JPH11273997A - Electronic part and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To bring silver used as wiring in a substrate into contact with a Cu-Ag conductor film and to prevent electrical disconnection by allowing a conductor pattern to include the Cu-Ag conductor film and to adhere to a substrate. SOLUTION: Electronic parts include a substrate 1 and a conductor pattern 2. Then, the conductor pattern 2 includes a Cu-Ag conductor film 20 thus constituting a circuit element. The Cu-Ag conductor film 20 is allowed to adhere onto the substrate 1. The substrate 1 is composed by a multilayer substrate and an inner conductor 30 that mainly consists of silver is provided inside. The internal conductor 30 is led to the surface of the substrate 1 via a through hole conductor 31 that mainly is made of silver and is connected to the Cu-Ag conductor film 20 being formed on the surface of the substrate 1, thus preventing electrical disconnection from being generated due to the tendency to liquid phase at an area to the Cu-Ag conductor film 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electronic component and a method for manufacturing the same. Electronic components according to the present invention, for example,
It is suitable as a surface mount electronic component used in the field of wireless devices such as mobile phones and car phones, or various other communication devices.

[0002]

2. Description of the Related Art In this type of electronic component, a multilayer wiring structure has conventionally been adopted as means for realizing high-density wiring. Prior art documents that disclose a multilayer wiring structure include, for example, Japanese Patent Publication No. 3-78798 and Japanese Patent Publication No. 26-78798.
No. 14778 is known. These known documents describe a glass-composite composition of glass and ceramic.
A low temperature fired multilayer substrate using a ceramic material is disclosed. A conductor mainly composed of silver is formed inside the multilayer substrate, and a wiring pattern made of copper is formed on the surface thereof. In this prior art, since a conductor mainly composed of silver is formed inside a multilayer substrate, when forming a ceramic multilayer substrate, baking in air that is effective in promoting binder removal can be performed. Further, since the wiring pattern made of copper is formed on the surface of the multilayer substrate, there is an advantage that silver migration and solder erosion on the surface of the multilayer substrate can be prevented and a wiring pattern having high conductivity can be formed.

[0003] In the production of a multilayer substrate, glass and ceramic materials are mixed in a resinous binder to form a sheet, and a conductive paste mainly made of silver and made into a paint using a glass frit and a binder is screened on the sheet. It is applied by a printing method or the like to form a wiring pattern. Next, the sheets on which the wiring patterns are formed are stacked, and the stacked body is integrated by hot pressing. Next, by heat treatment
The binder (the resin component in the sheet) is removed, and the glass-ceramic material and the conductor mainly composed of silver are sintered together. As a result, a multilayer wiring structure having a wiring made of a sintered conductor film containing silver as a main component is obtained inside the multilayer substrate. The sintered conductor film containing silver as a main component firmly adheres to the substrate due to the glass frit contained therein.

Next, a wiring pattern mainly composed of copper is formed on the surface of the multilayer substrate. This wiring pattern forming method is slightly different between the above two known examples. The former is
A method is disclosed in which a copper paste is applied on a multilayer substrate by applying a screen printing method or the like, and then the conductor is sintered in a reducing atmosphere. In the latter, nickel is first deposited on a multilayer substrate by electroless plating, and then copper is deposited by electrolytic plating. And the method of patterning a copper plating film using a photolithography technique is disclosed.

[0005]

Among the above-mentioned prior arts, a conductor mainly composed of silver is formed inside a ceramic multilayer substrate, and a conductor pattern mainly composed of copper is formed on a surface of the ceramic multilayer substrate by a thick film printing method. Although the technology formed by application has the above-mentioned advantages, it also has the following problems to be solved.

First, it is necessary to expose the wiring inside the multilayer substrate to the surface of the substrate through through holes and the like, and to connect to the conductor formed on the surface. However, when silver is used as the internal wiring and a copper paste containing copper as a main component is printed on the surface in a thick film, the exposed silver conductor comes into contact with the copper paste formed on the substrate surface. When the copper paste is sintered in this state, the contact area between the copper and silver is 60%.
At temperatures above 0 ° C., the atoms diffuse with each other and form a liquid phase. Due to this liquid phase, the contact portion containing silver and copper shrinks more extremely during firing than the surrounding copper pattern. Due to this shrinkage, a gap is formed between the contact portion and the copper pattern around the contact portion.

In order to avoid the disconnection, it is necessary to use a copper paste that can be sintered at about 600 ° C. Actually, there is a copper paste that can be sintered at about 600 ° C.
However, copper paste is generally fired at about 900 ° C., and the copper paste fired at 900 ° C. or higher has a higher frequency band than the copper paste that can be sintered at about 600 ° C. A good conductor with low high-frequency loss can be formed. In other words, when a copper paste that can be sintered at about 600 ° C. is used, wiring made of silver inside the substrate and
Although it is possible to avoid electrical disconnection between the conductor made of copper and formed on the substrate surface, it is not possible to obtain a good conductor having a small high-frequency loss up to a high frequency band.

The electrical disconnection between the wiring made of silver inside the substrate and the conductor made of copper on the surface of the substrate and the deterioration of the high-frequency characteristics are caused by the use of copper. It is also conceivable that the conductor formed on the substrate is made of silver. However, since silver has a high reaction activity, there is a risk that the insulation resistance between the conductor patterns is reduced or silver migration occurs depending on the surrounding environment.

Moreover, since silver easily diffuses and transfers into the solder, when the external connection electrode formed for connection with a motherboard or the like is formed of silver as described above, the external connection electrode is formed at the time of soldering. However, there is a possibility that a so-called solder erosion phenomenon, which is caused by diffusion migration into molten solder and disappearing, that is, a solder erosion phenomenon may occur.

Further, when a conductor pattern is formed by etching a sintered conductor film containing silver as a main component, since the sintered conductor film is attached to a substrate by a glass frit, the conductor pattern is formed. In this case, an etching solution for dissolving the glass frit, for example, an acidic etching solution such as nitric acid cannot be used. At present, usable etching solutions are limited to a mixed solution of ammonia and aqueous hydrogen peroxide or an aqueous solution containing potassium cyanide and ammonium persulfate. However, when a mixed solution of ammonia and aqueous hydrogen peroxide is used, the etching rate is slow, the etching process requires a long time, and a large amount of the etching solution is required. It must be handled with care for fire and is not intended for mass production. Etching using an aqueous solution containing potassium cyanide and ammonium persulfate uses an etching solution that is extremely toxic to the human body, so ensuring the safety of workers becomes extremely important, and the etching solution and its Strict management is required for storage, maintenance and disposal of materials, and considering the costs involved, it is not suitable for mass production.

