JP2000307345A - Oscillator and oscillation characteristic control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain miniaturization and improvement in the performance and reliability of a structure for trimming by forming a conductor, with which the inner portion of an inductor is electrically pulled out onto a front side main surface or rear side main surface, on the inner wall surface of a through hole or bottomed hole previously provided on the side face of a substrate or on the substrate so as to control oscillation characteristics by partial cutting. SOLUTION: An inner conductor pattern layer 1-c constituting an inductor is trimmed, the electric length is extended just for 2αand the width is narrowed as well. Since the inductance of the inductor composed of the parallel ground conductor of a distribution constant type high frequency circuit can be improved by extending the electric length or narrowing the width, the oscillation frequency of a module before trimming is set a little higher than a prescribed value. Control is performed for providing the required oscillation frequency by lowering the oscillation frequency by remarkably changing the inductance constituting the oscillator by trimming.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oscillator and a method for adjusting the oscillation characteristics thereof, and more particularly, to a portable telephone, a portable information terminal, a wireless LAN transceiver, a satellite communication terminal, and a GP.
The present invention relates to a small oscillator mounted on various wireless communication devices using a high frequency band such as an S receiver and a method for adjusting the oscillation characteristics thereof. Particularly, in a high frequency application of several hundred MHz or more, a module which is a main part of the oscillator is used. This is suitable for downsizing.

[0002]

2. Description of the Related Art In recent years,
With the miniaturization of terminal devices for high-frequency communication systems represented by mobile phones, one of the high-frequency components mounted on these devices has been increasing.
Oscillation circuit modules such as a voltage controlled oscillator (VCO), which is one of them, have been further reduced in size. In these high-frequency (especially applications of several hundred MHz or more) small oscillator modules, variations in the characteristics of mounted components and dimensions of the wiring patterns on the board cannot be ignored, and adjustments are made to individual modules. It is practically indispensable to match characteristics such as the oscillation frequency with predetermined design specifications. As a means for these adjustments, generally, a part of a circuit pattern formed on a component mounting surface of a circuit board is cut off by a mechanical means such as a sand blaster or a luter or an optical means such as a laser beam, so that a conductor is cut. In addition to a method of adjusting an inductor constituting an oscillation circuit by changing the length and teeth of a pattern (Japanese Patent Application Laid-Open No. 6-13807), in order to further reduce the size of a module,
Means for mounting a part of an inductor (Japanese Patent No. 2662748) and a capacitor constituting an oscillation circuit inside the substrate by forming a multilayer circuit board (Japanese Patent No. 253).
No. 1000) is also used.

FIG. 14 is a structural view of an example of an oscillator in which a part of an inductor constituting an oscillator is drawn out to the surface of a substrate. The oscillator has a triplate structure sandwiched between a back ground conductor 22 and an interior ground conductor 23 on a printed wiring board 21. A part of the stripline inductor conductor 24a to be mounted is connected to a conductor pad 24b provided on the substrate surface via a through hole 25, and the pad 24b on the substrate surface is By performing the trimming as shown in 26, the electrical length of the inductor is changed, and the adjustment of the inductance, that is, the adjustment of the oscillation (device) characteristics such as the oscillation frequency is performed.

[0006] FIG. 16 shows that the capacitor constituting the oscillator is mounted on a substrate, one electrode of the capacitor disposed on the surface of the substrate is trimmed, and the capacitance of the capacitor is adjusted to adjust the oscillation characteristics. FIG. 4 is a cross-sectional structural view of an example of an oscillator that performs the following. In this case, the inductor constituting the resonance circuit is a printed circuit board 21 similar to the above case.
Is connected inside the inductor as a strip line 24 in a triplate structure, one end of which is drawn out through the through hole 25 onto the substrate surface. The surface electrode 28 is mounted on the substrate by a surface electrode 28 facing the internal ground conductor 23 via a dielectric substrate.
By trimming the electrode 8 and adjusting the electrode area, the capacitance of the capacitor is adjusted, that is, the oscillator is adjusted.

However, in the above two cases, a part of the circuit is provided inside the substrate in order to reduce the size. However, when adjusting each module, a part of the internal conductor pattern is used as a component of the substrate. A means for pulling out on the mounting surface and performing trimming or the like on the portion is used (portion 24b in FIG. 14 and portion 28 in FIG. 16). The trimming pad occupies a certain area on the component mounting surface. This is the same when no interior decoration method is used.

