JP2003017359A - High capacity flat capacitor element and capacitor film and capacitor sheet constituting the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high capacity flat capacitor element (multicapacitor element) which is arranged on a common substrate with IC and LSI and is suitable for forming a flat circuit board, and to provide a capacitor film and a capacitor sheet as semi-products. SOLUTION: A pair of capacitor films (first capacitor film and second capacitor film) where inorganic dielectric thin film layers and a plurality of pattern metallic vapor deposition electrodes which are two-dimensionally detached are sequentially formed on one face of a heat resistant insulating plastic film are prepared. The capacitor sheet is formed where the directions of faces with the pattern metallic vapor deposition electrodes arranged thereon become similar, and the corresponding pattern metallic vapor deposition electrodes on the first and second capacitor films are laminated and bonded so that they are almost overlapped and are not partially overlapped. A plurality of capacitor sheets are laminated and a through hole conductor path is formed in a non- overlap part and it is derived to one face of the laminate. Thus, a plurality of planar capacitor elements are arranged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat capacitor element (multi-capacitor element) (multicapacitor element) suitable for forming a flat circuit board by being arranged on a printed circuit board together with IC, LSI and the like in various electric and electronic devices. ), And a capacitor film and a capacitor sheet as a semi-finished product suitable for the structure.

[0002]

2. Description of the Related Art In recent years, electric and electronic devices have rapidly become smaller and smaller.
Thinning is pursued, and miniaturization of individual parts incorporated in equipment and high-density mounting on a printed circuit board are progressing.

Semiconductors, small resistors, low-capacitance capacitors, and the like have made remarkable progress due to their thin mounting technologies, and have achieved a total mounting thickness of 1 mm or less. However, in the circuit part of the power supply and drive in the equipment,
It is difficult to achieve thin and high-density mounting because of the necessity of using switching power supply parts and high-capacity capacitors, and despite the efforts, it is difficult to achieve the high goals of small size and low profile of the entire equipment.

As the high-capacity capacitors mainly used in the power supply section and the drive section, aluminum electrolytic capacitors, aluminum solid electrolytic capacitors, tantalum electrolytic capacitors, tantalum solid electrolytic capacitors, and various high-capacity ceramic capacitors are used according to design specifications. Has been. Of these, aluminum or tantalum electrolytic capacitors that are often used because of their large capacity per element volume are
Due to restrictions such as the use of a metal sealed case, the shape is tubular or square, and it is the most difficult to make it thin.

Also in solid electrolytic capacitors and high-capacity ceramic capacitors, it is difficult to realize an element thickness of 3 mm or less, and the price is high.

Further, the high capacity capacitor as described above is
It is usually selected individually according to the device design and all are individually mounted.

[0007]

In view of the above-mentioned circumstances, a main object of the present invention is to provide a high capacity flat capacitor element suitable for installation on a common circuit board together with IC, LSI, etc., preferably a mounting height. It is to provide a high-capacity flat capacitor element capable of realizing 3 mm or less.

Another object of the present invention is to provide a flat capacitor element having a plurality of blocked capacitor elements having the same capacitor element outer shape but different capacitances as needed.

Another object of the present invention is to provide a flat capacitor element which can be realized as a unit of various capacitances or a blocked capacitor element while being thin as a whole.

A further object of the present invention is to provide a capacitor film and a capacitor sheet as a semi-finished product suitable for constructing the above-mentioned flat capacitor element.

An additional object of the present invention is to provide a flat circuit board in which the above-mentioned flat capacitor element is mounted on the same board together with IC, LSI and the like.

[0012]

In the order of production, the capacitor film of the present invention comprises, first of all, an inorganic dielectric thin film layer and a plurality of patterns which are planarly spaced from each other on one surface of a heat resistant insulating plastic film. The metal vapor deposition electrode layers are successively formed.

As a basic form of the capacitor sheet of the present invention, a first capacitor film and a second capacitor film each having the structure of the above-mentioned capacitor film are provided with patterned metal vapor deposition electrodes thereof. The laminated surfaces are laminated so that the facing surfaces of the patterned metal vapor deposition electrodes on the first and second capacitor films are substantially overlapped but partially non-overlapped.

