropic conductive film) is also conceivable. That is,
Bump electrode of each electronic component and flexible circuit board 1
An ACF (anisotropic conductive film) is interposed between the first conductive pattern and the first conductive pattern, and then heat-pressed. Thereby, the ACF
The necessary electrical connection between the electronic components 121 and 122 and the conductive pattern of the flexible circuit board 11 is obtained by the conductive particles therein. In addition, various methods such as ACP (anisotropic conductive paste) bonding, NCP bonding for obtaining electrical connection by contraction force of insulating resin, and metal eutectic bonding such as gold-gold and gold-tin using bumps can be considered. In some cases, face-up mounting using a wire bonding method is also applicable. Furthermore, mounting of an ultra-thin IC package is conceivable, and the mounting form of the electronic component is not particularly limited.

As shown in FIG. 1B, the flexible circuit board 11 is bent at the first bending position shown in FIG. 1A (arrow A). That is, the first area 111
The second region 112 is folded. At this time, the second region 112 is formed so that the second region 112 does not protrude from the first region 111.
The area 112 has a smaller area than the first area 111.

The flexible circuit board 11 has an opening 13 at a position corresponding to the bending. The opening 13 is provided in expectation of an action of reducing the bending stress of the flexible circuit board 11. In particular, FIG.
In the second bending position shown in (a), that is, at the time of bending in the direction of arrow B, the effect of stress reduction is high.

If the opening 13 is not provided, the stress of the flexible circuit board 11 becomes considerably strong as the center position of the bending, and there is a concern that the conductor may be peeled off or cut off even around the flexible circuit board 11. Therefore, it is very difficult to form a wiring pattern or the like even if the opening 13 is not provided. Therefore, the opening 13 is provided to improve the reliability of the bent form of the flexible circuit board 11.

Further, an insertion bar 15 is provided as a bending relieving member for the second region 112. Insert bar 15
In the bent shape of the flexible circuit board 11 in the direction of arrow B, the second region 112 is inserted so as to have a gentle curve.

The insertion bar 15 is used for the flexible circuit board 1.
If the reliability in 1 is sufficient, deployment is not necessarily required. However, with this insertion bar 15,
The bending stress of the second region 112 is surely reduced and contributes to high reliability. The insertion bar 15 also has the advantage that the position of the bending can be easily determined.

The insertion bar 15 is connected to the flexible circuit board 1.
A configuration is such that a part that contacts with 1 is attached with a double-sided tape or the like. Alternatively, the flexible circuit board 11 may be removed after the bent form is determined.
This contributes to product weight reduction.

As shown in FIG. 1C, the flexible circuit board 11 is finally bent in the direction of arrow B to make it compact. That is, the first region 111 is outside,
The electronic components 121 and 122 are bent so that the second region 112 is on the inside, and the laminated form of the electronic components 121 and 122 is fixed. For this purpose, in this example, the electronic components 121 and 122 are folded together with the laminated support 14 that protects them (FIG. 1A).

Referring again to FIG. 1A, the flexible circuit board 11 has an electronic component 12 in a first region.
1, 122, the so-called spacers 14 (14
a, 14b) are fixed. The spacers 14 each have an outer frame having a predetermined thickness to protect the stack of the electronic components 121 and 122.

As for the spacer 14, an integral type is adopted here. That is, 14 as a substantial spacer
An extremely thin region 141 exists between a and 14b. The thin region 141 forms a bendable region for at least a compact bending form as shown in FIG. Thereby, the integrated spacer 1
4 is fixed on the first region 111 of the flexible circuit board 11.

It is conceivable that the integrated spacer 14 is formed of, for example, a molded product of a polyimide resin in consideration of reflow heat resistance, or a combination tape made of a composite processed product obtained by laminating a plurality of double-sided tapes.
In addition, a metal member (for example, aluminum, stainless steel, copper, or the like) can be used as long as it does not constitute an integral type. In that case, insulation treatment may be performed as needed.

The substantial spacers (14a, 14b)
Each of the electronic components (121, 122) to be mounted has a thickness that does not hinder stacking. Also, the thin region 141
Is preferably as thin as possible because it includes a bent portion, and has a thickness of, for example, about 0.1 to 0.2 mm. If it is not difficult to handle as an integral spacer 14, it may be thinner.

