JP2010016050A - Electronic circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique relating to an electronic circuit capable of preventing adverse effects by static electricity without changing the arrangement and shape of a land to connect a connector. <P>SOLUTION: The electronic circuit includes a land part provided on a substrate and composed of solder for connecting the terminal of an electronic component onto the substrate, and a ground part provided on the substrate as a reference potential point for receiving the static electricity charged to the land part. The land part has a dischtarge part for discharging the charged static electricity, and the ground part has a receiving part for receiving the static electricity discharged from the discharge part. The receiving part is provided facing the discharge part so as to efficiently receive the static electricity discharged from the discharge part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic circuit.

  In an electronic circuit used for a control circuit or the like, it is necessary to take measures against static electricity in order to prevent a circuit failure or the like. For example, Patent Document 1 discloses an electrostatic discharge circuit including an IC provided on a substrate, a signal line pattern for connecting the IC, and a pointed electrostatic discharge pattern provided between the signal line pattern and the reference potential dotted line pattern. Techniques related to this are disclosed.

Further, in Patent Document 2, in a wiring board on which a conductor pattern for connecting electronic components is formed, a place where the impedance is increased in a conductor pattern to which static electricity is applied when an object charged with static electricity comes close to or contacts , And a technique for forming a discharge path by bringing a location where the impedance is increased close to a GND conductor pattern wired in the vicinity of the location is disclosed.
Japanese Utility Model Publication No. 5-76071 JP 2001-7455 A

  As a countermeasure against electrostatic discharge (ESD) in an electronic circuit, a technique for making the shape of a land to which a pin of an electronic component is connected easy to discharge is known. Here, FIG. 1 shows an example of a conventional electronic circuit having a land shape that is easy to discharge. In this conventional electronic circuit, the land 202 to which the pin 201 of the electronic component is connected is provided with a protruding portion 204 that protrudes toward the ground 203 and promotes discharge. The circuit pattern 206 extending from the land 202 is also provided with a protruding portion 205 that promotes discharge.

  According to such a conventional electronic circuit, by providing the protrusions 204 and 205 on the land 202 and the circuit pattern 206, discharge to the ground 203 can be promoted. However, in recent electronic circuits, in order to ensure the quality of the product on which the electronic circuit is mounted, the shape of the land is defined in advance, and there are not a few cases where changes are not allowed. In addition, the impedance of the circuit pattern is controlled particularly in a high-frequency circuit or the like, and there is a possibility that the impedance is distorted if the shape of the circuit pattern is changed.

  In view of the above background, it is an object of the present invention to provide a technique related to an electronic circuit that can suppress adverse effects due to static electricity without changing the arrangement and shape of lands that connect terminals of electronic components.

  In the present invention, in order to solve the above-described problem, the ground to which static electricity discharged from the land is applied is devised so that the static electricity charged to the land is efficiently received by the ground.

More specifically, the present invention provides a land portion made of solder for connecting a terminal of an electronic component on the substrate and the static electricity provided on the substrate and charged on the land portion. A ground portion as a reference potential point for receiving, the land portion having a discharge portion for discharging static electricity to be charged, and the ground portion having a reception portion for receiving static electricity discharged from the discharge portion. The receiving part is an electronic circuit provided to face the emitting part so as to efficiently receive the static electricity emitted from the emitting part.

  In the electronic circuit according to the present invention, the receiving portion of the ground portion is provided so as to face the emitting portion so as to efficiently receive the static electricity discharged from the emitting portion of the land portion. Therefore, the static electricity charged to the land portion and the terminals of the electronic components connected to the land portion can be efficiently received by the ground portion without changing the shape and arrangement of the land portion. As a result, adverse effects due to static electricity in the electronic circuit can be suppressed.