When a method of depositing copper by plating is adopted instead of the above-described thick film printing method, in general, a plating film is formed while leaving distortion in a plating process. When the thickness is increased to about 10 μm, the adhesion strength of the plating film to the substrate tends to decrease. When the adhesion strength of the conductor film is reduced, it is difficult to obtain a sufficient adhesion strength to the mother board when the above-described external connection electrode is formed.

Further, when the plating film is formed thick, it is difficult to form a uniform plating film thickness on the entire surface of the substrate, and the plating film varies in thickness. This variation in film thickness reduces the pattern forming accuracy when forming a very fine line pattern using photolithography technology. This is because the accuracy of pattern formation using photolithography generally depends largely on the state of the formed conductor surface.

An object of the present invention is to provide an electronic component capable of avoiding electrical disconnection between a wiring inside a substrate and a conductive film formed on the surface of the substrate, and a method for manufacturing the same.

Another object of the present invention is to provide, for example, 650
An object of the present invention is to provide an electronic component that can be fired at a low temperature of up to 850 ° C. and a method for manufacturing the same.

Still another object of the present invention is to provide an electronic component capable of reducing the warpage of a fired substrate and a method of manufacturing the same.

Still another object of the present invention is to provide an electronic component capable of patterning a conductive film formed on a substrate surface without deteriorating the adhesive force, and a method of manufacturing the same.

Still another object of the present invention is to provide an electronic component having a conductor film having a low conductor resistance and a method for manufacturing the same.

[0018]

In order to solve the above-mentioned problems, an electronic component according to the present invention includes a substrate and a conductor pattern. The substrate has an internal conductor therein, and the internal conductor constitutes a wiring conductor connected to the conductor pattern. The conductor pattern is made of a conductor film containing copper as a main component and containing silver (hereinafter referred to as a Cu-Ag conductor film), and constitutes a circuit element. The Cu-Ag conductor film is attached on the substrate.

In the electronic component according to the present invention, the conductor pattern includes a Cu—Ag conductor film, and the Cu—Ag conductor film is adhered on the substrate. This structure provides a great advantage when a conductor film is formed on a multilayer substrate. That is, when configuring a multilayer substrate, generally, a wiring mainly composed of silver is provided inside the multilayer substrate. This wiring is exposed on the surface of the substrate through a through hole or the like, and is connected to a conductor film formed on the surface of the substrate. In the present invention, since the Cu—Ag conductor film constituting the conductor pattern is attached on the substrate, silver used as wiring inside the substrate comes into contact with the Cu—Ag conductor film. In this case, it is possible to avoid occurrence of electrical disconnection due to liquid phase between silver used as the internal wiring of the substrate and the Cu-Ag conductor film.

Moreover, in the case of a Cu-Ag conductor paste,
By setting the conditions of the composition ratio of the paste composition, firing can be performed at a temperature of less than 900 ° C, for example, at a low temperature of 650 to 850 ° C. For this reason, it is possible to reduce energy consumption for manufacturing and extend the life of the firing furnace. In addition, since a Cu-Ag conductor paste that can be fired at a low temperature can be used, the warpage of the multilayer substrate generated in the conductor film firing step can be extremely reduced.

Further, the Cu-A used in the present invention
Since the g conductor film has a composition in which Cu is a main component and silver is added as an additive, the degree of deteriorating the adhesive force of the glass frit that bonds the Cu-Ag conductor film to the substrate is used as a Cu etchant. Ferric chloride (FeCl ₃ ), which has a small amount, can be used. For this reason, a Cu-Ag conductor film having a large adhesive force can be obtained.

In the case of a conductor film made of Cu alone, it is necessary to fire at a temperature of 900 ° C. or more in order to obtain a conductor film having a low resistance. Under a temperature condition lower than this, for example, around 600 ° C., sintering becomes insufficient and the conductor resistance increases. On the contrary,
In the case of a Cu—Ag conductor film, by sintering at a low temperature of, for example, 650 to 850 ° C., it is possible to almost completely sinter and realize a low conductor resistance.

The above effect of the Cu—Ag conductor film is affected by the content of added silver. The preferable content of silver is such that the sum of copper and silver in the Cu—Ag conductor film is 100%.
When it is wt%, it is 0.3 to 30 wt%.

In the present invention, the conductor pattern is used as an element constituting a passive circuit. The conductor pattern forms a required passive circuit alone or in combination with other components. The passive circuit specifically includes at least one of an inductor, a capacitor, and a resistor. The above-described passive circuit may be a single function circuit, or may constitute a function circuit combining some of them. A typical example of a functional circuit based on the combination is a circuit such as a filter, a coupler, or a phase shifter. The conductor pattern and other components are appropriately selected according to the intended passive circuit.

When silver is used as the internal conductor of the substrate,
It can be fired in air, and the binder in the substrate can be easily removed. Carbon contained in the binder has the property of easily remaining in the substrate, but when fired in air,
This is because carbon can be easily treated as carbon dioxide gas by oxygen in the air. In addition, since there is no need for firing in a nitrogen atmosphere, it is easy to maintain and control the atmosphere in the firing furnace.

Further, when the internal conductor is mainly composed of silver, as described above, the electrode disconnection between the Cu-Ag conductor film adhered to the surface of the substrate due to the liquid phase phenomenon during firing. Does not occur.

The substrate preferably comprises a composite composition including a ceramic component and a glass component. More preferably, the substrate has a polished surface. In this case, the Cu-Ag conductor film is attached to the polished surface. The present invention discloses specific examples of preferred ceramic and glass components.

Further, as another aspect, the electronic component according to the present invention may have an insulating layer and another conductor pattern. In this case, the insulating layer covers the conductor pattern, and the another conductor pattern is supported by the insulating layer. More specifically, the another conductor pattern is a conductor film containing copper as a main component. According to such a structure, it is possible to further increase the number of layers and achieve further downsizing and higher functionality.

