JP2002299782A - Circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit board, capable of accurately measuring characteristics of a circuit function element inside the circuit substrate, without lowering the jointing strength of the circuit substrate to a mother board. SOLUTION: In a circuit substrate, there is formed, at an end face of a circuit board 1 formed with a predetermined circuit network, a signal potential terminal electrode 2 which comprises an end face conductor 2b clad on the inner wall face of a recess part 2a (2d, 2e), in the substrate thickness direction and a land conductor 2c clad in a periphery of an opening of the recess part 2a. If the opening width of the recess part 2d at the end face of the substrate 1 is set as W1 and the width of the land conductor film 2c is W2 , and the width of the end face conductive film is set as W3 , W1 >W2 >W3 (a central axis is common in each case).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit board used for various electronic devices and electronic devices.

[0002]

2. Description of the Related Art In recent years, electronic equipment and devices have been
Demands for miniaturization, thinning, high functionality, low cost, and the like have become even stronger. To fulfill those requirements,
2. Description of the Related Art A component (hereinafter, referred to as an electronic circuit module) in which a plurality of circuit function elements are arranged in a laminated circuit board and a plurality of circuit function elements are combined is frequently used.

In an electronic circuit module, for example, a plurality of strip line conductor films are arranged on a laminated substrate (hereinafter, simply referred to as a circuit substrate) to form a plurality of resonance circuit portions or a plurality of filter circuit portions. For example, an antenna switching component in which the filter circuit unit is further combined can be exemplified. Other examples include a high-frequency amplifier circuit component and a high-frequency oscillation circuit component.

FIG. 6 is an exploded view of a conventional circuit board 60 for an electronic circuit module. As shown, the circuit board 60
Is a laminated substrate formed by laminating, for example, three dielectric layers 1a to 1c. A predetermined internal wiring conductor 61 and a via hole conductor 62 are formed in a circuit board 60. Various electrode components 63 are mounted on the surface of the circuit board 60. Further, a signal potential terminal electrode 64 and a ground potential terminal electrode 65 are formed on the end face and the back face of the substrate.

[0005] Specifically, the terminal electrodes 64 and 65 are formed in a concave portion 64 formed on the end face of the substrate 60 and extending in the thickness direction of the substrate.
a, 65a, end surface conductor films 64b, 65b formed on the inner wall surfaces of the recesses 64a, 65a, and end surface conductor films 64b, 6
5b, and includes land conductor films 64c and 65c formed around the recesses 64a and 65a. Note that the land conductor films 64c and 65c are the end face conductor films 6
4b and 65b are always formed around the opening when they are formed, and are formed on the front side and / or the back side of the substrate 60. Further, on the back surface of the circuit board 60, as shown in FIG. 7, back terminal electrode films 66 and 67 in which the land conductor films 64c and 65c are extended are formed. at the same time,
In order to shield the circuit board 60 from the back side, a shield conductor film 68 serving as a ground potential is formed in a blank portion of the board.

That is, the back terminal electrode film 67 at the ground potential
Connects both the terminal electrode 64 and the shield conductor film 68. On the other hand, the back terminal electrode film 66 on the signal side
Are arranged so as to be electrically separated from the adjacent back surface terminal electrode 67 of the ground potential and the shield conductor film 68.

[0007]

In the electronic circuit module, a circuit function element formed inside the circuit board 60, for example, a resonance circuit section and a filter circuit section composed of a strip line or the like operate as designed. It is important to do. This can be done by a continuity test of the wiring when only the internal wiring conductors serving as the wiring of the circuit network such as a multilayer wiring board are used. In addition, the characteristics of the filter circuit section are affected, which affects the operation of the high-frequency circuit. For this reason, before mounting the electronic components, the characteristics of the circuit functional element are checked, and in order to prevent unnecessary mounting and mounting of the electronic components, only the characteristics of the circuit board during the manufacturing process, that is, for example, the characteristics of the strip line conductor alone. Measurements must be taken reliably.

