JP3979355B2 - Multilayer substrate, multilayer substrate manufacturing method, non-reciprocal circuit device, and communication apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multilayer substrate, a method for manufacturing the multilayer substrate, a non-reciprocal circuit element, and a communication device.
[0002]
[Prior art]
Conventionally, non-reciprocal circuit elements such as circulators and isolators have a characteristic of transmitting power only in a predetermined specific direction and not transmitting in the reverse direction. Utilizing this characteristic, for example, an isolator is used in a transmission circuit unit of a mobile communication device such as an automobile phone or a mobile phone.
[0003]
[Patent Document 1]
JP-A-9-289402
[0004]
As this type of nonreciprocal circuit device, for example, as described in Patent Document 1, a device that obtains desired electrical characteristics by trimming a capacitor electrode of a matching capacitor formed on the surface of a multilayer substrate is known. Yes. This non-reciprocal circuit element trims the matching capacitor after connecting the matching capacitor and the center electrode. Accordingly, since the capacitor electrode is covered with the center electrode, the area of the capacitor electrode that can be trimmed is reduced, and the adjustment range of the electrical characteristics is reduced. Particularly in recent years, nonreciprocal circuit elements used in mobile communication devices have been miniaturized, and the electrode area of the matching capacitor itself has also been reduced. Therefore, it is extremely problematic to reduce the area that can be trimmed. Further, since the electrical characteristics are adjusted after assembly, not only the laminated substrate but also other components such as ferrite and the center electrode are wasted because the trimming adjustment has failed, which increases the cost.
[0005]
Therefore, in order to solve this problem, a laminated substrate 330 provided with matching capacitors C1 to C3 shown in FIG. 13, a ferrite provided with a center electrode mounted on the laminated substrate 330, a permanent magnet, and these Non-reciprocal circuit elements (isolators) composed of a metal case that covers a component have been proposed. This nonreciprocal circuit element trims the matching capacitors C1 to C3 before connecting the matching capacitors C1 to C3 and the center electrode.
[0006]
That is, as shown in FIG. 14, the multilayer substrate 330 includes a dielectric sheet 342 provided with hot-side capacitor electrodes 371a to 373a, ground connection electrodes 331, circuit electrodes 317, resistors 375, and via holes 318 on the surface, A dielectric sheet 344 having hot-side capacitor electrodes 371b to 373b provided on the surface, and dielectric sheets 343 and 345 having ground electrodes 374 provided on the surface, respectively. A ground electrode for soldering to the metal case is also formed on the back surface of the dielectric sheet 345. The multilayer substrate 330 is trimmed so as to divide the capacitor electrodes 371a to 373a by forming the trimming grooves 380 in the capacitor electrodes 371a, 372a, and 373a provided on the surface in a single state. Therefore, the problem of the nonreciprocal circuit device described in Patent Document 1 can be solved.
[0007]
[Problems to be solved by the invention]
However, in the non-reciprocal circuit device including the multilayer substrate 330 shown in FIG. 13, after trimming the capacitor electrodes 371a to 373a for trimming, the center electrodes are respectively connected to the capacitor electrodes 371a to 373a for trimming such as solder paste and conductive paste. Electrical connection is made using a connecting material. Therefore, there is a problem that a part of the trimming groove 380 is filled with these connection materials, and the divided trimming capacitor electrodes 371a to 373a are connected again. In particular, when trimming is performed such that the trimming capacitor electrodes 371a to 373a are divided by a laser, the groove width of the trimming groove 380 is as narrow as 10 μm to 100 μm, and there is a high possibility of short-circuiting. Although it is possible to prevent short-circuiting by deleting all of the unnecessary divided electrodes, in this case, the trimming time becomes long.
[0008]
In addition, the hot-side capacitor electrodes 371a to 373a and the ground connection electrode 331 are close to each other, and there is a high possibility of short-circuiting at locations other than the trimming groove 380.
[0009]
In order to cope with such a problem, it is conceivable that the capacitor electrode is provided inside a laminated body made of dielectric layers, and the capacitor electrode is trimmed by irradiating a laser from the outer layer of the laminated body. However, even in this case, the trimmed capacitor electrode and the scattered matter from the dielectric layer adhere to the connection electrode provided on the surface of the laminated body, resulting in poor soldering between the connection electrode and the center electrode. Although the scattered matter can be removed by washing or air blowing, there is a problem that it takes time and effort to remove it.