In most cases, these modules are provided with a metal cap shield for covering a component mounting surface in order to avoid electromagnetic interference with adjacent components to be mounted and to protect mounted components. However, when trimming the board surface on the component mounting surface side in this way, after adjusting in advance in consideration of the deviation in characteristics caused by covering the cap shield, cover the cap shield or trim the slit for trimming. A method is used in which a cap shield provided with holes and holes is placed on a substrate, trimmed with a laser or the like, and then the slits and holes of the cap shield are closed with a conductive seal or the like. In the former case, since the characteristics such as the oscillation frequency of the module are shifted by applying the cap shield, it is necessary to perform trimming adjustment in which these differences are predicted in advance. Since individual variations in characteristics are inherently large, it is a reality that a uniform offset cannot cope with it, and precise adjustment is impossible. In the case of the latter, laser trimming is performed after the cap shield is covered, so that dust in the trimmed portion scattered by trimming is trapped inside the cap and easily adheres to the peripheral part, resulting in a loss of reliability. Invite.

As a means for solving the above problem, it is conceivable that the inner conductor is pulled out to the back side of the substrate and trimming is performed on the back side. However, when such a structure is adopted, trimming is performed with a certain area on the back side. It is necessary to provide a pad for use. As a result, it is difficult to shield the back surface of the module, and it is necessary to take measures such as providing a cap seal similar to that on the mounting surface side, and it is hardly a practical method in this application requiring miniaturization. Similarly, as a method for solving the above problem, by performing laser trimming in the vertical direction from the back surface of the substrate toward the inside, the electrode area of the multilayered internal capacitor is adjusted, and the oscillator is adjusted. A method has been proposed (JP-A-9-15)
3737 publication).

FIG. 17 is a cross-sectional view of the entire module of this embodiment. A capacitor 27 constituting a resonance circuit is built in a substrate by laminating electrodes 27a and 27b in a layered manner with a dielectric layer of the substrate interposed therebetween. ing. In this case, as shown at 28 in FIG. 18, by performing laser trimming in the vertical direction from the back side of the module, the area of the electrodes 27a and 27b of the internal capacitor 27 is adjusted, and the module is adjusted. According to this method, although the above problem is solved, in order to adjust the capacitance range to some extent, it is necessary to make the electrode structure of the capacitor a multilayer structure of at least three to four or more layers. However, this results in an increase in the thickness of the substrate and an increase in cost.

In view of the above problems, one of the objects of the present invention is to trim a conductor pattern portion for extracting a part of an interior conductor pattern mainly constituting an inductor of a resonance circuit to a substrate surface. An object of the present invention is to provide a small-sized, high-performance, and highly reliable oscillator module and a highly accurate adjustment method thereof.

[0010]

According to the present invention, an oscillator circuit component is mounted on a front main surface of a circuit board made of a dielectric, and a ground conductor is disposed on a rear main surface so as to cover most of the circuit. In the substrate substantially parallel to the ground conductor, at least a part of the inductor element constituting the oscillation circuit is mounted, and a conductor that electrically draws out the mounted part of the inductor element to the front main surface or the back main surface, An oscillator is provided which is formed on a side surface of a substrate so that oscillation characteristics can be adjusted by partially removing the hole or on an inner wall surface of a through hole or a bottomed hole provided in the substrate in advance. That is, the present invention provides that at least a part of an inductor element constituting an oscillation circuit is provided inside a circuit board, and a part of the built-in inductor is provided on a front side or a back side main surface. A conductor is electrically drawn out along the inner wall surface of the bottomed hole, so that at least a part of the drawn-out conductor portion can be trimmed and the oscillation characteristics can be adjusted without increasing the size of the oscillator. In particular, when the lead conductor to the surface of the interior inductor is formed on the side surface of the substrate, the trimming can be easily performed from the side surface after the completion of module assembly.

Further, if the lead conductor portion of the interior inductor is formed in a recess provided on the side surface (outer peripheral portion) of the substrate or in a portion where the corner of the substrate is cut, the area of the trimming portion can be increased, and the area is wider. An adjustment range can be obtained. Furthermore, the trimming portion is preferably damaged because of the effect of reducing the risk of damage due to physical contact with the outside and the occurrence of misalignment. Further, a structure in which a metal cap shield covering components mounted on the surface of the substrate is covered so as to overhang a dent in a peripheral portion of the substrate or a notch in a corner portion where the side surface lead-out conductor is provided. Then
The trimming part of the inductor element that forms part of the oscillation circuit can be prevented from being directly exposed to the outside, and can be affected by electromagnetic effects on other electronic components placed around the oscillator or by electromagnetic interference from outside the surroundings This is preferable because the effect that the influence on the oscillator can be suppressed can be obtained. Also, the lead conductor of the internal inductor is changed to a conductor pattern on the side surface of the substrate, and the inner wall of a through hole (through hole) or a non-through hole (bottomed hole) provided in a direction perpendicular to or substantially perpendicular to the main surface of the substrate. The upper conductor or the conductor filled in the hole (hereinafter referred to as VIA hole) can prevent the trimming of the inductor element forming a part of the oscillation circuit from being directly exposed to the outside. In addition to suppressing the electromagnetic effects on the electronic components and the electromagnetic interference from outside the surroundings on the oscillator, the trimming part is damaged due to physical contact with the outside, causing misalignment. The danger of doing so is reduced. It is preferable because the effect is obtained.

