JP2000323345A - High-frequency electronic parts and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide high-frequency electronic parts having a good high-frequency characteristic and a method by which the electronic parts can be manufactured at a high yield. SOLUTION: An insulating substrate 1 carries a conductor pattern 2. The pattern 2 contains a first conductive film 21 and a second conductive film 22. The first conductive film 21 is stuck to the surface of the substrate 1. The second conductive film 22 is stuck to the surface of the first conductive film 21 to cover the surface 211 and both side faces 212 and 213 of the film 21, and has outwardly expanding portions 221 and 222 the thicknesses of which increase as going toward the surface 211 side of the first conductive film 21 from both side faces 212 and 213 of the film 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high-frequency electronic component and a method for manufacturing the same. The high-frequency electronic component according to the present invention is used for various communication devices including, for example, mobile phones, car phones, and the like, and is a single-function component such as a chip coil, a chip capacitor or a chip filter, or a composite component combining these components. including. In the present invention,
The wafer refers to a substrate on which a large number of these single-function components or composite components are formed, or a substrate provided for formation.

[0002]

2. Description of the Related Art Conventionally, in a high-frequency circuit of 100 MHz or higher, for example, as disclosed in Japanese Patent Application Laid-Open No. 9-199365, a conductive film is formed on a substrate by using a conductive paste, and then a predetermined amount is formed by etching. A conductor pattern was formed.

[0003] Japanese Patent Publication No. 35-3723 discloses a method in which a copper paste is printed on a resin substrate, dried, and then copper-plated by electroplating. Furthermore, Japanese Patent No. 2802181 discloses a technique in which an oxidized copper film is formed on a ceramic substrate and then copper plating is performed by, for example, a PVD method.

[0004] The conductive film obtained through the above-described conventional process is as follows.
The film cross section becomes substantially trapezoidal or substantially rectangular. In a conductive film having this cross-sectional shape, the high-frequency characteristics (Q value) depend on the cross-sectional area of the film. The cross-sectional area of the film can be ensured by increasing the film thickness or increasing the film width. In such a high-frequency electronic component, it is necessary to form a conductive film with high precision and a small line width. Therefore, in securing the cross-sectional area, it is suitable to increase the film thickness while suppressing the line width. However, increasing the film thickness involves various problems. It is described below.

First, in this type of method for manufacturing a high-frequency electronic component, a number of high-frequency electronic component elements are formed on one wafer. However, when a conductive paste is formed on a wafer in a wafer process, the thicker the conductive paste, the greater the variation in the film thickness distribution in the wafer surface. Depending on the conditions at the time of coating, in the plane of the wafer,
A thickness variation of about ± 5 μm may occur. If there is such a thickness variation, where the conductive film is thin,
On the other hand, when the etching of the conductive film proceeds excessively, the conductive film becomes too thin. On the contrary, in a place where the film thickness is large, a short-circuit portion remains between the patterns due to insufficient etching. These defects are:
Decrease yield.

Next, since the conductive film is subjected to isotropic etching, the side etching (under-etching) of the conductive film located under the resist film becomes large where the thickness of the conductive film is large. Cannot be obtained.

Further, as the thickness of the conductive film increases, the stress generated at the interface between the conductive film and the wafer increases, and after firing the conductive film, the entire wafer is warped.
When such a warp occurs, the adhesiveness between the mask and the wafer deteriorates, and the pattern accuracy decreases.

In order to avoid the above-mentioned problems, the thickness of the conductive film must be kept within a certain value. For this reason, there has been a limit in improving the high frequency characteristics. In particular, it has been difficult to suppress the loss caused by the skin effect that occurs in the high frequency region.

Furthermore, since the cross-sectional shape of the conductive film is rectangular or trapezoidal, it is not possible to eliminate a pointed portion where a high-frequency magnetic field is concentrated due to the localization of a high-frequency current in the conductor cross section. For this reason, the localization of the high-frequency current cannot be eliminated, so that the conductor loss in the high-frequency body cannot be improved.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a high-frequency electronic component having good high-frequency characteristics and a method of manufacturing the high-frequency electronic component at a high yield.

Another object of the present invention is to provide a high-frequency electronic component capable of avoiding over-etching and under-etching of a conductive film and improving the yield, and a method of manufacturing the same.

Still another object of the present invention is to provide a high-frequency electronic component having a conductive film having a high-precision line width and a method of manufacturing the same.

Still another object of the present invention is to provide a high-frequency electronic component in which a high-frequency loss due to a skin effect is reduced and high-frequency characteristics are improved.