[0010]
Therefore, an object of the present invention is to provide a multilayer substrate and a method for manufacturing the multilayer substrate in which the disadvantages caused by the trimming of the capacitor capacitance by the laser are eliminated, and a high-performance, highly reliable and small multilayer substrate, a method for manufacturing the multilayer substrate, An object of the present invention is to provide a nonreciprocal circuit device and a communication device.
[0011]
[Means and Actions for Solving the Problems]
In order to achieve the above object, a laminated substrate according to the present invention is electrically connected to a laminated body formed by stacking a plurality of dielectric layers and a center electrode of a nonreciprocal circuit element provided on the surface of the laminated body. A connection electrode for a center electrode for connection, and a capacitor electrode provided in the laminated body, wherein the capacitor electrode is a mask that covers the connection electrode for the center electrode and has another portion as an opening. The capacitor is trimmed by placing it on the surface of the laminate and irradiating a laser from the opening.
[0012]
Further, the method for manufacturing a multilayer substrate according to the present invention includes stacking a plurality of dielectric layers, a capacitor electrode, and a connection electrode for a center electrode for electrically connecting to the center electrode of the nonreciprocal circuit element. A step of forming a laminated body provided with a connection electrode for the surface and the capacitor electrode provided therein, and a mask having an opening in the other part covering the connection electrode for the center electrode is placed on the surface of the laminated body. And trimming the capacitor capacity by irradiating a laser from the opening.
[0013]
With the above configuration, since the capacitor electrode is provided inside the laminate, the area of the capacitor electrode that can be trimmed is increased, and the capacitance adjustment range is expanded. Furthermore, since only the minimum necessary electrodes such as a center electrode connection electrode are formed on the surface of the multilayer substrate for electrical connection to the center electrode of the nonreciprocal circuit element, a conductive material such as solder spreads. It has no structure. Since the capacitor capacitance is trimmed using a mask that covers the connection electrode, the scattered matter generated by laser irradiation does not adhere to the connection electrode, eliminating the problem of poor soldering with the center electrode. Is done. Note that the scattered matter adheres to the surface of the laminate and corresponds to the opening of the mask, but does not adhere to the connection electrode at all, so there is no risk of deterioration in reliability. This means that the step of removing the deposits by washing or air blowing can be omitted.
[0014]
In the manufacturing method according to the present invention, the mask may be made of stainless steel or resin, or may be made of brass, copper, iron or the like. In particular, a stainless steel mask is excellent in wear resistance and is easy to maintain since it does not cause oxidation or rust problems.
[0015]
The mask may be provided with a probe for measuring a capacitor capacity. The mask is placed on the surface of the laminated body, the capacitor capacity is measured using a probe, the capacitor capacity is trimmed based on the measured value, and then the trimmed capacitor capacity is measured again using the probe.
[0016]
By adopting this process, it is possible to perform initial capacitance measurement, laser trimming, and capacitance measurement after trimming in a short time using an automatic machine, and the cost reduction of non-reciprocal circuit elements can be achieved.
[0017]
Further, when measuring the capacitor capacity with a probe, it is preferable to use a resin mask. Since no ground current flows during the capacitance measurement, it is possible to measure a stable capacitance with a small measurement error, and an irreversible circuit element with a small variation in frequency characteristics can be obtained. In addition, the resin is excellent in processability and dimensional stability, and can be processed thinly and finely, and is optimal for manufacturing a multilayer substrate of a non-reciprocal circuit element having a reduced size.
[0018]
When the nonreciprocal circuit device is an isolator, a termination resistor is built in the multilayer substrate. In this case, it is preferable to perform trimming by irradiating the terminal resistor with a laser from the opening of the mask as necessary. In this case, a probe for measuring the termination resistance is attached to the mask.
[0019]
Furthermore, the nonreciprocal circuit device and the communication device according to the present invention are improved in performance and reliability by including the laminated substrate.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Embodiments of a multilayer substrate, a multilayer substrate manufacturing method, a non-reciprocal circuit element, and a communication device according to the present invention will be described below with reference to the accompanying drawings.