The electronic component according to the present invention usually includes an external connection electrode. This external connection electrode is provided on the insulating layer. The external connection electrode may have a solder layer on a surface.

In order to manufacture the above-mentioned electronic component, in the manufacturing method according to the present invention, a Cu—Ag conductor paste is applied onto the substrate, and the Cu—Ag conductor film is subjected to processes such as drying, binder removal and firing. To form Next, the Cu-A
A conductor pattern is formed by applying photolithography technology to the g conductor film.

Obviously, according to such a manufacturing method, an electronic component according to the present invention having the above-mentioned advantages can be obtained.

Other objects, features and advantages of the present invention will be described in more detail with reference to the accompanying drawings which are embodiments. The drawings are merely examples.

[0033]

FIG. 1 is a sectional view of an electronic component according to the present invention. Referring to the drawings, an electronic component according to the present invention includes a substrate 1 and a conductor pattern 2. The conductor pattern 2 includes a Cu-Ag conductor film 20 and forms a circuit element. The Cu—Ag conductor film 20 is attached on the substrate 1.

The illustrated substrate 1 is formed of a multilayer substrate, and has an internal conductor 30 containing silver as a main component inside the multilayer substrate 1. The internal conductor 30 is led out to the surface of the substrate 1 through a through-hole conductor 31 containing silver as a main component, and is connected to the Cu-Ag conductor film 20 formed on the surface.

According to this structure, the inner conductor 3 of the substrate 1
The occurrence of electrical disconnection due to liquid phase between silver used as 0 and the Cu—Ag conductor film 20 can be avoided. That is, the Cu-Ag conductor film 20 is formed by applying a Cu-Ag conductor paste on the substrate 1 exposing the internal conductor 30 made of silver and baking it. In this case, when the Cu-Ag conductor paste is baked, a liquid phase occurs at a contact portion between the silver-containing internal conductor 30 provided on the substrate 1 and the Cu-Ag conductor paste. However, since the copper component and the silver component are widely dispersed in the Cu—Ag conductor paste, the liquid phase that occurs during firing is different from that of the entire Cu—Ag conductor paste applied on the substrate 1,
It occurs between the inner conductor 30 made of silver and exposed on the substrate 1. For this reason, there is no local liquid phase between different metals of the copper and the internal conductor made of silver, which is a problem in the related art, and no electrical disconnection due to the liquid phase.

In addition, even if it is said that the liquid phase is caused during the firing, the liquid phase must be completely formed after the liquid phase starts.
Since there is a temperature range to some extent, by setting a firing temperature condition under which the Cu—Ag conductor paste does not flow, the Cu—Ag conductor film 2 having a certain quality is formed on the multilayer substrate 1.
0 can be formed.

Moreover, the Cu—Ag conductor paste is made of Cu
Can be sintered at a lower firing temperature condition than a Cu paste using solely. That is, Cu and Ag are alloyed by the liquid phase, but the melting point itself is reduced accordingly. For example, in the case of a Cu paste, it is necessary to bake at about 900 ° C., but in the case of a Cu—Ag conductor paste, 900 ° C. is set by setting the composition ratio of the paste composition.
Baking can be performed at a temperature lower than ℃, for example, a low temperature of 650 to 850 ℃. For this reason, it is possible to reduce energy consumption for manufacturing and extend the life of the firing furnace.

In the case of a conductor film made of Cu or Ag alone, it is necessary to fire at a temperature of 900 ° C. or more in order to obtain a conductor film having a low resistance. Temperature conditions below this, for example 600
At about ℃, the sintering becomes insufficient and the conductor resistance increases.
On the other hand, in the case of the Cu—Ag conductor film 20, for example, 6
It can be fired at a low temperature of 50 to 850 ° C., sintered almost completely, and realize a low conductor resistance.

Further, in the present invention, since a Cu—Ag conductor paste that can be fired at a low temperature can be used, the warpage of the multilayer substrate 1 generated in the conductor film firing step can be extremely reduced.

Further, the Cu-A used in the present invention
Since the g conductor film 20 has a composition containing Cu as a main component and silver as an additive, it is formed using ferric chloride (FeCl ₃ ).
Can be etched. The etching solution of ferric chloride (FeCl ₃ ) has a small degree of deteriorating the adhesive strength of the glass frit that bonds the Cu—Ag conductive film 20 to the substrate 1. Can be obtained.

The above-described functions and effects will be described in further detail in the section of the description of the manufacturing method described later.

The content of silver contained in the Cu—Ag conductor film is determined by adding the total of copper and silver in the Cu—Ag conductor film to 100 wt.
%, It is 0.3 to 30% by weight. Within this range, the above-described effect of adding silver can be reliably obtained, and silver migration and solder erosion can be prevented. When the silver content is less than 0.3 wt%,
It becomes difficult to uniformly disperse silver, and the effect of adding silver is impaired. If the silver content exceeds 30% by weight, silver migration and solder erosion become remarkable, and C
The advantages of alloying u-Ag are lost.

In the present invention, the conductor pattern 2 is used as an element constituting a passive circuit. Conductor pattern 2
Constitutes the necessary passive circuit alone or in combination with other components. The passive circuit specifically includes at least one of an inductor, a capacitor, and a resistor. The above-described passive circuit may be a single function circuit, or may constitute a function circuit combining some of them. A typical example of the functional circuit by the combination is a filter or a coupler. The conductor pattern 2 and other components are appropriately selected according to the intended passive circuit.

In the embodiment, the substrate 1 includes the inner conductor 30
And the internal conductor 30 constitutes a wiring conductor connected to the conductor pattern 2. Thereby, the multilayered substrate 1 can be obtained.

Further, the electronic component shown in the embodiment has the insulating film 4 and another conductor pattern 50. The insulating film 4 covers the conductor pattern 2, and the conductor pattern 50 is supported by the insulating film 4. Conductor pattern 50
Is a conductor film containing copper as a main component. According to such a structure, it is possible to further increase the number of layers and achieve further downsizing and higher functionality.

Further, the illustrated electronic component includes external connection electrodes 51 and 52. The external connection electrodes 51, 5
2 is provided on the conductor pattern 50. The external connection electrodes 51 and 52 may have a solder layer on the surface. The solder layer includes a solder bump or a solder precoat.

