JP2007035739A - Circuit board and circuit board manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit board and a manufacturing method of the same circuit board for realizing size reduction and high density of circuit board, accurately testing natural circuit wires for propagating high-frequency signals in the course of the board manufacturing process, assuring higher application efficiency of electronic components to be embedded in the circuit board, removing restrictions on the manufacturing process, and improving the board manufacturing yield. <P>SOLUTION: The circuit board 21 comprises a flexible board 25 provided with the projected portions 31A, 31B projected more than a laminating part 32, and insulating layers 22A, 22B embedding electronic components. A monitor electrode for testing of the predetermined area is provided at the area guided from the adjacent area of the natural circuit wires in the circuit structure for propagating high-frequency signals. The flexible board circuit wires are provided up to the projected areas 31A, 31B from the circuit structure for propagating low-frequency signals, and these are connected with contact electrodes 27A, 27B for testing at the projected areas 31A, 31B. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a structure of a circuit board and a manufacturing method.

  Conventionally, in order to meet the demand for miniaturization and high density of MCM (multi-chip module), a circuit board is provided in which an electronic component is embedded in an insulating layer and the insulating layer is laminated (patent). Reference 1).

  Here, the configuration of a circuit board with reference to Patent Document 1 is shown in FIG. The circuit board 11 is formed by laminating a plurality of insulating layers 12. A plurality of electronic components 13 are embedded in part of the insulating layer 12, and circuit wiring for connecting the electronic components 13 is provided between the plurality of insulating layers 12. Insulating layer via holes 14 for connecting circuit wirings between different layers are provided in each insulating layer 12.

  In such a circuit board 11, the circuit board 11 itself can be miniaturized and densified, and the circuit wiring length connecting the electronic components 13 can be shortened. This shortening can suppress parasitic components (parasitic inductance, parasitic capacitance) caused by circuit wiring when a high frequency signal in, for example, a microwave band or a millimeter wave band is handled.

  However, in such a circuit board 11, after a circuit element such as the electronic component 13 is embedded in the insulating layer 12, the probe for inspection cannot be brought into contact with the internal circuit wiring for probing. It was difficult to check the electrical characteristics and confirm the connection state or electronic component mounting state.

  In addition, since inspection cannot be performed in the middle of manufacturing a circuit board, even if a failure occurs during manufacturing, it can be confirmed only in the final process, resulting in unnecessary process costs and a decrease in yield. was there.

  In addition, it is possible to carry out probing by pulling out an inspection electrode from the built-in electronic component 13 to the surface of the circuit board 11, but if such an inspection electrode is provided, the circuit board 11 can be reduced in size and density. This is not desirable because the circuit area increases against this requirement.

  On the other hand, a protruding portion is provided on a flexible substrate, which is a flexible substrate, and an inspection electrode is provided on the protruding portion (hereinafter, the inspection electrode provided on the protruding portion is referred to as a contact electrode) for probing. Thus, a technique that enables confirmation of a connection state or circuit operation is known (see Patent Document 2).

Here, the configuration of the flexible substrate with reference to Patent Document 2 is shown in FIG. Rigid portions (laminated portions) 1 and 2 are portions that are made difficult to bend by forming a plurality of flexible substrates in layers, and flex portions (projecting portions) 3 are bent by being formed from a single-layer flexible substrate. It is the part that made it easy to do. The rigid portions (laminated portions) 1 and 2 are connected by a protruding portion 3. Electronic parts 5, 6, 7, and 8 are mounted on the surfaces of the rigid parts (laminated parts) 1 and 2. Further, a lead wire is provided from the circuit inside the rigid portions (laminated portions) 1 and 2 to the projecting portion 3, and a contact electrode 4 for electrical property inspection is provided at the tip of the lead wire. As a result, the probe is brought into contact with the contact electrode 4 to perform probing, so that it is possible to check the connection state or circuit operation and to inspect the electrical characteristics, and to suppress the circuit area of the rigid parts (laminated parts) 1 and 2. become. In this system, the rigid portion (laminated portion) can be configured as a component built-in substrate.
JP 2002-280744 A JP 2000-59032 A

  However, in Patent Document 2, a certain length of lead wire is required for the contact electrode from the original circuit wiring to the protruding portion. If the measurement point is a high-frequency circuit, this long lead wire has a parasitic component (parasitic inductance or parasitic capacitance) of the lead wire itself, which affects the inspection result and circuit characteristics. Further, if a flex part (protrusion part) is provided so as to connect a plurality of rigid parts (laminate parts), the substrate size is increased by the size of the flex part (protrusion part) itself.

  Further, when the contact electrode is provided, the probing can be performed only after the protrusion and the contact electrode are provided, so that the manufacturing process (process design) is restricted. Therefore, if a problem occurs before the flex part (protrusion part) is provided, probing must be performed after the flex part (protrusion part) and the contact electrode are formed, and the first time the problem is detected. And there was a possibility that the non-defective product rate in the manufacturing process was lowered.