Still another object of the present invention is to provide a high-frequency electronic component which alleviates local concentration of a high-frequency magnetic field and avoids characteristic deterioration due to local concentration of a high-frequency magnetic field, and a method of manufacturing the same.

Still another object of the present invention is to provide a method of manufacturing a high-frequency electronic component which has good adhesion between a mask and a wafer and can improve the pattern accuracy of a conductive film.

[0016]

In order to solve the above-mentioned problems, a high-frequency electronic component according to the present invention includes an insulating base and a conductor pattern. The insulating base supports the conductor pattern.

The conductor pattern includes a first conductive film and a second conductive film. The first conductive film is attached on a surface of the insulating base. The second conductive film is adhered on the first conductive film, covers a surface and both side surfaces of the first conductive film, and covers the first conductive film from both side surfaces of the first conductive film. The thickness increases toward the surface side of the conductive film, and has a portion that swells outward.

As described above, the conductor pattern includes the first conductive film and the second conductive film. The first conductive film is attached on a surface of the insulating substrate, and the second conductive film is attached on the first conductive film. That is, it has a two-layer film structure. The first conductive film may be formed by a process of applying, drying, baking, and further patterning a conductive paste on a wafer used as an insulating substrate in a wafer process before being divided as a high-frequency electronic component. it can. In this case, since the second conductive film is formed later on the first conductive film, it is not necessary to increase the thickness of the first conductive film. For this reason, the distribution of the thickness of the first conductive film in the wafer surface can be made uniform, and variations in the film thickness can be suppressed. Therefore, the first conductive film can be prevented from being over-etched and under-etched, and the yield can be improved.

Further, a side etching (under etching) of the conductive film located under the etching resist film.
And a conductive film having a desired line width can be obtained.

Further, since the thickness of the first conductive film may be small, the stress generated at the interface between the first conductive film and the wafer is reduced, and the wafer generated after firing the first conductive film is reduced. Warpage can be reduced. Therefore, the adhesion between the mask and the wafer is improved, and the pattern accuracy of the first conductive film is improved.

Since the second conductive film covers the surface and both side surfaces of the first conductive film, even if, for example, an over-etched portion or side etching occurs in the first conductive film, The above-described etching defect portion can be compensated for by the second conductive film. At the time of forming the second conductive film, the first conductive film is already formed on the insulating base, so that the second conductive film can be formed by a wet plating method such as an electroless plating method. .

Further, the thickness of the second conductive film increases from both sides of the first conductive film toward the surface of the first conductive film, and the second conductive film has a portion which swells outward. Due to this cross-sectional shape, the high-frequency current caused by the skin effect mainly
Flow through the conductive film. Therefore, high-frequency loss due to the skin effect can be reduced, and high-frequency characteristics are improved.

Moreover, since the second conductive film has a cross-sectional shape with a continuous curve as a whole, it is possible to avoid local concentration of the high-frequency magnetic field due to high-frequency current and deterioration of characteristics due to local concentration of the high-frequency magnetic field. it can. The second conductive film having the above-described cross-sectional shape can be realized by employing an electroless plating method.

To manufacture the high-frequency electronic component according to the present invention, first, a first conductive film is formed on the surface of a wafer serving as an insulating base. Next, a second conductive film is formed over the first conductive film by an electroless plating method. Thus, a second conductive film having a predetermined cross-sectional shape can be formed.

Preferably, heat treatment is performed after forming the second conductive film by electroless plating. According to this heat treatment, the electric resistance of the second conductive film can be reduced. The heat treatment is preferably performed under a temperature condition of 300 ° C. or more and less than 900 ° C. Within this range, the first conductive film containing a frit or the like is not thermally degraded.

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

[0027]

FIG. 1 is an exploded perspective view of a high-frequency electronic component according to the present invention, and FIG. 2 is a sectional view of the high-frequency electronic component shown in FIG. Referring to the drawing, the high-frequency electronic component according to the present invention includes an insulating base 1 and a conductor pattern 2. The insulating substrate 1 is made of an inorganic sintered body. The conductor pattern 2 constitutes a circuit element. In the embodiment, the conductor pattern 2 has a spiral pattern 203,
Functions as a coil. Of the two ends of the spiral pattern 203, one end that appears outside is connected to the terminal electrode 201. An external connection electrode 51 is attached to the surface of the terminal electrode 201.

