JP2002075784A - Thin-film capacitor, its manufacturing method and its mounting structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin-film capacitor minimized in thickness from a board to an external terminal electrode (salient pole), a method for manufacturing the same and its mounting structure. SOLUTION: The thin-film capacitor comprises a capacitor body formed by coating a lower electrode 11, a thin-film dielectric layer 12 and an upper electrode 13 on the surface of an insulating board 1 having a plurality of through-holes 2 and second through-holes 3 penetrating in a board thickness direction, a first salient pole 15 embedded in a lower electrode 11 part on the hole 2, and a second salient pole 16 embedded in an upper electrode 13 part on the hole 3. The poles 15 and 16 are obtained by suction through the holes 2 and 3 before curing. This thin-film capacitor 10 is disposed underneath an IC chip 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film capacitor, and more particularly to a thin film capacitor having a large capacity and a low inductance, which is used for bypassing high-frequency noise or preventing fluctuation of a power supply voltage.

[0002]

2. Description of the Related Art In recent years, as electronic devices have become smaller and more sophisticated, there has been a growing demand for electronic components installed in the electronic devices to be smaller, thinner, and compatible with high frequencies.

In particular, in a high-speed digital circuit of a computer which needs to process a large amount of information at high speed, the clock frequency in the CPU chip is from 100 MHz to several hundred MHz, and the clock frequency of the bus between chips is also from 30 MHz, even at the personal computer level. The high-speed operation is remarkable at 75 MHz.

As the degree of integration of IC circuits increases and the number of elements in a chip increases, the power supply voltage tends to decrease in order to suppress power consumption. As the speed, density, and voltage of these IC circuits increase, passive components such as thin-film capacitors must also exhibit excellent characteristics with respect to high-frequency or high-speed pulses, as well as miniaturization and large capacity. ing.

On the other hand, various problems associated with the high-speed operation of the IC circuit are more serious than miniaturization of each element. Of these, the most important in the function of removing high-frequency noise, which is the role of the thin film capacitor, is that the instantaneous drop in the power supply voltage that occurs when simultaneous switching of logic circuits occurs at the same time is the energy stored in the thin film capacitor. Is a function to reduce by supplying instantaneously. This is a so-called decoupling thin film capacitor.

The performance required of a decoupling thin film capacitor is how quickly current can be supplied in response to a current fluctuation in a load section faster than a clock frequency.
Therefore, it must function reliably as a thin film capacitor in the frequency range from 100 MHz to 1 GHz.

However, an actual thin film capacitor element has a resistance component and an inductance component in addition to the capacitance component. The impedance of the capacitance component decreases with increasing frequency, and the inductance component increases with increasing frequency. For this reason, as the operating frequency increases, the inductance of the element limits the transient current to be supplied, which causes an instantaneous decrease in the power supply voltage on the logic circuit side or new voltage noise. As a result, an error occurs in the logic circuit.

In particular, in recent IC circuits, the power supply voltage has been reduced in order to suppress an increase in power consumption due to an increase in the total number of elements, and the allowable fluctuation range of the power supply voltage has been reduced. Therefore, it is very important to reduce the inductance of the decoupling thin film capacitor element itself in order to minimize the voltage fluctuation width during high-speed operation.

As a method of reducing the inductance,
A thin film capacitor as shown in FIG. 10 has been proposed.

Referring to FIG. 1, a capacitor body in which a lower electrode 91, a thin film dielectric layer 92, and an upper electrode 93 are laminated on an insulating substrate 90 is formed, and the capacitor body is covered with an insulating protective layer 94. Was.

Here, the first external terminal electrode 95 is connected to the lower electrode 9 exposed from the insulating protection layer 94 of the capacitor body.
On one part (extending portion) 91a, solder bumps and the like are arranged. Further, the second external terminal electrode 96 is
Part of the upper electrode 93 serves as an insulating protective layer 94 of the capacitor body.
In this configuration, solder bumps and the like are arranged on a part of the upper electrode 93 exposed from the substrate. In order to reduce the inductance, a plurality of first and second external terminal electrodes 95 and 96 are alternately arranged so as to be adjacent to each other.