According to another aspect of the present invention, an oscillation circuit component is mounted on a front main surface of a circuit board made of a dielectric, and a ground conductor is disposed on a rear main surface so as to cover most of the surface. Substantially parallel to the ground conductor in the circuit board, at least a part of the inductor element constituting the oscillation circuit is mounted, and the mounted part of the inductor element is a front side or a back side main surface on the side surface of the board or on the circuit board. When adjusting the oscillation characteristics of an oscillator having a lead conductor electrically drawn out along the inner wall surface of a preformed through hole or bottomed hole, the area of the lead conductor is variably cut off. A method for adjusting an oscillation characteristic of an oscillator is provided. That is, according to the present invention, the area (length, width) of the internal conductor pattern (inductor element), which mainly constitutes the inductance component of the oscillation circuit, can be changed with respect to the lead conductor (pattern) that leads to the substrate surface. Done to
Oscillation (device) characteristics such as oscillation frequency can be adjusted, so the length of the inductor conductor that constitutes the oscillation circuit can be adjusted without providing adjustment pads on the component mounting surface of the circuit board or the ground shield surface on the back side. The sheath width can be changed, and the module can be reduced in size.

More specifically, when trimming the dent in the outer peripheral portion of the substrate where the cap shield is overhanging or the cutout conductor in the corner portion of the substrate, trimming is performed from the side surface or the rear surface of the substrate to form a dent in the outer peripheral portion. And moving the trimming point along the edge direction of the notch at the corner of the board backside, the trimming can be performed after covering the component mounting surface on the board surface with the cap shield. ,
This is preferable because the problem of deviation of the adjustment point as in the case where the cap shield is put on after the trimming is eliminated, and the effect that it is possible to perform highly accurate adjustment is obtained. Further, with respect to an oscillator having a structure in which a lead conductor is provided in a through hole or a bottomed hole (in this case, an opening is provided on the back surface side of the substrate), trimming is performed from the back surface side of the substrate, and A method of moving the trimming point along the edge portion can be used.

According to still another aspect of the present invention, an oscillation circuit component is mounted on a front main surface of a circuit board, and a ground conductor is disposed on a main surface of a back surface so as to cover most of the circuit board. In the dielectric layer, at least a part of the inductor element constituting the oscillation circuit is mounted, and a lead conductor electrically drawn out from the mounted part of the inductor element to the front or back main surface adjusts the oscillation characteristics. An oscillator characterized in that the oscillator has been partially removed for the purpose of the present invention.

[0015]

[First Embodiment] A first embodiment of an oscillator according to the present invention will be described below with reference to the drawings. FIG. 1 shows a voltage controlled oscillator (VC) having an internal conductor pattern as one embodiment of an oscillator according to the present invention.
O) is an exploded perspective view of the module, and FIG. 2 is a sectional view of FIG.

1 and 2, a voltage controlled oscillator VC
In the module M of D), a chip resistor, a chip type capacitor, a transistor, and a surface mount type component 2 of a varicap diode are mounted on the surface of a copper printed wiring board 1 made of glass epoxy (resin) by reflow soldering, and the upper part thereof is mounted. Thus, the cap shield 3 formed by bending a thin metal plate is covered.

Further, the printed wiring board 1 includes a component mounting conductor pattern surface (layer) 1-a on the front side, an interior grounding conductor layer 1
-B and a grounded conductor layer 1-d on the back side, and has a four-layer laminated board structure composed of an interior stripline conductor pattern layer 1-c having a triplate structure. ) Has a thickness of about 10 to 30 μm,
Front side component mounting pattern surface 1-a and interior ground conductor layer 1-
b and between the interior conductor pattern layer 1-c and the ground conductor layer 1-d on the back surface are about 15
0 μm, interior ground conductor layer 1-b and interior conductor pattern layer 1
The thickness of the glass epoxy substrate between −c is about 200 μm. One end of the interior conductor pattern layer 1-c is provided on the side surface of the substrate, and a notch (through hole) connecting the conductor pattern surface 1-a of the front layer, the interior ground conductor layer 1-b, and the ground conductor layer 1-d on the back surface is provided. Halved) is grounded via a conductor 1-e provided on the inner wall, and the other end is provided on the side surface of the notch recess 8 provided on the side of the substrate from the interior conductor layer 1-c. It is drawn out to the substrate surface by a side conductor 1-f provided over the surface conductor pattern surface 1-a, and is connected to a predetermined point on the substrate surface conductor pattern surface 1-a. The interior ground conductor 1-b of the second layer has a side conductor 1 by an insulating band 10 in a notched dent portion.
-F is electrically insulated. In addition to the above, Vcc of the conductor pattern surface 1-a which is a wiring on the upper surface of the substrate is used.
(4) Each terminal of the control terminal (5) and the RF output terminal (6) is provided with a conductor (not shown) provided on an inner wall of a notch (a half of a through hole) provided on a side surface of the substrate.
It is routed to the back side of the substrate via g, 1-h, and 1-i.