The partial non-overlapping relationship is, for example, that the corresponding patterned metal vapor deposition electrodes on the first capacitor film and the second capacitor film have substantially the same shape. And by laminating the second capacitor film with a slight offset,
Alternatively, (b) it is achieved by providing notches at different positions of the patterned metal vapor deposition electrodes corresponding to each other.

Further, the capacitor sheet of the present invention has a plurality of pairs of the first capacitor film and the second capacitor film as a form closer to a finished product, and
At two non-overlapping portions of the pair of patterned metal vapor deposition electrodes on the second capacitor film and the corresponding capacitor film, respectively, and through holes penetrating all of the laminated capacitor films are formed. Conductors independently connected to one and the other of the pair of patterned metal vapor deposition electrodes are exposed on one surface of the capacitor sheet through the through holes to form individual capacitor elements, resulting in each of the capacitor films. The structure has a plurality of capacitor elements, which is substantially the same as the number of patterned metal vapor deposition electrodes formed on the substrate.

In the flat capacitor element of the present invention, in the capacitor sheet, the plurality of capacitor elements are divided into an arbitrary number of blocks, and the capacitor elements included in each block are commonly connected. The structure has elements.

Further, the circuit board of the present invention is provided with the above flat capacitor element in parallel with an IC or an LSI on a common board.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described more specifically with reference to the accompanying drawings with respect to its embodiments.

FIG. 1 is a partial schematic sectional view in the thickness direction of an embodiment of the capacitor film of the present invention. Referring to FIG. 1, a capacitor film A includes an inorganic dielectric thin film layer 2 and a plurality of patterned metal vapor deposition electrodes (hereinafter, simply referred to as “pattern electrodes”) which are planarly spaced from each other on one surface of a heat resistant insulating plastic film 1. 3 layers are formed successively.

As the film material constituting the heat resistant insulating plastic film 1, a film material generally used as a base film of a metallized film capacitor is used, and more preferably, a preferred method of forming the inorganic dielectric thin film layer 2 is used. Deposition conditions (for example, 100 to 15)
0 ° C.), through-hole conductor filling conditions (plating or metallikon) described later, and heat resistance that can withstand the temperature conditions (for example, 260 ° C.) that the capacitor element of the present invention may undergo during the mounting process on a printed circuit board. And, if necessary, it is preferably composed of a film material satisfying the conditions of chemical resistance and further the heat shrinkage ratio of less than 5%.
Examples of preferable heat-resistant insulating film materials include polyethylene naphthalate, polyphenylene sulfide, polyether sulfone, polyether ether ketone, syndiotactic polystyrene, polyaramid, and polyimide. Generally, the thickness of the heat resistant insulating film 1 is preferably in the range of 0.5 to 25 μm, but the number of layers is increased to increase the capacity of the obtained capacitor element of the present invention (for example, 10
0 to 1000 layers), and in order to suppress the total thickness of the capacitor element to 3 mm or less, a thickness of about 0.5 to 6 μm is more preferable.

The inorganic dielectric material constituting the inorganic dielectric thin film layer 2 preferably has an intrinsic dielectric constant of 10 or more, particularly 50 or more. For example, titanates such as barium titanate, titanium oxide, and oxides. An inorganic dielectric selected from the group consisting of tantalum, Pb-based composite perovskite compounds, and mixtures and complex oxides containing these as the main components is used.

As a method for forming the inorganic dielectric thin film layer 2 on the plastic film 1, a coating method in which a coating material in which an inorganic dielectric powder is dispersed is applied and dried,
A sputtering method or the like in which an inorganic dielectric target is irradiated with an electron beam or an ion beam to deposit scattered matter of the inorganic dielectric under vacuum is used, but the sputtering method is preferably used from the effect of forming the inorganic dielectric thin film layer. To be

