JP2018006445A - Printed wiring board, sticking board, and manufacturing method of printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate impedance matching by setting a constant characteristic impedance inexpensively in a signal line of undefined characteristic impedance.SOLUTION: A printed wiring board is a board where a signal line having one end connected with the terminal of a transmission side device, and the other end connected with a reception side device for receiving a signal sent from the transmission side device, an adhesive layer having stickiness, a base material layer consisting of an insulator, and a ground conductor layer consisting of a conductor and connected with the ground of the printed wiring board, are superposed in this order, and includes a sticking board that is stuck to the signal line so as to cover the same.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a printed wiring board provided with a signal line.

  In a printed wiring board, it is required to reduce radiation noise as much as possible so as to ensure the stability of operation and have no adverse effect on the surroundings. Noise suppression measures include reducing the impedance of the ground pattern, removing high-frequency components from the signal, equalizing the characteristic impedance of the signal pattern, and installing a conductive layer that provides a shielding effect.

  For example, Patent Document 1 describes an example of a printed wiring board provided with a conductive layer. Specifically, Patent Document 1 discloses at least a part of either a ground line pattern or a power line pattern on a substrate on which a circuit pattern including a ground line pattern, a power line pattern, and a signal line pattern is formed. An insulating layer is formed so as to cover the circuit pattern except for, and a conductive layer is formed on the insulating layer so as to be connected to an uninsulated portion of the ground line pattern or power line pattern, and adjacent IC pins are inserted. A printed wiring board is also described in which a part of the conductive layer is formed between the holes so as not to contact the IC pin land. With this configuration, the conductive layer 4 that has not been formed directly below the IC is formed also between the IC pin insertion holes so as to increase the effect of the conductive layer (Patent Document 1: Claim 1, invented). See the problem you are trying to solve).

Japanese Utility Model Publication No. 03-06860

  In recent years, signal speed has been increased. As the frequency of the signal is higher, the resistance component, inductance component, and capacitance component of the signal line cannot be ignored. When the characteristic impedance of the signal line is not matched with the impedance of the device that transmits and receives signals using the signal line, a reflected wave is generated at the connection portion between the signal line and the device. The signal waveform is disturbed by the reflected wave. Information (data) may not be transmitted or received accurately due to disturbance of the signal waveform. In addition, when the impedances are not matched, noise may be emitted from the signal line and become a source of large noise.

  Many signal lines are provided in the printed wiring board. The characteristic impedance of the signal line is affected by the distance from the ground and the signal frequency. In a printed wiring board, there may be a signal line that does not have a certain characteristic impedance depending on the distance from the ground and the convenience of wiring. In particular, in an inexpensive printed wiring board having a small number of layers such as a single-sided board, a conductive surface (solid ground, conductive layer) cannot be provided. In a signal line that does not have a certain characteristic impedance, the characteristic impedance can be changed according to the distance (position in one signal line) from one hole (land) of the signal line.

  Such a signal line having an indefinite characteristic impedance has a problem that it is difficult or impossible to match the impedance of the device. As a result, among the inexpensive printed wiring boards such as single-sided boards, noise may be emitted from signal lines with undefined characteristic impedance, and information (data) may not be transmitted and received accurately.

  Here, in the technique described in Patent Document 1, as shown in FIG. 1, an undercoat layer and a conductive layer are formed on the circuit pattern of the substrate so as to exclude a plurality of IC pin insertion holes and on one side of the substrate. The paste layer and overcoat layer must be formed by screen printing. Therefore, there are problems that the manufacturing process is complicated and time-consuming, and the manufacturing cost is high. Further, it is not always possible to match the impedance of a specific signal line and IC.

  In view of the above problems, the present invention makes it possible to easily perform impedance matching by setting a constant characteristic impedance to a signal line having an indefinite characteristic impedance at a low cost.