FIG. 3 is a circuit diagram of the module. A transistor Tr, a resistor R, a bicap diode Vc, and a capacitor C that constitute a circuit of the module M shown in FIG. 3 are constituted by components 2 mounted on the surface of a printed circuit board (circuit board) 1 and oscillate. The inductor L constituting the circuit is mainly composed of a strip plate conductor pattern layer 1-c provided inside the substrate in a triplate structure and a side conductor 1- formed on the cutout recess 8 of the substrate.
f, a part of the surface conductor pattern surface 1-a connected to the side conductor. The module M changes the capacitance of the varicap diode Vc by controlling the voltage applied to the control terminal 5 shown in FIG.
The oscillation frequency of the obtained RF signal is changed.

However, variations in characteristics of individual elements constituting a circuit, dimensional variations in a printed wiring board,
Since the oscillation frequency varies in each module due to the variation in the physical conditions at the time of mounting the components, the module manufacturing process is performed so that the varicap diode achieves the design target oscillation frequency range by applying a predetermined control voltage. , The inductance of the inductor L constituting the oscillation circuit is adjusted for each module. The adjustment of the inductance of the inductor L is performed by adjusting the length and width of the interior conductor pattern layer 1-c constituting the inductor L.

FIG. 4 is a perspective view of the inductor L constituted by the interior conductor pattern layer 1-c and the side conductor 1-f in the present embodiment as viewed from the module surface side, and FIG. 5 is a conductor pattern constituting the inductor L. FIG. 4 is a development view in which is developed on a plane. In the inductor, the cutout 1-e side of one substrate is grounded through the side surface of the substrate, and the other is a component of another oscillator mounted on the surface of the substrate via the side conductor 1-f on the side surface of the substrate. Connected to the component 2 as By trimming the portion indicated by the thick line 9 in FIGS. 4 and 5, the electrical length of the conductor pattern forming the inductor can be increased by approximately 2α and the width can be reduced. In an inductor composed of parallel grounded conductors of a distributed constant type high-frequency circuit, it is possible to increase the inductance by increasing the electrical length or narrowing the width. The oscillation frequency of the module before the operation is performed is set to be higher than a predetermined value, and the inductance L constituting the oscillator is largely changed by trimming the portion 9, thereby lowering the oscillation frequency to the required value. Adjustment to obtain the oscillation frequency of

In this embodiment, the width of the trimming portion is about several tens μm and the length is about 0 to 1 mm. This trimming is
After the assembly of the module is completed, the YAG laser beam 12 is irradiated from the side surface of the module as shown in FIGS. In trimming, apply a probe to each terminal of the actual module,
This is performed while monitoring the oscillation frequency while the module is operating, and the trimming length is increased while moving the irradiation point of the trimming laser beam 12 in the direction of the white arrow A in FIGS. By the way, function trimming for stopping the trimming is performed. Instead of monitoring the frequency, an external PLL
A method of connecting a (PHASE-LOCKED LOOP) circuit, causing the module to oscillate at a predetermined oscillation frequency, and monitoring the voltage of the control terminal 5 at that time can also be used.

In the case of this embodiment, as shown in FIG. 2, the cap shield 3 has an overhanging structure above the trimming portion, so that the electromagnetic interference between the trimming portion and the outside can be suppressed. Since it is possible to perform trimming with the cap shield 3 attached, the trim shield can be trimmed from the component mounting surface side and then covered with the cap shield as in the method of covering the cap shield. It is not necessary to consider in advance the deviation of characteristics such as the oscillation frequency, and highly accurate trimming adjustment is possible. Also, the side conductor 1-f
The surface of the copper that forms the surface is blackened by the oxidation treatment, reducing the reflectance of the laser light, enabling processing with less power and at the same time facilitating the adjustment of the optimum laser light power. There is also. Needless to say, the method of improving the absorptance of laser light by blackening the surface may be performed by using a coloring agent such as a dye. The YAG laser light used for trimming includes, in addition to a fundamental oscillation wave having a wavelength of 1060 nm, a second harmonic (SHG: oscillation wavelength 1/2) obtained by passing the fundamental oscillation wave through a nonlinear optical element, and a third harmonic. By using a wave (THG: oscillation wavelength １ ／) and a fourth harmonic ((FHG: oscillation wavelength ４)), FIG.
As shown in the above, a method of improving the absorptivity to the side conductor 1-f such as copper to be trimmed may be adopted. As a method of trimming the side conductor 1-f, a mechanical method using a microluter can be used instead of the method using the laser beam.