  The land portion connects the terminals of the electronic component on the substrate, more specifically, on the wiring circuit pattern formed on the substrate. The land portion has a discharge portion, and the discharge portion discharges static electricity charged in the land portion. The land portion can be made of solder, but the shape is not particularly limited. The shape and arrangement of the land portions do not need to be changed in principle, and may be a shape and arrangement that are defined in advance according to the electronic component to be mounted. For example, the land portion may have a rectangular shape, a polygonal shape, or a circular shape in plan view. When the land portion is rectangular or polygonal, the land portion has a corner portion. From a region protruding from an adjacent region such as a corner, charged static electricity is likely to be released to the outside. Therefore, when the land portion has a corner portion, the discharge portion can be constituted by the corner portion. However, it is not limited to such a mode, and the discharge portion does not necessarily have to protrude from the adjacent region. The corner may have a sharp shape or a chamfered tip portion. Further, the land portion may be provided with a protrusion for facilitating discharge of charged static electricity within a range in which the quality of the product on which the electronic circuit is mounted can be ensured.

  The ground portion accepts static electricity charged in the land portion. The ground portion is grounded and functions as a reference potential point. The electronic circuit according to the present invention is characterized in that the arrangement and shape of the ground portion are devised so as to receive static electricity more efficiently in accordance with the land portion. The ground portion has a receiving portion that receives static electricity discharged from the discharging portion, and the receiving portion is provided so as to face the discharging portion, so that the static electricity discharged from the discharging portion is efficiently received by the receiving portion. . In other words, static electricity discharged from the land portion is efficiently applied to the ground portion. As a result, it is possible to suppress adverse effects due to static electricity of the electrical component on which the electronic circuit according to the present invention is mounted without changing the shape, arrangement, or the like of the land portion.

  The receiving part in this invention is a part which receives the static electricity discharge | released from a discharge | release part, The shape etc. are not specifically limited. For example, when the projecting portion is a ground portion side projecting portion projecting to the land portion side, static electricity discharged from the emitting portion can be received more efficiently. However, the protruding portion is not limited to such a mode. When the ground portion has a corner portion, the corner portion may be a receiving portion and may be opposed to the discharge portion. Since the receiving portion formed of the corner faces the discharge portion, it becomes possible to receive the static electricity discharged efficiently. The corner may have a pointed shape or a shape with a chamfered tip.

  In addition, the receiving portion does not need to have a shape protruding with respect to an adjacent region such as a corner portion or a protruding portion, and a linear end portion (for example, when the ground portion is rectangular in plan view, One side). In such a case, the direction of the linear end portion with respect to the output direction of the static electricity discharged from the discharge portion should be devised so that the receiving portion composed of the linear end portion can efficiently receive the static electricity. That's fine. Specifically, when the receiving portion is a linear end portion, the end portion is substantially orthogonal to an output reference line indicating an output direction of static electricity discharged from the emitting portion. Should be provided. As a result, the distance between the emitting portion and the receiving portion is shortest, and the ground portion can accept the static electricity that is efficiently discharged.

  Here, the electronic circuit according to the present invention can be configured to further include a thin-film resist portion that covers the surface of the substrate. The resist unit may be configured such that a space between the receiving unit and the receiving unit is removed so that the receiving unit efficiently receives static electricity discharged from the emitting unit. By removing the resist between the discharge portion and the receiving portion, that is, the portion serving as a passage for static electricity, the receiving portion can receive the static electricity discharged more efficiently. Note that the resist may have a function of restricting the solder that constitutes the land portion from flowing out at a portion that contacts the end portion of the land portion. Therefore, the resist portion may be removed so that the function of restricting the flow of such solder is ensured and the receiving portion efficiently receives the static electricity discharged from the discharging portion.