[0021]
[First embodiment, see FIGS. 1 to 8]
FIG. 1 shows an exploded perspective view of an embodiment of a non-reciprocal circuit device according to the present invention. The nonreciprocal circuit device 1 is a lumped constant isolator. As shown in FIG. 1, the lumped constant isolator 1 generally includes a metal case composed of a metal upper case 4 and a metal lower case 8, a permanent magnet 9, a ferrite 20, and center electrodes 21, 22, and 22. And a central electrode assembly 13 and a laminated substrate 30.
[0022]
The metal upper case 4 has a substantially box shape and includes an upper portion 4a and four side portions 4b. The metal lower case 8 includes left and right side portions 8b and a bottom portion 8a. In order to form a magnetic circuit, the metal upper case 4 and the metal lower case 8 are made of, for example, a material made of a ferromagnetic material such as soft iron, and Ag or Cu is plated on the surface thereof.
[0023]
In the center electrode assembly 13, three center electrodes 21, 22, and 23 are arranged on the upper surface of the rectangular microwave ferrite 20 so as to intersect with each other at approximately 120 degrees with an insulating layer (not shown) interposed therebetween. ing. In the first embodiment, the center electrodes 21, 22, and 23 are configured by two lines. The center electrodes 21, 22, and 23 may be wound around the ferrite 20 using a copper foil, or may be formed by printing a silver paste on or inside the ferrite 20. However, since the printed electrodes have higher positional accuracy of the center electrodes 21, 22 and 23, the connection with the laminated substrate 30 is stabilized. In particular, in the case where the connection is made with small connection electrodes P1, P2, P3 (described later) as in the first embodiment, it is more reliable that the center electrodes 21, 22, 23 are formed by printing. Good workability.
[0024]
As shown in FIG. 2, the multilayer substrate 30 includes a dielectric sheet 41 provided with center electrode connection electrodes P1, P2, P3, a ground connection electrode 31, and via holes 18, hot capacitor electrodes 71a, 72a, 73a, Dielectric sheet 42 provided with circuit electrode 17 and resistor 75 on the surface, dielectric sheet 44 provided with hot-side capacitor electrodes 71b, 72b and 73b on the surface, and dielectric provided with ground electrode 74 on the surface. It consists of body sheets 43, 45 and the like. A ground electrode for soldering to the lower case 8 is also formed on the back surface of the dielectric sheet 45.
[0025]
The electrodes P1 to P3, 17, 31, 71a to 73a, 71b to 73b, and 74 are formed on the dielectric sheets 41 to 45 by a method such as pattern printing. As a material for the electrodes P1, P2, P3, etc., Ag, Cu, Ag—Pd, etc., which have low resistivity and can be fired simultaneously with the dielectric sheets 41 to 45, are used. The surfaces of the electrodes P1, P2, P3, etc. are Au plated with Ni plating as a base. Ni plating increases the adhesion strength between Ag and Au plating of the electrodes P1, P2, P3 and the like. Au plating improves solder wettability and has high electrical conductivity, so that the isolator 1 can have low loss.
[0026]
The thickness of the electrodes P1, P2, P3, etc. is about 2 to 20 μm. The dielectric sheets 41 to 45 are made of Al. ₂ O _Three As the main component and SiO ₂ , SrO, CaO, PbO, Na ₂ O, K ₂ O, MgO, BaO, CeO ₂ , B ₂ O _Three Is a low-temperature sintered dielectric material containing one or more of them as subcomponents. The sheet thickness of the dielectric sheets 41 to 45 is about 10 to 200 μm.
[0027]
The resistor 75 is formed on the surface of the dielectric sheet 42 by a method such as pattern printing. As the material of the resistor 75, cermet, carbon, ruthenium or the like is used. The resistor 75 alone constitutes a termination resistor R. Note that the terminating resistor R may be omitted, and in this case, a circulator is configured.
[0028]
The via hole 18 is formed by forming a via hole hole in the dielectric sheets 41, 42, and 43 in advance by laser processing, punching process, or the like, and then filling the via hole hole with a conductive paste.