In order to alternately arrange the first and second external terminal electrodes 95 and 96 at a predetermined interval, the current between the first and second external terminal electrodes 95 and 96 is equally divided.

Then, the thin film capacitor thus obtained is
On the mounting board on which the C chip is mounted, it is arranged near the IC chip.

[0014]

In the thin film capacitor, the first and second external terminal electrodes 95 and 96 are mounted on a part of the lower electrode 91 or a part of the upper electrode 93. Protruding above the upper electrode 93 by an amount corresponding to the height of the first and second external terminal electrodes 95 and 96.

Therefore, when a ball grid having a diameter of about 100 μm is used as the external terminal electrodes 95 and 96, the thickness of the entire thin film capacitor is the thickness of the substrate 41 (for example, 250 μm) and the thickness of the capacitor body (lower electrode + thin film). The thickness of the dielectric layer + upper electrode = 1 μm) and the thickness of the external terminal electrode (diameter of the ball grid 100 μm) are each added, and the total thickness is about 350 μm. In addition, the external terminal electrodes 95 and 96 have a thickness of 20 μm.
When the conductive paste of m is applied and cured, the whole becomes about 270 μm. The whole is about 270-350μ
For about m, this capacitor had to be provided separately on the mounting board separately from the IC chip.

That is, when this thin-film capacitor is arranged on a mounting board to be connected to an IC chip, it is necessary to arrange the thin-film capacitor and the IC chip side by side.
Projection electrode of C chip and external terminal electrode 9 of thin film capacitor
There was a difference in the distance between the wiring patterns 5 and 96, and it was difficult to reduce the inductance of the entire wiring pattern.

The present invention has been devised in view of the above-mentioned problems, and an object of the present invention is to provide a thin film capacitor in which the thickness from a substrate to an external terminal electrode (protruding electrode) is minimized, and a method of manufacturing the same. It is in.

Further, using this thin film capacitor, an IC
An object of the present invention is to provide a mounting structure capable of reducing the inductance between the IC chip and the IC chip when mounting on a chip.

[0019]

According to a first aspect of the present invention, there is provided an insulating substrate having a plurality of first through holes and second through holes penetrating in a thickness direction of the substrate. A lower electrode covering the thin film dielectric layer, an upper electrode covering the surface opening of the second through-hole, and a capacitor body formed by sequentially forming an insulating protective layer are arranged, and the upper surface of the capacitor body is A first protruding electrode partially embedded in the lower electrode on the surface opening of the first through-hole, and partially embedded in the upper electrode on the surface opening of the second through-hole; A thin film capacitor comprising a second protruding electrode inserted therein.

According to a second aspect of the present invention, a surface opening of the first through-hole is closed on a surface of an insulating substrate having a plurality of first through-holes and second through-holes penetrating in the thickness direction of the substrate. Forming a lower electrode so as to expose a surface opening of the second through hole; and exposing a lower electrode surface located at the surface opening of the first through hole on the lower electrode; Forming the thin film dielectric layer so as to expose a surface opening of the second through hole; and
A step of exposing a surface of a lower electrode located at a surface opening of the first through hole and forming an upper electrode to close a surface opening of the second through hole; Forming an insulating protective layer exposing a lower electrode surface located at the surface opening and an upper electrode surface located at the surface opening of the second through hole; and forming a protruding electrode in a region where each electrode is exposed from the insulating protective layer. Arranging a conductor member to be formed, and sucking from the back surface openings of the first and second through holes, embedding a part of the conductor member in each electrode, and curing to form a protruding electrode. And a method for producing a thin film capacitor.

According to a third aspect of the present invention, there is provided a structure in which an IC chip having a projecting electrode on a mounting surface and the thin film capacitor are mounted on a mounting substrate having a wiring pattern on at least a surface thereof, wherein the thin film capacitor is The thin-film capacitor is arranged on the mounting substrate in a region surrounded by the projecting electrodes, and the projecting electrodes of the thin-film capacitor and the projecting electrodes of the IC chip are connected via the wiring pattern. The mounting structure.