The spiral pattern 203 is covered with an insulating layer 4 made of an organic insulating material or the like. Another conductor pattern 5 is formed on the surface of the insulating layer 4. The inner end of the spiral pattern 203 is led out to the surface side of the insulating layer 4 through a via hole 40 provided in the insulating layer 4,
Lead conductor 5 of conductor pattern 5 provided on the surface of insulating layer 4
0, it is connected to the external connection electrode 52. The external connection electrode 52 is attached to the terminal electrode 202 adhered to the surface 10 of the insulating base 1 with the adhesive 3. The external connection electrodes 51 and 52 may have a solder layer on the surface 10.

FIG. 3 is an enlarged sectional view showing a part of the conductor pattern 2. As shown, in the high-frequency electronic component according to the present invention, the conductor pattern 2
And the second conductive film 22. The first conductive film 21
It is attached on the surface of the insulating substrate 1. Second conductive film 22
Is deposited on the first conductive film 21 and the first conductive film 2
1 covers the front surface 211 and both side surfaces 212 and 213. The thickness of the second conductive film 22 increases from both side surfaces 212 and 213 of the first conductive film 21 toward the surface 211 of the first conductive film 21, and the second conductive film 22 swells outward.
21, 222. Therefore, the maximum film width W2 of the second conductive film 22 is larger than the film width W1 of the first conductive film 21. Further, the second conductive film 2 is formed from the surface of the insulating substrate 1.
2 is equal to the thickness t of the first conductive film 21.
1 and the thickness t2 of the second conductive film 22. Second
The thickness t2 of the conductive film 22 is the surface 21 of the first conductive film 21.
The thickness is based on 1.

As described above, the conductor pattern 2 has the first shape.
, And a second conductive film 22. The first conductive film 21 is attached on the surface of the insulating base 1,
The second conductive film 22 is attached on the first conductive film 21. That is, it has a two-layer film structure. The first conductive film 21
In a wafer process before dividing as a high-frequency electronic component, a conductive paste is applied to a wafer used as the insulating substrate 1, dried, baked, and further, for example,
It can be formed by a process of patterning by a photolithography step. In this case, as described later, the second conductive film 21 is formed on the first conductive film 21 later.
Since the conductive film 22 is formed, it is not necessary to increase the thickness t1 of the first conductive film 21. For this reason, the film thickness distribution of the first conductive film 21 in the wafer surface can be made uniform, and variations in the film thickness can be suppressed. Therefore, the first conductive film 21 can be prevented from being over-etched or under-etched, and the yield can be improved.

Further, side etching (under etching) of the conductive film located below the etching resist film.
And a conductive film having a desired line width can be obtained.

Further, since the thickness of the first conductive film 21 may be small, the stress generated at the interface between the first conductive film and the wafer is reduced, and the stress generated after firing the first conductive film 21 is reduced. Wafer warpage can be reduced. For this reason, the adhesion between the mask and the wafer is improved, and the pattern accuracy of the first conductive film 21 is improved.

Since the second conductive film 22 covers the surface 211 and both side surfaces 212 and 213 of the first conductive film 21, the first conductive film 21 has, for example, an over-etched portion or a side-etched portion. Even when such a phenomenon occurs, the above-described etching defect portion can be compensated for by the second conductive film 22. When the second conductive film 22 is formed, since the first conductive film 21 has already been formed on the insulating substrate 1, the second conductive film 22 is wet-plated by an electroless plating method or the like. It can be formed by a method.

Further, the thickness of the second conductive film 22 increases from both side surfaces 212 and 213 of the first conductive film 21 toward the surface of the first conductive film 21, and the portion 221 bulges outward. , 222. Due to this cross-sectional shape, the high-frequency current caused by the skin effect is mainly caused by the second conductive film 2.
It will flow through 2. Therefore, high-frequency loss due to the skin effect can be reduced, and high-frequency characteristics are improved.

Moreover, since the second conductive film 22 has a cross-sectional shape with a continuous curve as a whole, local concentration of the high-frequency magnetic field due to localization of the high-frequency current in the conductor cross section is eliminated. For this reason, the conductor loss in the high frequency band is improved, and the deterioration of the characteristics of the high frequency component formed using this conductor can be avoided. The second conductive film 22 having the above-described cross-sectional shape can be realized by employing an electroless plating method.

In the second conductive film 22, it is preferable that the outwardly expanding portions 221 and 222 have a substantially arc-shaped cross section. Local concentration of high-frequency magnetic field due to high-frequency current, and characteristic degradation due to local concentration of high-frequency magnetic field,
This is because it can be avoided more effectively.