If the spacer 14 is a molded product of the above polyimide resin, the back side (not shown) is fixed on the flexible circuit board 11 via an adhesive member such as a double-sided tape or an adhesive. Further, an adhesive member such as a double-sided tape or an adhesive is disposed on the laminated fixed side of the spacers 14a and 14b. Thereby, as shown in FIG. 1C, each of the electronic components 121, 12
2 are fixed when they are stacked.

If the spacer 14 is the above-mentioned combination tape, the back side (not shown) is fixed on the flexible circuit board 11 via an adhesive member of a double-sided tape.
Further, the adhesiveness of the double-sided tape is secured in advance on the laminated fixed side of the spacers 14a and 14b. Thereby, the electronic component 1
21 and 122 are fixed when they are stacked.

Although not shown, the electronic component 12
It is conceivable that some small electronic components (peripheral elements) related to 1,122 are also mounted. For example, a chip capacitor or a chip resistor is used. Furthermore, a crystal required for clock generation may be mounted. The spacers 14 that have been changed to an appropriate shape for mounting these peripheral elements
Protected by

FIG. 2 is a sectional view taken along line F2-F2 in FIG. 1, and FIG. 3 is a sectional view taken along line F3-F3 in FIG. According to FIGS. 2 and 3, the electronic components 121 and 122 are mounted face-down on the mounting portion 111 of the flexible circuit board 11 by the appropriate method described above. On the back surface of the flexible circuit board 11, an array type electrode BGA is shown.

FIG. 2 shows the details of the shape of the spacer 14 and the insertion bar 15 for alleviating the bending stress of the flexible substrate. That is, the insertion bar 1
Adjacent sides of the spacers 14a and 14b on the side where 5 is provided are shaved in height by the insertion bar 15 provided.

According to FIGS. 2 and 3, the spacer 14 is provided with an adhesive member (double-sided tape, adhesive, etc.) ADH at a predetermined position or on the entire contact surface. Thereby, the laminated form of the electronic components 121 and 122 is fixed together with the spacer 14.

According to the configuration of the first embodiment, in the flexible circuit board 11, the first region 1 including the mounting portion
11 is divided into two such that the second region 112 of the wiring portion is folded. Thereby, the effective area of the pattern wiring of the second region 112 can be widened. This allows
As the electronic components 121 and 122, mounting of a multi-terminal IC can be expected.

In addition, the form in which the first region 111 and the second region 112 are folded is such that the wiring portion is hidden by the mounting portion. Thereby, the electronic component 12 with the spacer 14
The compactness of 1,122 laminated forms is achieved.

The flexible circuit board 11 can be formed in a substantially rectangular shape. Therefore, the co-extraction efficiency of the flexible base material is very good. As a result, the cost of the flexible base material is reduced, which contributes to a reduction in product cost.

Further, as described above, the opening 13 is provided at a position corresponding to the bending of the flexible circuit board 11, and the insertion bar 15 is provided to positively ease the bending of the flexible circuit board 11. Has been made. Thereby, the flexible circuit board 11
Local bending stress is reduced. As a result, the reliability is further improved with respect to defects such as peeling or cutting of the conductor.

FIG. 4 is a sectional view showing the structure of a semiconductor device according to a second embodiment of the present invention, which is similar to FIG. The same parts as those in the first embodiment are denoted by the same reference numerals. The second embodiment differs from the first embodiment mainly in the following two points.

First, the external terminal portion is a connector terminal CNCT instead of the array type electrode BGA. The connector terminal CNCT extends forward and is not formed in a cross section.

Second, a hook claw 145 for fitting and a claw receiving portion 146 into which the claw 145 is fitted are provided at a predetermined portion of the spacer 14. As a result, the connecting points of the spacers 14 are fixed by the claw 145 and the claw receiving portion 146.

Also, a state in which the insertion bar (15) is removed is shown. That is, the second region 11 of the bent flexible circuit board 11 supported by the insertion bar (15)
2 is securely pressed in the region D sandwiched between the spacers 14 and has a fixed shape. If necessary, the region D may be fixed by an adhesive member. If the insertion bar (15) is removed, a corresponding reduction in weight can be expected. Of course, as shown in FIG. 2, the configuration may be such that the insertion bar 15 is kept inserted.

According to the above configuration, in addition to the effects shown in the first embodiment, the three-dimensional module product has an effect of excellent reworkability. That is, the connector terminal CN
The CT can be easily removed, and the claw 145 and the claw receiving portion 146 can be easily formed to have easily removable structures. However, in the configuration of the connector terminal CNCT, the developed form of the flexible circuit board 11 does not become rectangular, and the cooperating efficiency in the flexible base material is reduced.