  In order to achieve the above object, a printed wiring board according to claim 1 includes a signal line and a pasting board. In the signal line, a terminal of a transmitting device is connected to one end, and a receiving device that receives a signal sent by the transmitting device is connected to the other end. The adhesive substrate is a substrate in which an adhesive layer having adhesiveness, a base material layer made of an insulator, and a ground conductor layer made of a conductor and connected to a ground of a printed wiring board are sequentially stacked and covers the signal line. Thus, the substrate is attached to the signal line.

  According to the present invention, a constant characteristic impedance can be set at a low cost for a signal line having an indefinite characteristic impedance. And impedance matching can be facilitated.

1 is a diagram illustrating an example of a multifunction machine according to an embodiment. It is a figure which shows an example of the printed wiring board mounted in the multifunctional device which concerns on embodiment. It is a figure which shows an example of the sticking board | substrate which concerns on embodiment. It is the figure which expanded a part of printed wiring board concerning an embodiment. It is a figure which shows an example of a microstrip line. It is a figure which shows an example of the conventional printed circuit board. It is a figure which shows an example of the printed wiring board which affixed the sticking board which concerns on embodiment to a signal wire | line.

  Hereinafter, the printed wiring board 1 according to the present invention will be described with reference to FIGS. An apparatus for mounting the printed wiring board 1 according to the present invention includes an image forming apparatus. In the following, the multifunction peripheral 100 will be described as an example of an image forming apparatus on which the printed wiring board 1 is mounted. However, each element such as the configuration and arrangement described in this embodiment does not limit the scope of the invention and is merely an illustrative example.

(Outline of image forming apparatus)
First, a multifunction peripheral 100 according to the embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating an example of a multifunction peripheral 100 according to the embodiment.

  The multi-function device 100 includes a main control unit 2. The main control unit 2 controls the operation of the entire apparatus and controls each unit of the multifunction peripheral 100. The main control unit 2 is provided with a CPU 21. Further, the main control unit 2 is provided with a ROM 22 for storing control programs and data, a RAM 23 for storing programs and data necessary for processing so that the CPU can use them, and an ASIC 24 for performing image processing necessary for printing.

  The main control unit 2 is connected to the image reading unit 3 so as to be communicable. The image reading unit 3 reads a document and generates image data. The main control unit 2 controls the operation of the image reading unit 3. The main control unit 2 is connected to the operation panel 4 so as to be communicable. The operation panel 4 displays a setting screen, the status of the multifunction peripheral 100, and a message. In addition, the operation panel 4 accepts a user operation on a touch panel and hard keys provided on the operation panel 4. Then, the main control unit 2 recognizes the setting operation content performed on the operation panel 4. Then, the main control unit 2 controls the multifunction device 100 so as to operate according to the user's setting.

  The multifunction device 100 includes a printing unit 5. The printing unit 5 includes an engine control unit 50, a paper feeding unit 5a, a conveying unit 5b, an image forming unit 5c, and a fixing unit 5d. The engine control unit 50 actually controls printing-related processes such as paper feeding, paper conveyance, toner image formation, transfer, and fixing. The engine control unit 50 and the main control unit 2 are connected to be communicable. The main control unit 2 gives the engine control unit 50 a print instruction, the contents of the print job, and image data used for printing. Based on the received content, the engine control unit 50 controls the paper feeding unit 5a, the conveyance unit 5b, the image forming unit 5c, and the fixing unit 5d. Specifically, various types of rotating bodies related to paper feeding, conveyance, image formation, transfer, and fixing are rotated to control printing.

  The engine control unit 50 supplies sheets one by one to the sheet feeding unit 5a. The engine control unit 50 transports the supplied paper to the transport unit 5b through the image forming unit 5c and the fixing unit 5d to a discharge tray (not shown). The engine control unit 50 causes the image forming unit 5c to form a toner image to be placed on the sheet conveyed by the conveyance unit 5b. Further, the engine control unit 50 fixes the toner image transferred onto the sheet to the fixing unit 5d. The conveyance unit 5b discharges the sheet on which the toner image is fixed to the discharge tray.

  The multifunction device 100 includes a communication unit 25. The communication unit 25 is an interface for connecting to a network. Thereby, the main control part 2 can communicate via a network. The communication unit 25 receives print data including data indicating print contents such as image data and data indicating settings related to printing from the computer 200. The main control unit 2 causes the printing unit 5 to perform printing based on the printing data.