[0029]
Capacitor electrodes 71a, 71b, 72a, 72b, 73a, 73b constitute matching capacitors C1, C2, C3 facing the ground electrode 74 with the dielectric sheets 42, 43, 44 interposed therebetween, respectively. These matching capacitors C 1, C 2, C 3 and termination resistor R together with the electrodes P 1, P 2, P 3, 17, 31 and the via hole 18 constitute an electric circuit inside the multilayer substrate 30.
[0030]
The above dielectric sheets 41 to 45 are laminated, and further, a plurality of dummy dielectric sheets 47 with electrodes not formed on the surface in advance are laminated thereunder, and then integrally fired, as shown in FIG. Such a laminated substrate 30 is obtained. An input terminal electrode 14, an output terminal electrode 15, and a ground terminal electrode 16 are provided at both ends of the multilayer substrate 30, respectively. The input terminal electrode 14 is electrically connected to the capacitor electrodes 71a and 71b, and the output terminal electrode 15 is electrically connected to the capacitor electrodes 72a and 72b. The ground terminal electrodes 16 are electrically connected to the circuit electrode 17 and the ground electrode 74, respectively. These terminal electrodes 14, 15, and 16 are formed by applying a conductive paste such as Ag, Ag-Pd, or Cu and then baking or dry plating. Moreover, it is good also as the electrodes 14, 15, 16 by forming a via hole in the side surface of each sheet | seat.
[0031]
The laminated substrate 30 is normally formed in a mother board state (see FIGS. 6 and 7), and is folded from the mother board 100 to a desired size by folding along the half cut grooves 101 formed at a predetermined pitch on the mother board 100. The laminated substrate 30 is obtained. Alternatively, the laminated substrate 30 having a desired size may be cut out from the mother board 100 by cutting the mother board 100 with a dicer or a laser.
[0032]
The multilayer substrate 30 obtained in this way has matching capacitors C1, C2, C3 and a terminating resistor R inside. Trimming of the matching capacitors C1, C2, C3 is performed before connecting the matching capacitors C1, C2, C3 and the center electrodes 21, 22, 23. Further, the termination resistor R is also trimmed as necessary.
[0033]
That is, the multilayer substrate 30 is trimmed (deleted) by laser with the inner (second layer) capacitor electrodes 71a, 72a, 73a together with the surface dielectric in a single state. For trimming, for example, a YAG fundamental wave, second harmonic wave, or third harmonic laser is used. The reason why the laser is used is that a fast and accurate processing can be obtained. The trimming may be efficiently performed on the laminated substrate 30 in the mother board state.
[0034]
Here, laser trimming will be described. Laser trimming is performed on the capacitor electrodes 71a, 72a, 73a, and the mask 50 shown in FIG. 4 is used. The mask 50 covers the center electrode connection electrodes P 1, P 2, P 3 and the terminal electrode 31 provided on the surface of the laminated substrate 30, and has other portions as openings 51. The mask 50 is placed on the surface of the multilayer substrate 30 in the state shown in FIG. 4, and the capacitor capacitance is trimmed by irradiating a laser through the opening 51. Trimming marks are shown as trimming grooves 80 and 81.
[0035]
In laser trimming, the trimming depth gradually increases from the start of trimming (laser scanning). Therefore, in order to completely cut the electrode, the trimming start position is set slightly away from the end of the electrode. There is a need to. Specifically, a position away from the end of the electrode by 50 μm is preferable. This numerical value varies depending on the scanning speed of the laser, the thickness of the dielectric sheet and the electrode, and the like.
[0036]
The conditions for laser trimming are as follows, and the values in parentheses are specific numerical values in experiments conducted by the present inventors.
Laser: 3rd harmonic of YAG laser with laser diode as light source
Output: 1.5-2.5W (2.0W)
Oscillation frequency: 2 to 4 KHz (3 KHz)
Scanning speed: 30 to 60 mm / s (50 mm / s)
Number of scans: 4-10 times (7 times)
Distance between mask and electrode: (0.1mm)
Scanning start position: A position away from the electrode edge (50 μm)
[0037]
In the first embodiment, since laser trimming is performed using the mask 50 covering the electrodes P1, P2, P3, 31, the scattered matter generated by laser irradiation does not adhere to these electrodes, and the center electrode The problem of poor soldering with 21, 22, 23 is eliminated.