In the thin film capacitor according to the present invention, at least first and second through holes are formed penetrating in the thickness direction of the insulating substrate, and a capacitor main body is formed on one main surface thereof.
Then, a first protruding electrode depressed in the lower electrode is arranged in a part of the lower electrode located on the surface opening of the first through hole. Further, a second protruding electrode depressed in the upper electrode is arranged on a part of the upper electrode located on the surface opening of the second through hole.

Therefore, the protrusion amount of the protruding electrode is reduced only by the portion where the protruding electrode is depressed as compared with the related art, and the overall thickness of the thin film capacitor is reduced, so that a thin film capacitor having a reduced height can be achieved.

For example, the protruding electrode may be a protruding electrode whose surface is slightly protruded from the surface of the insulating protective layer. That is, in addition to the substrate 250 μm, the element portion (lower electrode + thin film dielectric layer + upper electrode) 1 μm, the protective film portion 5 μm, the first and second terminal electrodes only have a thickness of 10 μm. Therefore, the total thickness can be reduced to about 260 μm.

In the method for manufacturing a thin film capacitor according to the present invention, a conductor member serving as a first protruding electrode and a second protruding electrode is formed by using an insulating substrate having first and second through holes formed therein. Is disposed, and then the conductor member disposed on the lower electrode is sucked from the back surface opening of the first through hole, and the conductor member serving as the first protruding electrode is depressed into a part of the lower electrode. Can be done. Further, the conductor member disposed on the upper electrode is sucked from the back surface opening of the second through hole, and the conductor member serving as the second protruding electrode can be depressed in a part of the upper electrode.

Thus, the amount of protrusion of the first and second protruding electrodes can be arbitrarily controlled, so that the protrusion can be made equal to or slightly protrude from the surface of the insulating protective layer.

That is, a thin-film capacitor with a reduced height can be manufactured very easily.

As described above, the entire thickness of the entire thin film capacitor can be made extremely thin, for example, stably smaller than 300 μm. Therefore, for example, the mounting is performed together with the IC chip having the protruding electrodes formed by the ball grid. ICs formed by protruding electrodes when placed on a substrate
The thin film capacitor can be arranged in the gap between the chip and the mounting board, that is, below the IC chip. As a result, since the protruding electrodes of the thin film capacitor and the protruding electrodes of the IC chip extend substantially radially, the wiring pattern between them is made the shortest distance on the mounting board, and the difference between the distances of the respective wiring patterns is reduced. Can be reduced.

Therefore, the thin-film capacitor having a reduced inductance due to the positions where the first projecting electrode and the second projecting electrode are formed can be mounted on the mounting board in a low inductance state.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a thin film capacitor of the present invention,
The manufacturing method and the mounting structure will be described with reference to the drawings.

FIG. 1 is a sectional view of a thin film capacitor according to the present invention, and FIGS. 2 to 8 are plan views showing main steps of a method of manufacturing the thin film capacitor.

As shown in FIG. 1, the thin-film capacitor of the present invention is formed by laminating a lower electrode 11, a thin-film dielectric layer 12, an upper electrode 13, and an insulating protective layer 14 on one main surface of an insulating substrate 1. The formed capacitor body 10 is formed.

As shown in FIG. 2, the insulating substrate 1 is made of, for example, a ceramic material such as alumina. The insulating substrate 1 has two types of through holes 2, 3 penetrating in the thickness direction. Specifically, it is formed by punching in a state of a green sheet to be the insulating substrate 1.

The two types of through-holes 2 and 3 are, for example, second through-holes 3 arranged near the outer peripheral portion of the insulating substrate 1.
And a first through hole 2 surrounded by a second through hole 3 near the center of the insulating substrate 1.

A lower electrode 11 is formed on one main surface of the insulating substrate 1, for example, near the center of the surface so as to cover the surface opening of the first through hole 2. I have. The lower electrode 11 is formed so as to cover the surface opening of the first through hole 2 and to expose the second through hole 3 formed near the outer peripheral portion of the insulating substrate 1. For example, as shown in FIG. 3, the opening 11b is formed so that the second through hole 3 is exposed.