The starting ends of the outwardly expanding portions 221 and 222 are preferably substantially coincident with the contact positions P1 and P2 between the insulating substrate 1 and the first conductive film 21. According to this configuration, it is possible to more reliably realize the elimination of the etching defect portion of the first conductive film 21, the reduction of the high frequency loss caused by the skin effect, and the avoidance of the local concentration of the high frequency magnetic field.

As described above, the first conductive film 21
It is a sintered conductive film. In this case, the first conductive film 21 is made of C
It may contain at least one of u, Ag and Au. In particular, Cu is preferably used as a main component in terms of cost and low electric resistance. The first conductive film 21 may include Pd. The first conductive film 21 has a thickness t1 of 2 to 2.
It is preferably in the range of 7 μm. First conductive film 21
If the thickness t1 of the first conductive film 22 is smaller than 2 μm,
It takes time to grow the plating, and mass productivity is reduced. When the thickness t1 of the first conductive film 21 exceeds 7 μm,
The above-described problem due to the increase in film thickness occurs.

As described above, the second conductive film 22 is preferably made of an electroless plating film. As the second conductive film 22, a plating bath in which a plating film having the same composition as the first conductive film 21 is formed is used. That is, a plating bath containing at least one of Cu, Ag, and Au is used. Particularly preferably, a plating bath for Cu plating is used. By forming the second conductive film 22 as a plating film having the same composition as the first conductive film 21, the first conductive film 21 and the second conductive film 22 can be firmly adhered. The thickness t2 of the second conductive film 22 based on the surface 211 of the first conductive film 21 is preferably in the range of 1 to 6 μm. Aspect ratio as conductor pattern 2 (T / W1)
Can be set in the range of 0.1 to 1. Particularly preferably, W1 is about 10 μm and the aspect ratio (T / W
The second conductive film 22 is formed so that 1) becomes substantially 1. When the aspect ratio is approximately 1, a good Q value can be secured.

The insulating substrate 1 is preferably made of a sintered body. By appropriately selecting the components and the like, the insulating base 1 made of a sintered body can satisfy the machinability, the strength, the smoothness of the surface 10, and the like 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.

Further, it is possible to obtain a high-frequency electronic component having an insulating substrate 1 with a smooth surface 10 and few defects by selecting the type of inorganic component constituting the insulating substrate 1 or the content of each component. Can also.

The insulating substrate 1 is preferably made of a composite composition containing a ceramic component and a glass component. More preferably, insulating substrate 1 has a polished surface. The insulating substrate 1 made of a composite composition containing a ceramic component and a glass component can be an insulating substrate 1 having extremely few defects and having smoothness in comparison with an insulating layer made of a single ceramic or single glass. Further, by containing a ceramic component, the strength becomes higher than that of glass alone.

The insulating base 1 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 shorter firing 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 constituting the insulating substrate 1 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 this is the case. In particular, a volume ratio of 60 to 70
The range of% is optimal.

FIG. 4 is a diagram showing a state in which the high-frequency electronic components shown in FIGS. 1 and 2 are mounted on a motherboard 70. As shown, the high-frequency electronic component according to the present invention is:
It is mounted on the motherboard 70 with the surface on which the conductor pattern 2 is formed facing the mounting surface 73 of the motherboard 70. The solder layers 81 and 82 provided on the external connection electrodes 51 and 52 correspond to the electrodes 71 and 7 on the motherboard 70.
2 is melted by heat treatment such as solder reflow. Thus, the external connection electrodes 51 and 52 of the high-frequency electronic component and the electrodes 71 and 72 provided on the motherboard 70 are electrically and mechanically connected.

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 and a capacitor. 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 2 and other components are appropriately selected according to the intended passive circuit. The following is an example of such an application.

FIG. 5 is a diagram showing a high-frequency electronic component according to an embodiment of the present invention.
FIG. 6 is a sectional view taken along line 6-6 of FIG. 5, FIG. 7 is a sectional view taken along line 7-7 of FIG.
FIG. 8 is a sectional view taken along line 8-8 in FIG. 5, and FIG. 9 is an equivalent circuit diagram of the LPF shown in FIGS. In the figure, the same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals.

The insulating substrate 1 is made of an inorganic sintered body as described above. The conductor pattern 2 includes a first capacitor electrode 204
, The second capacitor electrode 205 and the inductor electrode 2
03, and terminal electrodes 201 and 202. As described with reference to FIG. 3, the conductor pattern 2 including these electrodes 201 to 205 includes a first conductive film 21 and a second conductive film 22.
And is constituted by. Therefore, the operation and effect described with reference to FIGS.