The substrate 1 is preferably made of a composite composition containing a ceramic component and a glass component. More preferably, substrate 1 has a polished surface 10. Cu-Ag
The conductor film 20 is attached to the polished surface 10. In the embodiment, the substrate 1 is divided into an insulating layer 11 and a reinforcing layer 12 with the inner conductor 30 as a boundary.
0 is provided on the surface of the insulating layer 11. The substrate 1 is a sintered body made of a composite composition containing a ceramic component and a glass component. Even if the substrate 1 made of a sintered body has warped due to firing, this warping is eliminated by polishing, and the conductor pattern 2 made of the Cu—Ag conductive film 20 is formed on the surface 10 without such warping. Can be formed. For this reason, it becomes possible to adapt the ceramic substrate 1 to a semiconductor manufacturing technique and to form a highly accurate conductor pattern 2 in a photolithography process. Therefore, the accuracy of the constant value of each circuit element formed by the conductor pattern 2 can be improved, and the circuit element and a functional circuit that is an aggregate of the circuit elements can be designed in a small pattern area.

In addition, the insulating layer 11 made of a composite composition containing a ceramic component and a glass component can be formed by appropriately selecting the mixing ratio of the glass component and the ceramic component, the components, and the like, so that the machinability, strength, and surface smoothness can be improved. Properties can be satisfied almost simultaneously. Even in the case of individually dividing with a dicing saw or the like to make chips, good cutting properties can be ensured and mass productivity can be improved. Therefore, the entire baking warpage and unevenness generated during baking of the substrate 1 can be easily removed by surface polishing. Also, by selecting the type of inorganic component constituting the insulating layer 11 or the content of each component, etc., it is possible to obtain an electronic component having the insulating layer 11 with a smooth surface, no defect, and less warpage. Can also.

The insulating layer 11 made of a composite composition containing a ceramic component and a glass component should be a substrate 1 having extremely few defects and having smoothness in comparison with an insulating layer made of a single ceramic or single glass. it can. Further, by containing a ceramic component, the strength becomes higher than that of glass alone. Furthermore, the fluidity at the time of manufacturing the substrate 1 is lower than that at the time of using the glass alone,
A multilayer wiring structure can be obtained.

The insulating layer 11 made of a composite composition containing a ceramic component and a glass component has a relatively low firing temperature of 1000 ° C. or less and a short baking time of about 10 minutes as compared with the case where the ceramic component alone is sintered. Baking is possible during the temperature holding time. Therefore, as compared with the case where the ceramic component alone is fired, the production equipment is inexpensive and the production time is short, so that mass productivity is good.

The ceramic component for forming the insulating layer 11 is selected from the group consisting of alumina, magnesia, spinel, silica, mullite, forsterite, steatite, cordierite, strontium feldspar, quartz, zinc silicate and zirconia. Further, a material containing at least one kind can be used.

As the glass component, borosilicate glass,
A glass containing at least one selected from the group consisting of lead borosilicate glass, barium borosilicate glass, strontium borosilicate glass, zinc borosilicate glass, and potassium borosilicate glass can be used. The content of the glass component is 50% by volume based on the total volume of the composite composition.
It is desirable that it is above. In particular, a volume ratio of 60 to 70
The range of% is optimal.

The reinforcing layer 12 is integrated with the insulating layer 11 on the side opposite to the surface 10 of the insulating layer 11. By having the above-described reinforcing layer 12, the strength of the substrate 1 can be ensured while the thickness of the insulating layer 11 is reduced. Reinforcement layer 1
2 may be made of a material different from that of the insulating layer 11, but is desirably made of the same material from the viewpoint of unifying the manufacturing process.

FIG. 2 is a diagram showing a state in which the electronic components shown in FIG. As shown in the figure, the electronic component according to the present invention is configured such that the surface on which the conductor pattern 2 made of the Cu-Ag
0 is mounted on the motherboard 70 so as to face the mounting surface 73. The solder layers 81 and 82 provided on the external connection electrodes 51 and 52 correspond to the electrodes 71 and
It is melted by heat treatment such as solder reflow on 72. Thus, the external connection electrodes 51 and 52 of the electronic component and the electrodes 71 and 72 provided on the motherboard 70 are electrically and mechanically connected.

FIG. 3 is an exploded perspective view of a low pass filter (hereinafter referred to as LPF) as an embodiment of the electronic component according to the present invention. FIG. 4 is a sectional view taken along line 4-4 in FIG. 5 is a sectional view taken along line 5-5 in FIG. 3, FIG. 6 is a sectional view taken along line 6-6 in FIG. 3, and FIG. 7 is an equivalent circuit diagram of the LPF shown in FIGS. I have. In the figure, FIG.
The same reference numerals are given to the same components as those shown in FIG.

The conductor pattern 2 includes a first capacitor electrode 204, a second capacitor den electrode 205, an inductor electrode 203, and terminal electrodes 201 and 202. The capacitor electrode 204 is made of the Cu-Ag conductor film 20. The Cu-Ag conductor film 20 is attached on the polished surface 10 of the insulating layer 11 constituting the substrate 1.

The substrate 1 is formed of a multilayer substrate, and has an internal conductor 30 mainly composed of silver and a through-hole conductor 31 inside the multilayer substrate 1. Inner conductor 30
Is led out to the surface of the substrate 1 through the through-hole conductor 31 mainly composed of silver, and is connected to the Cu-Ag conductor film 20 formed on the surface. As described above, since the internal conductor 30 and the through-hole conductor 31 mainly composed of silver come into contact with the Cu—Ag conductor film 20, an electrical problem due to the liquid phase between different metals, which has been a problem in the past. There is no disconnection.

One end of the capacitor electrode 205 is connected to the terminal electrode 201. The coil conductor 203 has a spiral pattern, and the outer peripheral end is connected to the terminal electrode 201 together with one end of the capacitor electrode 205.

The capacitor electrode 205 and the coil conductor 203
And the terminal electrodes 201 and 202 also
In the same manner as described above, it is made of the Cu—Ag conductor film 20. The Cu-Ag conductor film 20 is attached on the surface 10 of the insulating layer 11 constituting the substrate 1. Therefore, not only the capacitor electrode 204, but also the capacitor electrode 205, the coil conductor 203, and the terminal electrodes 201 and 202 can obtain a good conductor pattern with little high-frequency loss up to a high frequency band.