For the purpose of forming a high capacity flat capacitor element, the inorganic dielectric thin film layer 2 has a thickness of 0.01-1 μm.
The thickness is preferably in the range of m, particularly 0.05 to 0.5 μm. The above-mentioned inorganic dielectric has been used for a magnetic capacitor in the past, but the inorganic dielectric layer is generally obtained through a step of molding and firing a powder inorganic dielectric, and its thickness is It was on the order of several μm to mm. This is not preferable considering the capacitance of the capacitor, which is inversely proportional to the thickness of the dielectric layer. On the other hand, in the present invention, due to the stacking effect with the plastic film 1 having excellent toughness and the dense structure of the dielectric layer 2 which is preferably formed by sputtering, a thin film layer having the above-described thickness and a large area can be obtained. However, the strength of the composite film as a whole, and hence the strength of the capacitor film A, can sufficiently withstand the subsequent operations such as laminating and laminating, and finally by laminating and laminating with an adhesive described later, Sufficient strength is given to the obtained multilayer capacitor element.

Next, a plurality of layers of patterned metal vapor deposition electrodes (pattern electrodes) 3 are provided on the inorganic dielectric thin film layer 2 so as to be planarly separated from each other. As the planar shape of the pattern electrode 3, for example, a quadrangle (square or rectangle) 3a as shown in (a) of FIG. 2 (details of which will be described later) is used, but it may be any shape such as a round shape or a hexagon. obtain.
In addition, as shown in FIG. 2B, the notch 3 is formed at an appropriate position.
The shape 3b1 or 3b2 provided with c (for example, a square) may be used. The shape of the plurality of pattern electrodes 3 provided on each capacitor film A may be different, but for the purpose of the present invention, it is more suitable to arrange a plurality of the same shape.

The pattern electrodes 3 thus separated are
1, vapor-deposited metal such as Zn, preferably Al, for example, Japanese Patent Publication No. 3-59981 or Japanese Patent Publication No. 8-26449.
As described in Japanese Patent Application Laid-Open No. 2004-242242, a masking oil (preferably made of perfluoroalkyl polyether) is pattern-coated on a non-electrode forming portion, and then metal deposition is selectively performed on the non-coating portion (that is, an electrode forming portion). In addition to being preferably formed by the method, after the aqueous ink is pattern-coated on the non-electrode forming portion, metal vapor deposition is performed on the entire surface, and then the deposited metal of the non-electrode forming portion is removed by washing with the aqueous ink pattern below. It can also be formed by a method of selectively leaving the pattern electrode 3. Metal deposition for electrode formation is
Although a vapor deposition method including sputtering or the like can be generally adopted, a vacuum vapor deposition method in a narrow sense by heating the vapor deposition source is simple and is preferably used for forming a fine pattern.

In this way, the film thickness of the pattern electrode 3 thus formed is appropriately in the range of 200 to 1000 Å in the case of Al, for example. The width of each electrode of the pattern electrode 3 is basically arbitrary, but is assigned as a capacitor region on the product circuit board, for example, 1 to
To form a multi-capacitor element having 2 to 3 or more capacitor blocks in an area of 100 cm ² is, 5~400mm ^2, and particularly about 10 to 100 mm ² are suitable. Further, it is preferable that the distance between the individual electrodes is as small as possible, for example, 1 mm or more is sufficient.

As one of the most basic aspects of the capacitor sheet of the present invention, the first capacitor film A1 and the second capacitor film A2 each having the structure of the above capacitor film A are formed on the pattern electrodes 3 ( 3a, 3b1, 3b2) have the same orientation (for example, all face up), and the corresponding pattern electrodes 3 (both 3a or 3b1) on the first capacitor film A1 and the second capacitor film A2.
And 3b2) are obtained by laminating and laminating so that they are substantially overlapped but partially non-overlapped.

FIGS. 2A and 2B show electrodes 3 (3a, 3b1, 3b) for explaining two modes of the laminated relationship between the first and second capacitor films A1 and A2.
It is a schematic plan view seen from the lower surface side having 2), and in each case, the first capacitor film A1 and the second capacitor film A2, which are actually to be laminated to each other, are displayed vertically adjacent to each other. Although the left and right relative positions are shown in the drawing, it is premised that they are actually stacked without any deviation in the vertical direction of the drawing.