The conductor pattern 2 is covered with the insulating film 4. A conductor pattern 5 containing copper as a main component is attached to the surface of the insulating film 4. The conductor pattern 5 includes capacitor electrodes 501 to 503 and external connection electrodes 51 to 54.
And The capacitor electrode 501 is connected to the capacitor electrode 20 forming the conductor pattern 2 with the insulating film 4 interposed therebetween.
5. 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 is connected to the lead conductor 504.
And the lead conductor 504 is connected to the inner peripheral end of the coil conductor 203 through the hole 45 provided in the insulating film 4. As a result, the coil conductor 203 is connected to the external connection electrode 52.

The external connection electrode 51 is connected to the terminal electrode 2 of the conductor pattern 2 through the through hole 41 provided in the insulating film 4.
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 connected to the capacitor electrodes 204 constituting the conductor pattern 2 by through holes 43 and 44 provided in the insulating film 4.

FIG. 9 shows an electric circuit of the LPF shown in FIGS. In FIG. 9, 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. 9, according to FIGS.
A small LPF is obtained.

FIG. 10 is a diagram showing a state in which the high-frequency electronic components shown in FIGS.
As illustrated, the high-frequency 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 high-frequency electronic component 9 and the electrodes 71 and 72 provided on the motherboard 70 are electrically and mechanically connected by solder layers 81 and 82. The solder layers 81 and 82 are attached to the external connection electrodes 51 to 54 in advance, and the electrodes 71 and 72 on the motherboard 70 are attached.
Above, it can be melted by heat treatment such as solder reflow.

Next, a method for manufacturing a high-frequency electronic component according to the present invention will be described with reference to FIGS. FIG. 11 is a flowchart showing the steps of manufacturing the high-frequency electronic component according to the present invention, and FIGS. 12 to 22 are views showing the steps shown in FIG. Hereinafter, the order of the steps will be described with reference to FIG. 11, and each step will be individually described in detail with reference to FIGS. 12 to 22.

<Preparation of Wafer> First, a wafer is prepared using a dielectric material. This wafer becomes the insulating substrate 1 shown in FIGS. There is no material limitation on the dielectric material for the wafer, but when obtaining a high-frequency electronic component used in a high-frequency band exceeding 1 GHz, the relative dielectric constant is 15%.
It is desirable to use no more than 10, preferably no more than 10 dielectric materials. 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 wafer 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 composed of 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 wafer manufacturing method, a green sheet method is preferable. In the green sheet method, ceramic particles and glass frit are mixed, a vehicle such as a binder and a solvent is added thereto, and these are kneaded to form a paste (slurry). Using this paste, for example, by a doctor blade method, an extrusion method, or the like, preferably 0.05
A predetermined number of green sheets having a thickness of about 0.5 mm are prepared. In this case, the glass preferably has a particle size of about 0.1 to 5 μm, and the aggregate ceramic particles preferably have a particle size of about 1 to 8 μm. Examples of the vehicle include ethyl cellulose, polyvinyl butyral, methacrylic resin, a binder such as an acrylic resin such as butyl methacrylate, a solvent such as ethyl cellulose, terpineol, and butyl carbitol, and other various dispersants, activators, and plasticizers. May be appropriately selected according to the conditions.

The laminated body obtained through the laminating and hot pressing steps is subjected to a binder removing step to remove the binder present in the laminated body by a heat treatment, and further to a temperature of 1000 ° C. or less, preferably about 800 to 1000 ° C. More preferably, firing is carried out at a temperature of 850 to 900 ° C. for about 10 minutes. As a result, a wafer obtained by integrally sintering the green sheet is obtained. FIG. 12 shows a cross-sectional view of the wafer 1 obtained as described above.

<Conductor Paste Application Step> Using the wafer 1 prepared as described above, as shown in FIG. 13, a conductor paste is applied on one surface of the wafer 1 to form a first conductive film 21. I do. As a coating method, a screen printing method is desirable. The applied film thickness of the first conductive film 21 is made as thick as possible as long as the absolute value of the film thickness variation after baking can be minimized. Specifically, the conductor thickness after firing is 5 to 6 μm.
m.

When the screen printing method is adopted, the conductor paste preferably has high fluidity (leveling property). In the screen printing method, the conductor paste is extruded with a squeegee through a screen, so that traces of mesh on the screen and traces of movement of the squeegee remain on the applied conductor paste. These traces remain on the conductor film after sintering, and when photolithography is performed, pattern accuracy is deteriorated. In particular, the edge of the line pattern tends to be rough.