  Therefore, the object of the present invention is to accurately check the electrical characteristics of high-frequency signals, check the connection state, or check the electronic component mounting state in the middle of the board manufacturing process while realizing the miniaturization and high density of the circuit board. Another object of the present invention is to provide a circuit board and a circuit board manufacturing method capable of improving the board manufacturing yield with high use efficiency of electronic components embedded in the circuit board, without restrictions on the manufacturing process.

  In order to solve the above problems, a circuit board according to the present invention is a circuit board having a laminated portion in which a plurality of insulating layers are laminated, and circuit wiring is provided between the insulating layers of the laminated portion. At least one insulating layer is provided with a protruding portion protruding from the laminated portion in the surface direction, and an inspection electrode connected to the circuit wiring is provided on each surface of the protruding portion and the laminated portion. It is characterized by.

  As described above, the laminated portion and the protruding portion are provided, the inspection electrode (contact electrode) is provided on the protruding portion, and the inspection electrode (hereinafter referred to as a monitor electrode) is provided on the laminated portion. Probing can be performed using these inspection electrodes while minimizing the size and increasing the density. Therefore, it is possible to easily check the electrical characteristics of the electronic component and confirm the connection state or the electronic component mounting state. For example, when it is necessary to increase the area of the circuit board in order to provide the monitor electrode in the stacked portion, the contact electrode may be provided in the protruding portion for the measurement point. Further, if it is not necessary to increase the area of the circuit board even if the monitor electrode is provided in the laminated portion, the monitor electrode may be provided in the laminated portion as it is. Thus, by properly using the monitor electrode and the contact electrode according to the situation, it is possible to maximize the miniaturization and density of the laminated portion.

In addition, when the function of the protrusion is only the inspection function and only the contact electrode and the lead line are formed, the substrate size can be suppressed by cutting the protrusion. In addition, it is not always necessary to cut the protruding portion. In that case, it is preferable to use the protruding portion by providing another circuit or to use the contact electrode as an external connection terminal.
The monitor electrode is provided at a position where it is drawn close to the original circuit wiring, and the size thereof is set to a size that can be reliably probed, for example, approximately the same area as the probe tip. By doing so, parasitic components (parasitic inductance, parasitic capacitance) of the leader line can be suppressed, and circuit characteristics, particularly high frequency characteristics can be accurately measured. Further, even if probe marks are generated by probing on the monitor electrode, the original circuit wiring and circuit characteristics are not affected. Furthermore, the size of the substrate (product) can be suppressed by suppressing the size of the monitor electrode in this way.

  In order to solve the above problems, in the circuit board of the present invention, the circuit wiring includes a high-frequency circuit unit through which a high-frequency signal propagates and a low-frequency circuit unit through which a low-frequency signal propagates. The inspection electrode is provided only on the surface of the laminated portion, and the inspection electrode for the low frequency circuit portion is provided on the surface of the protruding portion or both the surface of the laminated portion and the protruding portion depending on the case. Provide.

  In this way, it is possible to suppress the occurrence of parasitic components due to lead lines, particularly in the high-frequency circuit section, while minimizing the size and density of the circuit board. As a result, the high frequency characteristics of the original circuit configuration can be inspected, and the connection state or electronic component mounting state can be confirmed. Further, when probing the low-frequency circuit unit, the contact electrode and the monitor electrode are appropriately used as appropriate, so that the stacked portion of the circuit board can be reduced in size and density.

In order to solve the above problems, a circuit board according to the present invention includes an electronic component connected to the circuit wiring, and the electronic component is embedded in the stacked portion.
Here, the electronic component of the present invention includes not only a semiconductor and a chip component but also an element such as a printed resistor.

  As a result, the circuit board can be further reduced in size and density, and the length of the circuit wiring connecting the electronic components can be shortened. This shortening and the provision of only monitor electrodes in the high-frequency circuit block can further suppress the generation of parasitic components due to circuit wiring, and the original circuit characteristics even in the case of high-frequency signals in the microwave band and millimeter wave band Can be measured accurately.

  Further, even after the electronic component is embedded in the circuit board, it is possible to perform probing using a contact electrode drawn from the electronic component to the protruding portion or a monitor electrode provided on the surface of the laminated portion.

  In addition, if both a contact electrode and a monitor electrode are provided in a single electronic component, the monitor electrode is used in the process before embedding the electronic component in the circuit board, and after the embedding, the monitor electrode is not embedded with the electronic component. Probing is possible by using contact electrodes. As a result, the probing process may be performed before or after the process of forming the contact electrode, and restrictions can be eliminated from the manufacturing process.

  In order to solve the above problems, in the circuit board of the present invention, the insulating layer provided with the projecting portion is made of a flexible substrate.

  As described above, in order to form the protruding portion with a flexible substrate (for example, a flexible substrate), the protruding portion can be bent. In addition, since a general flexible substrate is easy to process, it is easy to remove the protruding portion.