  The electronic circuit according to the present invention may further include a line-shaped wiring circuit pattern portion through which an electrical signal extending from the land portion flows. In this case, in order to efficiently receive the static electricity charged in the wiring circuit pattern portion, a ground portion having a receiving portion including a corner portion or a protruding portion may be provided in the vicinity of the wiring circuit pattern. Good. The position where the ground portion for receiving static electricity from the wiring circuit pattern portion is provided so as to ensure the quality of the product on which the electronic circuit is mounted. According to the present invention, since it is not necessary to change the shape of the wiring circuit pattern portion, it is possible to suppress a situation in which the impedance of the wiring circuit pattern portion is distorted.

  In addition, this invention is good also as a manufacturing method of the design method of the electronic circuit mentioned above, the electronic component provided with the electronic circuit mentioned above, or the electronic component provided with the electronic circuit mentioned above. For example, in the case of a manufacturing method of an electronic component, a land portion made of solder that is provided on a substrate and connects terminals of the electronic component on the substrate, and the land portion that is provided on the substrate is charged. A method of manufacturing an electronic component having an electronic circuit including a ground portion serving as a reference potential point that accepts static electricity, wherein the discharge portion discharges static electricity charged to a land provided in the land to the ground portion. A method of manufacturing an electronic component comprising an electronic circuit provided to receive a static electricity discharged from a receiving portion, the receiving portion being provided to face the discharging portion so as to efficiently receive the static electricity discharged from the discharging portion It can be.

  ADVANTAGE OF THE INVENTION According to this invention, the technique regarding the electronic circuit which can suppress the bad effect by static electricity can be provided, without changing the arrangement | positioning and shape of the land which connect the terminal of an electronic component.

  Next, an embodiment of an electronic circuit according to the present invention will be described based on the drawings.

<First embodiment>
FIG. 2 is a plan view of the electronic circuit according to the first embodiment. FIG. 3 shows an AA cross section in FIG. The electronic circuit according to the first embodiment includes an insulating substrate 11, electronic component pins 2, lands 3, and a ground 4. The electronic circuit which concerns on 1st embodiment can be used for the electronic component used for ECU (Electric Control Unit) which performs various electronic controls of a vehicle, for example.

  A predetermined wiring circuit pattern 12 made of a copper foil portion and a ground 4 made of a copper foil portion are provided on the insulating substrate 11 to constitute the printed board 1. Although not shown in FIG. 2, the surface of the printed board 1 is coated with a resist 5 by being subjected to a resist process by a screen printing process or the like. The resist 5 usually covers the surface of the printed circuit board 1 except for a portion where an electronic component pin (hereinafter also simply referred to as a pin) 2 is connected, that is, a region where the land 3 is provided.

  The land 3 is provided on a portion of the wiring circuit pattern 12 made of a copper foil portion to which the pin 2 of the electronic component is connected. The land 3 is made of solder and electrically connects the wiring circuit pattern 12 and the pin 2. The land 3 according to the first embodiment has a substantially rectangular shape in plan view, and the surface area of the land 3 is designed to be larger than the area of the connection surface of the pin 2 so that the pin 2 can be stably placed. . Since the land 3 according to the present embodiment is substantially rectangular, it has four corners, but the corner 31 facing the corner 41 on the ground side (hereinafter referred to as a land-side corner). Corresponds to the discharge part in the present invention. Accordingly, static electricity charged on the land 3 or charged on the pin 2 is discharged (discharged) toward the corner 41 on the ground side from the corner 31 on the land side corresponding to the emission portion of the present invention. .

  The land 3 can be formed by a conventional method. That is, when the resist 5 is coated, the region where the lands 3 are provided (in this embodiment, a rectangular region) is left, and cream solder is applied to the regions where the lands 3 are provided by, for example, screen printing. After the pins 2 are placed on the cream solder and temporarily fixed, the cream solder is heated (reflowed) to fix the pins 2 on the wiring circuit pattern 12. Thereby, formation of the land 3 and connection of the pin 2 are completed.