As a countermeasure, it is necessary to remove traces on the coating surface due to the leveling property of the conductor. One of the means to improve the leveling property is to add
For example, adding an ethylcellulose-based resin as a binder.

It is preferable to use a conductor containing copper as a main component as the conductor paste. The first conductive film 21 formed on the wafer 1 is etched as described below, and the sintered conductive film is adhered to the wafer 1 by a glass brit included in the conductor paste. . Therefore, an acidic etching solution that dissolves the glass frit cannot be used. If the sintered conductor film is mainly composed of copper, the commonly used ferric chloride (FeC
l ₃ ) Aqueous solution can be used. According to this etchant, it is possible to form a target conductor pattern while minimizing the influence on the glass bullets on which the first conductive film 21 is adhered to the wafer 1.

<Drying and Firing Step> Next, the applied first conductive film 21 is dried, debindered, and fired. When the first conductive film 21 contains copper as a main component, the steps of removing the binder and firing must be performed in a nitrogen atmosphere.

<Polishing Step> It is impossible to remove even fine pores on the surface of the conductor film after sintering the conductor, even if the conductor paste with improved leveling is used. O. from the surface of the conductor film In a region of about 5 μm, fine pores and copper-grown lumps are present in a coarse state. For example, a fine pattern of about 10 μm is not in a good state for forming a precise pattern. Therefore, it is necessary to make the surface almost mirror-like by polishing. Polishing can be performed by a polishing process using fine abrasive grains or the like.

<Conductor Pattern Forming Step> Next, a photolithography technique is applied to the first conductive film to perform a patterning process so as to obtain a target conductor pattern. When applying photolithography technology,
As shown in FIG. 4, a photoresist PR is applied, and then,
The photoresist PR is exposed through a photomask PM on which a target pattern is formed. Thereafter, as shown in FIG. 15, the uncured portions of the photoresist PR are removed (developed). The exposed portion of the first conductive film 21 is removed by, for example, a chemical etching process.
Through this pattern forming step, a first conductive film 21 having a target pattern is obtained as shown in FIG.

First conductive film 21 having desired pattern
In order to obtain (1), a method of directly forming a conductor pattern by a screen printing method is also possible, but a photolithography technique is suitable for forming a high-definition pattern. That is, a photoresist PR is applied on the first conductive film 21 formed over the entire surface of the wafer 1 by a spin coater or the like, and the photoresist PR is primarily cured by heat treatment or the like, and then as shown in FIG. Next, the photomask PM is brought into contact with the photoresist PR, exposed to light, and developed as shown in FIG. 15 to form a resist pattern having a target pattern.

In the manufacturing method of the present invention, since the warpage of the wafer 1 is reduced, the photoresist PR
The photomask PM can be closely attached. Therefore, in FIG. 15, the resist pattern moldability is improved.

Next, the wafer 1 on which the resist pattern has been formed is subjected to a heat treatment as required, and the photoresist PR is secondarily cured. Thereafter, the first conductive film 21 having the target pattern is immersed in an etching bath or placed in a shower cleaning bath with an etchant to remove the conductive film other than the target pattern, as shown in FIG. Get. If the first conductive film 21 containing copper as a main component, it is possible to apply an aqueous solution of ferric chloride (FeCl ₃₎ as an etching solution, thereby bonding the first conductive film 21 on the wafer 1 Etching can be performed satisfactorily while minimizing the influence of the glass frit.

<Electroless Plating Step> Next, a second conductive film 22 is formed on the first conductive film 21 by an electroless plating method. Thereby, as shown in FIG. 17, the second conductive film 22 having a predetermined cross-sectional shape can be formed.

Preferably, a heat treatment is performed after forming the second conductive film 22 by electroless plating. According to this heat treatment, the electric resistance of the second conductive film 22 can be reduced. The heat treatment is preferably performed under a temperature condition of 300 ° C. or more and less than 900 ° C. Within this range, the first conductive film 21 containing a frit or the like and sintered on the insulating substrate is used.
No thermal degradation.