  Further, in order to solve the above problems, the circuit board of the present invention has the circuit wiring arranged on both main surfaces of the insulating layer provided with the projecting portion, and the circuit wiring on both main surfaces is connected to the projecting portion. A via hole is provided.

  Thus, by providing circuit wiring on each of the two main surfaces of the insulating layer provided with the protruding portion, the insulating layer provided with the protruding portion can be disposed in the middle of other insulating layers, It can be configured as part of the substrate. Further, more contact electrodes can be provided by providing circuit wirings on both main surfaces of the protruding portion and further providing via holes for connecting the circuit wirings.

  In order to solve the above-mentioned problem, the circuit board of the present invention is configured such that the protrusions are provided in a plurality of insulating layers, and the sizes of the protrusions are different for each insulating layer.

  In this way, by providing a plurality of protrusions and varying the sizes of the protrusions, the protrusions do not interfere with each other when the probes are brought into contact with each other, and many probes can be brought into contact at the same time. it can.

  In order to solve the above problems, the circuit board according to the present invention is formed by cutting the projecting portion near the boundary with the laminated portion and coating the cut surface with an insulating material.

  The substrate (product) size can be suppressed by cutting the protruding portion in this way. Also, by coating the cut surface with an insulating material, the cut portion of the lead wire of the monitor electrode can be insulated, which is suitable as an actual product.

  In order to solve the above problems, a circuit board manufacturing method according to the present invention includes a circuit board manufacturing process, and an inspection probe abutting on the inspection electrode so that an electrical characteristic, a connection state, or an electronic component mounting state Are sequentially performed.

  In this way, a circuit board with a protrusion is manufactured, and further, the probe is brought into contact with the contact electrode of the protrusion to inspect the finished state of the circuit board, thereby reducing the size and increasing the density of the circuit board. Even if it exists, the product which checked the electrical property and confirmed the connection state or the electronic component mounting state can be manufactured.

  In order to solve the above-described problem, the circuit board manufacturing method of the present invention applies a test probe to a test electrode provided on a predetermined insulating layer among the plurality of insulating layers in the process of manufacturing the circuit board. The electrical characteristics, the connection state, or the electronic component mounting state are inspected in contact with each other, and then another insulating layer is laminated on the insulating layer provided with the inspection electrode.

  In this way, in the process of manufacturing a circuit board, probing and inspecting the board finish state, the circuit board that has been reduced in size and increased in density, electrical characteristics, connection state, or electronic component mounting state Therefore, the substrate manufacturing yield can be improved.

  In addition, since the substrate finish state is inspected during the manufacturing process, it is possible to quickly detect the occurrence of a defect and to easily grasp the defective part and the defective process, so that measures can be taken at an early stage. Further, in the subsequent process, it is possible to prevent the electronic components from being wasted and to increase the use efficiency of the electronic components.

  Moreover, in order to solve the said subject, the circuit board manufacturing method of this invention cut | disconnects the said protrusion part after the above-mentioned process, and coats the cut | disconnected surface with an insulating material.

  For this reason, even if it is a circuit board which implement | achieved size reduction and high density, a manufacturing yield is high and a circuit board suitable as a product form can be manufactured.

  According to the present invention, the circuit board can be miniaturized and densified, and even in the case of circuit wiring through which a high-frequency signal propagates, high-frequency characteristics and connection state without being affected by the lead wire or electrode for inspection, or The electronic component mounting state can be accurately inspected. In addition, since the finished state is inspected during the board manufacturing process, it is possible to easily grasp the defective part and the defective process, to take measures at an early stage, and to increase the utilization efficiency of the electronic components mounted on the circuit board, Furthermore, restrictions can be removed from the manufacturing process.

A first embodiment of the present invention will be described with reference to FIGS.
FIG. 3 is a circuit board according to this embodiment. The circuit board of the present embodiment has a configuration in which a flexible board having a protruding portion is held between two insulating layers. 3A is a cross-sectional view of this circuit board in the stacking direction (cross-sectional view along AA ′ in FIG. 3B), and FIG. 3B is a cross-sectional view of the circuit board in the stacking direction (FIG. 3A). FIG. 3C is a top view of only the flexible substrate used in the circuit board as seen from the stacking direction (upward direction in FIG. 3A).
In these drawings, the insulating layer 22A is mainly described with reference symbols, and the insulating layer 22B is not described. The insulating layer 22B has no symbol, but has a configuration similar to that of the insulating layer 22A.

  A flexible substrate 25 shown in FIG. 3A is made of a thin plate-like base material made of a material such as an epoxy material or polyimide, and flexible substrate circuit wirings 26 (26A to 26C) are formed on both main surfaces thereof. Yes. Further, an insulating film is provided on substantially the entire surface so as to cover the flexible substrate circuit wirings 26 (26A to 26C) on both main surfaces, and the flexible substrate circuit wiring 26 (26A to 26C) is formed from a part of the insulating coating. The exposed portions are used as contact electrodes 27 (27A, 27B) and connection electrodes 29 (29A to 29C). Further, flexible substrate via holes 35 (35A, 35B) are provided inside the flexible substrate 25, and the flexible substrate circuit wirings 26 (26A) on the upper main surface side and the lower main surface side by the flexible substrate via holes 35 (35A, 35B). ~ 26C) to conduct each other.