(Printed wiring board 1)
Next, an example of the printed wiring board 1 mounted on the multifunction peripheral 100 according to the embodiment will be described. FIG. 2 is a diagram illustrating an example of the printed wiring board 1 mounted on the multifunction peripheral 100 according to the embodiment.

  The multifunction device 100 includes a main control unit 2 as a main control board. In addition, the multi-function device 100 is provided with a sub-control board that communicates with the main control unit 2 and performs control in accordance with instructions and commands from the main control unit 2. The sub control board of the printing unit 5 is the engine control unit 50 (see FIG. 1).

  The sub-control board can also be provided inside the image reading unit 3 and the operation panel 4 (see FIG. 1). The sub control board provided in the image reading unit 3 controls the operation of the image reading unit 3 based on an instruction from the main control unit 2. The sub control board provided on the operation panel 4 controls display on the display panel based on an instruction from the main control unit 2 and recognizes the operation contents of the user. Note that a sub-control board for operation control may be provided for a part of the printing unit 5 such as the paper feeding unit 5a. Further, if the substrate of the main control unit 2 is a single-sided substrate, the printed wiring board 1 according to the embodiment may be used for the main control unit 2.

  The printed wiring board 1 according to the embodiment can be used as the sub control board. Moreover, a single-sided board can be used for the printed wiring board 1 (sub control board) according to the embodiment. The single-sided board is a board on which the pattern of the signal lines 8 is printed on one side of the board. In the printed wiring board 1 according to the embodiment, the signal line 8 is provided on one side of the board, and the adhesive substrate 7 according to the embodiment is attached to the signal line 8. Of the signal lines 8 of the printed wiring board 1, for example, the adhesive substrate 7 is attached to the signal line 8 that transmits a high-frequency signal (details will be described later).

  One end of the signal line 8 is connected to a terminal of the transmission side device 6s. The other end of the signal line 8 is connected to a receiving device 6r that receives a signal sent from the transmitting device 6s. In FIG. 2, a clock signal generation unit 6c that generates a clock signal with a high frequency is illustrated as the transmission side device 6s. The receiving device 6r in FIG. 2 is a device that operates by receiving a clock signal such as a CPU, a custom IC, a microcomputer, and a RAM provided on each control board. Note that the transmitting device 6s may be a CPU, a custom IC, a microcomputer, etc. that handle high frequency signals.

(Attached substrate 7)
Next, an example of the sticking substrate 7 according to the embodiment will be described with reference to FIG. FIG. 3 is a diagram illustrating an example of the adhesive substrate 7 according to the embodiment.

  In FIG. 3, the upper diagram is a diagram of the adhesive substrate 7 as viewed from above, and the lower diagram is a diagram as viewed from the side. As shown in the lower diagram of FIG. 3, the adhesive substrate 7 is a substrate in which an adhesive layer 71, a base material layer 72, and a ground conductor layer 73 are stacked in this order from the bottom. The sticking substrate 7 can also be a flexible substrate. In the case of a flexible substrate, the adhesive layer 71, the base material layer 72, and the ground conductor layer 73 have a thickness that allows the adhesive substrate 7 to be bent or bent.

  The adhesive layer 71 has adhesiveness. The adhesive layer 71 is a layer for preventing the attaching position of the attaching substrate 7 from shifting. The adhesive substrate 71 can fix the adhesive substrate 7 on the signal line 8 of the printed wiring board 1 (see FIG. 4). The adhesive layer 71 is formed by an adhesive film, a double-sided tape, a thinly applied adhesive, or the like. The adhesive layer 71 is insulative because it may contact the signal line 8 or some terminal.

  The adhesive layer 71 may be provided so that the adhesive layer 71 does not contact the signal line 8 when the adhesive substrate 7 is attached to the printed wiring board 1 (signal line 8). FIG. 3 shows an example in which the adhesive layer 71 is provided on both ends of the sticking substrate 7 in the direction perpendicular to the direction of the signal line 8. In this case, the adhesive substrate 7 is attached such that the signal line 8 is positioned between the adhesive layer 71 and the adhesive layer 71, and the signal line 8 and the adhesive layer 71 are not in contact with each other.