[0038]
That is, when trimming is performed without using the mask 50, scattered objects adhere to the electrodes P1, P2, P3, and 31 as indicated by hatching in FIG. However, the use of the mask 50 prevents the scattered matter from adhering to the electrodes P1, P2, P3, and 31 as indicated by hatching in FIG.
[0039]
The scattered matter adheres to a portion of the surface of the laminated substrate 30 corresponding to the opening 51 of the mask 50 (see the oblique lines in FIG. 5B). However, since it does not adhere to the electrodes P1, P2, P3, and 31 at all, the reliability does not deteriorate even if the deposit is not removed from the surface of the laminated substrate 30 by washing or air blowing.
[0040]
As the material of the mask 50, stainless steel, brass, copper, iron or the like can be used. Moreover, resin may be used as described later. In particular, the stainless steel mask 50 is excellent in wear resistance, has no problems of oxidation and rust, and is easy to maintain.
[0041]
In the first embodiment, since the trimming capacitor electrodes 71a, 72a, 73a are provided in the multilayer substrate 30, the capacitor electrode region that can be trimmed is increased, the capacitance adjustment range is expanded, and the multilayer substrate is expanded. The good product rate of 30 can be improved.
[0042]
Further, only the minimum necessary connection electrodes P1, P2, P3, and 31 are formed on the surface of the multilayer substrate 30, and the conductive material such as solder does not spread. Accordingly, it is possible to prevent a problem that the conductive material flows into the trimming groove 80 (see FIG. 4) and the divided capacitor electrodes 71a, 72a, 73a are connected again. Since the distance between the connection electrodes P1, P2, P3, 31 can be increased, the size of the center electrode assembly 13 can be increased. Accordingly, since the inductance formed by the center electrodes 21, 22, and 23 is increased, the pass band width of the isolator 1 can be widened, and the electrical characteristics can be improved.
[0043]
Further, since the capacitor electrodes 71a, 72a, 73a located in the outermost layer are used as the trimming capacitor electrodes, the thickness of the dielectric layer to be removed at the time of trimming can be minimized. Furthermore, since the number of electrodes that obstruct trimming is reduced (in the case of the first embodiment, only the connection electrodes P1, P2, P3, and 31), the capacitor electrode area that can be trimmed is widened, and the capacitance adjustment range is widened. it can.
[0044]
Furthermore, since the trimming capacitor electrodes 71a, 72a and 73a are rectangular, the electrode width is constant, so that a substantially proportional relationship is established between the position of the trimming groove 80 and the obtained capacitance value. , Capacitance adjustment work becomes easy.
[0045]
Further, the trimming capacitor electrodes 71a, 72a, 73a overlap only with the center electrode connection electrodes P1, P2, P3 in the stacking direction of the dielectric sheets 41-45. Thus, other electrodes that hinder trimming can be prevented from overlapping with the trimming capacitor electrodes 71a, 72a, 73a. In addition, if the trimming capacitor electrodes 71a, 72a, 73a overlap the ground connection electrode 31, a capacitance is formed at that portion, so that there is a problem that trimming accuracy is deteriorated.
[0046]
Further, in FIG. 3, the multilayer substrate 30 is provided with hot-side capacitor electrodes 73a and 73b of the matching capacitor C3 on one side and hot-side capacitor electrodes 71a and 71b of the matching capacitor C1 on the right end of the other side. The hot-side capacitor electrodes 72a and 72b of the matching capacitor C2 are provided at the left end of the other side. In other words, the hot-side capacitor electrodes 73a and 73b of the termination resistor-side matching capacitor C3 are arranged on the side of the multilayer substrate 30 where the termination resistor R is arranged, and the hot-side capacitor electrodes 71a and 73a of the input-side matching capacitor C1 are arranged. 71b is disposed on the input side of the multilayer substrate 30, and the hot side capacitor electrodes 72a and 72b of the output side matching capacitor C2 are disposed on the output side of the multilayer substrate 30. As a result, it is possible to obtain matching capacitors C1, C2, and C3 in which trimming adjustment is easy and the area of the multilayer substrate 30 is effectively used.