  Further, as shown in FIGS. 3B and 3C, in the flexible substrate 25, a plurality of flexible substrate circuit wirings 26 (26A to 26C) are arranged in approximately one direction (protruding portion 31A and protruding portion 31B, respectively). Are arranged at predetermined intervals so as to be substantially parallel to each other. Further, the flexible substrate circuit wiring 26 (26A to 26C), the contact electrode 27 (27A, 27B), and the connection electrode 29 (29A, 29B, 29C) can be formed on both main surfaces of the flexible substrate 25, respectively. Those provided only on the main surface side, those provided on both main surface sides so as to face each other, those provided so as to connect the two main surfaces by the flexible substrate via hole 35 (35A, 35B), etc. Arranged in various ways. Thus, by providing the flexible substrate circuit wiring 26 (26A to 26C), the contact electrode 27 (27A, 27B), and the connection electrode 29 (29A, 29B, 29C) on each of the two main surfaces, the flexible substrate 25 is formed. And can be provided in an intermediate layer of the circuit board 21 (intermediate between the insulating layers 22A and 22B) and can be used as a component of the circuit board. In addition, the contact electrodes 27 (27A, 27B) can be provided on both main surfaces of the flexible substrate 25, and more contact electrodes 27 (27A, 27B) can be provided as the circuit board 21 as a whole. .

  In addition, the insulating layers 22A and 22B shown in FIG. 3 (A) are made of a thin plate-like thermosetting material, in which an electronic component 23 (23A to 23C) is embedded, and the surface layer surface is a main surface corresponding to the surface layer surface. Circuit wiring 28 (28A to 28F) is provided. Further, the connection surface circuit wiring 34 (34A to 34G) is provided on the connection surface (one surface to which the flexible substrate 25 is bonded) facing the surface layer surface, and the circuit wiring on the surface layer surface and the connection surface is connected to the insulating layer via hole 24 (24A to 24A). 24D).

Here, both main surfaces of the flexible substrate 25 are held between the connection surface (lower main surface) of the insulating layer 22A and the connection surface (upper main surface) of the insulating layer 22B, and the connection electrodes 29 (29A of the flexible substrate 25) To 29C) are connected to the connection surface circuit wiring 34 (34A to 34G) of the insulating layers 22A and 22B to constitute the circuit board 21.
Here, a portion of the circuit board 21 where the flexible substrate 25 and the insulating layers 22A and 22B are laminated is referred to as a laminated portion 32, and portions where the flexible substrate 25 protrudes from the laminated portion 32 are referred to as protruding portions 31A and 31B.
The projecting portions 31A and 31B are provided with contact electrodes 27 (27A and 27B), and flexible substrate circuit wirings 26 (26A to 26C) provided on the flexible substrate 25 (part of the lead lines of the present invention). ). The flexible substrate circuit wiring 26 (26A to 26C) includes connection electrodes 29 (29A to 29C) provided on the laminated portion 32 of the flexible substrate 25 and connection surface circuit wiring 34 provided on the insulating layer 22 (22A and 22B). It connects with the electronic component 23 (23A-23C) via (34A-34G) etc.

  Further, the monitor electrode 30 (30A, 30B) is partially provided on the surface layer circuit wiring 28 (28A to 28F). The monitor electrode 30 (30A, 30B) is provided where it is drawn close to the original circuit wiring, and its size is a predetermined area. This area is a size that can reliably contact the tip of the probe to be contacted. It is sufficient to determine the probe tip size and the probing position accuracy.

  Here, the connection structure will be described based on the elements and circuits located in the AA ′ cross section in FIG. 3 (A) and FIG. 3 (B).

  In the AA ′ cross section, the contact electrode 27 </ b> A is provided on the protruding portion 31 </ b> A of the flexible substrate 25. The contact electrode 27A is connected to one end of a flexible substrate circuit wiring 26A provided in the inner layer of the flexible substrate 25. The other end of the flexible circuit board wiring 26A is connected to the electronic component 23A embedded in the insulating layer 22A via the connection electrode 29A and the connection surface circuit wiring 34B of the insulating layer 22A. Further, it is also connected to connection surface circuit wiring and electronic components on the insulating layer 22B side through a flexible substrate via hole 35A in the flexible substrate 25.

  A contact electrode 27 </ b> B is provided on the protruding portion 31 </ b> B of the flexible substrate 25. The contact electrode 27B is connected to one end of a flexible substrate circuit wiring 26C provided in the inner layer of the flexible substrate 25. The other end of the flexible substrate circuit wiring 26C is connected to the connection surface circuit wiring 34F of the insulating layer 22A via the connection electrode 29C. The connection surface circuit wiring 34F is connected to other circuit wiring and electronic components through the connection surface of the insulating layer 22A.