On the lower electrode 11 of the insulating substrate 1,
A thin film dielectric layer 12 is deposited. As shown in FIG. 4, the thin film dielectric layer 12 has an opening 12a for exposing the lower electrode 11 on the first through hole 2, and an opening 12b for exposing the second through hole 3. have.

The upper electrode 1 is formed on the thin film dielectric layer 12.
3 is formed. As shown in FIG. 5, the upper electrode 13 is formed so as to cover the surface opening of the second through hole 3 and to expose the opening 12a of the thin film dielectric layer 12. That is, the opening 12 of the thin film dielectric layer 12
A part of the lower electrode 11 located on the first through-hole 2 is exposed from the opening 13a exposing a.

Further, on the upper electrode 13, an insulating protective layer 14 is formed. As shown in FIG. 6, the insulating protection layer 14 is formed on the lower electrode 11 positioned on the first through hole 2.
The opening 14a exposing a part of the opening is formed.

Further, an opening 14b exposing a part of the upper electrode 13 located on the second through hole 3 is formed.

Further, the plurality of openings 1 of the insulating protection layer 14 are formed.
Protruding electrodes 15 and 16 are formed on 4a and 14b.

The protruding electrode 15 is connected to the opening 14 of the holding layer 14.
a, it is connected to a part of the lower electrode 11. The protruding electrodes 15 are arranged in a rectangular shape at equal intervals near the center of the insulating protective layer 14. The protruding electrode 16 is connected to a part of the upper electrode 13 via the opening 14b of the holding layer 14. The protruding electrodes 16 are arranged in a rectangular shape at equal intervals so as to surround the protruding electrodes 15 near the outer peripheral portion of the insulating protective layer 14.

Here, in the thin film capacitor of the present invention, the protruding electrode 15 is disposed so that a part thereof is depressed in a part of the lower electrode 11, and the protruding electrode 16 is partially disposed so as to correspond to the upper electrode 13. It is arranged to sink into a part of it.

With such a configuration, the protruding electrodes 15, 1
6 has a very small amount of protrusion from the insulating protective layer 14.

As described above, the lower electrode 11 and the upper electrode 1
3 causes a predetermined capacitance component to be generated between the lower electrode 11 and the upper electrode 13.

In practice, the plurality of protruding electrodes 15 connected to the lower electrode 11 and the plurality of protruding electrodes 16 connected to the upper electrode 13 are derived.

The direction of current flow between the protruding electrodes 15 and 16 is radial, and the current path is very short, so that low inductance can be achieved.

The diameter of the first and second through holes 2 and 3 of the insulating substrate 1 is desirably 300 μm or more. Further, the thickness of the insulating substrate 1 is desirably 50 to 250 μm. This is because if the thickness of the insulating substrate 1 is reduced, the strength is reduced, and if the thickness is increased, the effect of reducing the thickness of the thin film capacitor is lost.

The capacitor body 10 (lower electrode 1)
1. The thickness of the thin film dielectric layer 12 and the upper electrode 13 is 0.5
It is preferable that the thickness be 2.0 μm. Also, the protective film 14
Is preferably 2 to 10 μm. Further, it is desirable that the protruding electrodes 15 and 16 are formed to have a thickness of 5 to 15 μm.

When these electrodes become thinner, each of the electrodes 11,
13, the deposition of the thin film dielectric layer 12 becomes unstable. Also, when the thickness of each of the electrodes 11, 13 and the thin film dielectric layer 12 increases, the overall thickness naturally increases, and the action as a thin film capacitor decreases.

In order to increase the efficiency of the manufacturing process, it is desirable that the insulating substrate 1 is made of, for example, a large insulating substrate. That is, the formation of the through-holes 2 and 3 depends on each of the lower electrodes 1.
1, 21, the thin film dielectric layer 12, the upper electrode 13, and the insulating protective layer 14 can be formed over a plurality of element regions. In the final step, this large substrate is formed according to each element region. Cutting and splitting can be performed.