More specifically, the measurement is performed on the terminal electrode films on the back surface of the circuit board and the terminal electrodes on the end surfaces using a probe of a measuring device.

Here, in order to efficiently manufacture the circuit board 60, the high-frequency characteristics are not measured after each circuit board area is separated (divided, cut), but the state of the large circuit board before separation is measured. It is desirable to measure with.

However, the large circuit board 80 is
As shown in the figure, the circuit board region to be a circuit board has a repetitive pattern so as to be adjacent to each other.

For this reason, through-holes serving as the recesses 64a and 65a are formed across the separation line (virtual) separating the adjacent circuit board regions, and the end surface conductor film 64b is formed around the inner wall surface and the opening of the through-hole. 65b, land conductor films 64c, 65
c will be formed. As a result, focusing on the adjacent circuit board regions, the signal potential terminal electrode 64 of one circuit board is connected to the signal potential terminal electrode 6 of the other circuit board region.
4 and, in some cases, the ground potential terminal electrode 65.

Therefore, on a conventional large circuit board, the characteristics of the circuit board area will be examined by using the terminal electrodes 64 (66) of the signal potential and the terminal electrodes 65 (67) of the ground potential. However, since it is connected to another circuit area, it was not possible to accurately measure the circuit board area.

For this reason, a semiconductor element,
After mounting a thick-film resistance element, various electronic components, and the like, and performing a separation process, it is necessary to inspect high-frequency characteristics. For this reason, there has been a problem that the detection of defective products is delayed and the number of unnecessary steps increases.

The present invention has been made in view of the above problems, and has as its object to provide a signal potential terminal electrode on an end face of a circuit board without reducing the bonding strength between the circuit board and an external motherboard board. It is an object of the present invention to provide an electronic circuit module which can be completely electrically separated from an adjacent circuit board region in the state of a large board even if it is arranged, and can accurately measure a single characteristic of the circuit board.

[0015]

A circuit board according to the present invention comprises a concave portion extending in the thickness direction of the substrate, an end surface conductor attached to the inner wall surface of the concave portion, In a circuit board on which a signal potential terminal electrode composed of a land conductor attached around an opening is arranged, the opening width of the concave portion of the signal potential terminal electrode is W ₁ , the width of the land conductor is W ₂ , and the width of the end face conductor is W. _The circuit board is characterized in that when W is ₃ , W ₁ > W ₂ > W ₃ (the central axes of the widths are common).

Further, the end face of the circuit board is further provided with:
A ground potential terminal electrode is formed of a concave portion extending in the thickness direction of the substrate, an end surface conductor attached to the inner wall surface of the concave portion, and a land conductor attached around the opening of the concave portion.

Further, the circuit board is extracted from a large circuit board in which a plurality of circuit board areas are arranged vertically and horizontally.

According to the present invention, since the signal potential terminal electrode formed on the end face of the circuit board is smaller than the width of the opening, it is smaller than the width of the land conductor film forming the terminal electrode.
In the state of a large substrate, it can be electrically separated from the terminal electrodes in the adjacent circuit board region. Further, the width of the land conductor film is smaller than the width of the end surface conductor film. As a result, the land conductor film in one circuit board region and the land conductor film in the other circuit board region are not connected to each other, and furthermore, the end surface conductor film in one circuit board region and the land conductor film in the other circuit board region are not connected. There is no connection with a conductor film.

Thus, in the circuit board areas adjacent to each other,
The signal potential terminal electrode can be completely independent in the circuit board region, and thus, when measuring the individual characteristics of each circuit board region, the characteristics of the circuit board can be accurately measured without fail. As a result, the characteristics of the measured circuit board can be corrected and adjusted in the state of a large-sized board.

Thus, in the manufacture of the circuit board, the measurement, correction and adjustment of the characteristics, and the mounting of the shield case after the mounting of the electronic components can be performed before and after the shield case attaching step, and the production efficiency is maintained and improved.