  The ground (GND) 4 receives static electricity emitted from the corner 31 on the land side. The ground 4 constitutes a part of a wiring circuit pattern made of a copper foil portion that constitutes the printed circuit board 1. In the embodiment, however, the ground 4 is referred to as a ground in order to distinguish it from the wiring circuit pattern 12 on the ground side. And The ground 4 functions as a reference potential point by being grounded (not shown). The ground 4 according to the present embodiment has a ground-side corner 41, and is further provided so that the ground-side corner 41 faces the land-side corner 31. In addition, the corner | angular part 41 by the side of a ground is equivalent to the receiving part of this invention. By providing the ground-side corner 41 so as to face the land-side corner 31 in this way, static electricity charged to the land 3 is efficiently applied to the ground 4 via the ground-side corner 41. Is done.

  According to the electronic circuit according to the first embodiment described above, the ground side corner 41 provided on the ground 4 is provided so as to face the land side corner 31. Static electricity charged on the land 3 can be received efficiently. That is, static electricity charged on the land 3 is efficiently applied to the ground 4. As a result, adverse effects due to static electricity in the electronic circuit can be suppressed. In the electronic circuit according to the present embodiment, static electricity is efficiently applied to the ground 4 only by devising the arrangement and shape of the ground 4 without changing the arrangement and shape of the land 3. If the shape and arrangement of the land 3 are changed, there is a possibility that the quality of the product on which the electronic circuit is mounted cannot be ensured, and in order to avoid such a situation, it is necessary to perform careful design again. . However, according to the electronic circuit according to the present embodiment, such a situation can also be prevented. That is, the quality of the product on which the electronic circuit is mounted can be ensured, and it is not necessary to perform a detailed design again.

<Second embodiment>
Next, an electronic circuit according to the second embodiment will be described. In addition, about the structure similar to the electronic circuit which concerns on 1st embodiment, the description is abbreviate | omitted by attaching | subjecting the same code | symbol.

FIG. 4 shows a cross-sectional view of an electronic circuit according to the second embodiment. The electronic circuit according to the second embodiment is different from the electronic circuit according to the first embodiment in that the resist between the land 3 and the ground 4 is removed. As described above, in the electronic circuit according to the first embodiment, the surface of the printed circuit board 1 is covered with the resist 5 except for the region where the land 3 is provided. In contrast, in the electronic circuit according to the second embodiment, the resist for the path of static electricity applied between the land 3 and the ground 4, in other words, from the land-side corner 31 to the ground-side corner 41 is removed. It is. In the electronic circuit according to the first embodiment, since the resist 5 exists between the land 3 and the ground 4, the static electricity discharged from the corner 31 on the land side goes around the upper side of the resist, and the ground side Applied to the corner 41 (indicated by an arrow in FIG. 3). That is, in the electronic circuit according to the first embodiment, the path of static electricity is curved. In contrast, in the electronic circuit according to the second embodiment, the path of static electricity applied from the land-side corner 31 to the ground-side corner 41 is linear (indicated by an arrow in FIG. 4). As a result, according to the electronic circuit according to the second embodiment, it is possible to more efficiently accept the static electricity charged in the land 3 by the ground 4.

  Note that the resist has a function of restricting the solder constituting the land 3 from protruding to the ground side when the land 3 is provided, in other words, a function of adjusting the outer shape of the land 3. Therefore, as an aspect other than the above, the electronic circuit may be configured to ensure such a resist function and to further shorten the path of static electricity. Here, FIG. 5 shows a sectional view of a modification of the electronic circuit according to the second embodiment. The electronic circuit according to the modified example basically has the same configuration as the electronic circuit according to the first embodiment, but the cross-sectional shape of the resist 5a interposed between the land 3 and the ground 4 is the first embodiment. This is different from the resist 5 of the electronic circuit.