  Further, as shown in FIG. 3B, the surface layer circuit wiring 28C is provided with a monitor electrode 30A used for contacting and inspecting the probe in the vicinity of the original circuit wiring. As shown in FIG. 3A, the surface layer circuit wiring 28C is connected to the connection surface circuit wiring 34D through the insulating layer via hole 24B at one end located in the section AA ′. The connection surface circuit wiring 34D is connected to terminals of the electronic component 23B and the electronic component 23C, and the other terminals of the electronic component 23B are connected to the connection electrode 29B of the flexible substrate 25 via the connection surface circuit wiring 34C. Further, the connection electrode 29B is connected to connection surface circuit wiring and electronic components on the insulating layer 22B side through the flexible substrate via hole 35B. The other terminal of the electronic component 23C is connected to the surface layer circuit wiring 28E via the connection surface circuit wiring 34E and the insulating layer via hole 24C. As shown in FIG. 3B, the surface layer circuit wiring 28E is provided with a monitor electrode 30B used for probing.

  The surface layer circuit wiring 28A of the insulating layer 22A is connected to the connection surface circuit wiring 34A of the insulating layer 22A via the insulating layer via hole 24A in the section AA ′. Further, the surface layer circuit wiring 28B and the surface layer circuit wiring 28D simply pass through the surface layer of the insulating layer 22A in the section AA ′. The surface layer circuit wiring 28F is connected to the connection surface circuit wiring 34G through the insulating layer via hole 24D.

The circuit board 21 is configured by the circuit wiring and the electronic components as described above.
Here, taking the circuit configuration of a voltage controlled oscillator described later as an example, the circuit board 21 is configured with the connection structure as described above. The present invention can be implemented with any circuit configuration other than the voltage controlled oscillator.

Next, an example of probing the circuit board 21 will be described with reference to FIG.
4A is a cross-sectional view (AA ′ cross-sectional view) in the stacking direction of the circuit board 21 similar to FIG. 3A. Here, the contact electrode 27C virtually located on another cross-section is shown in FIG. The monitor electrode 30A is shown to be located on the same cross section.
FIG. 4B is a circuit diagram of the voltage controlled oscillator built in the circuit board 21. Here, among all the monitor electrodes and contact electrodes, the monitor electrode 30A and the contact electrodes 27A, which contact the probe in this example. Only 27B and 27C are displayed as terminals.

Here, an example of the inspection method of the connection state and electronic component mounting state of an electronic component will be described.
In this voltage controlled oscillator, as shown in FIG. 4B, on the amplifier circuit side, a contact electrode is provided between the collector of the transistor TR1 acting as an amplification stage and the emitter of the transistor TR2 acting as a buffer stage via a lead line. 27C is connected. Further, a contact electrode 27A is connected to the base of the transistor TR2 via a lead line.

  As shown in FIG. 4A, in this example, the probe is brought into contact with each of the two contact electrodes 27A and 27C, and the pn junction diode characteristic between the base and the emitter of the transistor TR2 is measured. Here, the electronic component 23D is an integral component of the transistor TR1 and the transistor TR2, and a terminal corresponding to the base of the transistor TR2 among the plurality of terminals of the electronic component 23D is connected to the contact electrode 27A as a flexible substrate. A terminal corresponding to the emitter of the transistor TR2 is connected to the contact electrode 27C via a flexible substrate circuit wiring (not shown) or a connection electrode (not shown). Connected.

  At this time, if the diode characteristics (voltage-current characteristics) as shown in FIG. 4C can be confirmed, it can be seen that the transistor TR2 is correctly mounted and connected.

  Although not illustrated here, the mounting and connection state of the semiconductor element can also be confirmed using a surge protection diode provided between the semiconductor input terminal and the ground and between the power supply lines.

  Such an inspection method can be used not only for measuring the transistor TR2, but also for measuring the pn junction diode characteristics between the base and emitter of the transistor TR1. In this case, the circuit wiring connected to the base of the transistor TR1 and the circuit wiring connected to the emitter of the transistor TR1 are circuit portions through which high-frequency signals propagate (circuit portions surrounded by broken lines in FIG. 4B). Instead, a monitor electrode is provided in the laminated portion for probing.

  If a contact electrode is provided in a circuit portion connected to the base and emitter of the transistor TR1 so as to be connected via a lead line, a parasitic component resulting from them is generated, which affects the high frequency characteristics. High frequency characteristics cannot be measured accurately. Therefore, high frequency characteristics are accurately measured by probing these portions by providing monitor electrodes that can shorten the length of the lead lines instead of contact electrodes.