Further, since the signal potential terminal electrode and the ground potential terminal electrode in the concave portion of the end face are formed on the end face of the substrate, even if it is soldered to the motherboard, a solder rising portion is formed at that part. Therefore, the bonding strength with the motherboard is maintained.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a circuit board according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is an exploded perspective view of a circuit board according to the present invention. In addition, in the exploded perspective view of FIG. 1, particularly, in order to clarify the structure of the present invention, the conductors attached to the back surface of the circuit board are also exploded. FIG. 2 is a back view of the circuit board of the present invention, and FIG. 3 is a side view of an end face portion of the circuit board. 2 and 3, the shield case is omitted.

In the figure, the electronic component module 10
Circuit board 1 in which a plurality of dielectric layers 1a to 1c are laminated
And a shield case 9.

Examples of the circuit board 1 include a multilayer ceramic circuit board and a glass epoxy insulating board laminated in multiple layers. In particular, the circuit board 1 is a multilayer ceramic circuit board formed by laminating a plurality of dielectric ceramic layers (dielectric layers) 1a to 1c in consideration of characteristics as a high-frequency circuit and high density of an electronic circuit network. Is preferably used.

Further, between the dielectric layers 1a to 1c,
An internal wiring conductor film 12 constituting a predetermined circuit network is formed,
In each of the dielectric layers 1a to 1c, a via-hole conductor 11 that is connected to the internal wiring conductor film 12 and various conductors disposed on both main surfaces of the circuit board 1 is formed. Here, examples of the conductor attached to the internal wiring conductor film 12 or both main surfaces include a conductor film having an inductance component such as a strip line, a capacitance electrode forming a capacitance component, and the like.
When it operates alone as an inductance component or a capacitance component, or an LC resonance circuit portion, a filter circuit portion, and a lumped constant inductance component and a capacitance component.
Further, there are an LC resonance circuit section, a filter circuit section, and the like, each of which includes a distributed constant inductance component and a capacitance component.

On the surface of the circuit board 1, the above-mentioned conductor (surface wiring conductor film 13) is formed. On the surface wiring conductor film 13, electronic components 7 such as IC chips and chip-shaped electronic components are formed. Has been implemented.

The above-mentioned internal wiring conductor film 12 and surface wiring conductor film 13 of the circuit board 1 are connected to various terminal electrodes and are connected to an external motherboard.

The parts that are actually connected to the motherboard are:
The terminal electrodes 2, 3, and 5 are formed such that the end surface and the back surface of the circuit board 1 are rogue. The terminal electrode 2 is a signal potential terminal electrode, and the terminal electrodes 3 and 5 are ground potential terminal electrodes.

These terminal electrodes 2, 3, 5 are connected to the substrate 1
2a, 3a, 5a formed on the end face of
a, 3a, 5a, end surface conductors 2b, 3b, 5
b and land conductor films 2c, 3c, 5c formed around the openings on the back surfaces of the recesses 2a, 3a, 5a.

The concave portion 2a of the signal potential terminal electrode 2 among the terminal electrodes 2, 3, 5 is a first concave portion 2d having a substantially rectangular opening having a wide opening at the end face portion of the circuit board 1, and the circuit substrate 1 The second recess 2e is recessed in the center direction. The conductor film is not substantially formed on the inner wall of the first concave portion 2d. A terminal conductor 2b is formed on the inner wall surface of the second recess 2e. Also,
The land conductor film 2c of the signal potential terminal electrode 2 is formed so as not to extend to the end surface of the circuit board 1 due to the presence of the first recess 2d.

In particular, after the terminal electrodes 3 and 5 at the ground potential, a part of the shield case 9 is inserted and arranged in the concave portion 5a having a large opening shape, and is joined to the end surface conductor 5b via solder.

In FIG. 2, the land conductor film 2c is connected to a wide back terminal electrode 4 attached to the back surface of the substrate 1. In addition, the land conductor film 3c which becomes the ground potential
Is connected to the back surface shield conductor 6 on the back surface of the substrate 1. That is, the land conductor film 5c and the back shield conductor 6 are common.