In the electroless plating method for forming the second conductive film 22, a plating bath in which a plating film of the same system as the first conductive film 21 is formed is used. That is, Cu, Ag
Alternatively, a plating bath containing at least one kind of Au is used.
Particularly preferably, a plating bath for Cu plating is used. By forming the second conductive film 22 as a plating film of the same system as the first conductive film 21, the first conductive film 2 is formed.
The first and second conductive films 22 can be firmly adhered. The plating thickness of the second conductive film 22 is 5 to 6 μm.
The target is about m. However, in the case of copper electroless plating, the deposition rate of copper is very slow, and at least 3 (μm / 30 minutes)
Therefore, it cannot be made too thick in consideration of mass productivity.

<Insulating Layer Forming Step> Next, as shown in FIG. 18, the 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 shown in FIG. 19, the conductive pattern 2 formed on the wafer 1 and the conductive pattern formed on the insulating film 4 are also formed on the applied insulating film 4 by using a photolithography technique, as shown in FIG. A hole (via) or the like for connection is formed.

<Step of Forming Upper Conductor> Next, as shown in FIG. 20, the insulating film 4 is formed by vapor deposition, sputtering, plating or the like.
The conductive film 5 is formed thereon. The conductive film 5 preferably contains copper as a main component. The thickness of the conductive film 5 may be about 1 to 4 μm.

<Protective Layer Forming Step> Next, as shown in FIG. 21, 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, since the external connection electrode is a relatively large pattern as compared with the pattern formed on the insulating base 1, it may be formed by a screen printing method.

The insulating film to be the uppermost layer of the high-frequency component according to the present invention is formed to serve as a protective layer. As the material, the above-described resin is preferable, and finally, the protective film formed on the external connection portion is removed so that the external connection electrode of the high-frequency component according to the present invention is exposed. Etching is suitable as the removing method, but the external connection electrode has a relatively large pattern as compared with the pattern formed on the substrate. Therefore, it is also possible to form an insulating film by a printing method using a screen.

<Individual Dividing Step> Next, as shown in FIG. 22, the substrate is divided along cutting lines X1-X1, and divided into individual high-frequency electronic components. At this time, since the insulating base 1 is the glass-ceramic insulating base 1, it can be easily divided by a dicing saw or the like. As described above, the high-frequency electronic component according to the present invention is completed.

In the above embodiment, 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, 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.

Further, in the embodiment, the insulating substrate and the wafer having no conductor inside are shown, but the insulating substrate and the wafer having a multilayer structure having the internal conductor or the internal wiring may be used.

Although the present invention has been described in detail with reference to preferred specific embodiments, it will be understood by those skilled in the art that various modifications can be made in the form and details without departing from the spirit and scope of the present invention. It is clear to

[0082]

As described above, according to the present invention, the following effects can be obtained. (A) It is possible to provide a high-frequency electronic component having good high-frequency characteristics and a manufacturing method capable of manufacturing this high-frequency electronic component at a high yield. (B) It is possible to provide a high-frequency electronic component capable of avoiding over-etching and under-etching of a conductive film and improving the yield, and a method for manufacturing the same. (C) It is possible to provide a high-frequency electronic component having a conductive film having a high-precision line width and a method of manufacturing the same. (D) A high-frequency electronic component with reduced high-frequency loss due to the skin effect and improved high-frequency characteristics can be provided. (E) It is possible to provide a high-frequency electronic component which alleviates local concentration of a high-frequency magnetic field and avoids characteristic deterioration due to local concentration of a high-frequency magnetic field, and a method of manufacturing the same. (F) It is possible to provide a method of manufacturing a high-frequency electronic component that has good adhesion between a mask and a wafer and can improve pattern accuracy of a conductive film.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a high-frequency electronic component according to the present invention.

FIG. 2 is a sectional view of the high-frequency electronic component shown in FIG.

FIG. 3 is an enlarged partial sectional view of a conductor pattern of the high-frequency electronic component shown in FIGS.

FIG. 4 is a cross-sectional view showing a mounting state of the high-frequency electronic component shown in FIGS.

FIG. 5 is an exploded perspective view showing another embodiment of the high-frequency electronic component according to the present invention.

FIG. 6 is a sectional view taken along line 6-6 in FIG. 5;

FIG. 7 is a sectional view taken along the line 7-7 in FIG. 5;

FIG. 8 is a sectional view taken along line 8-8 in FIG. 5;

FIG. 9 is an equivalent circuit diagram of the LPF shown in FIGS. 5 to 8;

FIG. 10 is a partial cross-sectional view showing a state where the LPF shown in FIGS. 5 to 9 is mounted on a motherboard.

FIG. 11 is a flowchart showing a manufacturing process of the high-frequency electronic component according to the present invention.

FIG. 12 is a view showing a manufacturing process of the high-frequency electronic component according to the present invention.