  Further, as another example of the inspection method of the electronic component mounting state, an inspection method in which the probe is brought into contact with each of the contact electrode 27B and the monitor electrode 30A shown in FIG. 4B and the conduction impedance of the inductor L1 is measured. Show. The contact electrode 27B is connected between the inductor L1 and the control voltage input terminal Vc via a lead wire. On the other hand, the monitor electrode 30A is provided on the surface layer circuit wiring 28C between the cathode of the varactor diode VD1 and the inductor L1, and is formed by a short lead line from the surface layer circuit wiring 28C and an electrode having a predetermined area. A probe is brought into contact with each of the contact electrode 27B and the monitor electrode 30A, and the conduction impedance of the inductor L1 is measured. Thereby, the mounting state and the connection state of the inductor L1 are confirmed.

  Here, when monitoring the high-frequency characteristics of the circuit wiring connected to the cathode of the varactor diode VD1 and the circuit portion connected to the anode (the LC circuit portion surrounded by the broken line in FIG. 4B), When monitoring with a contact electrode, a parasitic component is generated due to the lead line and the contact electrode, which affects the high frequency characteristics. Therefore, high frequency characteristics are accurately measured by probing these portions by providing monitor electrodes instead of contact electrodes.

The circuit configuration of this voltage controlled oscillator will be described next.
On the amplifier circuit side, a base bias circuit including resistors R1, R2, and R3 for applying a base bias voltage to the amplification stage transistor TR1 and the buffer stage transistor TR2 is provided, and between the collector of the transistor TR1 and the emitter of the transistor TR2. A high-frequency bypass capacitor C9 is provided, a grounding capacitor C4 is provided at the emitter of the transistor TR1, a resistor R4 for obtaining an output voltage, a capacitor C6 for applying this output voltage to the base of the transistor TR2, and an emitter of the transistor TR1. And a feedback capacitor C5 for feeding back the signal from the base to the base.

  Further, the collector of the transistor TR2 is provided with a power supply terminal Vb and a high frequency bypass capacitor C10 via an inductor L3, and an output terminal Vout is provided via a high frequency bypass capacitor C7 and a DC cutoff capacitor C8. Yes.

  On the resonance circuit side, an inductor L2 is provided at the anode of the varactor diode VD1, and a capacitor C2 is provided at the cathode of the varactor diode VD1. Further, a connection point between the capacitor C2 and the inductor L1 is connected to the amplifier circuit via a coupling capacitor C3.

  Here, on the amplification circuit side, the power supply voltage Vb is applied to the collector of the transistor TR2 via the inductor L3, and the oscillation signal is output as the output voltage Vout via the capacitor C8 connected to the collector. It is composed. On the resonance circuit side, the control voltage Vc is applied to the cathode of the varactor diode VD1 via the inductor L1, and the resonance signal is input to the base of the transistor TR1 via the capacitor C3. .

  The voltage controlled oscillator having the circuit configuration as described above is built in the circuit board 21. The circuit wiring that affects the high frequency characteristics is not contact electrodes but is provided with a monitor electrode on the laminated portion 32 and probing, thereby accurately inspecting the high frequency characteristics without affecting the original circuit wiring. In addition, the portion not surrounded by the broken line in the figure is a circuit wiring through which a low frequency signal or a direct current signal propagates, and the area of the circuit board can be suppressed by properly using the monitor electrode and the contact electrode according to the layout of the circuit wiring. .

  In addition, the monitor electrode 30 provided in the laminated portion 32 is provided where it is pulled out from the original circuit wiring, and the area of the contact electrode whose characteristics are evaluated can be reliably probed (determined by the probe tip size and the probing position accuracy). Say it. By doing so, even if probe traces due to the probe occur on the monitor electrode, the original circuit wiring and circuit characteristics are not affected. Further, the size of the substrate (product) can be suppressed.

  In addition, since the protruding portion is a flexible substrate, the protruding portion can be bent. In addition, it is possible to freely set whether to provide a monitor electrode at the measurement point or to connect the contact electrode via a leader line, but only the high frequency circuit part is a monitor electrode that can shorten the leader line length. It is preferable that the contact electrode and the monitor electrode are properly used according to the circuit wiring routing layout.

Next, FIG. 5 shows an example of the manufacturing process of the component built-in insulating layer 22A of this embodiment.
(A) In the manufacturing process of the component built-in insulating layer 22 </ b> A of this embodiment, first, a conductor layer pattern to be the connection surface circuit wiring 34 (34 </ b> A to 34 </ b> G) is formed on the support plate 33. The connection surface circuit wiring 34 (34A to 34G) is formed by sticking a copper foil (Cu foil) on the support plate 33 or forming a copper plating (Cu plating) and etching it to a desired pattern.

(B) Next, the electronic component 23 (23A to 23C) is placed and connected to a predetermined position on the connection surface circuit wiring 34 (34A to 34G).

(C) Next, an insulating sheet with a conductor layer is laminated so as to seal the connection surface circuit wiring 34 (34A to 34G) and the electronic component 23 (23A to 23C), and the insulating layer 22A is substantially configured.