FIG. 6 is a plan view of the module of the present example as viewed from the back side, and shows the Vcc terminal (4), the control terminal (5), and the R terminal.
Most of the terminal except for the F output terminal (6) and the insulating band 11 around it is covered with the ground conductor 1-d. Although the above example is a configuration using glass epoxy as the material of the wiring board, the same structure and adjustment can be applied to a configuration using a substrate using a glass ceramic material or the like as well as organic materials such as phenol and aramid. The application of the law is effective.

[First Modification of First Embodiment] Next,
A first modification of the first embodiment will be described below. FIG. 20 is a perspective view of a substrate showing a structure of an interior inductor L portion in this modification, FIG. 21 is a developed plan view of a conductor pattern forming the inductor L, and FIG. 22 is an enlarged cross section near a trimming portion of the present example. FIG.
In this modification, the structure of the module is substantially the same as that of the above-described embodiment. However, the trimming for the side conductor 1-f formed on the side surface of the notch 8 of the substrate is shown in FIGS. As shown in FIG. 22, the irradiation is performed by irradiating the YAG laser 12 from the back side of the substrate. In this example, the processing focal spot diameter of the YAG laser is about 50 μm, and the center of the spot is operated in the direction of arrow A along the edge of the notch 8 on the back side of the substrate. The length of the focused beam waist portion of the laser spot in the direction of the beam irradiation optical axis (depth of processing focus) is ± 300 μm, and when the focal center is aligned with the center in the substrate thickness direction (the thickness of the substrate 1 becomes approximately 600μ
m), the side conductor 1 on the rear surface of the notch 8
It is possible to trim all -f in the thickness direction by one irradiation.

By performing the function trimming in the same manner as in the first embodiment, the electrical length of the inductor L is reduced to 2 × α as shown in FIG.
And the oscillation characteristics can be adjusted. The module structure of this modification is the same as that of the first embodiment, as shown in FIG.
The cap shield 3 is overhanged on the upper part of the substrate, and the irradiation of the trimming laser light 12 is performed from the back side of the substrate. Although this also hits the inner surface, the beam is out of the processing focus at that portion, and the reflectivity of the laser beam to the metal is high (FIG. 19), so that no influence occurs.

As an example of the first embodiment and its modification, the example in which the irradiation of the trimming laser beam 12 is performed from the vertical direction on the side of the substrate and the vertical direction on the back of the substrate has been described, as shown in FIG. Trimming laser beam 1
Irradiation 2 can be performed from any angle within a range of an angle θ that is not blocked by the cap shield 3 and the substrate 1 itself. Although the trimming can be performed by a mechanical means such as a router, as described in the first embodiment, in the present modification, it is also possible to use a router instead of the laser beam 12. It is possible. 24 and 25 show an example in which the trimming method of the present modified example is performed by a router 16. FIG. 24 is a perspective view of a part of the substrate, and FIG. 25 is an enlarged sectional view of the vicinity of the trimming part. In the same example, the laser light is used by bringing the router blade 16 rotating at high speed in the R direction about the axis B into contact with the side conductor 1-f and scanning the router rotation axis B in the direction of the arrow A. As in the case described above, trimming of the portion 9 within the thick line frame is performed.
In addition, various methods described in the first embodiment can be applied to this modification.

[Second Modification of First Embodiment] Next,
The second modification of the first embodiment will be described below. FIG. 7 is a perspective view of a substrate conductor pattern constituting the inductor of the present example. In this modification, the side conductor 1- 1 equivalent to that in the first embodiment is used.
f ′ is formed on a side surface 8 ′ obtained by diagonally notching a substrate corner, and is irradiated with a YAG laser 12 from the side surface of the module perpendicularly to the surface to scan in the direction A in FIG. The function trimming of the nine thick lines is performed in the same procedure as in the first embodiment. Also in this case, similarly to the first embodiment, trimming is performed in a state where the cap shield 3 is overhanged over the cutout portion 8 'where the side conductor 1-f' is formed. Done. Structures and procedures other than those described above and variations thereof are all the same as those of the first embodiment.

Further, with respect to the module having a board shape having the cutout side surface 8 'of this modification, it is needless to say that the same variation as that of the first modification can be made. FIG. 26 shows an example of performing trimming by irradiating the laser 12 from the back side to the substrate shape of this modification, and FIG. 27 shows an example of performing trimming from the back side using a luter. In the first embodiment and the present modification, as the concave shape of the outer periphery of the substrate on which the side conductor 1-f is formed, a rectangular shape (including those with rounded corners) and the outer peripheral corner portion of the substrate are slanted. Although the cut example was given,
In addition, it may have various arcs such as a circle, an ellipse, and an ellipse, or any curved shape.