FIGS. 3A and 3B show the first and second capacitor films A laminated in the left-right positional relationship as described in FIGS. 2A and 2B, respectively.
2 is a schematic cross-sectional view in the thickness direction showing a laminated state of two examples of the capacitor sheet of the present invention obtained by pasting No. 1 and A2 via the adhesive layer 4. (However, in FIG. 1, the electrode surface is expressed as if it is facing upward, but in FIG. 3, the electrode surface is expressed as facing downward according to the structure of the product capacitor element.) FIG. And (b) are respectively shown in FIG.
FIG. 3 is a view for explaining the positional relationship of electrodes in the capacitor sheet of the present invention showing the laminated state in (a) and (b).
It is the model top view (only an electrode position is shown) seen from the lower surface side of (a) and (b). 4 (a) and (b),
Pattern electrodes 3a (A1) and 3a (A2), or 3
Focusing only on b1 (A1) and 3b2 (A2), whether the contour lines that can be seen from the lower surface side (displayed by solid lines) or the contour lines that are hidden behind the other (displayed by dotted lines) are formed are indicated by solid lines and dotted lines. It is displayed.

Non-overlapping portions of corresponding pattern electrodes represented by the portion of the pattern electrode 3a or 3b1 on the first capacitor film A1 surrounded by the solid line and seen from the lower surface side in FIGS. 4A and 4B. The dimension (two locations for a pair of corresponding pattern electrodes) is such that, for example, in a drill to be described later, through-hole formation by laser processing and conductor embedding form a state in which each conductor leads to only one of the corresponding pattern electrodes. It is preferable that the width is as narrow as possible. For example, a region of 1 to 3 mm square is sufficient.

As the adhesive forming the adhesive layer 4, it is desirable to use an adhesive composed of a resin having good heat resistance, for example, an epoxy adhesive, a silicone adhesive, an imide adhesive, a urethane adhesive. A cyanoacrylate adhesive or the like is preferably used. The thickness of the adhesive layer 4 is
It is preferably as thin as possible within the range of ensuring the adhesive strength, and is usually about 0.1 to 2 μm after curing.

The capacitor sheet B (of the present invention, which is composed of the capacitor films A1 and A2 bonded to each other in the above-described laminated relationship shown in FIGS. 2 to 4 and has the laminated structure of FIG. 3 (a) or (b). B1 or B2) is suitable for storing or supplying to the market as a semi-finished product by being rolled into a roll shape as it is. Then, in accordance with the capacity and dimensions of the flat capacitor element to be placed and used on the final circuit board, the plane dimension is determined, and the necessary number of layers is determined, and the flat capacitor element is set as follows. It may be formed.

That is, generally, a wide capacitor sheet having the laminated structure shown in FIG.
The laminated capacitor sheet is cut according to the required plane dimension, laminated by the number of laminated layers determined according to the required capacity, and laminated while aligning in a planar manner to form a laminated capacitor sheet.

FIG. 5 shows such a capacitor sheet B2.
FIG. 4 is a cross-sectional view of a laminated structure in which 7 layers of (the laminated structure shown in FIG. 3 (b)) are laminated, in which case the included seven first capacitor films A1 and seven second capacitor films A1 are respectively The layers are stacked so that they overlap each other almost completely. Therefore, the seven pairs of electrodes 3b1 and 3b2, which are substantially at the same position on the plane, form two non-overlapping portions in a plane that are vertically aligned. Then, in the same way as through-hole processing of a normal multi-layer printed circuit board, through holes are formed in the stacking direction by drilling or laser processing at individual non-overlapping parts, and metal conductors such as Cu and tin alloys are plated inside the holes by plating or metallikon. If a conductor path made of a material is formed, a set of 7 electrodes 3b1 and a set of 7 electrodes 3b2 are perpendicular to each other in 7 pairs of capacitor films (7 capacitor sheets) located in the same plane. In common with each other, and separated from the other electrode sets, a laminated structure of seven-layer unit capacitors electrically connected to each other is formed. This electrically becomes a parallel junction structure of seven unit capacitors. FIG. 6 (a) corresponds to FIG. 5 and shows a laminated state in which conductor paths 7 (71 conducting to the electrode 3b1 and 72 conducting to the electrode 3b2) are formed in the through holes, and FIG. 6 (b) shows the bottom surface thereof. FIG. 3 is a diagram, represented by a square represented by a square having a pair of conductor tracks 7 (71 and 72) (only 6 × 5 = 30 is shown for convenience, but a larger number can be arranged). As described above, one capacitor element C has a capacity of seven unit capacitors in this example.