The signal potential terminal electrodes 2 are connected to the signal potential wiring conductors of the internal wiring conductor film 12 and the surface wiring conductor film 13 of the circuit board 1. The connection method is
For example, the internal wiring conductor film 1 between the dielectric layers 1a and 1b
2 is directly connected to the end surface conductor 2b in the second recess 2e. Further, this is achieved by connecting to the land conductor film 3c and the back surface terminal electrode 4 by the via hole conductor 11.

The ground potential terminal electrodes 3 and 5
The internal wiring conductor film 12 and the surface wiring conductor film 13 of the circuit board 1
It is connected to the middle ground potential wiring conductor. The connection method is, for example, that the internal wiring conductor film 12 between the dielectric layers 1a and 1b is directly connected to the end face conductors 3b, 5c in the recess 3a.
b. Further, this is achieved by connecting the via conductor 11 to the land conductor film 3c and the shield conductor film 6.

A gap is formed between the signal-side back terminal electrode 4 and the shield conductor film 6 at the ground potential. Then, even when the back surface terminal electrode 4 is soldered to the motherboard, a control is performed so that a solder bridge does not occur between the shield conductor film 6 at the ground potential.

On the surface of such a circuit board 1,
The surface wiring conductor film 13 is formed, and the electronic component element 7 is disposed on the surface.

The surface of the substrate 1 is covered with a shield case 9. As a material of the shield case 9, iron, nickel silver, aluminum, SUS, copper, or the like is used.

The shield case 9 has an opening on one side (the front side of the substrate) and a projection 9a extending from the side surface. The protruding piece 9a extends from the side surface of the shield case 9 and is joined to the end conductor 5b at the ground potential via solder. Although the number of joints between the shield case 9 and the end face of the substrate 1 is two in the figure, the shield case 9 can be stably attached by providing three or more joints on different sides. it can.

Here, the feature of the present invention is that the terminal electrodes 2, 3,
5 is formed, and, in the signal potential terminal electrodes 2, W ₁ the opening width of the first recess 2d in the end face of the substrate, the width of the land conductor layer 2c W _2, the width W of the end face conductive film 2b ₃ when _{a, W 1> W 2> W} 3 ( the central axis both common) has become.

As described above, the end surface conductor 2b and the land electrode 2c of the signal potential terminal electrode 2
Due to d, it does not reach the end surface (separation surface portion) of the circuit board 1.

That is, in a state of a large circuit board in which a plurality of circuit boards 1 are connected to each other in this state, as shown in FIG. It does not reach the region B to be the substrate 1 at all. That is, the terminal electrode 2 of the signal potential of the circuit board regions A and B
Is completely separated by the most opening width W ₁ is larger first recess 2d become through holes (20d).

Therefore, in the state of the large circuit board, it is possible to individually measure the circuit characteristics of each of the circuit board areas A and B during the manufacturing process described later.

When the circuit board 1 is used as an electronic module and soldered to a mother board, the land electrodes 2c, 3c and the back terminal electrodes 4,
5, and the melted solder goes up to the end surface conductors 2b, 3b, 5b formed on the end surface of the substrate 1, and a strong solder joint can be maintained at the end surface portion of the circuit board 1.

A method of manufacturing the circuit board 1 of the electronic circuit module will be described.

First, a green sheet made of a dielectric material to be the circuit board 1, for example, a glass-dielectric ceramic material is formed. Specifically, the ceramic powder described above,
The slurry obtained by uniformly kneading the frit of the low melting glass component, the organic binder, and the organic solvent is tape-formed to a predetermined thickness by a doctor blade method, and cut into a predetermined size to form a sheet.

The green sheet is a large green sheet including a plurality of circuit board areas A, B,.

Next, for each circuit board region on the green sheet, a via hole conductor 11 penetrating through the thickness of the green sheet is provided.
A through hole having a predetermined diameter, such as a hole, is formed by punching.