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;

FIG. 21 is a view showing a manufacturing process after the manufacturing process shown in FIG. 20;

FIG. 22 is a view showing a manufacturing process after the manufacturing process shown in FIG. 21;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating base 2 Conductor pattern 21 First conductive film 22 Second conductive film

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05K 1/16 H05K 3/18 J 5E343 3/06 H01F 15/00 D 3/18 H01G 4/40 321A F Term (reference) 4E351 AA07 BB01 BB03 BB09 BB17 BB31 BB32 BB33 BB35 BB49 CC01 CC07 CC12 CC22 CC31 DD04 DD05 DD06 DD20 DD21 DD41 DD52 EE01 EE10 EE11 EE24 GG01 GG07 GG11 5E062 DD01 5E070 AA01 AB07 CB01 AB06 AC01 AD05 AE01 BC01 BC02 BD01 BD07 BD08 BE13 CE01 EE05 FF03 GG01 GG02 GG10 5E343 AA23 BB14 BB15 BB24 BB25 BB48 BB52 BB62 BB72 DD02 DD25 DD26 DD33 EE23 EE26 ER39 GG01 GG08 GG13

Claims (18)

[Claims] 1. A high-frequency electronic component including an insulating base and a conductive pattern, wherein the insulating base supports the conductive pattern, and the conductive pattern includes a first conductive film and a second conductive film. A conductive film, wherein the first conductive film is attached on a surface of the insulating base, the second conductive film is attached on the first conductive film, and the first conductive film is A high-frequency wave covering a surface and both side surfaces of the conductive film, and having a portion that increases in thickness from the both side surfaces of the first conductive film toward the surface side of the first conductive film and expands outward. Electronic components. 2. The high-frequency electronic component according to claim 1, wherein the outwardly swelling portion has a substantially arc-shaped cross section. 3. The high-frequency electronic component according to claim 1, wherein a starting end of the outwardly bulging portion substantially coincides with a contact position between the insulating base and the first conductive film. High-frequency electronic components. 4. The high-frequency electronic component according to claim 1, wherein the first conductive film is a sintered conductive film. 5. The high-frequency electronic component according to claim 1, wherein the first conductive film includes at least one of Cu, Ag, and Au. 6. The high-frequency electronic component according to claim 5, wherein the first conductive film contains Pd. 7. The high-frequency electronic component according to claim 1, wherein the first conductive film has a thickness in a range of 2 to 7 μm. 8. The high-frequency electronic component according to claim 1, wherein the second conductive film is an electroless plating film. 9. The high-frequency electronic component according to claim 1, wherein the second conductive film includes at least one of Cu, Ag, and Au. 10. The high-frequency electronic component according to claim 1, wherein the second conductive film has a thickness of 1 based on the surface of the first conductive film. High frequency electronic components in the range of ~ 6 [mu] m. 11. The high-frequency electronic component according to claim 1, comprising at least one of a coil, a capacitor, and a coupler. 12. A method for manufacturing a high-frequency electronic component, wherein the high-frequency electronic component includes an insulating base and a conductor pattern, wherein the insulating base supports the conductor pattern, The pattern includes a first conductive film and a second conductive film, wherein the first conductive film is attached on a surface of the insulating base, and wherein the second conductive film is formed of the first conductive film. And covers the surface and both side surfaces of the first conductive film. The film is formed from both side surfaces of the first conductive film toward the surface side of the first conductive film. The method for manufacturing the high-frequency electronic component includes forming the first conductive film on a surface of a wafer serving as the insulating base, wherein the first conductive film is formed, The second conductive film is formed on the first conductive film,
A method for manufacturing a high-frequency electronic component including a step of forming by an electroless plating method. 13. The manufacturing method according to claim 12, wherein a heat treatment is performed after forming the second conductive film by an electroless plating method. 14. The manufacturing method according to claim 13, wherein the heat treatment is performed under a temperature condition of 300 ° C. or more and less than 900 ° C. 15. The manufacturing method according to claim 12, wherein the step of forming the first conductive film comprises: applying a conductive paste on a surface of the wafer; Drying and sintering, and patterning the sintered conductor paste by applying a photolithography technique. 16. The manufacturing method according to claim 15, wherein the conductive paste contains at least one of Cu, Ag, or Au and a glass frit. 17. The manufacturing method according to claim 16, wherein the conductor paste contains Pd. 18. The manufacturing method according to claim 12, wherein the electroless plating is performed using a plating bath containing at least one of Cu, Ag, and Au.