The conductor pattern 2 is covered with the insulating film 4. A conductor pattern 50 containing copper as a main component is attached to the surface of the insulating film 4. The conductor pattern 50 includes capacitor electrodes 501 to 503 and external connection electrodes 51 to 5.
And 4. The capacitor electrode 501 has the capacitor electrode 2 forming the conductor pattern 2 with the insulating film 4 interposed therebetween.
05. The capacitor 501 is connected to the external connection electrode 52
Is conducted. Capacitor electrodes 502 and 503
Are attached to the surface of the insulating film 4 at a distance from each other,
The capacitor electrode 204 commonly faces the capacitor electrode 204 constituting the conductor pattern 2. The capacitor electrode 502 is connected to the external connection electrode 52 together with the capacitor electrode 501.
The capacitor electrode 503 is connected to the external connection electrode 51.

The external connection electrode 52 has a lead conductor 504, and the lead conductor 504 is connected to the inner peripheral end of the coil conductor 203 through a hole 45 provided in the insulating film 4. Thus, the coil conductor 203 is connected to the external connection electrode 52.

The external connection electrode 51 is connected to the terminal electrode 20 of the conductor pattern 2 through the through hole 41 provided in the insulating film 4.
1, the external connection electrode 52 is connected to the terminal electrode 202 of the conductor pattern 2 through the through hole 42. The external connection electrodes 53 and 54 are formed through the through holes 4 provided in the insulating film 4.
3 and 44 connect to the capacitor electrode 204 constituting the conductor pattern 2.

FIG. 7 shows an electric circuit of the LPF shown in FIGS. In FIG. 7, the capacitor C1 is obtained by the capacitor electrode 205 and the capacitor electrode 501 facing each other with the insulating film 4 interposed therebetween. Capacitor C2
Is obtained by the capacitor electrode 204 and the capacitor electrode 503 facing each other with the insulating film 4 interposed therebetween. The capacitor C3 is opposed to the capacitor electrode 204 with the insulating film 4 interposed therebetween.
And the capacitor electrode 502. The inductance L1 is generated by the coil conductor 203. As is clear from the circuit diagram of FIG. 7, according to FIGS.
A small LPF is obtained.

FIG. 8 is a view showing a state in which the electronic components shown in FIGS. As shown, the electronic component 9 according to the present invention is mounted on the motherboard 70 with the surface of the insulating film 6 facing the mounting surface 73 of the motherboard 70. The external connection electrodes 53 and 54 of the electronic component 9 and the electrodes 71 and 72 provided on the motherboard 70 are formed by solder layers 81 and 82.
Electrically and mechanically connected. Furthermore, since the internal conductor 30 provided inside the substrate 1 serves as a ground electrode, it is possible to shield the LPF circuit from electromagnetic effects applied from the outside. The solder layers 81 and 82 are connected to the external connection electrodes 51 to
On the electrodes 71, 72 on the motherboard 70, they can be melted by heat treatment such as solder reflow.

In the high-frequency circuit section of an actual device, the entire high-frequency circuit section is covered by a metal shield cover. At this time, the frequency characteristics of components mounted on the high-frequency circuit unit and whose upper surface side is not shielded by the GND potential are affected by the GND potential of the shield cover, and thus change. This tendency becomes more pronounced as the frequency increases. According to the electromagnetic shield structure shown in the embodiment, the above phenomenon can be avoided.

Next, a method of manufacturing an electronic component according to the present invention will be described with reference to FIGS. FIG. 9 is a flowchart showing a manufacturing process of the electronic component according to the present invention, and FIGS. 10 to 20 are diagrams showing each process shown in FIG.
Hereinafter, the order of the steps will be described with reference to FIG. 9, and the details of each step will be described with reference to FIGS. 10 to 20.

<Sheet Forming Step> In the sheet forming step,
A sheet for the substrate is formed using the dielectric material.
The material of the dielectric material is not limited as long as a conductive paste can be printed and a conductive pattern can be formed by firing. In the embodiments, description will be made on the assumption that a dielectric material which can be co-fired with silver is used.

In order to obtain an electronic component used in a high frequency band exceeding 1 GHz, it is desirable to use a dielectric material having a relative dielectric constant of 15 or less, preferably 10 or less. The reason is that, in the high-frequency band as described above, if the relative dielectric constant is too large, the stray capacitance between the formed conductor patterns cannot be ignored, and the pattern design becomes difficult. The substrate also needs to have good machinability for processing described later.
Therefore, as the dielectric material, a composite composition obtained by mixing a glass material as a base material and a ceramic material as an aggregate is optimal.

Specific examples of the dielectric material include, for example, alumina (εr ≒ 10), magnesia (εr ≒ 9), spinel (εr ≒ 9), silica (εr ≒ 4), mullite (εr ≒ 4).
r ≒ 6.5), forsterite (εr ≒ 6), steatite (εr ≒ 6), cordierite (εr ≒ 5), zirconia (εr ≒ 10) and the like. For example, 1
What is necessary is just to select more than a kind suitably.

The content of glass in the dielectric material comprising the composite composition is preferably 50% or more by volume, particularly preferably 60 to 70%. When the content of glass is less than the above range, it is difficult to form a composite composition, and strength and moldability are reduced. Further, the glass material desirably has a relative dielectric constant equivalent to that of a ceramic material as an aggregate. Specific examples include potassium borosilicate glass, borosilicate glass, lead borosilicate glass, barium borosilicate glass,
Examples generally include glass frit such as strontium borosilicate glass and zinc borosilicate glass, and potassium borosilicate glass, lead borosilicate glass, and strontium borosilicate glass are particularly preferable. As an example of the composition of glass, SiO _2: 50-65 wt%, Al ₂ O _3: 5~15 wt%, B ₂ O _3: 8 wt% or less, C
Examples of 1 to 4 kinds of aO, SrO, BaO, and MgO: 15 to 40% by weight, and PbO: 30% by weight or less can be given.
The composition may further contain at least one selected from Bi ₂ O ₃ , TiO ₂ , ZrO ₂ , and Y ₂ O _{3 at} a content of 5% by weight or less.

