JP3888037B2 - Semiconductor device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor device using a flexible circuit board, and more particularly, to a semiconductor device that constitutes a three-dimensional mounting module that is inexpensive and is required to be reduced in size, thickness, and weight.
[0002]
[Prior art]
Unlike rigid circuit boards, flexible circuit boards have 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 is used for TCP (Tape Carrier Package), COF (Chip On Flexible or Film), and the like, and is particularly indispensable for miniaturization of various media devices.
[0003]
In addition, system LSI technology is also important for realizing miniaturization, thinning, and weight reduction of media devices. The system LSI is steadily advancing the technology to one chip while incorporating the peripheral circuit LSI. However, in the development of a system LSI, a long development period and a chip cost increase due to mixing different types of processes are caused. As a result, the short delivery time and low cost required by media devices cannot be satisfied.
[0004]
[Problems to be solved by the invention]
For the reasons described above, there has been an increasing demand for system function mounting mainly for three-dimensional mounting, and integration of system LSI and mounting technology has become important. In the media equipment industry, the degree of growth is determined by frequency (high speed) and delivery (short delivery). For this reason, the connection length and wiring length of the built-in LSI must be shortened as much as possible depending on the mounting and package technology. For these reasons, the three-dimensional mounting module has been put into practical use after being devised in various ways.
[0005]
For example, the following configuration of a three-dimensional mounting module has hitherto been put into practical use or in a practical use stage. First, as (A), a TCP (Tape Carrier Package) is stacked, and the connection between chip stacks is achieved by a TCP outer lead. Further, as (B), a wiring frame is provided between the TCP stacks to achieve connection between the chip stacks. In addition, as (C), there are various techniques such as stacking at the chip level and connecting the chip stacks with a conductive material.
[0006]
According to such a conventional technique, chip stacks need to be electrically connected via some interposer. Such interposer connection configurations include an external connection configuration such as (A) and (C) above and an internal connection configuration such as (B) above. In any case, there are various restrictions such as the size of the IC to be combined, the IC terminal position, and the wiring design. Therefore, as a three-dimensional mounting module, the range of freedom of IC types and combinations is narrow, and design time is increased due to restrictions, so that the short delivery time and low cost required by media equipment cannot be satisfied.
[0007]
The present invention has been made in consideration of the above-mentioned circumstances, has a high degree of freedom in the types, combinations and wirings of ICs, and has excellent ease of assembly in three dimensions, quick delivery, low cost, and high reliability. It is an object of the present invention to provide a semiconductor device having a three-dimensional mounting module configuration using a flexible flexible circuit board.
[0008]
[Means for Solving the Problems]
A semiconductor device according to the present invention includes a flexible circuit board having a first area and a second area, and at least the first area and the second area being folded, and an external terminal provided on the flexible circuit board. A plurality of electronic components mounted on the mounting portion of the flexible circuit board, and a predetermined outer frame provided to protect the electronic components. And the laminated support provided on the flexible circuit board, wherein the first region is a region including the mounting portion, and the second region is a region not including the mounting portion. The flexible circuit board is folded so that the first region is on the outside and the second region is on the inside. That it is fixed, characterized by.
[0009]
According to the semiconductor device of the present invention, the flexible circuit board has a configuration in which the second region is folded over the first region, and the effective area of the wiring region is widened. In addition, the form in which the first region and the second region are folded is a configuration in which the wiring region is hidden in the mounting portion. Thereby, the lamination | stacking form of the said electronic component with the said lamination | stacking support body is compactized.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1A to 1C are schematic views showing the configuration of the semiconductor device according to the 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 including a wiring portion. The flexible circuit board 11 is made of a soft base material such as polyimide that can be bent freely. In the first region 111 and the second region 112, although not shown, a predetermined conductive pattern is formed under the protective film.
[0011]
In addition, an external terminal part for mounting on the main board is provided on the back side of the flexible circuit board 11 (not shown). For example, an array type electrode such as BGA (Ball Grid Array) is conceivable.