Next, for each circuit board region on the green sheet, the above-mentioned through-hole is filled with an Ag-based conductive paste, and a conductor film or the like to be the internal wiring conductor film 12 is formed. In addition, this internal wiring conductor film 12 is a circuit functional element,
For example, it is also used as a conductor film for a strip line conductor film, a capacitor, and the like. At the same time, a conductive film to be the surface wiring conductive film 13 and a conductive film to be various electrode pads are formed on the green sheet positioned as the outermost layer by printing an Ag-based conductive paste and drying. Also, on the back side of the green sheet located at the lower side of the outermost layer, terminal electrodes 2, 3, 5, a conductor film to be the back side terminal electrode 4, a conductor film to be the shield conductor film 6, and a land if necessary The conductor films 2c and 3c are formed. Here, the land conductor films 2c, 3
c is formed continuously over the circuit board regions adjacent to each other.

Here, the conductive paste that becomes the internal wiring conductor film 12 and the via hole conductor 11 is made of an Ag-based paste (Ag alone,
Ag alloys such as Ag-Pd and Ag-Pt) powders, glass components, organic binders such as ethylcellulose, and solvents are homogeneously mixed. The conductive paste of various conductors exposed on the surface of the substrate was obtained by homogeneously mixing Ag-based (Ag alone, Ag alloy such as Ag-Pd) powder, Au-based powder, Pt powder, inorganic binder, organic binder, and solvent. Things are used.

The green sheets on which the conductor films are formed as described above are stacked and integrated in the stacking order to form a large-sized unfired circuit board including a plurality of circuit board areas. After that, if necessary, a division groove is formed according to the shape of each electronic circuit module.

Next, through-holes which become the recesses 2a, 3a, and 5a are formed at boundaries between the circuit board regions of the unsintered large-sized circuit board after separation so as to straddle these boundaries.
In other words, the circular through-holes are formed in the terminal electrodes 3 and 5 at the ground potential, and the conductor films serving as the end face conductor films 3b and 5b and the land conductor films 3c and 5c are formed on the inner wall surfaces of the through-holes. A conductive film to be used (shared with the shield conductive film 6) is formed. Specifically, the conductive paste is printed in a range covering the opening while sucking from one opening of the through hole. In the signal potential terminal electrode 2 portion, the first concave portion 2d
Through hole 20d and second through hole 2d
0e is formed, and a conductor film to be the end face conductor 2b is formed only on the inner wall surface of the through hole 20e.

Specifically, for example, a circular through hole 30 serving as the concave portion 3a and the concave portion 2e is formed in the large-sized circuit board in the unfired state.
a and 20e are formed. Next, the through holes 30a, 20e
Inside, end face conductors 3b and 2b are formed by adhesion. At this time, since the conductive paste is printed so as to cover at least the entire opening of the through hole, the land conductor film 2c,
3c is formed and connected to the back surface terminal electrode 4 and the shield conductor film 6. In this state, the structure in which the terminal electrodes 3 and 5 are at the ground potential is completed.

Thereafter, in the signal potential terminal electrode 2, a conductor film to be the end face conductor 2b is formed, and the through-hole 20e is formed.
A through hole 20d serving as the first concave portion 2d is formed so as to divide the land conductor film 2c formed around the opening.
That is, the opening width W ₁ which is substantially rectangular at the boundary between adjacent circuit board regions and is larger than the width W ₂ of the land conductor film 2c.
To form As a result, a part of the conductor film serving as the end face conductor 2b adhered to the inner wall surface of the through hole 20e becomes the end face conductor 2b.
b is the width W ₃ of the opening side of, smaller than the width W ₂ of the opening side of the land conductor layer 2c. Thereby, the end surface conductor 2b is
The portion that becomes the concave portion 2a can be completely separated from the end face conductor film 2b of the signal potential terminal electrode 2 in another circuit board region.

Next, the large-sized circuit board in the unfired state is fired in an air atmosphere or a neutral atmosphere. The firing process includes a binder removal process and a sintering process.