As a sheet manufacturing method, a green sheet method is preferable. In the green sheet method, a ceramic particle and a glass frit are mixed, a vehicle such as a binder and a solvent are added thereto, and these are kneaded to form a paste (slurry). Using this paste, for example, a doctor blade method or an extrusion method Etc., preferably from 0.05 to
A predetermined number of green sheets having a thickness of about 0.5 mm are prepared. In this case, the particle size of the glass is about 0.1 to 5 μm,
The aggregate ceramic particles preferably have a size of about 1 to 8 μm. As the vehicle, ethyl cellulose, polyvinyl butyral, and methacrylic resin, a binder such as an acrylic resin such as butyl methacrylate, a solvent such as ethyl cellulose, terpineol, butyl carbitol,
Any of various other dispersants, activators, plasticizers and the like may be appropriately selected according to the purpose. Sheets 11, 101 to 101 in FIG.
Reference numeral 105 denotes a green sheet obtained in this manner.

<Sheet Punching Step> In the sheet punching step, through holes are formed in the green sheet obtained in the sheet forming step by using a punching machine or a die press.

<Inner Conductor Printing Step> In the inner conductor printing step, the inner conductor and the through-hole conductor are formed on the green sheet by, for example, a screen printing method. FIG.
, The inner conductor 30 is provided on the surface of the green sheet 105.
Are printed on the sheet 11 and the through-hole conductors 31
Are formed. The through-hole conductor 31 of the green sheet 11 is formed by filling a through-hole with a conductive paste at the same time as forming a through-hole land pattern (described later). As the conductor paste, it is preferable to mix silver powder and glass frit, add the same vehicle as described above, knead these, and form a slurry. In this case, the content of the silver powder is 80 to 9
It is preferably about 5% by weight. The average particle size of the conductive particles is preferably about 1.01 to 5 μm.

<Lamination and Hot Pressing Step> In the lamination and hot pressing step, the green sheets 101 to 105 obtained through the above-described steps are laminated in the order shown in FIG. And 40-120 ° C, 50-1000Kgf / cm
By performing the heat press at about ^2, the green sheet 1
A laminate of Nos. 01 to 105 and 11 is obtained. The green sheets 101 to 104 on which nothing is printed are laminated in order to adjust the thickness of the entire substrate, and the number and the like are arbitrary.

<Binder Removal and Firing Step> The laminate obtained through the laminating and hot pressing steps is subjected to a binder removing step, and the binder present in the laminate is removed by a heat treatment. Is 800-10
The sintering is carried out by holding at a temperature of about 00 ° C., more preferably 850 to 900 ° C. for about 10 minutes. FIG.
Reference numeral 1 denotes a laminate after the binder removal and firing steps. A multilayer substrate having an internal conductor 30 between a reinforcing layer 12 formed by integrally sintering green sheets 101 to 105 and an insulating layer 11 is obtained. Can be The insulating layer 11 is provided with a through-hole conductor 31. One end of the through-hole conductor 31 is connected to the internal conductor 30, and the other end is connected to the through-hole land pattern 32 on the surface of the insulating layer 11.

Here, since the inner conductor 30 and the through-hole conductor 31 are mainly composed of silver as described above, they can be fired in air, and the binder in the substrate can be easily removed. This is because carbon contained in the binder has a property of easily remaining in the substrate, but when calcined in air, the carbon is easily treated as carbon dioxide gas by oxygen in the air. In addition, since there is no need for firing in a nitrogen atmosphere, it is easy to maintain and control the atmosphere in the firing furnace.

<Multilayer Substrate Polishing Step> In the multilayer substrate (FIG. 11) obtained through the firing step, the entire substrate is warped by the firing step. Since the conductor pattern formed on the substrate surface of the electronic component according to the present invention is formed by a photolithography technique described later, the accuracy of the conductor pattern depends on the flatness of the substrate. That is, for this reason, it is necessary to have adhesiveness to a photomask, or to apply a photoresist uniformly or to irradiate light uniformly. In the multi-layer substrate polishing step, the surface of the substrate is polished (wrapped) to remove the warp of the entire substrate.

Here, the multilayer substrate is made of a composite composition of glass and ceramic and has good machinability, so that lapping can be easily performed. This eliminates warpage of the entire multilayer substrate and improves the smoothness of the substrate surface. FIG. 12 shows the multilayer substrate after polishing. The surface 10 of the multilayer substrate is polished, the through-hole land pattern 32 on the surface 10 is removed, and the through-hole conductor 31 having an area smaller than the through-hole land pattern 32 is formed.
It can be exposed on the surface 10. Therefore, the degree of freedom in designing a circuit pattern on the surface of the multilayer substrate is increased.

<Surface Conductor Printing Step> Next, as shown in FIG.
A Cu-Ag conductor paste containing copper as a main component and containing silver is applied to substantially the entire surface to form a Cu-Ag conductor film 20. The Cu-Ag conductor paste is made into a paint by mixing a Cu powder, an Ag powder, a glass frit, and a binder. The content of silver contained in the Cu—Ag conductor paste is 0.3 to 30 watts when the total of copper and silver in the Cu—Ag conductor paste is 100 wt%.
t%.

There is no limitation on the method of applying the conductor paste. A typical example is a screen printing method, but since the multilayer substrate has been obtained by polishing to have flatness,
Spin coating in which a conductive paste is applied dropwise while rotating the multilayer substrate can be used. At that time, since the conductor paste cannot be applied at a time by spin coating, the application and the drying of the coating film are repeatedly performed, so that the Cu—Ag conductor film 20 having the target coating film thickness is obtained.
It is preferable to obtain

As described above, since the Cu—Ag conductor paste is applied on the substrate 1 by printing means or the like to form the Cu—Ag conductor film 20, the Cu—Ag conductor film can be formed more easily than when the thin film technique or the wet plating technique is applied. The Cu—Ag conductor film 20 can be easily formed thick. Therefore, a conductor pattern having a small actual resistance loss in a high frequency band can be obtained. In particular, when forming a spiral coil pattern (see FIG. 3), a spiral pattern directed from the outside to the inside is formed by the above-described printing means and the like, and further, terminal electrodes connected to the inside and outside of the spiral pattern By applying thin film technology such as evaporation or sputtering or wet plating technology,
A coil having a high Q in a high frequency band can be obtained.