(D) Next, a hole to be the insulating layer via hole 24 (24A to 24D) is formed in the insulating layer 22A provided by lamination, and the hole is filled with a conductor to form the insulating layer via hole 24 (24A to 24D). Then, the conductor layer is further etched to form a pattern that becomes the surface layer circuit wiring 28 (28A to 28F). In this step, not only the surface layer circuit electrodes 28 (28A to 28F) but also monitor electrodes 30 (30A, 30B) (not shown), which serve as inspection electrodes with which the probe comes into contact in the subsequent inspection, are formed in the conductor layer. Form.

(E) Next, the support plate 33 is removed. Thereby, the insulating layer 22A is formed.

  The insulating layer 22A of this embodiment is manufactured through the above steps. Not only the insulating layer 22A but also the insulating layer 22B are manufactured by a similar process.

  The inspection of the substrate finish state such as the connection state, the component mounting state, and the high frequency characteristics is performed at a process stage (for example, FIG. 3, FIG. 6B, or FIG. 7B) at which each substrate structure is completed. As a result, it is possible to quickly detect the occurrence of a defect, and it is possible to easily grasp the defect location and the defect process. Then, by programming so that the electronic component is not mounted in the subsequent process at the defect occurrence location, it is possible to prevent the electronic component from being wasted and to increase the use efficiency of the electronic component.

  Next, in FIG. 6, the step of laminating the insulating layer manufactured by the above-described steps on the flexible substrate 25, the configuration in which the build-up wiring board is further formed, and the protruding portion are further cut, and the insulating material is formed on the cut surface. FIG.

(A) An insulating layer 22A manufactured by the above process, an insulating layer 22B manufactured by the same process, and a flexible substrate 25 are prepared. A conductive adhesive for bonding and conduction is applied to the exposed portion of the flexible circuit board wiring 26 (26A to 26C) where the connection electrode is exposed, and the insulating layer 22B, the flexible substrate 25, and the insulating layer 22A are bonded. To do.

(B) A build-up wiring board (insulating layer 22C, electrode pattern) is further formed under the insulating layer 22B to form the circuit board 21. Since the circuit board 21 includes the contact electrodes 27 (27A, 27B) on the projecting portions 31A, 31B and the monitor electrode 30 (not shown) on the laminated portion 32, the electronic component 23 (23A-23C) is provided. Even after mounting and embedding on the circuit board 21, it is possible to perform inspection by contacting the contact electrode 27 (27A, 27B) and the monitor electrode 30 (30A, 30B) with an inspection probe. You can check the characteristics, connection status, and electronic component mounting status.

(C) After the probing is performed, a build-up wiring board (insulating layer 22D) is further formed on the insulating layer 22A, and the protruding flexible substrate 25 is cut to form the circuit board 21 in a block shape. . Further, the side surface and the upper surface that have been cut are coated with an insulating material to form a coating layer 36. By doing so, it is difficult to be affected by the external environment. Since the flexible substrate 25 is generally easy to process, the protruding portion can be easily removed. And the circuit board area of the circuit board 21 whole can be made small by cut | disconnecting a protrusion part.

  As described above, the circuit board 21 having the protrusion is manufactured, and the probe is brought into contact with the contact electrode of the protrusion to inspect the electrical characteristics, the connection state, or the electronic component mounting state. By removing the protrusions, it is possible to manufacture a product in which the electrical characteristics are inspected and the connection state or the electronic component mounting state is confirmed even with the circuit board 21 that has been reduced in size and increased in density.

  Also, in the process of manufacturing the circuit board 21, by performing probing and inspecting the electrical characteristics, the connection state, or the electronic component mounting state, a monitor that does not affect the high-frequency characteristics by realizing miniaturization and high density. By providing the electrode 30 (30A, 30B) in the laminated portion 32, the circuit board 21 can be manufactured while reliably confirming the high frequency characteristics, the connection state, or the electronic component mounting state.

  When both the contact electrode 27 (27A, 27B) and the monitor electrode 30 (30A, 30B) are provided on a single electronic component 23 (23A-23C), the contact electrode 27 (27A of the protruding portions 31A, 31B is provided. 27B), the electrical characteristics can be inspected using the monitor electrode 30 (30A, 30B) provided in the vicinity of the electronic component 23 (23A to 23C). . After that, even if another insulating layer is laminated and the monitor electrode 30 (30A, 30B) is buried, if probing is performed using the contact electrode 27 (27A, 27B) at that time, Since the monitor electrode 30 (30A, 30B) is not required on the new surface layer of the substrate 21, the probing can be performed while the area is suppressed. As described above, the probing process may be performed prior to the process of forming the contact electrodes 27 (27A, 27B), and restrictions can be reduced from the process table.

Next, a second embodiment of the present invention will be described.
The circuit board of this embodiment has a configuration in which a plurality of flexible boards and a plurality of circuit boards are stacked. Further, the plurality of flexible substrates are configured such that the protruding portions have different lengths in the protruding direction.