Then, corresponding to FIG. 6A, lands or bumps 81 and 82 which are electrically connected to the conductor paths 71 and 72 respectively are formed by, for example, a plating method as shown in the sectional view of FIG. The lands or bumps form the connection terminals with the substrate after resin-molding the laminated capacitor element shown in FIG. 7 together with, for example, an epoxy resin.

FIG. 8 is a bottom terminal side plan view of an example of the flat capacitor element of the present invention after being molded with the resin 9 in this manner. In this example, each has a capacity of seven unit capacitors. A flat capacitor element in which 6 × 12 = 72 capacitor elements C are arranged in a plane is shown.

An example of a preferred use form of the flat capacitor element of the present invention corresponds to the example of FIG.
As shown in, by disassembling 72 capacitor elements into, for example, 8 blocks and connecting the capacitor elements for each block in common, two blocks having a capacity of 15 × C and a capacity of 6 × C are provided. Is formed as a flat capacitor element having capacitor elements that are blocked so as to have various capacities, such as four blocks having two capacitors and two blocks having a capacitance of 9 × C. The wiring for such blocking may be directly provided on the lower surface of the flat capacitor element of FIG. 8, or the wiring structure as shown in FIG. 9 may be provided corresponding to the bumps 81 and 82 of FIG. The flat capacitor element of FIG. 8 is directly arranged on the circuit board 10 having the terminals on the upper surface and the lower surface which are designed to be joined to other circuit elements, and formed into blocks on the spot. A flat capacitor element having a capacitor element may be formed.

In the above example, for convenience of description, the present invention has been described with a focus on a configuration example of a flat capacitor element in which 6 × 12 capacitor elements C having a seven-layer capacitor sheet laminated structure are planarly arranged. However, this is an example, and for example, the number of arrayed capacitor elements C is also reduced by reducing the planar dimension of each capacitor element.
For example, it is easy to arrange about four capacitor elements in a capacitor arrangement area of about 1 cm ² . Further, for example, if the thickness of one capacitor sheet is about 2 to 4 μm, it is possible to suppress the total flat capacitor element thickness to 3 mm or less even if 500 layers are laminated.

[0039]

As described above, according to the present invention, I
A high-capacity flat capacitor element suitable for being installed on a common circuit board together with C, LSI, etc. is provided, and a small mounting height of, for example, 3 mm or less can be realized.
Further, a flat capacitor element having the same planar shape and including blocked capacitor elements of various capacities is realized.
Further, a capacitor film and a capacitor sheet as a semi-finished product suitable for forming such a flat capacitor element are provided.

[Brief description of drawings]

FIG. 1 is a partial schematic sectional view in a thickness direction of an example of a capacitor film of the present invention.

2A and 2B are schematic plan views showing examples of the pattern electrode shapes on the first and second capacitor films and the left and right positional relationships between these capacitor films, respectively.

3A and 3B correspond to FIGS. 2A and 2B, respectively, and are schematic cross-sectional views in the thickness direction showing an example of a basic laminated structure of a capacitor sheet of the present invention to be formed. Fig.

4A and 4B are schematic bottom views showing the positional relationship of electrodes on a pair of capacitor films in the capacitor sheet having the laminated structure of FIGS. 3A and 3B, respectively.

FIG. 5 is a partial sectional view of an example of a capacitor sheet of the present invention having a 7-layer laminated structure.

6A is a schematic cross-sectional view showing a state in which a conductor path is formed by through holes in the laminated structure of FIG. 5, and FIG.
Schematic bottom view.

7 is a schematic cross-sectional view of an example of a flat capacitor element in which a land or a bank as a lower surface side takeout terminal is further provided on the laminated structure of FIG.