[Second Embodiment] Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG.
1 is an exploded perspective view of a voltage controlled oscillator (VCO) module having an internal conductor pattern according to the present invention. This module has substantially the same structure as that of the first embodiment, but the following mainly describes parts that are different from the first embodiment. The circuit configuration of this module is represented by the same circuit diagram as that of FIG. 3 shown in the first embodiment, and the transistor Tr, the resistor R, the varicap diode Vc, and the capacitor C that constitute the circuit of the module are connected to a circuit board. 1
Is configured by components 2 mounted on the surface of the device. The inductor L that constitutes the oscillation circuit is mainly composed of a strip line internal conductor pattern layer 1-c that is internally provided inside the substrate in a triplate structure, and a lead conductor 1-k that is formed on the inner wall of the substrate through hole 13; Is formed by a part of the surface conductor pattern surface 1-a connected to the surface.

In the present embodiment, one end of the interior conductor pattern layer 1-c is connected to the surface pattern surface 1-a provided on the side surface of the substrate and the interior ground conductor layer 1-c, as in the first embodiment. b and the ground conductor layer 1-d on the back surface are grounded via a conductor (a half of a through-hole) 1-e provided on the inner wall of the notch for connecting the ground conductor layer 1-d on the back surface. Drawn through the lead conductor 1-k provided on the inner wall surface of the substrate through-hole 13 having a diameter of 0.4 mm.
It is connected to a predetermined point on the surface conductor pattern surface 1-a. On the back side of the substrate, an insulating band 10 is provided around the through hole 13, and the lead conductor 1-k provided on the inner wall of the through hole 13 is electrically connected to the ground conductor 1-d on the back side of the substrate. Insulated. Also, regarding the second-layer interior ground conductor 1-b, an insulating band 10 is provided around the substrate through-hole 13 so that the lead-out conductor 1-b on the inner wall is provided.
h is electrically insulated.

FIG. 9 is an enlarged cross-sectional view of the vicinity of the substrate through-hole 3 in this embodiment, FIG. 10 is a perspective view of the vicinity of the substrate through-hole 13, FIG. 11 is a plan view of the module of this embodiment viewed from the back side,
FIG. 12 shows the interior conductor pattern 1-c and the side lead conductor 1.
FIG. 13 is a developed view in which an inductor L constituted by -h is developed on a plane. The circuit diagram of this module is the same as FIG. 3 shown in the first embodiment.

The conductor pattern forming the inductor L is formed by a lead conductor 1-h on the inner wall surface of the substrate through hole 13.
As shown in FIGS. 10 to 12, the electrical length is roughly illustrated by performing trimming along the inner circumferential direction of the substrate through-hole 13 (the direction of arrow A in the drawings) (portions in the thick line frame in FIGS. 9 to 12). As shown in Fig. 12, while the length is increased by 2α,
The width can also be reduced. In the inductor constituted by the parallel ground conductor of the distributed constant type high-frequency circuit, it is possible to increase the inductance by increasing the electrical length or narrowing the width. The oscillation frequency of the module before the trimming is set higher than a required value, and the trimming of the portion 9 is performed to lower the oscillation frequency by changing the inductance L constituting the oscillator to a higher value. Adjustment to obtain the required oscillation frequency is performed.

This trimming is performed by irradiating a YAG laser beam 12 from the back side of the module after all the modules have been assembled, as shown in FIGS. 9 and 10. Trimming is performed by actually applying a probe to each terminal of the module and monitoring the oscillation frequency while the module is operating, and moving the irradiation spot 9 of the trimming laser light 12 in the direction of arrow A while trimming the trimming length. Is performed, and when the oscillation frequency reaches a predetermined oscillation frequency, the trimming is stopped.

Instead of monitoring the frequency, P
A method of connecting the LL circuit to oscillate the module at a predetermined oscillation frequency and monitoring the voltage of the control terminal 5 at that time can also be used. In this example, the diameter of the irradiation beam spot 9 of the YAG laser is about 50 μm, and the beam spot is set so that the center of the beam spot is located 25 μm inward from the edge portion of the substrate through hole 13 on the back side of the substrate toward the hole center. The beam center is scanned in a circumferential direction concentric with the substrate through-hole 13 at a radius of −25 μm of the substrate through-hole 13. The vertical length (depth of processing focus) of the beam waist of the laser beam 12 is about ± 300 μm, and the center of the focus in the vertical direction is set to the interior ground conductor layer 1-b of the substrate.
By adjusting the distance to the vicinity, the lead conductor 1-h between the interior conductor pattern layer 1-c and the surface conductor pattern surface 1-a can be trimmed by a single irradiation. In this case,
Although the cross-sectional shape of the substrate through-hole 13 used for trimming is circular, the shape can take various shapes such as an ellipse, an oval, and a rectangle. Further, the inside of the substrate through-hole 13 is not a hollow, and the conductor may be filled up to the center.