[0047]
In general, an isolator used in a mobile communication device often has a larger capacitance of the resistance matching capacitor C3 than the capacitance of the input / output matching capacitors C1 and C2. Therefore, in order to ensure the capacitance of the resistance-side matching capacitor C3, the area of the hot-side capacitor electrodes 73a and 73b of the matching capacitor C3 is the total area of the hot-side capacitor electrodes of the matching capacitors C1, C2, and C3. It is preferable to set it to be 1/3 or more of.
[0048]
The laminated substrate 30 also has a built-in termination resistor R. Like the matching capacitors C1, C2, and C3, the termination resistor R can be adjusted together with the surface dielectric to adjust the resistance value. . Since the resistance value increases when the width of the resistor 75 becomes narrow even at one place, the resistor 75 is cut halfway in the width direction. Since the termination resistor R is built in the laminated substrate 30, there is no fear that Ni plating or the like is applied to the surface of the resistor 75 when Ni plating or Au plating is applied to the surfaces of the electrodes P1, P2, P3, etc. The resistance value of the termination resistor R does not decrease. As shown in FIG. 4, in the first embodiment, three trimming grooves 80 for dividing the trimming capacitor electrodes 71a, 72a, and 73a and one trimming groove 81 for cutting the resistor 75 are provided. It is formed on the laminated substrate 30.
[0049]
The above components are assembled as follows. That is, as shown in FIG. 1, the permanent magnet 9 is fixed to the ceiling of the metal upper case 4 with an adhesive. On the laminated substrate 30, the center electrode assembly 13 is connected to center electrode connection electrodes P 1, P 2, each of which has one end of each of the center electrodes 21, 22, 23 of the center electrode assembly 13 formed on the surface of the laminated substrate 30. Mounting is performed by soldering to P3 and soldering the other end of each of the center electrodes 21, 22, and 23 to the ground connection electrode 31. Since the connection electrodes P1, P2, P3, and 31 have a small area, the center electrode assembly 13 can be positioned by a self-alignment effect when the solder is melted.
[0050]
Further, since both end portions of the center electrodes 21, 22, 23 have only a minimum necessary extending portion on the bottom surface of the ferrite 20, the trimming grooves 80, 81 on the upper surface of the multilayer substrate 30 are provided in the center electrodes 21, 22. , 23 does not cross. Therefore, the solder is prevented from flowing into the trimming grooves 80 and 81 through the center electrodes 21, 22, and 23 on the bottom surface of the ferrite 20, and the reliability is improved. Note that the soldering of the center electrodes 21, 22, 23 and the connection electrodes P1, P2, P3, 31 may be efficiently performed on the laminated substrate 30 in the mother board state.
[0051]
The laminated substrate 30 is placed on the bottom portion 8a of the metal lower case 8, and the electrode provided on the back surface of the sheet 47 is connected and fixed to the bottom portion 8a by solder, so that the ground terminal electrode 16 is electrically connected to the bottom portion 8a. Connected to. Thereby, since sufficient earthing can be taken, the electrical characteristics of the isolator 1 can be improved.
[0052]
Then, the side part 8b of the metal lower case 8 and the side part 4b of the metal upper case 4 are joined by solder or the like to form a metal case, which also functions as a yoke. That is, the metal case forms a magnetic path that surrounds the permanent magnet 9, the center electrode assembly 13, and the laminated substrate 30. The permanent magnet 9 applies a DC magnetic field to the ferrite 20.
[0053]
FIG. 8 is an electrical equivalent circuit diagram of the isolator 1. The matching capacitor C3 and the terminating resistor R are connected in parallel between the center electrode connection electrode P3 and the ground terminal electrode 16.
[0054]
[Refer to 2nd Embodiment and FIGS. 9-11]
FIG. 9 shows a method of using a mask 55 provided with a probe 58 for measuring the capacitances of the capacitors C1, C2, and C3 when performing laser trimming on the capacitor electrodes 71a, 72a, and 73a. In addition, the structure of the laminated substrate 30 is the same as that of the said 1st Embodiment, the code | symbol attached | subjected in FIG. 9 shows the same member as 1st Embodiment, and the overlapping description is abbreviate | omitted.