The binder removal process is for burning out the organic components contained in the green sheet or the conductor film serving as the circuit board, and is performed, for example, in a temperature range of 600 ° C. or less.

In this process, in each of the circuit board regions A, B,... To become the circuit board 1, the internal wiring conductor film 12 including the circuit functional element, and the end face conductor formed on the inner wall of the through hole to become the recesses 2d, 3a. Films 2b, 3b, and via-hole conductors 11 are formed. On the surface of the circuit board 1, the surface wiring conductor film 13, various electrode pads, and on the back surface of the substrate, the terminal electrodes 4, the shield conductor film 6.
Is formed.

Thereafter, if necessary, a thick-film resistance element connected to the surface wiring conductor film and an insulating protection film having a predetermined shape are formed.

Next, individual circuit characteristics of each of the circuit board areas A, B,... Are measured. This characteristic means, for example, that the stripline conductor film or capacitor is formed by a thick film technique, so that the printing displacement of the conductive paste, printing bleeding,
Due to misalignment of the green sheets, the designed characteristics may not be obtained. In order to correct the circuit board areas A and B, characteristics of each circuit board area are measured. Specifically, one of the two contacts of the characteristic measuring device probe is connected to the terminal electrode 3 at the ground potential, and the other contact is connected to the signal potential terminal electrode 2 to measure various characteristics. Do.

As a result of the measurement of the characteristics of the circuit functional element as described above, if the characteristic is poor, a defective marking is described in the circuit board area before dividing the circuit board, and the manufacturing process For example, the electronic component element 7 is not mounted. As a result of the measurement, adjustment and correction of the characteristics are performed by irradiating a laser to an adjustment conductor formed on the surface and partially removing the laser, and adjusting the characteristics.

Next, if necessary, the circuit board regions A and B
Various electronic component elements 7 are mounted on the surface of. Note that the various electronic component elements 7 may be mounted before the measurement of the above characteristics.

Next, the shield case 9 covers each circuit board area of the large circuit board. This shield case 9
Solder is filled into the end face conductor films 3b and 5b of the through holes that become the concave portions 3a and 5a, and the protruding pieces 9a of the shield case 9 are inserted into the through holes and soldered by reflow processing.

Thereafter, the large circuit board is separated for each circuit board area, and the electronic circuit module 1 using the circuit board is completed.

Although an Ag-based material or an Au-based material is used as the material of the above-described conductor, if a ceramic material and a firing atmosphere (neutral or reducing atmosphere) are used, C
A u-based conductor material can be used.

The mounting of the electronic component element 7 and the attachment of the shield case 9 may be performed after the large circuit board is separated from the circuit board.

According to the electronic circuit module 10 of the present invention, the signal potential terminal electrodes 2 on one circuit board area A are connected to the signal potential terminal electrodes 2 on the other circuit board area B in the state of a large board. Even if the circuit characteristics and high-frequency characteristics of each circuit board region are measured, they are arranged so as to be adjacent to each other even if the circuit characteristics and the high-frequency characteristics of each circuit board region are measured, because they are separated by the substantially rectangular through-holes 20d having openings larger than the width of the land conductor film 2c. It is completely unaffected by the network of the matching circuit board area. That is, the characteristics of only the pure circuit board 1 can be measured. In addition, characteristics can be corrected and adjusted at an early stage of the manufacturing process, and defective products can be removed, thereby reducing unnecessary processes.

The terminal electrodes 2 on the end face of the circuit board 1
Since the number of 3, 5 does not decrease, the joining strength between the circuit board 1 and the motherboard does not decrease.

Further, since the diameter of the terminal electrodes 2, 3, and 5, or the cut amount toward the center of the substrate can be set to about 400 μm or less, high-density mounting of the entire circuit substrate 1 can be realized.

In order to prevent unnecessary connection due to printing deviation or the like, it is desirable that the distance between the signal-side back electrode 4 and the ground potential shield conductor 6 be 100 μm or more.