  Specifically, the side of the resist 5a that contacts the land 3 is designed to be higher than the copper foil that forms the circuit pattern on which the pin 2 is placed, and the side of the resist 5a that contacts the land 3 contacts the ground 4 of the resist 5a. It is designed so that the height gradually decreases toward. The height of the resist 5a on the land 3 side only needs to be high enough to restrict the solder constituting the land 3 from protruding. On the other hand, the height of the resist 5a on the ground 4 side is preferably the same as or lower than the height of the copper foil constituting the ground 4 so that static electricity can be received by the ground 4 more efficiently. Thus, by devising the shape of the resist 5a interposed between the land 3 and the ground 4, the function of forming the land 3 included in the resist 5a is ensured, and the static electricity discharged from the land 3 is more efficiently generated. It can be applied to the ground.

<Third embodiment>
Next, an electronic circuit according to the third embodiment will be described. In addition, about the structure similar to the electronic circuit which concerns on embodiment mentioned above, the description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  FIG. 6 is a plan view of an electronic circuit according to the third embodiment. The electronic circuit according to the third embodiment is provided with a protrusion 6 for efficiently receiving static electricity discharged from the land-side corner 31 at a position facing the land-side corner 31. Different from the configuration of the electronic circuit according to the first embodiment.

  More specifically, in the electronic circuit according to the third embodiment, the linear end 42 on the land 3 side is a reference line (in FIG. 6) indicating the discharge direction of static electricity discharged from the corner 31 on the land side. Designed to be orthogonal to the dotted line). The land-side linear end portion 42 of the ground 4 has a land-side corner at a portion that intersects the reference line indicating the emission direction, in other words, at a portion where the distance from the land-side corner portion 31 is the shortest. A protrusion 6 for efficiently receiving static electricity discharged from the portion 31 is provided.

According to the electronic circuit according to the third embodiment, since the protrusion 6 provided on the ground 4 is provided so as to face the corner 31 on the land side, the ground 4 is charged to the land 3. Can efficiently accept the static electricity. That is, static electricity charged on the land 3 is efficiently applied to the ground 4. And also in the electronic circuit according to the present embodiment, static electricity is efficiently applied to the ground 4 only by devising the arrangement and shape of the ground 4 without changing the arrangement and shape of the land 3. It is possible to suppress adverse effects caused by static electricity that can occur in electronic circuits.

  In the electronic circuit according to the present embodiment, the protrusion 6 is provided at the linear end 42 on the land side of the ground 4. However, the projecting portion 6 is not provided, and the linear end 42 on the land 3 side is designed so as to be orthogonal to the reference line indicating the discharge direction of the static electricity discharged from the corner 31 on the land side. May be. Here, FIG. 7 shows a plan view of a modification of the electronic circuit according to the third embodiment. As shown in the figure, in the electronic circuit according to this aspect, the projecting portion 6 is not provided, and the linear end portion 42 on the land 3 side is discharged from the corner portion 31 on the land side. It is designed to be simply orthogonal to a reference line indicating the direction (indicated by a dotted line in FIG. 7).

  Here, for example, as in the comparative example in FIG. 8, when the linear end portion 42 of the ground 4 is arranged in parallel with the end portion of the land 3, the static electricity discharged from the corner portion 31 on the land side. Some of them are difficult to accept at Grand 4. That is, in the comparative example shown in FIG. 8, the path of static electricity indicated by the arrow indicated by the symbol L is long, and the input direction of the static electricity indicated by the symbol L to the end portion 42 of the ground 4 is not orthogonal. . As a result, static electricity is less likely to be applied to the ground 4 than when the linear end 42 on the land 3 side is orthogonal to the reference line indicating the discharge direction of static electricity discharged from the corner 31 on the land side. . Therefore, the direction of the end portion 42 can also be obtained by making the straight end portion 42 of the ground 4 orthogonal to the reference line indicating the discharge direction of the static electricity discharged from the corner portion 31 on the land side as in the electronic circuit of the modification. The application rate to the ground can be improved as compared with an electronic circuit in which is not considered.