The configuration of the connector terminal CNCT may be adopted in the configuration of the first embodiment. Also,
The configuration of the claw 145 and the claw receiving portion 146 may be adopted in the configuration of the first embodiment. Further, the spacer 14 is shown as an integral type, but is not limited to this, and a separate type may be used. By the way, if the spacer 14 is integrated, it contributes to the improvement of the assemblability.

FIG. 5 shows a main configuration of a semiconductor device according to a third embodiment of the present invention.
This is a modification. In the first embodiment, the first region 111
Has a configuration in which the second region 112 includes only the wiring portion and does not include the mounting portion. However, the present invention is not limited to this. As in the third embodiment, a mounting section may be set in the second area 112. Element (electronic parts 121, 1)
If the layouts 22) do not overlap each other, there is no problem in the bent form. The spacer (not shown) may have a minimum height to protect each element (electronic components 121 and 122). A separate type may be adopted, or an integral type which overlaps the entire area of the flexible circuit board 11 (excluding the opening 13) may be adopted.

FIG. 6 shows a main configuration of a semiconductor device according to a fourth embodiment of the present invention.
This is a modification. A plurality of elements (IC chips, peripheral elements, etc.) are laid out so as not to overlap each other, following the first modification. In this way, there is no problem in the bent form. The spacer (not shown) may have a minimum height for protecting each element. A separate type or an integrated type that overlaps the entire area of the flexible circuit board 11 (excluding the opening 13) may be used.

As described above, according to each of the embodiments, the present invention provides a three-dimensional mounting module having a high degree of freedom in the types, combinations, and wirings of ICs, and excellent three-dimensional assembling easiness. In consideration of the fact that a plurality of peripheral elements can be mounted, it is possible to make an optimal module in terms of electrical characteristics. As a result, short-term, low-cost module commercialization required by media devices can be expected.

[0044]

As described above, according to the semiconductor device of the present invention, in the flexible circuit board, the second region is divided into the first region and the second region is folded.
The effective area of the wiring portion is wide, and a configuration in which these wiring portions are hidden by the mounting portion is achieved. Also, measures to alleviate bending stress can be easily deployed. Thereby, the lamination form of the electronic component including the spacer is downsized with high reliability.

As a result, three-dimensional mounting using a flexible circuit board with a short delivery time, low cost, and high reliability, which has a high degree of freedom in the type, combination, and wiring of ICs and is excellent in ease of assembling in three dimensions. A semiconductor device having a module configuration can be provided.

[Brief description of the drawings]

FIGS. 1A to 1C are schematic views showing the configuration of a semiconductor device according to a first embodiment of the present invention in the order of assembly.

FIG. 2 is a sectional view taken along line F2-F2 in FIG.

FIG. 3 is a sectional view taken along line F3-F3 in FIG.

FIG. 4 shows a configuration of a semiconductor device according to a second embodiment of the present invention in a cross-sectional view according to FIG.

FIG. 5 shows a main configuration of a semiconductor device according to a third embodiment of the present invention, which is a first modification of the layout of electronic components.

FIG. 6 shows a main configuration of a semiconductor device according to a fourth embodiment of the present invention, which is a second modification of the layout of electronic components.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Flexible circuit board 111 ... 1st area | region (mounting part) 112 ... 2nd area | region (wiring part) 121, 122 ... Electronic component 13 ... Opening 14 ... Spacer 141 ... Spacer thin area 145 ... Claw 146 ... Claw receiving part 15 Insert bar ADH Adhesive member BGA Array type electrode CNCT Connector terminal

Claims (2)

[Claims] A flexible circuit board having at least a first area and a second area formed such that at least the first area and the second area are folded; and an external terminal provided on the flexible circuit board. In the flexible circuit board, an opening provided at a position corresponding to the bending, a plurality of electronic components mounted corresponding to the mounting portion of the flexible circuit board, each provided to protect the electronic component A laminated support constituting a predetermined external frame, wherein the flexible circuit board is bent so that the first region is on the outside and the second region is on the inside, and the electronic component is attached with the laminated support. A semiconductor device, which is stacked and fixed. 2. The semiconductor device according to claim 1, further comprising a bending relaxation member in a second region of the flexible substrate.