In the case of this example, as shown in FIG.
Since the trimming is performed in a state where the cap shield 3 is put on the upper part of the trimming portion, the laser light emitted from the back side of the substrate passes through the substrate through hole 13 and then strikes the cap shield 3. The height from the substrate surface to the ceiling inside the cap shield 3 is about 1.2m
m, the surface of the cap shield 3 is out of the range of the processing focal depth of the beam and is hardly affected. Also, since trimming is possible with the cap shield 3 attached, the oscillation frequency caused by the cap seal being applied, such as a method of applying the cap seal after trimming from the component mounting surface side, etc. It is not necessary to consider the deviation of the characteristics in advance, and highly accurate trimming adjustment is also possible. In addition, the lead conductor 1
The method for applying the laser light to copper forming -h to improve the absorption of the laser light, coloring the surface of the portion, and using the harmonics of the laser light are also described in the first embodiment. The same usage as that applied to the side conductor 1-f is possible. Further, as a method of trimming the lead conductor 1-f, it is of course possible to use a mechanical method using a microluter instead of the method using the laser beam.

In the above example, a structure using glass epoxy as a material of the wiring board is used. However, the same applies to a structure using a substrate using a glass ceramic material as well as organic materials such as phenol and aramid. The application of the structure and the adjustment method is effective.

[Modification of Second Embodiment] Next, a modification of the second embodiment will be described below.
FIG. 13 is a cross-sectional view of the vicinity of the trimming portion of the present example.
In this modification, the electronic components mounted on the surface of the board are sealed with epoxy resin 14 in place of the metal plate cap shield in the second embodiment, and a conductive sheet 15 is attached on the surface. Then, a part of the conductive sheet 15 is connected to the ground terminal 1-e on the side of the substrate. In the present modification, the sealing resin 14 also flows into the trimming substrate through-hole 13 ′ in which the lead conductor 1-h is provided on the inner wall, but the substrate is similar to the second embodiment. By irradiating the laser beam 12 from the back surface, trimming of a part of the sealing resin 14 in the hole and the lead-out conductor 1-h at the irradiation spot 9 (the hatched portion in the thick frame in the figure) is performed. . Although the sealing resin 14 is partially trimmed also on the upper part of the substrate, since its thickness is about 1 mm, the upper part is out of the range of the laser processing focal depth, and the trimming hole does not penetrate to the surface. All other structures and procedures and variations thereof are the same as those of the second embodiment.

[0038]

According to the present invention, a conductor (pattern) for pulling out a built-in inductor element to the front or back surface of a substrate.
Since the trimming is performed on the portion itself, it is not necessary to provide a trimming conductor pad on the component mounting surface on the substrate, and the oscillator module can be further reduced in size.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a voltage controlled oscillator according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the voltage controlled oscillator according to the first embodiment of the present invention.

FIG. 3 is a circuit diagram of a voltage controlled oscillator according to the first embodiment of the present invention.

FIG. 4 is a perspective view of the printed circuit board built-in inductor according to the first embodiment of the present invention.

FIG. 5 is a developed plan view of the board-embedded inductor according to the first embodiment of the present invention.

FIG. 6 is a rear plan view of the voltage controlled oscillator according to the first embodiment of the present invention.

FIG. 7 is a perspective view of a board-embedded inductor according to a second modification of the first embodiment of the present invention.

FIG. 8 is an exploded perspective view of a voltage controlled oscillator according to a second embodiment of the present invention.

FIG. 9 is a sectional view near a trimming portion of a voltage controlled oscillator according to a second embodiment of the present invention.

FIG. 10 is a perspective view of a trimming portion according to a second embodiment of the present invention.

FIG. 11 is a rear plan view of the voltage controlled oscillator according to the second embodiment of the present invention.

FIG. 12 is an exploded plan view of a substrate-embedded inductor according to a second embodiment of the present invention.

FIG. 13 is a sectional view near a trimming portion of a voltage controlled oscillator according to a modification of the second embodiment of the present invention.

FIG. 14 is an explanatory perspective view showing a structural example of a conventional oscillator.

FIG. 15 is a detailed plan view of a trimming part showing a structural example of a conventional oscillator.

FIG. 16 is an explanatory sectional view showing a structural example of a conventional oscillator.

FIG. 17 is an explanatory sectional view showing a structural example of a conventional oscillator.