[0012]
In the flexible circuit board 11, electronic components 121 and 122 are mainly mounted face down in the first region 111. The electronic components 121 and 122 may be a memory chip, a system LSI chip, a control unit, and various other types.
[0013]
As such face-down mounting of the electronic components 121 and 122, for example, soldering between the bump electrode of each electronic component and a predetermined conductive pattern of the flexible circuit board 11 is conceivable. Moreover, the connection by ACF (anisotropic conductive film) is also considered. That is, ACF (anisotropic conductive film) is interposed between the bump electrode of each electronic component and a predetermined conductive pattern of the flexible circuit board 11 and thermocompression bonded. Thereby, the necessary electrical connection between each of the electronic components 121 and 122 and the conductive pattern of the flexible circuit board 11 is obtained by the conductive particles in the ACF. In addition, various conceivable methods such as ACP (anisotropic conductive paste) bonding, NCP bonding in which electrical connection is obtained by the contraction force of the insulating resin, and metal eutectic bonding such as gold-gold and gold-tin by bumps are possible. In some cases, face-up mounting using a wire bonding method is also applicable. Furthermore, it is possible to mount an ultra-thin IC package, and the mounting form of the electronic component is not particularly limited.
[0014]
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 second region 112 is folded over the first region 111. At this time, the second region 112 has a smaller area than the first region 111 so that the second region 112 does not protrude from the first region 111.
[0015]
The flexible circuit board 11 is provided with an opening 13 at a location corresponding to the bending. The opening 13 is provided in anticipation of the action of reducing the bending stress of the flexible circuit board 11. In particular, the stress relieving effect is high at the time of bending in the second bending position shown in FIG.
[0016]
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 even around it. Therefore, it is very difficult to form a wiring pattern 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.
[0017]
Further, an insertion bar 15 is provided as a bending relaxation member for the second region 112. 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 arrow B direction.
[0018]
If the insertion bar 15 has sufficient reliability in the flexible circuit board 11, the insertion bar 15 is not necessarily required to be provided. However, the insertion bar 15 reliably reduces the bending stress of the second region 112 and contributes to high reliability. The insertion bar 15 also has an advantage that the position of bending is easily determined.
[0019]
The insertion bar 15 is configured to be affixed with a double-sided tape or the like at a part in contact with the flexible circuit board 11. Or you may remove, if the bending form of the flexible circuit board 11 becomes settled. This contributes to weight reduction of the product.
[0020]
As shown in FIG. 1C, the flexible circuit board 11 is finally bent in the direction of the arrow B to be compact. That is, the stacked configuration of the electronic components 121 and 122 is fixed by bending the first region 111 to the outside and the second region 112 to the inside. Therefore, in this example, it is folded with the laminated support body 14 protecting the electronic components 121 and 122 (FIG. 1A).
[0021]
Referring to FIG. 1A again, the flexible circuit board 11 is fixed with a laminated support body of electronic components 121 and 122, so-called spacers 14 (14a and 14b), in the first region. The spacer 14 has an outer frame with a predetermined thickness in order to protect the lamination of the electronic components 121 and 122.
[0022]
As for the spacer 14, an integral type is adopted here. That is, an extremely thin region 141 exists between 14a and 14b as substantial spacers. The thin region 141 forms a foldable region for at least a compact folding form as shown in FIG. Thus, the integrated spacer 14 is fixed on the first region 111 of the flexible circuit board 11.
[0023]
Such an integrated spacer 14 may be composed of, for example, a polyimide resin molded product considering reflow heat resistance, or a combination tape made of a composite processed product obtained by bonding a plurality of double-sided tapes. In addition, a metal member (for example, aluminum, stainless steel, copper, etc.) can be used if it does not constitute an integral type. In that case, you may perform an insulation process as needed.
[0024]
The substantial spacers (14a, 14b) have a thickness that does not hinder the stacking of the electronic components (121, 122) to be mounted. Moreover, since the thin area | region 141 contains a bending part, the thinner one is good, for example, is made into thickness about 0.1-0.2 mm. If handling as the integrated spacer 14 is not difficult, it may be thinner.