Generally, the substrate 1 is contained in the conductive paste.
A glass frit is added to increase the adhesive strength with the glass. In addition, as described above, the thickness of the conductor made of the conductor paste can be easily increased. For this reason, sufficient adhesion strength to a motherboard or the like can be obtained.

<Drying / Firing Step> Coated Cu-Ag
The conductor film 20 is dried, removed from the binder, and fired.
C coated on the surface of the multilayer substrate of the electronic component according to the present invention
Since the u-Ag conductor film 20 is mainly composed of copper, the binder removal and firing are performed in a nitrogen or neutral atmosphere. The firing temperature also has a relationship with the firing time,
An appropriate temperature is set in a temperature range of 50 ° C.

In this step, when the Cu—Ag conductor paste is fired, the silver internal conductor 3 provided on the substrate 1
A liquid phase is formed at a contact point between 0 and the Cu-Ag conductor paste. However, since the copper component and the silver component are widely dispersed in the Cu-Ag conductor paste, C
The liquid phase that occurs when the u-Ag conductor paste is fired occurs between the entire Cu-Ag conductor paste applied on the substrate 1 and the internal conductor 30 made of silver exposed on the substrate 1. For this reason, there is no local liquid phase between different metals of the copper and the internal conductor made of silver, which is a problem in the related art, and no electrical disconnection due to the liquid phase.

Even if it is said that the liquid phase is caused during the firing, the liquid phase must be completely formed after the liquid phase starts.
Since there is a temperature range to some extent, by setting a firing temperature condition under which the Cu—Ag conductor paste does not flow, the Cu—Ag conductor film 2 having a certain quality is formed on the multilayer substrate 1.
0 can be formed.

In addition, the Cu—Ag conductor paste is made of Cu
Can be sintered at a lower firing temperature condition than a Cu paste using solely. That is, Cu and Ag are alloyed by the liquid phase, but the melting point itself is reduced accordingly. For example, in the case of a Cu paste, it is necessary to bake at about 900 ° C., but in the case of a Cu—Ag conductor paste, as described above, depending on the setting of the composition ratio of the paste composition and the setting of the baking time, it is 650 to 650. Baking can be performed in a temperature range of 850 ° C. For this reason, it is possible to reduce energy consumption for manufacturing and extend the life of the firing furnace.

When the multilayer substrate 1 is made of a composite composition containing a ceramic component and a glass component, the constituent material of the multilayer substrate 1 tends to soften as the temperature at which the conductive film is fired increases. After the firing step, the multilayer substrate 1 was likely to warp. In the present invention, since a Cu-Ag conductor paste that can be fired at a low temperature can be used, the warpage of the multilayer substrate 1 that occurs in the conductor film firing step can be extremely reduced.

Further, in the case of a conductor film made of Cu alone, it is necessary to fire at a temperature of 900 ° C. or more in order to obtain a conductor film having a low resistance. Under a temperature condition lower than this, for example, around 600 ° C., sintering becomes insufficient and the conductor resistance increases. On the other hand, in the case of the Cu—Ag conductor film 20, for example, 650 to 8
By firing at a low temperature of 50 ° C., it can be almost completely sintered, and a low conductor resistance can be realized.

The surface of the Cu—Ag conductor film 20 after firing is
Usually, since it is in a rough state, Cu-Ag
Preferably, the surface of the conductive film 20 is polished to a mirror surface such as buffing. Thereby, the surface of the Cu—Ag conductor film 20 is smoothed, and a thin conductor pattern can be formed with high precision.

<Pattern Forming Step> Next, as shown in FIG. 14, a photolithography technique is applied to the Cu—Ag conductor film 20 to perform a patterning process so as to obtain a desired conductor pattern. In patterning, first, a photoresist is applied to the entire surface of the Cu—Ag conductor film 20. As a coating method, a spin coating method is preferable.

Next, exposure is performed through a photomask on which a target pattern is formed. Thereafter, development is performed to remove the resist film. The exposed portion of the Cu-Ag conductor film is removed by, for example, a chemical etching process.

Here, the Cu—Ag conductor film 20 used in the present invention has a composition containing Cu as a main component and silver as an additive.
The u-Ag conductor film 20 can be etched by using a common ferric chloride (FeCl ₃ ) as a Cu etching solution. Ferric chloride (FeCl ₃ ) etchant is Cu
The degree of deterioration of the adhesive strength of the glass frit that bonds the Ag conductor film 20 to the substrate 1 is small. For this reason,
A Cu—Ag conductor film 20 having a large adhesive force can be obtained. Therefore, the electronic component according to the present invention has a sufficient fixing strength to the motherboard and can be a mounted component in which the electrodes are not lost due to the solder.

<Insulating Layer Forming Step> Next, as shown in FIG. 15, an insulating film 4 is applied on the surface on which the conductor pattern 2 is formed by means such as spin coating. The insulating film 4 is suitably made of a resin-based material such as a polyimide-based or epoxy-based material. As the resin-based material, a material having photosensitivity is preferably used. A resin-based material having photosensitivity has an advantage that a high-precision pattern can be formed by applying photolithography technology.

<Step of Forming Upper Conductor> Next, as shown in FIG. 16, a photolithography technique is applied to the insulating film 4 to perform pattern processing for the next step. FIG.
In the figure, reference numeral 400 indicates a blank pattern.

Next, as shown in FIG. 17, copper is deposited on the insulating film 4 by vapor deposition, sputtering, plating, or the like.
A copper conductor film 5 is formed. The thickness of the copper conductor film 5 is 0.5 to 3
The thickness may be about μm, and sputtering which is relatively fast can be used.

Next, as shown in FIG. 18, a target conductor pattern 50 is obtained by applying a photolithography technique to the copper conductor film 5. Reference numeral 500 in FIG. 18 indicates a cut pattern generated by the pattern processing of the copper conductor film 5.

As described above, after the conductive pattern 2 is formed on the substrate 1 by applying the photolithography technique, the insulating film 4 made of a resin such as polyimide or epoxy is formed, and further deposited, sputtered or sputtered. The copper conductor film 5 is formed by wet plating. Then, the photolithography technique is applied again to form the conductor pattern 50 of the copper film, so that the conductor pattern can be multilayered. For this reason, a multilayered electronic component can be obtained.