It should be noted that the present invention is not limited to the above example, and that various changes and improvements can be made without departing from the spirit of the present invention.

For example, it goes without saying that a glass epoxy insulating substrate may be used instead of the multilayer ceramic circuit board as the insulating substrate material.

The present invention uses the network analyzer in the state of the large circuit board of the circuit board of the present invention (FIG. 1) and the state of the large circuit board of the conventional circuit board (FIG. 6) using a network analyzer.
The frequency characteristics of each circuit board region alone from 00 MHz to 6 GHz were measured. In addition, a strip line conductor film performing a resonance action was formed as the internal wiring conductor film 12 inside the circuit board, and the frequency-impedance (Z) characteristics of the entire circuit including the internal wiring conductor film 12 were measured.

According to the present invention, as shown in the characteristics shown in FIG. 5, it is found that accurate characteristics can be measured without noise in the frequency range of 2 to 5 GHz, and the frequency characteristics at 100 MHz to 6 GHz are measured. However, it is also possible to evaluate the characteristics in the millimeter-wave / microwave region, including the measurement of the insulation resistance value when a DC voltage is applied.

On the other hand, conventionally, noise (influence of other circuit board areas) is superimposed as shown in the characteristics of FIG. It can be understood that they cannot be measured.

[0074]

According to the present invention, the signal potential terminal electrode formed on the end face of the circuit board is electrically disconnected from the adjacent circuit board in the state of a large circuit board from which a plurality of circuit boards can be extracted. Since it can be maintained, the characteristics of each circuit board can be reliably measured in the state of a large-sized board. Therefore, the characteristics of the circuit board can be easily corrected and adjusted, and the production efficiency is greatly improved.

Further, since the signal potential terminal electrode and the ground terminal electrode are formed on the end face of the board, the bonding strength between the circuit board and the mother board can be maintained.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a circuit board according to the present invention.

FIG. 2 is a plan view of the back side of the circuit board of the present invention.

FIG. 3 is a side view of an end face portion of the circuit board of the present invention.

FIG. 4 is a plan view of the back surface side of the large substrate according to the present invention.

FIG. 5 is a diagram showing high-frequency characteristics of a circuit board region in a large circuit board state according to the present invention.

FIG. 6 is an exploded perspective view of a conventional circuit board.

FIG. 7 is a plan view of the back side of a conventional circuit board.

FIG. 8 is a plan view of the back side of a conventional large substrate.

FIG. 9 is a diagram showing high frequency characteristics of a circuit board region in a conventional large circuit board state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Electronic circuit module 1, 60 Circuit board 1a-1c Dielectric layer 2, 3, 5 Terminal electrode 2a, 3a Depression 2b, 3b, 5b Terminal electrode conductor 2c, 3c, 5c Land electrode 2d First depression 2e Second Recess 20d Through hole 20e Through hole 6 Shield conductor film 9 Shield case 9a Protrusion

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H05K 3/46 H05K 3/46 H

Claims (3)

[Claims] 1. A concave portion extending in the thickness direction of a substrate, an end surface conductor attached to an inner wall surface of the concave portion, and a land conductor attached around an opening of the concave portion on an end surface of the circuit board on which a predetermined circuit network is formed. In the circuit board on which the signal potential terminal electrodes are arranged, when the opening width of the concave portion of the signal potential terminal electrode is W ₁ , the width of the land conductor is W ₂ , and the width of the end face conductor is W ₃ , W ₁ > W ₂ >
Circuit board, characterized in that W is _3. 2. A ground potential terminal electrode comprising a concave portion extending in the thickness direction of the substrate, an end surface conductor attached to an inner wall surface of the concave portion, and a land conductor attached around the opening of the concave portion are arranged on an end surface of the circuit board. The circuit board according to claim 1, wherein: 3. The circuit board according to claim 1, wherein the circuit board is extracted from a large circuit board in which a plurality of circuit board areas are arranged vertically and horizontally.