  In addition, you may provide the adhesion layer 71 so that the adhesion layer 71 of the sticking board | substrate 7 and the signal wire | line 8 may contact | connect. In this case, for example, the adhesive layer 71 may be provided over the entire lower surface of the base material layer 72. In this case, the sticking substrate 7 can be stuck to the signal line 8 as if a work tape is stuck.

  The base material layer 72 is an insulator. When the sticking substrate 7 is a flexible substrate, the base layer 72 can be a thin film (film shape) of an insulating resin such as polyimide or polyester. Further, a paper phenol substrate (a plate formed by infiltrating a phenol resin into an insulating paper) or a glass epoxy substrate (a plate in which an epoxy resin is infiltrated into glass fiber) may be used for the base material layer 72. There is no restriction | limiting in particular in the material of the base material layer 72. FIG. The ground conductor layer 73 is a layer connected to the ground of the printed wiring board 1. The ground conductor layer 73 is a conductive metal layer (for example, copper foil).

  The sticking substrate 7 has only three layers. Therefore, the sticking substrate 7 can be easily made from a material for a printed circuit board provided with a copper foil layer. In addition, processes such as printing, etching, and punching are not required, and the sticking substrate 7 can be prepared inexpensively and easily.

(Attaching the adhesive substrate 7 to the signal line 8)
Next, using FIG. 4 to FIG. 6, attachment of the adhesive substrate 7 to the signal line 8 of the printed wiring board 1 according to the embodiment will be described. FIG. 4 is an enlarged view of a part of the printed wiring board 1 according to the embodiment. FIG. 5 is a diagram illustrating an example of the microstrip line MS. FIG. 6 is a diagram illustrating an example of a conventional single-sided printed board. FIG. 7 is a diagram illustrating an example of the printed wiring board 1 in which the adhesive substrate 7 according to the embodiment is attached to the signal line 8.

  The lower part of FIG. 4 is an enlarged view of the signal line 8 portion of the printed wiring board 1 (single-sided board). A state in which the signal line 8 is formed on the insulating base material 10 of the printed wiring board 1 by a conductor such as a copper foil is schematically shown.

  In the printed wiring board 1, the pasting board 7 is stuck to the signal line 8. The upper substrate in FIG. In the example of FIG. 4, an example is illustrated in which the adhesive substrate 7 is attached so that the signal line 8 is positioned in the center of the adhesive substrate 7 in the short direction (direction perpendicular to the direction of the signal line 8). The width of the sticking substrate 7 (the length in the direction perpendicular to the direction of the signal line 8) is set to a length sufficient to cover the signal line 8.

  Conventionally, some signal lines in a printed circuit board do not have a certain characteristic impedance due to the distance from the ground and the convenience of wiring design. Such a signal line cannot match the impedance between the output impedance of the transmitting device and the input impedance of the receiving device. For this reason, when a high-frequency signal such as a clock signal or an image signal is transmitted to such a signal line, a reflected wave or a standing wave is generated, and the signal waveform may be disturbed, and the signal may not be transmitted correctly. Further, when impedance matching is not achieved, the entire power input to the signal line is not received on the receiving side, and a part of the power is radiated as noise.

  In the printed wiring board 1 of the present embodiment, the pasting substrate 7 is pasted on the desired signal line 8. Thereby, a microstrip line MS as shown in FIG. 5 is formed in a pseudo manner. By forming the microstrip line MS, the signal line 8 can have a certain characteristic impedance.

In the microstrip line MS, the characteristic impedance can be obtained in advance by an approximate expression. An example of an approximate expression that can be applied when 0.1 <W / H <3.0 is shown as Equation 1 (other approximate expressions may be used depending on conditions).