  The manufacturing process of the circuit board of this embodiment will be described with reference to FIG.

(A) First, the first circuit board 41A in which the flexible board 45A is sandwiched by the insulating layer 42A and the insulating layer 42B is manufactured by the manufacturing process and the similar process shown in the first embodiment. At the same time, the second circuit board 41B in which the insulating layer 42C and the flexible board 45B are joined is manufactured. Here, the flexible substrate 45A and the flexible substrate 45B have different projecting portion sizes, and the flexible substrate 45B has a wider shape.

(B) Next, a conductive adhesive for bonding and conduction is applied to an exposed portion of the circuit wiring at a position to be a connection electrode of the flexible board 45B of the second circuit board 41B, so that the first circuit board It joins to the location on the insulating layer 42B side of 41A.

  Since the circuit board 41 formed by joining the first circuit board 41A and the second circuit board 41B is provided with a protruding portion on each of the flexible substrate 45A and the flexible substrate 45B, the contact electrode of each protruding portion and The above-mentioned probing can be performed by the monitor electrode of the laminated portion.

(C) In this probing, the flexible substrate 45A and the flexible substrate 45B have different sizes of the protruding portions, and the flexible substrate 45B has a wider shape. Many probes can be brought into contact with each other at the same time without interference.

  After probing, the protruding portions of the flexible substrate 45A and the flexible substrate 45B may be cut to form the circuit board 41 in a block shape, and the cut surface may be coated with an insulating material.

  As shown in the above embodiments, the present invention can be implemented regardless of the number of circuit boards and flexible boards stacked on the circuit board.

It is a figure which shows the structural example of the conventional circuit board. It is a figure which shows the structural example of the conventional flexible substrate. It is a figure which shows the structural example of the circuit board of 1st Embodiment. It is a figure explaining the example which performs probing. It is a figure which shows the example of a manufacturing process of an insulating layer. It is a figure explaining the other structural example of the circuit board of 1st Embodiment. It is a figure which shows the example of a manufacturing process of the circuit board of 2nd Embodiment.

Explanation of symbols

1,2,32-Laminated part (rigid part)
3,31-protruding part (flex part)
4,27-Contact electrode 5,6,7,8,13,23-Electronic component 11,21,41-Circuit board 12,22,42-Insulating layer 14,24-Insulating layer via hole 25,45-Flexible board 26 -Flexible substrate circuit wiring 28-Laminate surface layer circuit wiring 29-Connection electrode 30-Monitor electrode 33-Support plate 34-Laminate connection surface circuit wiring 35-Flexible substrate via hole 36-(insulating material) coating layer

Claims (10)

A circuit board comprising a laminated portion in which a plurality of insulating layers are laminated, and circuit wiring is provided between the insulating layers of the laminated portion,
At least one insulating layer of the plurality of insulating layers is provided with a protruding portion that protrudes from the stacked portion in the surface direction, and the inspection electrode connected to the circuit wiring is connected to each of the protruding portion and the stacked portion. A circuit board characterized by being provided on the surface of the board. The circuit wiring includes a high-frequency circuit unit through which a high-frequency signal propagates and a low-frequency circuit unit through which a low-frequency signal propagates,
The inspection electrode for the high frequency circuit part is provided only on the surface of the laminated part, and the inspection electrode for the low frequency circuit part is provided on the surface of the projecting part or both surfaces of the laminated part and the projecting part. The circuit board according to claim 1.   The circuit board according to claim 1, further comprising an electronic component connected to the circuit wiring, wherein the electronic component is embedded in the stacked portion.   The circuit board according to claim 1, wherein the insulating layer provided with the projecting portion is made of a flexible substrate.   5. The method according to claim 1, wherein the circuit wiring is arranged on both main surfaces of the insulating layer provided with the projecting portion, and a via hole is provided in the projecting portion to connect between the circuit wirings on the two main surfaces. Circuit board as described.   The circuit board according to claim 1, wherein the protrusion is provided on a plurality of insulating layers, and the size of the protrusion is different for each insulating layer.   The circuit board according to claim 1, wherein the projecting portion is cut in the vicinity of the boundary with the laminated portion, and the cut surface is coated with an insulating material.   A step of manufacturing the circuit board according to any one of claims 1 to 6, and a step of inspecting an electrical property, a connection state, or an electronic component mounting state by contacting an inspection probe to the inspection electrode; Are sequentially executed. A circuit board manufacturing method comprising:   In the process of manufacturing the circuit board according to claim 1, an inspection probe is brought into contact with an inspection electrode provided on a predetermined insulating layer among the plurality of insulating layers, so that electric characteristics are obtained. A circuit board manufacturing method comprising: inspecting a connection state or an electronic component mounting state, and then laminating another insulating layer on the insulating layer provided with the inspection electrode.   A method for manufacturing a circuit board, comprising: cutting the projecting portion after the step according to claim 8 or 9, and coating the cut surface with an insulating material.

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