[0055]
Similar to the mask 50 shown in the first embodiment, the mask 55 covers the electrodes P1, P2, P3, and 31 of the multilayer substrate 30 and has other portions as openings 56. Is applied to trim the capacitor electrodes 71a, 72a, 73a and the terminating resistor R as necessary. The probe 58 is attached to the lower surface of the mask 55 through a hole 57 formed at a position corresponding to the electrodes P1, P2, P3, 31 (see FIG. 10). The shape of each probe 58 is as shown in FIG. 11, and can be taken in and out of the holding cylinder 59 by a spring mechanism (not shown).
[0056]
In the second embodiment, the initial capacitances of the capacitors C1, C2, and C3 of the multilayer substrate 30 are measured before performing laser trimming. That is, the laminated substrate 30 is fixed, the mask 55 is lowered and placed on the laminated substrate 30, the probe 58 is lowered and its tip is brought into contact with the electrodes P 1, P 2, P 3, 31, and the capacitors C 1, C 2, C 3 Measure capacity.
[0057]
Next, the probe 58 is raised and separated from the electrodes P1, P2, P3, 31 and the trimming position determined based on the measured initial capacitance is irradiated with a laser to trim the capacitor electrodes 71a, 72a, 73a. . Thereafter, the probe 58 is lowered again to measure the trimmed capacitor capacity.
[0058]
The above steps (initial capacitance measurement, laser trimming, and capacitance measurement after trimming) are performed in a short time using an automatic machine, thereby achieving a reduction in the cost of nonreciprocal circuit elements. Of course, the effect of performing laser trimming using the mask 55 is the same as that of the first embodiment.
[0059]
By the way, when measuring a capacitor capacity with a probe, the mask 55 is preferably made of resin. Since no ground current flows during the capacitance measurement, it is possible to measure a stable capacitance with a small measurement error, and an irreversible circuit element with a small variation in frequency characteristics can be obtained. In addition, the resin is excellent in processability and dimensional stability, and can be processed thinly and finely, and is optimal for manufacturing a multilayer substrate of a non-reciprocal circuit element having a reduced size. In this sense, the mask 50 shown in the first embodiment may be made of resin.
[0060]
[Third Embodiment, FIG. 12]
In the third embodiment, a mobile phone will be described as an example of a communication device according to the present invention. FIG. 12 shows an electric circuit of the RF part of the mobile phone 220, 222 is an antenna element, 223 is a duplexer, 231 is a transmission side isolator, 232 is a transmission side amplifier, 233 is a band pass filter for transmission side stages, and 234 is transmission A side mixer, 235 is a reception side amplifier, 236 is a reception side interstage band pass filter, 237 is a reception side mixer, 238 is a voltage controlled oscillator (VCO), and 239 is a local band pass filter.
[0061]
Here, the lumped constant isolator 1 of the first embodiment can be used as the transmission-side isolator 231. By mounting these isolators, a mobile phone with improved electrical characteristics and high reliability can be realized.
[0062]
[Other Embodiments]
In addition, this invention is not limited to the said embodiment, It can change variously within the range of the summary.
[0063]
For example, the capacitor of the above embodiment is composed of a plurality of hot-side capacitor electrodes and a plurality of ground electrodes, but may be composed of one hot-side capacitor electrode and one ground electrode.
[0064]
Furthermore, the capacitor formed inside the multilayer substrate is not limited to the matching capacitor, and may be a capacitor for forming a low-pass filter, a trap circuit, or the like. In addition to the isolator, the nonreciprocal circuit device according to the present invention may be a circulator or a nonreciprocal circuit device with a built-in coupler.
[0065]
【The invention's effect】
As is clear from the above description, according to the present invention, the capacitor electrode is provided inside the multilayer body, and the capacitor capacitance is trimmed using a mask covering the connection electrode, and thus is generated by laser irradiation. The scattered matter does not adhere to the connection electrode, and the problem that the soldering failure with the center electrode is caused can be solved.
[0066]
In addition, a probe is attached to the mask, the capacitor is mounted on the surface of the laminate, the capacitor capacity is measured using the probe, the capacitor capacity is trimmed based on the measured value, and then the probe is used again. Since the trimmed capacitor capacitance is measured, the initial capacitance measurement, laser trimming, and the capacitance measurement after trimming can be performed in a short time using an automatic machine, thereby reducing the cost of nonreciprocal circuit elements. Achieved.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing an embodiment of a non-reciprocal circuit device according to the present invention.