  The distance between the signal line 8 and the ground is determined by the thickness H of the insulating layer (base material) of the substrate on which the microstrip line MS is formed. The relative dielectric constant εr of the insulating layer is also related to the characteristic impedance of the signal line 8 of the microstrip line MS. Since the characteristic impedance of the signal line 8 can be calculated in advance by the approximate expression, the signal line 8 is desired by selecting the thickness of the base material layer 72 of the adhesive substrate 7 and the material (relative dielectric constant) of the base material layer 72. The sticking substrate 7 can be designed to have the characteristic impedance of

  The base material layer 72 of the sticking substrate 7 has a relative dielectric constant and a thickness such that the difference between the characteristic impedance of the signal line 8 and the output impedance of the transmission side device 6s is within a predetermined allowable range or the same. Further, the base material layer 72 of the sticking substrate 7 has a relative permittivity and a thickness such that the difference between the characteristic impedance and the input impedance of the receiving device 6r is within a predetermined allowable range or the same.

  Alternatively, the output impedance of the transmitting device 6s and the input impedance of the receiving device 6r may be adjusted. In this case, the coil, the capacitor, and the resistance of the output terminal of the transmitting device 6s and the input terminal of the receiving device 6r are matched with the characteristic impedance of the signal line 8 to which the pasting substrate 7 obtained by calculation is pasted. One or more of them are connected in series or in parallel. For example, a circuit composed of a capacitor or a circuit composed of a capacitor and a coil is connected. Even in this case, it is possible to match the characteristic impedance of the signal line 8, the output impedance of the transmission side device 6s, and the input impedance of the reception side device 6r.

  FIG. 6 is a view of the surface of the conventional single-sided printed circuit board 1000 on which the signal line 81 is printed as viewed from above. FIG. 7 is a view of the surface on which the signal line 8 is printed, as viewed from above, of the single-sided printed wiring board 1 according to the present embodiment.

  6 and 7, one of the signal lines provided on each substrate is illustrated. Each of the signal lines 8 and 81 shown in FIGS. 6 and 7 has a horizontal direction (left-right direction) as a longitudinal direction. At both ends of each signal line 8, a hole 82 for inserting a terminal of the device and a land 83 for soldering around the hole 82 are provided.

  6 and 7, the device whose terminal is connected to the left hole 82 in the signal line 8 is illustrated as a transmission-side device 6s. In FIGS. 6 and 7, a device whose terminal is connected to the right hole 82 is illustrated as a receiving device 6r. In a single-sided substrate, the device may insert a terminal into the hole 82 from the back side of the surface on which the signal line 8 is provided. In FIGS. 6 and 7, the transmission side device 6 s and the reception side device 6 r are illustrated by broken lines as being provided on the back side of the surface on which the signal line 8 is provided.

  As shown in FIG. 6, a conventional single-sided printed circuit board 1000 may be provided with a ground line 84 along the signal line 81 above the signal line 81 in order to prevent noise.

  FIG. 7 shows the printed wiring board 1 according to the embodiment in a state where the sticking board 7 is stuck. An adhesive substrate 7 is attached to the printed wiring board 1 so as to cover the entire signal line 8 from one end to the other end from above. The bonding substrate 7 is bonded so that the ground conductor layer 73 of the bonding substrate 7 does not contact the hole 82, the terminal of the device inserted into the hole 82, and the solder deposited on the land 83. You may make it affix the sticking board | substrate 7 over the part except the hole 82 and the land 83 among the signal wires 8. FIG. In addition, since it is covered with the sticking board | substrate 7 and is invisible, in FIG. 7, the signal wire | line 8 is illustrated with the dashed-dotted line.

  Then, as shown in FIG. 7, a connection portion 9 that connects the ground pattern 85 disposed on the printed wiring board 1 and the upper surface (ground conductor layer 73) of the pasting substrate 7 is provided. The connection part 9 has conductivity. For the connection portion 9, solder or a conductive adhesive can be used. As a result, a conductive surface is formed on the upper surface of the signal line 8.