<Other embodiments>
Although the preferred embodiments of the present invention have been described above, the electronic circuit according to the present invention is not limited to these, and can include combinations thereof as much as possible. Note that the corners (corners on the land side, corners on the ground side) and the tips of the protrusions in the above-described embodiment can be more intensively realized by discharging or receiving static electricity by forming a pointed shape. It may be a curved shape or a curved shape. In the electronic circuit according to the above-described embodiment, the land 3 having a substantially rectangular shape in plan view has been described as an example. However, the shape of the land 3 may be a polygonal shape, a circular shape, or the like. In the above-described embodiment, the case where the static electricity charged in the land 3 is discharged has been described. However, in order to discharge the static electricity charged in the wiring circuit pattern more efficiently, the land 3 protrudes in the vicinity of the wiring circuit pattern. The part 6 and the corner 41 on the ground side may be provided. Furthermore, if the quality of the product on which the electronic circuit is mounted can be ensured, or if the impedance of the wiring circuit pattern is not disturbed, the land or wiring can be discharged more efficiently toward the ground. A protrusion or the like may be provided on the circuit pattern side.

An example of the conventional electronic circuit which has a land shape which is easy to discharge is shown. The top view of the electronic circuit which concerns on 1st embodiment is shown. The AA cross section in FIG. 2 is shown. Sectional drawing of the electronic circuit which concerns on 2nd embodiment is shown. Sectional drawing of the modification of the electronic circuit which concerns on 2nd embodiment is shown. The top view of the electronic circuit which concerns on 3rd embodiment is shown. The top view of the modification of the electronic circuit which concerns on 3rd embodiment is shown. A part of an electronic circuit as a comparative example is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Printed circuit board 2 ... Pin 3 ... Land 4 ... Ground 5 ... Resist 6 ... Protruding part 11 ... Insulating substrate 12 ... Wiring circuit pattern 31 ... Land Side corner 41 ... Ground side corner 42 ... End <Conventional example>
201 ... Pin 202 ... Land 203 ... Ground 204, 205 ... Protrusion 205 ... Pattern

Claims (7)

A land portion made of solder provided on a substrate and connecting terminals of the electronic component on the substrate;
A ground portion as a reference potential point that is provided on the substrate and receives static electricity charged in the land portion, and
The land portion has a discharge portion that discharges static electricity that is charged,
The ground part has a receiving part for receiving static electricity discharged from the discharge part,
The receiving part is an electronic circuit provided to face the emitting part so as to efficiently receive static electricity emitted from the emitting part. The land part has a corner part, and the discharge part consists of a corner part on the land part side,
The receiving portion is provided so as to face a discharge portion consisting of a corner portion on the land portion side so as to efficiently receive static electricity discharged from a discharge portion consisting of a corner portion on the land portion side. Item 2. The electronic circuit according to Item 1.   The electronic circuit according to claim 1, wherein the ground portion includes a corner portion, and the receiving portion includes a corner portion on the ground portion side.   The said receiving part is a protrusion part provided in the vicinity of this discharge | release part and protruding to the said land part side so that the static electricity discharge | released from the said discharge | release part may be received efficiently. The electronic circuit as described in any one of.   When the receiving portion is a linear end portion, the ground portion is provided so that the end portion is substantially orthogonal to an output reference line indicating an output direction of static electricity discharged from the discharge portion. The electronic circuit according to claim 1. It further comprises a thin film resist portion covering the surface of the substrate,
6. The resist unit according to claim 1, wherein a space between the discharge portion and the receiving portion is removed so that the receiving portion efficiently receives static electricity discharged from the discharge portion. An electronic circuit according to claim 1. It further comprises a thin film resist portion covering the surface of the substrate,
The resist portion is formed so that the receiving portion efficiently receives static electricity discharged from the discharge portion, and suppresses the solder constituting the land portion from flowing to the ground portion side. The electronic circuit according to any one of claims 1 to 5.

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