The insulating substrate 1 is formed by forming first through-holes 2 and second through-holes 3 at portions to be each element region of a large ceramic green sheet by punching, laser or the like, and firing. It can be formed by processing.

As the above-mentioned insulating substrate 1, alumina, sapphire, MgO single crystal, and SrTiO ₃ single crystal are used. In particular, alumina and sapphire are desirable in that they have low reactivity with the thin film, are inexpensive, have high strength, and are crystalline of the metal thin film.

The lower electrode 11 and the upper electrode 13 are made of platinum (Pt), gold (Au), palladium (Pd), copper (C
u) thin films and the like, and among these, platinum (Pt) and gold (Au) thin films and low-resistance copper (Cu) thin films are most suitable.
This is because Pt and Au have low reactivity with the dielectric and are hardly oxidized, so that a low dielectric constant phase is hardly formed at the interface with the dielectric.

Further, the thin film dielectric layer 12 has a high dielectric constant in a high frequency range. The thin film dielectric layer 12 is made of, for example, Pb, Mg, Nb as a metal element.
Preferably, the dielectric thin film is a dielectric thin film made of a perovskite-type composite oxide crystal containing, and has a relative dielectric constant of 1000 or more at a measurement frequency of 300 MHz (room temperature).

In the present invention, other than a dielectric thin film composed of a perovskite-type composite oxide crystal containing Pb, Mg and Nb, for example, a perovskite-type composite oxide crystal containing Ba and Ti, PZT, PLZT, SrTiO ₃ , Ta
₂ O ₅ or the like may be used. Such thin film dielectric layers 12, 22
Is manufactured by a known method such as a PVD method, a CVD method, and a sol-gel method.

The protruding electrodes 15 and 16 are formed by heating the solder paste or by applying and baking a silver-based conductive paste. The material is silver / palladium alloy, copper, nickel, gold, solder, or a material obtained by plating these with nickel / solder.

The protruding electrodes 15 and 16 are connected to the lower electrode 11.
And the upper electrode 13 is recessed.
Before curing 5 and 16, a suction process is performed from the back surface side of the insulating substrate 1 by using the first through hole 2 of the insulating substrate 1 so that the first protruding electrode 15 is depressed in the lower electrode 11. Using the second through-hole 3 of the insulating substrate 1, a suction process can be performed from the back surface side of the insulating substrate 1, and the second protruding electrode 16 can be recessed in the upper electrode 13. An arbitrary amount of the protruding electrodes 15 and 16 can be suctioned depending on the intensity and time of the suction, and the protruding amounts of the protruding electrodes 15 and 16 protruding from the insulating protective layer 14 can be arbitrarily controlled.

Next, the schematic steps of the manufacturing method of the present invention will be described.

First, a large-sized insulating substrate from which a large number of insulating substrates 1 including first and second through holes 2 and 3 can be extracted at predetermined positions is prepared. A lower electrode 1 is provided on each element region of the insulating substrate 1.
1. The thin-film dielectric layer 12 and the upper electrode 14 are respectively formed in a predetermined shape, and an insulating protective layer 24 is further formed.

Thereafter, the large-sized insulating substrate is divided and cut for each predetermined element region.

FIGS. 2 to 8 are plan views showing main steps in one element region in each large substrate.

As shown in FIG. 2, the insulating substrate 1 is provided with the first and second through holes 2 and 3 as described above, and is made of, for example, alumina ceramic.

The diameter of the first and second through holes 2 and 3 is 3
It is desirable that the thickness be not less than 00 μm. This diameter is 300
If it is less than μm, it becomes difficult to suck the inside of the through hole.

The thickness of the insulating substrate 1 is 50 to 250 μm.
m is desirable. This is because when the thickness of the insulating substrate 1 is reduced, the strength is reduced, and when the thickness is increased, the effect of reducing the thickness of the thin film capacitor 10 is lost.

Next, as shown in FIG. 3, a lower electrode 11 is formed on the insulating substrate 1. The lower electrode 11 forms a platinum (Pt), gold (Au), palladium (Pd), and copper (Cu) thin film by a high-frequency magnetron sputtering method or the like, and is then patterned into a predetermined shape. This patterning is performed by using a photolithography technique. Thereby, the second through hole 3
Is formed to expose the opening 11b.