  Further, by pasting the pasting substrate 7, it is not necessary to provide a part of the ground line 84 wired by the conventional printed wiring board 1. In FIG. 7, the portion of the ground line 84 that becomes unnecessary when the pasting substrate 7 is pasted is illustrated by a region surrounded by a two-dot chain line including a hatched pattern. By pasting the pasting substrate 7, the degree of freedom of wiring increases. Moreover, a wide ground can be secured.

  Thus, the printed wiring board 1 according to the embodiment includes the signal line 8 and the pasting board 7. The signal line 8 has a terminal of the transmission side device 6s connected to one end, and a reception side device 6r receiving a signal sent by the transmission side device 6s connected to the other end. The adhesive substrate 7 is a substrate in which an adhesive layer 71 having adhesiveness, a base material layer 72 made of an insulator, and a ground conductor layer 73 made of a conductor and connected to the ground of the printed wiring board 1 are stacked in this order, The substrate is attached to the signal line 8 so as to cover the signal line 8.

  By affixing the adhesive substrate 7 to the signal line 8, the distance between the signal line 8 and the ground (ground conductor layer 73) becomes constant, and the signal line 8 can be handled as the microstrip line MS. As a result, the signal line 8 can have a certain characteristic impedance. In addition, impedance matching can be achieved between the device connected to the signal line 8 and the signal line 8. Since the impedance can be matched, the reflected wave, standing wave, and unnecessary noise radiation from the signal line 8 are eliminated, and stable and accurate information (data) can be transmitted and received.

  Further, the pasting substrate 7 is simply stacked on each other, and no special processing is required. Furthermore, since it is only necessary to affix the adhesive substrate 7 to the signal line 8 of the printed wiring board 1, the signal line 8 can be provided with a certain characteristic impedance easily and inexpensively. Further, it is not necessary to attach the sticking substrate 7 to all the signal lines 8 arranged on the printed wiring board 1. Furthermore, in the microstrip line MS, the characteristic impedance can be adjusted by the thickness of the base material layer 72 and the relative dielectric constant. Therefore, it is possible to give the signal line 8 a desired characteristic impedance that matches a device connected to the signal line 8.

  The adhesive substrate 7 is attached only to the signal line 8 that preferably has a certain characteristic impedance, such as the signal line 8 that transmits a high-frequency signal or the signal line 8 that is connected to a device whose operation tends to be unstable due to disturbance of the signal waveform. What is necessary is just to affix (it is not necessary for the signal line 8 which transmits the signal with a low frequency). The printed wiring board 1 can be stably operated by simply attaching the sticking board 7.

  Moreover, the base material layer 72 of the sticking substrate 7 has a relative dielectric constant and a thickness such that the difference between the characteristic impedance of the signal line 8 and the output impedance of the transmitting device 6s is within a predetermined allowable range. Thereby, the characteristic impedance of the signal line 8 and the output impedance of the transmission side device 6s can be matched. Therefore, it is possible to suppress the generation of reflected waves at the connecting portion 9 minutes between the transmission side device 6s and the signal line 8, and to eliminate standing waves and unnecessary noise emission.

  Moreover, the base material layer 72 of the sticking substrate 7 has a relative dielectric constant and a thickness such that the difference between the characteristic impedance and the input impedance of the receiving device 6r is within a predetermined allowable range. Thereby, the characteristic impedance of the signal line 8 and the output impedance of the receiving device 6r can be matched. Therefore, it is possible to suppress the generation of a reflected wave at the connection portion 9 minutes between the receiving device 6r and the signal line 8, and to eliminate standing waves and unnecessary noise emission.

  In addition, the signal line 8 is printed on only one side of the substrate surface. As a result, even with a single-sided substrate that cannot be provided with a conductive layer (solid ground), such as a multilayer substrate, the specific signal line 8 can have a desired characteristic impedance simply by attaching the adhesive substrate 7. Further, it is not necessary to design the wiring of the printed wiring board 1 so as to surround the signal line 8 with a ground pattern so as to prevent noise emission and not disturb the signal waveform.