<Protective Layer Forming Step> Next, as shown in FIG. 19, a protective film 6 is formed. The material of the protective film 6 is preferably the above-mentioned resin. A portion of the protective film 6 corresponding to a terminal electrode serving as an external connection electrode is removed. As a removing method, a method of applying a photolithography technique and removing unnecessary portions by etching is suitable. However, the external connection electrode is compared to the pattern formed on the substrate.
Since it becomes a relatively large pattern, it may be formed by a screen printing method.

<Individual Dividing Step> Next, as shown in FIG. 20, the substrate is divided along cutting lines X1-X1, and divided into individual electronic components. At this time, since the substrate is a glass-ceramic substrate, it can be easily divided by a dicing saw or the like. Thus, the electronic component according to the present invention is completed.

In the above embodiments, the LPF has been described as an example. However, the present invention relates to various filters such as a band-pass filter, a high-pass filter, and a band elimination filter, various functional parts such as a coupler and a phase shifter, and the above-described functions. It can be applied to composite parts. Also coils,
It can also be applied to single-function individual components such as capacitors.

[0101]

As described above, according to the present invention,
The following effects can be obtained. (A) It is possible to provide an electronic component capable of avoiding electrical disconnection between a wiring inside a substrate and a conductive film formed on the surface of the substrate, and a method for manufacturing the same. (B) It is possible to provide an electronic component that can be fired at a low temperature of, for example, 650 to 850 ° C. and a method for manufacturing the same. (C) It is possible to provide an electronic component capable of reducing the warpage of a fired substrate and a method of manufacturing the same. (D) It is possible to provide an electronic component capable of patterning a conductive film formed on a substrate surface without deteriorating an adhesive force, and a method for manufacturing the same. (E) An electronic component having a conductor film with low conductor resistance and a method for manufacturing the same can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of an electronic component according to the present invention.

FIG. 2 is a cross-sectional view showing a mounted state of the electronic component shown in FIG.

FIG. 3 shows an LP as a specific example of an electronic component according to the present invention.
It is an exploded perspective view showing F.

FIG. 4 is a sectional view taken along line 4-4 in FIG. 3;

FIG. 5 is a sectional view taken along the line 5-5 in FIG. 3;

FIG. 6 is a sectional view taken along line 6-6 in FIG. 3;

FIG. 7 is an equivalent circuit diagram of the LPF shown in FIGS. 3 to 6;

FIG. 8 is a partial cross-sectional view showing a state where the LPF shown in FIGS. 3 to 7 is mounted on a motherboard.

FIG. 9 is a flowchart showing a manufacturing process of an electronic component according to the present invention.

FIG. 10 is a diagram showing a manufacturing process of the electronic component according to the present invention.

FIG. 11 is a view showing a manufacturing process after the manufacturing process shown in FIG. 10;

FIG. 12 is a view showing a manufacturing process after the manufacturing process shown in FIG. 11;

FIG. 13 is a view showing a manufacturing process after the manufacturing process shown in FIG. 12;

FIG. 14 is a view showing a manufacturing process after the manufacturing process shown in FIG. 13;

FIG. 15 is a view showing a manufacturing process after the manufacturing process shown in FIG. 14;

FIG. 16 is a view showing a manufacturing process after the manufacturing process shown in FIG. 15;

FIG. 17 is a view showing a manufacturing process after the manufacturing process shown in FIG. 16;

18 is a view illustrating a manufacturing process after the manufacturing process illustrated in FIG. 17;

FIG. 19 is a view showing a manufacturing process after the manufacturing process shown in FIG. 18;

20 is a view showing a manufacturing process after the manufacturing process shown in FIG. 19;

[Explanation of symbols]

 Reference Signs List 1 substrate 11 insulating layer 10 polished surface 12 reinforcing layer 2 conductive pattern 20 Cu-Ag conductive film

Continued on the front page (51) Int.Cl. ⁶ Identification code FI H05K 1/09 H05K 1/09 A 3/46 3/46 HL

Claims (15)

[Claims] An electronic component including a substrate and a conductor pattern, wherein the substrate has an internal conductor therein, and the internal conductor constitutes a wiring conductor connected to the conductor pattern. The conductor pattern is a conductor film containing copper as a main component and containing silver, and constitutes a circuit element. The conductor film is an electronic component attached to the substrate. 2. The electronic component according to claim 1, wherein the inner conductor is mainly composed of silver. 3. The electronic component according to claim 1, wherein a content of the silver contained in the conductor film is defined assuming that a total of copper and silver is 100 wt%. 0.3-30wt%
Electronic components. 4. The electronic component according to claim 1, wherein the substrate is formed of a composite composition including a ceramic component and a glass component. 5. The electronic component according to claim 4, wherein the substrate has a polished surface, and wherein the conductive film is attached to the polished surface. . 6. The electronic component according to claim 4, wherein the ceramic component is alumina, magnesia, spinel, silica, mullite, forsterite, steatite, cordierite, strontium feldspar, quartz, zinc silicate. And an electronic component containing at least one selected from the group consisting of zirconia. 7. The electronic component according to claim 4, wherein the glass component is borosilicate glass, lead borosilicate glass, barium borosilicate glass, strontium borosilicate glass, zinc borosilicate glass, and potassium borosilicate An electronic component including at least one selected from the group of glass. 8. The electronic component according to claim 1, further comprising: an insulating layer and another conductor pattern; wherein the insulating layer covers the conductor pattern; An electronic component, wherein the conductor pattern is supported by the insulating layer. 9. The electronic component according to claim 8, wherein the another conductor pattern is made of copper as a main component and a conductor film. 10. The electronic component according to claim 9, wherein the another conductor pattern includes an external connection electrode for external connection. 11. The electronic component according to claim 10, wherein the external connection electrode has a solder layer on a surface. 12. The electronic component according to claim 1, wherein the passive circuit includes at least one of an inductor, a capacitor, and a resistor. 13. The electronic component according to claim 1, wherein the passive circuit forms a circuit such as a filter, a coupler, or a phase shifter. 14. The method of manufacturing an electronic component according to claim 1, wherein a conductive paste containing copper as a main component and silver is applied to the substrate, and dried and debindered. And a process such as baking to form a conductor film, and applying a photolithography technique to the conductor film to form the conductor pattern. 15. The method for manufacturing an electronic component according to claim 14, further comprising the step of buffing the surface of the conductive film after firing.