Among these metallic materials, platinum (Pt)
A gold (Au) thin film and a low-resistance copper (Cu) thin film are optimal. This is because Pt and Au have low reactivity with the dielectric and are hardly oxidized, so that a low dielectric constant phase is hardly formed at the interface with the dielectric.

Next, as shown in FIG.
2 is formed on the lower electrode 11. Thin film dielectric layer 12
Desirably has a high dielectric constant in a high frequency region. The thin-film dielectric layer 12 is made of, for example, a perovskite-type composite oxide crystal containing Pb, Mg, and Nb as metal elements. Measurement frequency 300
A thin-film dielectric layer having a relative dielectric constant of 1000 or more at MHz (room temperature) is desirable. In the present invention, Pb, Mg, N
Other than the thin film dielectric layer 12 composed of a perovskite-type composite oxide crystal containing b, for example, a perovskite-type composite oxide crystal containing Ba and Ti, PZT, PLZT, SrTi
O ₃ , Ta ₂ O ₅ or the like may be used, and is not particularly limited. Such a thin film dielectric layer 12 is formed by a PVD method, a CVD method, or the like.
It is produced by a known method such as a sol-gel method.

The thin-film dielectric layer 1 formed as described above
2 is patterned into a predetermined shape. This patterning is performed by using a photolithography technique. Thereby, the thin film dielectric layer 12 has
An opening 12a exposing a part of the lower electrode 11 located on the first through hole 2 is formed, and an opening 12b exposing the second through hole 3 is formed.
The opening 12b is configured to cover the outer periphery of the opening 11b.

Next, as shown in FIG. 5, an upper electrode 13 is formed on the thin film dielectric layer 12. The upper electrode 13 is made of platinum (P) by a high-frequency magnetron sputtering method or the like.
t), gold (Au), palladium (Pd), and copper (Cu) thin films are formed, and then patterned into a predetermined shape. This patterning is performed by using a photolithography technique. Thereby, the upper electrode 13 is provided with the lower electrode 11 positioned on the first through hole 2.
An opening 13a exposing a part of is formed. The second
The through hole 3 is formed such that the opening on the surface side is closed by the upper electrode 13.

Among these metallic materials, platinum (Pt)
A gold (Au) thin film and a low-resistance copper (Cu) thin film are optimal. This is because Pt and Au have low reactivity with the dielectric and are hardly oxidized, so that a low dielectric constant phase is hardly formed at the interface with the dielectric.

Next, as shown in FIG. 6, an insulating protective layer 14 is formed on the upper electrode 13. The insulating protective layer 14 is formed, for example, by applying a material such as photosensitive polyimide by spin coating, and then by photolithography.

As a result, the insulating protective layer 14 has an opening 14 a where a part of the lower electrode 11 located on the first through hole 2 is exposed, and one of the upper electrodes 13 located on the second through hole 3. An opening 14b exposing the portion is formed.

The diameter of the openings 14a and 14b is
It has a diameter that is equal to or slightly larger than the diameter of the first through hole 2 and the second through hole 3, for example,
It is about 500 μm.

Next, conductor members to be the protruding electrodes 15 and 16 are formed. The conductor member is provided in the opening 14 of the insulating protective layer 14.
a and 14b are formed by being applied to a conductive paste. At the time of printing, the coating thickness is about 20 μm.

Next, the conductor member is sucked through the through holes 2 and 3 on the back surface side of the insulating substrate 1. For example, in the first through hole 2, as a result of a part of the lower electrode 11 being sucked into the through hole 2, the conductor member (which becomes the protruding electrode 15) located above the lower electrode 11 becomes a part of the lower electrode 11. It is in a state of sinking.

Further, for example, in the second through-hole 3, a part of the upper electrode 13 is sucked into the through-hole 3, so that the conductor member (which becomes the protruding electrode 16) located on the upper electrode 13 is The electrode 13 is in a state of being depressed.