  Moreover, the sticking substrate 7 is a flexible substrate. Thereby, the sticking board | substrate 7 can be made thin so that it can be bent or bent. Therefore, the sticking substrate 7 can be manufactured inexpensively and easily. Further, the pasting substrate 7 can be easily pasted according to the pattern of the signal line 8. In addition, processing such as cutting for matching with the signal line 8 can be easily performed.

  Further, the present invention can also be regarded as an invention of the adhesive substrate 7. The adhesive substrate 7 according to the present invention is a substrate in which an adhesive layer 71 having adhesiveness, a base material layer 72 made of an insulator, and a ground conductor layer 73 made of a conductor are stacked in this order, and is provided on the printed wiring board 1. The signal line 8 is pasted so as to cover it. This makes it possible to provide a low-cost substrate that can have characteristic impedance in the signal line 8 in which the characteristic impedance of the printed wiring board 1 is indefinite and impedance matching with the device cannot be achieved by simply pasting. Can be provided easily. Moreover, the generation of the reflected wave and the standing wave on the signal line 8 and the emission of noise can be prevented only by pasting the signal line 8 to which the high frequency signal is transmitted.

  Further, it can be regarded as an invention of a method for manufacturing the printed wiring board 1. The method for manufacturing a printed wiring board 1 according to the present invention includes a signal line 8 in which a terminal of a transmission side device 6s is connected to one end and a reception side device 6r that receives a signal transmitted by the transmission side device 6s is connected to the other end. An adhesive substrate 71, which is a substrate in which an adhesive layer 71 having adhesiveness, a base material layer 72 made of an insulator, and a ground conductor layer 73 made of a conductor and connected to the ground of the printed wiring board 1 are sequentially stacked. Paste to cover. As a result, even if there is a signal line 8 in the printed wiring board 1 where reflection is likely to occur and noise is likely to be radiated, the noise is not radiated and the signal transmission error is prevented by simply attaching the adhesive substrate 7. It can be lost. Accordingly, it is possible to manufacture the printed wiring board 1 with low noise, few reflected waves and standing waves on the signal line 8, and few operational errors.

  The embodiment of the present invention has been described above, but the scope of the present invention is not limited to this, and various modifications can be made without departing from the spirit of the invention.

  The present invention can be used for a printed wiring board such as a single-sided board.

DESCRIPTION OF SYMBOLS 1 Printed wiring board 6s Transmission side device 6r Reception side device 7 Adhesion board 71 Adhesive layer 72 Base material layer 73 Ground conductor layer 8 Signal line

Claims (7)

A signal line to which a terminal of a transmitting device is connected to one end, and a receiving device that receives a signal sent by the transmitting device is connected to the other end;
An adhesive layer having adhesiveness, a base material layer made of an insulator, and a ground conductor layer made of a conductor and connected to a ground of a printed wiring board in this order, and the signal line covering the signal line A printed wiring board comprising a sticking board which is a board to be attached to the board.   The base material layer of the sticking substrate has a relative permittivity and a thickness such that a difference between a characteristic impedance of the signal line and an output impedance of the transmitting device is within a predetermined allowable range. Item 4. A printed wiring board according to item 1.   The base material layer of the sticking substrate has a relative permittivity and a thickness such that a difference between the characteristic impedance and an input impedance of the receiving device is within a predetermined allowable range. Or the printed wiring board of 2.   4. The printed wiring board according to claim 1, wherein the printed circuit board is a single-sided board on which signal lines are printed only on one side of the board surface. 5.   The printed wiring board according to claim 1, wherein the sticking substrate is a flexible substrate.   A substrate in which an adhesive layer having adhesiveness, a base material layer made of an insulator, and a ground conductor layer made of a conductor are stacked in this order, and is attached so as to cover a signal line provided on a printed wiring board Affixing substrate. A signal line is provided in which a terminal of a transmitting device is connected to one end and a receiving device receiving a signal sent by the transmitting device is connected to the other end,
Adhesive adhesive layer, base material layer made of insulator, and conductive substrate made of conductors and stacked in order of ground conductor layer connected to the ground of the printed wiring board are attached so as to cover the signal line. A printed wiring board manufacturing method characterized by comprising:

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