FIG. 18 is a detailed cross-sectional view of a trimming portion in a structural example of a conventional oscillator.

FIG. 19 is a graph showing reflection characteristics of a typical metal.

FIG. 20 is a partial perspective view of a board-embedded inductor according to a first modification of the first embodiment of the present invention.

FIG. 21 is a developed plan view of a substrate-integrated inductor according to a first modification of the first embodiment of the present invention.

FIG. 22 is a sectional view showing the vicinity of a trimming portion according to a first modification of the first embodiment of the present invention.

FIG. 23 is an explanatory diagram illustrating a laser beam irradiation angle range according to the first embodiment of this invention.

FIG. 24 is an explanatory perspective view of a luter working example according to a first modification of the first embodiment of the present invention.

FIG. 25 is an explanatory cross-sectional view of an example of luter processing in a first modification of the first embodiment of the present invention.

FIG. 26 is an explanatory perspective view of a laser processing example according to a second modification of the first embodiment of the present invention.

FIG. 27 is an explanatory perspective view of a luter working example in a second modification of the first embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printed wiring board 2 Surface mount type component 3 Cap shield 1-a Surface component mounting surface Wiring pattern surface (layer) 1-b Interior ground conductor layer 1-c Interior conductor pattern layer 1-d Backside ground conductor layer 1-e Side surface Ground conductor 1-f Side conductor 1-f 'Side conductor 1-g Side Vcc terminal conductor 1-h Side control terminal conductor 1-i Side output terminal conductor 1-j Substrate dielectric layer 1-k Lead-out conductor 4 Vcc terminal 5 Control terminal 6 RF output terminal 7 Ground terminal Tr Transistor R Resistance Vc Varicap diode C Capacitor L Inductor 8 Substrate cutout dent 9 Trimming spot 10 Insulation band 11 Insulation band 12 Laser beam 13 Substrate through hole 13 'Substrate through hole 14 Sealing Resin 15 Conductive sheet 16 Luter A Laser scanning direction B Rotor rotation axis R Luterー Rotation direction α Electrical length changed by trimming θ Trimming angle

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 5J006 HD08 HD12 LA11 LA21 MA04 MA09 NA04 NC01 PA03 5J081 AA03 AA11 BB01 CC22 CC42 DD02 DD26 EE03 EE09 EE18 JJ04 JJ14 JJ23 KK02 KK09 KK11 KK17 KK22 KK25 MM01 MM07

Claims (7)

[Claims] 1. An oscillator circuit component is mounted on a front main surface of a circuit board made of a dielectric, and a ground conductor is disposed on the rear main surface so as to cover most of the circuit component. In parallel, a conductor that contains at least a part of the inductor element that constitutes the oscillation circuit and that electrically draws out the embedded part of the inductor element to the front main surface or back main surface can be adjusted for oscillation characteristics by partially removing it. An oscillator formed on a side surface of the substrate or on an inner wall surface of a through hole or a bottomed hole provided in the substrate in advance. 2. The substrate has a recess in an outer peripheral portion of a side surface thereof or a notch in a corner portion of the side surface, and a conductor for electrically drawing out an interior portion of the inductor element is formed on an inner wall surface of the recess or the notch. The oscillator of claim 1 formed above. 3. The oscillator according to claim 2, further comprising a conductive cap shield that simultaneously covers the dent or notch and the oscillation circuit component mounted on the front main surface of the substrate. 4. The substrate has a through hole or a bottomed hole in a direction perpendicular to the front side main surface thereof, and the conductor for electrically drawing out the interior part of the inductor element is provided with the through hole or the bottomed hole. 2. The oscillator according to claim 1, wherein the oscillator is filled inside. 5. An oscillator circuit component is mounted on a front main surface of a circuit board made of a dielectric, and a ground conductor is disposed on a rear main surface so as to cover most of the circuit component. In parallel, at least a part of the inductor element constituting the oscillation circuit is mounted, and the mounted part of the inductor element is formed on the side surface of the substrate to the front side or the back side main surface or the through hole or the bottom formed in the circuit board in advance. A method for adjusting an oscillation characteristic of an oscillator, comprising: variably cutting an area of the extraction conductor when adjusting the oscillation characteristic of the oscillator including an extraction conductor that is electrically extracted along an inner wall surface of the hole. . 6. The oscillation characteristic adjusting method for an oscillator according to claim 5, wherein cutting of the lead-out conductor is performed while moving from a side surface or a rear surface direction of the substrate along a dent or a notch edge of the side surface of the substrate. 7. The oscillator according to claim 5, wherein the extraction conductor is cut while moving from a rear surface direction of the substrate to a direction along an edge of an inner wall surface of a through hole provided in the substrate or a bottomed hole. Oscillation characteristic adjustment method.