As described above, the first and second through holes 2, 3
Through the protruding electrodes 15, 1 from the back side of the insulating substrate 1.
6 is sucked and depressed, so that the protruding electrode 1
The amount of protrusion of 5 and 16 (the amount of protrusion from the insulating protective layer 14) can be reduced.

Next, by curing the conductor member by heat curing, the conductor member depressed in a part of the lower electrode 11 becomes the protruding electrode 15 and the conductor member depressed in a part of the upper electrode 13. Becomes the protruding electrode 16. Thereby, the thin film capacitor shown in FIG. 7 is achieved.

When manufacturing using a large substrate,
The large insulating substrate is cut and separated so that the thin film capacitor shown in FIG. 7 can be extracted.

Further, in order to minimize the mounting area (with a small thin film capacitor), the cutting of the large substrate is performed by cutting the thin film capacitors 10a, 10a adjacent to each other as shown in the sectional view of FIG.
The cutting may be performed at the line xx which is the boundary line of 10b. At this time, it is desirable that the end of the upper electrode 13 be positioned inside from the cutting line so that the end of the upper electrode 13 is not exposed from the cut surface.

According to the above-described manufacturing method, the first through-hole 2 and the second through-hole 3 are formed in the insulating substrate 1, and the through-holes are formed before the step of curing the protruding electrodes 15, 16. It is very easy to control the amount of protrusion of the protruding electrodes 15 and 16 simply by performing the suction process through the steps 2 and 3, whereby a very thin thin film capacitor can be achieved. The protrusion amounts of the protruding electrodes 15 and 16 can be arbitrarily controlled.

Next, the mounting structure of the thin-film capacitor of the present invention having a reduced inductance and a reduced thickness will be described with reference to FIG. The thin film capacitor is an example used for a decoupling capacitor of an IC chip to be flip-chip bonded.

In the drawing, reference numeral 50 denotes a mounting board,
Denotes an IC chip, 52 denotes a projecting electrode of the IC chip 51, and 53 denotes a predetermined wiring pattern formed on the mounting substrate 50. Reference numeral 10 denotes a thin film capacitor of the present invention. Here, the wiring pattern 53 includes pad portions 53 a and 53 b formed on the surface of the mounting board 50 and the mounting board 50.
And has a connecting portion 53c for connecting to both pad portions 53a and 53b.

As shown in FIG. 9, this mounting structure
IC chip 5 surrounded by protruding electrodes 52 of chip 51
1 is that the thin film capacitor 10 is disposed below the first capacitor 1.

This is because the thickness of the thin film capacitor 10 is I
This can be realized because it is sufficiently smaller than the height of the protruding electrode 52 of the C chip 51.

The pad section 52a is connected to the IC chip 5
The pad portion 52b is formed at a position where it is joined to the one protruding electrode 52, and the pad portion 52b is formed at a position where it is joined to the protruding electrodes 15 and 16 of the thin film capacitor 10.

In the above mounting structure, the IC chip 5
This is because even if the height of the one protruding electrode 52 is about 300 μm, the overall thickness of the thin film capacitor 10 can be easily controlled such that it can be arranged below the IC chip 51. That is, as described above, the protruding electrodes 15, 16
By performing a suction process on the conductive member to be formed, the overall thickness of the thin film capacitor 10 can be controlled to be minimized, whereby the thin film capacitor 10 can be disposed below the IC chip 51.

Therefore, compared to the case where the thin film capacitor 10 is provided outside the IC chip,
The length of the wiring pattern 53 between the semiconductor device and the IC chip 51 can be minimized, and low inductance can be realized.

The mounting area on the mounting board 50 is
Since the thin-film capacitor 10 can be arranged in the area occupied by the IC chip 51, the mounting space can be reduced.
The mounting density can be increased.

[0089]

As described above in detail, in the thin film capacitor of the present invention, the first protruding electrode is disposed so as to be depressed in part of the lower electrode, and the second protruding electrode is depressed in part of the upper electrode. As a result, the overall thickness of the thin film capacitor can be minimized.