8 is a schematic bottom view of the flat capacitor element of FIG. 7 after further resin molding.

FIG. 9 is a schematic bottom view of a flat capacitor element including a blocked capacitor element.

[Explanation of symbols]

A, A1, A2: Capacitor film B, B1, B2: Capacitor sheet C: Capacitor element 1: Heat-resistant insulating plastic film 2: Inorganic dielectric thin film layer 3: Pattern metal deposition electrode (pattern electrode) 4: Adhesive layer 7, 71, 72: Conductor paths formed in through holes 8, 81, 82: Bump 9: Mold resin 10: Rigid substrate

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takashi Terauchi             510 Kakogawa, Furuoouchi, Noguchi Town, Kakogawa City, Hyogo Prefecture             Within Plastics Co., Ltd. (72) Inventor Tomohiro Baba             510 Kakogawa, Furuoouchi, Noguchi Town, Kakogawa City, Hyogo Prefecture             Within Plastics Co., Ltd. (72) Inventor Kazumi Onishi             510 Kakogawa, Furuoouchi, Noguchi Town, Kakogawa City, Hyogo Prefecture             Within Plastics Co., Ltd. F-term (reference) 5E082 AB05 EE07 EE37 FF05 FG06

Claims (9)

[Claims] 1. A capacitor film obtained by successively forming an inorganic dielectric thin film layer and a plurality of patterned metal vapor deposition electrode layers which are two-dimensionally separated from each other on one surface of a heat resistant insulating plastic film. 2. The inorganic dielectric layer comprises a group consisting of titanates such as barium titanate, titanium oxide, tantalum oxide, Pb-based complex perovskite compounds, and mixtures and complex oxides containing these as the main components. 2. A sputtering film of an inorganic dielectric material selected from the above.
Capacitor film. 3. A first capacitor film and a second capacitor film, each of which has the structure of the capacitor film according to claim 1 or 2, have the same orientation of the surfaces provided with the patterned metal vapor deposition electrodes, A capacitor sheet formed by laminating and laminating the corresponding patterned metal vapor deposition electrodes on the first and second capacitor films so as to substantially overlap with each other but partially not overlap with each other. 4. The first capacitor film and the second capacitor film are substantially the same in shape, but the first capacitor film and the second capacitor film are displaced from each other in plan view. The capacitor sheet according to claim 3, wherein non-overlapping portions of corresponding patterned metal vapor deposition electrodes are formed to be laminated and laminated. 5. The corresponding patterned metal vapor deposition electrodes on the first capacitor film and the second capacitor film have substantially the same shape, but since the notches are provided at different positions, at the positions of the notches, The capacitor sheet according to claim 3, wherein a non-overlapping portion of the corresponding patterned metal vapor deposition electrode is formed after laminating and laminating. 6. A plurality of pairs of the first capacitor film and the second capacitor film are included, and the stacking positional relationship between the first capacitor film and the second capacitor film in each pair is the relationship described in claim 3. Meet and plural first
6. The capacitor sheet according to any one of claims 3 to 5, wherein the plurality of corresponding patterned metal vapor deposition electrodes in the plurality of second capacitor films and the plurality of corresponding patterned metal vapor deposition electrodes are in a superposed relationship with each other without substantially misalignment. 7. The capacitor sheet according to claim 3, wherein the non-overlapping portions of the corresponding pair of patterned metal deposition electrodes on the first capacitor film and the second capacitor film respectively are provided at two positions. Through-holes are formed through all of the laminated capacitor films, and conductors independently connected to one and the other of the corresponding pair of patterned metal deposition electrodes are formed on one surface of the capacitor sheet through the through-holes. A flat capacitor element having a plurality of capacitor elements exposed to form individual capacitor elements and, as a result, substantially the same number of patterned metal deposition electrodes formed on each of the capacitor films. 8. The flat capacitor element according to claim 7, further comprising a blocked capacitor element in which the plurality of capacitor elements are divided into an arbitrary number of blocks and the capacitor elements included in each block are commonly connected. 9. A circuit board provided with the flat capacitor element according to claim 7 or 8 in parallel with an IC or an LSI on a common substrate.