[0025]
If the spacer 14 is a molded product of the 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 fixing side of the spacers 14a and 14b. Thereby, as shown in FIG.1 (c), when each electronic component 121,122 is laminated | stacked, it each fixes.
[0026]
If the spacer 14 is the combination tape, the back side (not shown) is fixed on the flexible circuit board 11 through an adhesive member of a double-sided tape. Furthermore, the adhesiveness of the double-sided tape is ensured in advance on the laminated fixing side of the spacers 14a and 14b. Thus, the electronic components 121 and 122 are fixed when stacked.
[0027]
Although not shown, it is conceivable that several small electronic components (peripheral elements) related to the electronic components 121 and 122 are mounted. For example, a chip capacitor or a chip resistor. Furthermore, a crystal necessary for clock generation may be mounted. These peripheral elements are also protected by a spacer 14 which is changed into an appropriate shape for mounting.
[0028]
2 is a cross-sectional view taken along line F2-F2 in FIG. 1, and FIG. 3 is a cross-sectional view taken along line F3-F3 in FIG. 2 and 3, the electronic components 121 and 122 are mounted face-down by the appropriate method described above on the mounting portion 111 of the flexible circuit board 11. An array type electrode BGA is shown on the back surface of the flexible circuit board 11.
[0029]
Further, FIG. 2 shows details of the shape of the spacer 14 and an insertion bar 15 that relieves bending stress of the flexible substrate. In other words, the adjacent sides of the spacers 14a and 14b on the side where the insertion bar 15 is provided are scraped in height by the amount of the insertion bar 15 provided.
[0030]
2 and 3, the spacer 14 is provided with an adhesive member (double-sided tape, adhesive, etc.) ADH at a predetermined location or the entire contact surface. Thereby, the lamination | stacking form of the electronic components 121 and 122 with the spacer 14 is being fixed.
[0031]
According to the configuration of the first embodiment, the flexible circuit board 11 is divided into two so that the second region 112 of the wiring portion is folded over the first region 111 including the mounting portion. Thereby, the pattern wiring effective area of the 2nd field 112 can be taken widely. As a result, it is possible to expect mounting of a multi-terminal IC as the electronic components 121 and 122.
[0032]
In addition, the form in which the first region 111 and the second region 112 are folded is a configuration in which the wiring portion is hidden from the mounting portion. Thereby, the compactness of the laminated form of the electronic components 121 and 122 with the spacer 14 is achieved.
[0033]
Further, the flexible circuit board 11 can be formed in a substantially rectangular shape. Therefore, the co-taking efficiency in the flexible substrate is very good. Thereby, a flexible base material becomes cheap and it contributes to a product cost reduction.
[0034]
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 relax the bending of the flexible circuit board 11. Yes. Thereby, the local bending stress of the flexible circuit board 11 is reduced. As a result, the reliability is further improved against problems such as peeling or cutting of the conductor.
[0035]
FIG. 4 shows a configuration of a semiconductor device according to the second embodiment of the present invention in a sectional view according to FIG. The same parts as those in the first embodiment are denoted by the same reference numerals. In the second embodiment, the following two points are mainly different from the first embodiment.
[0036]
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 in cross section.
[0037]
Second, a fitting claw 145 and a claw receiving portion 146 into which the fitting claw 145 is fitted are provided in a predetermined portion of the spacer 14. As a result, the joining points of the spacers 14 are fixed by the claw 145 and the claw receiving portion 146.
[0038]
Further, the state where the insertion bar (15) is removed is shown. In other words, the second region 112 of the flexible circuit board 11 supported by the insertion bar (15) and bent is surely pressed by 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, the weight can be reduced accordingly. Of course, as shown in FIG. 2, the insertion bar 15 may be still inserted.
[0039]
According to the said structure, in addition to the effect shown by the said 1st Embodiment, it has the effect excellent in rework property as a three-dimensional module product. That is, the connector terminal CNCT can be easily removed, and the claw 145 and the claw receiving portion 146 can easily be made to be removable. However, in the configuration of the connector terminal CNCT, the developed form of the flexible circuit board 11 is not rectangular, and the co-taking efficiency in the flexible base material is lowered.