The conductor member connected to the lower electrode on the first through hole formed on the insulating substrate and the conductor member connected to the upper electrode on the second through hole are connected to the rear surface of the substrate through the through hole. Therefore, the amount of protrusion of the conductor member serving as the protruding electrode can be arbitrarily controlled, whereby a thin-film capacitor having an extremely small overall thickness can be obtained.

Furthermore, since the entire thickness can be reduced, the thin film capacitor can be arranged on the mounting board by utilizing the lower part of the IC chip. This not only increases the mounting area, but also minimizes the length of the wiring pattern between the projecting electrodes of the IC chip and the projecting electrodes of the thin-film capacitor. Becomes possible. That is, it can be said that the thin film capacitor is suitable for a high frequency circuit.

[Brief description of the drawings]

FIG. 1 is a sectional structural view of a thin film capacitor of the present invention.

FIG. 2 is a plan view showing one main step in the method for manufacturing a thin film capacitor of the present invention.

FIG. 3 is a plan view showing one main step in the method for manufacturing a thin film capacitor of the present invention.

FIG. 4 is a plan view showing one main step in the method for manufacturing a thin film capacitor of the present invention.

FIG. 5 is a plan view showing one main step in the method for manufacturing a thin film capacitor of the present invention.

FIG. 6 is a plan view showing one main step in the method for manufacturing a thin film capacitor of the present invention.

FIG. 7 is a plan view showing one main step in the method for manufacturing a thin film capacitor of the present invention.

FIG. 8 is a partial cross-sectional view of another method of manufacturing the thin film capacitor of the present invention.

FIG. 9 is a cross-sectional view showing a mounting structure of the thin film capacitor of the present invention.

FIG. 10 is a sectional view showing a conventional thin film capacitor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Thin film capacitor 51 IC chip 50 Mounting board 52 Projecting electrode of IC chip 1 Insulating substrate 2 First through hole 3 Second through hole 11 Lower electrode 12 Thin film dielectric layer 13 Upper electrode 14 Insulation protection layer 15 First protrusion Electrode 16 Second protruding electrode

Claims (3)

[Claims] 1. A lower electrode and a thin film dielectric layer for covering a surface opening of a first through hole on a surface of an insulating substrate having a plurality of first through holes and second through holes penetrating in a thickness direction of the substrate. ,
An upper electrode covering the surface opening of the second through-hole and a capacitor body formed by sequentially forming an insulating protective layer are disposed, and a surface opening of the first through-hole on an upper surface of the capacitor body. Forming a first protruding electrode partially embedded in the lower electrode, and forming a second protruded electrode partially embedded in the upper electrode on the surface opening of the second through hole; A thin film capacitor characterized by the following. 2. An insulating substrate having a plurality of first through-holes and second through-holes penetrating in a thickness direction of a substrate, the surface opening of the first through-hole is closed on the surface of the insulating substrate, and the second through-hole is closed. Forming a lower electrode so as to expose a surface opening of the hole; exposing a lower electrode surface located at a surface opening of the first through hole on the lower electrode; Forming the thin film dielectric layer so as to expose the surface opening of the hole, exposing a lower electrode surface located on the surface opening of the first through hole on the thin film dielectric layer; And forming the upper electrode to close the surface opening of the second through-hole, and positioning the upper electrode at the surface opening of the first through-hole and the surface opening of the second through-hole. Forming an insulating protective layer that exposes the surface of the upper electrode, Arranging a conductor member to be a protruding electrode in a region where each electrode is exposed from the layer; and sucking a part of the conductor member into each electrode by sucking from a back opening of the first and second through holes. And forming a protruding electrode by curing the thin film capacitor. 3. A structure in which an IC chip having a projecting electrode on a mounting surface and the thin film capacitor are mounted on a mounting substrate having a wiring pattern on at least the surface thereof, wherein the thin film capacitor is mounted on the projecting electrode of the IC chip. A mounting structure for a thin film capacitor, wherein the mounting structure is arranged on a mounting substrate in an enclosed area, and a protruding electrode of the thin film capacitor and a protruding electrode of an IC chip are connected via the wiring pattern.