2 is an exploded perspective view of the multilayer substrate shown in FIG.
FIG. 3 is a plan view showing various electrodes formed on the laminated substrate.
FIG. 4 is a plan view showing a state where laser trimming is performed by placing a mask on the laminated substrate.
FIGS. 5A and 5B are plan views showing the state of attachment of scattered objects when laser trimming is performed without using a mask, and FIG. 5B is the state of attachment of scattered objects when laser trimming is performed using a mask. FIG.
FIG. 6 is a plan view showing a mother board state of the multilayer substrate.
7 is a plan view showing a state in which components are mounted on the multilayer substrate shown in FIG. 6;
FIG. 8 is an electrical equivalent circuit diagram of the non-reciprocal circuit device shown in FIG.
FIG. 9 is a perspective view showing a mask to which a probe is attached and a laminated substrate.
10 is a rear view of the mask shown in FIG. 9. FIG.
11 is an elevational view of the probe shown in FIG.
FIG. 12 is an electric circuit block diagram of a communication apparatus according to the present invention.
FIG. 13 is an external perspective view showing a conventional multilayer substrate.
14 is an exploded perspective view of the multilayer substrate shown in FIG.
[Explanation of symbols]
1 ... Lumped constant isolator
4,8 ... Metal case
9 ... Permanent magnet
13 ... Center electrode assembly
20 Ferrite
21-23 ... Center electrode
30 ... Multilayer substrate
31 ... Connection electrode for ground
50, 55 ... Mask
51, 56 ... opening
58 ... Probe
71a to 73a, 71b to 73b ... capacitor electrodes
74: Ground electrode
75 ... resistor
80, 81 ... Trimming groove
220 ... Mobile phone
C1 to C3 ... Matching capacitors
R: Termination resistance
P1 to P3 .. center electrode connection electrode

Claims (11)

A laminate formed by stacking a plurality of dielectric layers;
A central electrode connection electrode for electrically connecting to the central electrode of the non-reciprocal circuit element provided on the surface of the laminate;
A capacitor electrode provided inside the laminate,
The capacitor electrode is formed by trimming the capacitor capacitance by placing a mask with the other electrode opening covering the center electrode connection electrode on the surface of the laminate and irradiating a laser from the opening. There is,
A laminated substrate characterized by the above. 2. The multilayer substrate according to claim 1, wherein a termination resistor is built in the multilayer body, and the termination resistor is trimmed by irradiating a laser from an opening of the mask. A plurality of dielectric layers, a capacitor electrode, and a center electrode connection electrode for electrical connection to the center electrode of the nonreciprocal circuit element are stacked, and the center electrode connection electrode is provided on the surface and the capacitor electrode is disposed inside. A step of forming a laminate provided in
Covering the connection electrode for the center electrode, placing a mask with the other part as an opening on the surface of the laminate, and irradiating a laser from the opening to trim the capacitor capacitance; and
A method for manufacturing a laminated substrate, comprising: 4. The method for manufacturing a laminated substrate according to claim 3, wherein the mask is made of stainless steel. The method for manufacturing a multilayer substrate according to claim 3 or 4, wherein a probe for measuring a capacitance of the capacitor is attached to the mask. The capacitor is measured using the probe with the mask placed on the surface of the laminate, and the capacitor is trimmed based on the measured value, and then the trimmed capacitor is measured again using the probe. A method for manufacturing a laminated substrate according to claim 5, wherein: The method for manufacturing a laminated substrate according to claim 6, wherein the mask is made of a resin. 4. The multilayer substrate according to claim 3, further comprising a step of trimming the termination resistor by irradiating a laser from an opening of the mask, the termination resistor being built in the multilayer body. Manufacturing method. The method for manufacturing a laminated substrate according to claim 8, wherein a probe for measuring a termination resistance is attached to the mask. The laminated substrate according to claim 1 or 2,
With permanent magnets,
A ferrite to which a DC magnetic field is applied by the permanent magnet;
A plurality of central electrodes disposed on the ferrite;
A connection electrode for a multilayer substrate disposed on the ferrite;
A non-reciprocal circuit device comprising: A communication apparatus comprising the nonreciprocal circuit device according to claim 10.

Images