[0040]
The configuration of the connector terminal CNCT may be adopted in the configuration of the first embodiment. The configurations of the claw 145 and the claw receiving portion 146 may be employed in the configuration of the first embodiment. Moreover, although the spacer 14 showed the integral type, it is not restricted to this, You may use a separate type. Incidentally, if the spacer 14 is integrated, it contributes to improvement in assemblability.
[0041]
FIG. 5 shows a main configuration of the semiconductor device according to the third embodiment of the present invention, and is a first modification of the layout of the electronic component. In the first embodiment, the first region 111 includes the mounting portion, and 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 unit may be set in the second region 112. If the elements (electronic components 121 and 122) are laid out so that they do not overlap with each other, there will be no problem in the bent form. In addition, the spacer (not shown) may have a minimum height in order to protect each element (electronic component 121, 122). A separate type may be employed, or an integrated type that overlaps the entire area of the flexible circuit board 11 (excluding the opening 13).
[0042]
FIG. 6 shows the main configuration of the semiconductor device according to the fourth embodiment of the present invention, and is a second modification of the layout of the electronic components. According to the first modification, a plurality of elements (IC chip, peripheral elements, etc.) are laid out so as not to overlap each other. If it does in this way, there will be no trouble in a bending form. In addition, the spacer (not shown) may have a minimum height in order to protect each element. A separate type may be employed, or an integrated type that overlaps the entire area of the flexible circuit board 11 (excluding the opening 13).
[0043]
As described above, according to each embodiment, the present invention is a three-dimensional mounting module that has a high degree of freedom in the types, combinations, and wirings of ICs and that is easy to assemble in three dimensions. Considering the fact that a plurality of peripheral elements can be mounted, it is possible to make the module optimal in terms of electrical characteristics. As a result, it can be expected to produce a module product with a short delivery time and a low cost required by media equipment.
[0044]
【The invention's effect】
As described above, according to the semiconductor device of the present invention, the flexible circuit board is configured such that the second region is divided into two and folded into the first region. The effective area of the wiring portion is wide, and a configuration in which these wiring portions are hidden in the mounting portion is achieved. In addition, a bending stress mitigation measure can be easily deployed. Thereby, the lamination | stacking form of the electronic component with a spacer is compactized with high reliability.
[0045]
As a result, the 3D mounting module configuration using a flexible circuit board with high lead times, low cost, and high reliability, with a high degree of freedom in IC types, combinations and wiring, and excellent ease of assembly in 3D. A semiconductor device 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 assembling order, respectively.
2 is a cross-sectional view taken along line F2-F2 of FIG.
3 is a cross-sectional view taken along line F3-F3 in FIG.
FIG. 4 is a sectional view according to FIG. 2 showing a configuration of a semiconductor device according to a second embodiment of the present invention.
FIG. 5 is a main configuration of a semiconductor device according to a third embodiment of the present invention, and is a first modification of the layout of electronic components.
FIG. 6 is a main configuration of a semiconductor device according to a fourth embodiment of the present invention, and is a second modification of the layout of electronic components.
[Explanation 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 ... thin region 145 of spacer ... claw 146 ... claw receiving part 15 ... insertion bar ADH ... adhesive member BGA ... array type electrode CNCT ... connector terminal

Claims (2)

A flexible circuit board having a first region and a second region and formed so that at least the first region and the second region are folded;
An external terminal portion provided on the flexible circuit board;
In the flexible circuit board, an opening provided at a bent portion,
A plurality of electronic components mounted on the mounting portion of the flexible circuit board;
Each of which is provided so as to protect the electronic component and constitutes a predetermined outer frame, and includes a laminated support provided on the flexible circuit board,
The first region is a region including the mounting portion,
The second area is an area not including the mounting portion,
In the flexible circuit board, the electronic parts are laminated and fixed together with the laminated support body that is bent so that the first area is outside and the second area is inside.
A semiconductor device characterized by the above.   The semiconductor device according to claim 1, further comprising a bending relaxation member for the second region of the flexible circuit board.

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