JP2008047605A - Printed circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve mechanical strength of a mounted chip component. <P>SOLUTION: A printed circuit board (1) is used for mounting a chip component. The mechanical strength of the mounted chip component has anisotropy. The printed circuit board is provided with one or a plurality of dummy chip components (51, 52) that are mounted, so as to disperse at least an external force applied to the mounted chip component (41) from a direction of the part in the mounted chip component that has relatively weak mechanical strength. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a printed circuit board, and more particularly to a technical field of a printed circuit board on which an electrically functioning chip component is mounted.

  On this type of printed circuit board, a wiring pattern (conductor pattern) having a predetermined pattern is printed. In addition, holes called lands are formed on the printed circuit board. A chip component terminal is inserted into this land and soldered to mount the chip component. Here, in general, since the above-described chip component is mounted in a state of protruding at a predetermined height on the printed circuit board, when pressed by a jig or the like in the assembly process, the soldered portion is There is a risk of peeling.

  In order to deal with such a problem, for example, a technique related to a chip component that further includes a dummy terminal in addition to a terminal for causing the chip component to function has been proposed (see Patent Document 1). According to this technique, when the terminals and the dummy terminals are soldered to the land of the printed circuit board, the mounting strength of the chip component is increased by soldering the dummy terminals.

JP-A-9-129291

  However, for example, the technique disclosed in Patent Document 1 described above still has the following strength problems. That is, even if the number of dummy terminals is increased, the chip component itself is still pressed by a jig or the like, and thus there is a possibility that the strength problem has not been solved. In particular, a chip component that is mounted on the edge of a printed circuit board may be caught and skipped due to carelessness in the assembly process.

  The present invention has been made in view of the above-described problems, for example, and an object of the present invention is to provide a printed circuit board capable of improving the mechanical strength of a chip component to be mounted.

  In order to solve the above problems, a printed circuit board according to claim 1 of the present invention is a printed circuit board for mounting a chip component, and the mechanical strength of the mounted chip component has anisotropy. In addition, one or a plurality of dummy chip components are mounted so as to disperse an external force applied at least from the direction in which the mechanical strength is relatively weak with respect to the mounted chip components.

  The operation and other advantages of the present invention will become apparent from the best mode for carrying out the invention described below.

  Hereinafter, a printed circuit board according to an embodiment of the present invention as the best mode for carrying out the invention will be described.

  In order to solve the above-described problem, the printed circuit board according to the present embodiment is a printed circuit board for mounting a chip component, and the mechanical strength of the mounted chip component is anisotropic, One or a plurality of dummy chip components are mounted so as to disperse an external force applied at least from the direction in which the mechanical strength is relatively weak with respect to the chip components to be mounted.

  According to the present embodiment, the printed board is a printed board for mounting a chip component such as a thermistor, for example, and the mechanical strength of the mounted chip component is anisotropic. “Mechanical strength” as used herein refers to the mounting when a chip component is pressed by a jig or the like, for example, when an external force is mechanically applied to the chip component. This refers to the difficulty in peeling off the chip components. “Having anisotropy” means that the physical property of a substance varies depending on the direction, and in this case, the mechanical strength of the chip component varies depending on the direction. Therefore, when an external force is applied to the chip component mounted as described above from a direction in which the mechanical strength is relatively weak, the chip component may be separated from the printed board.

  However, according to the present embodiment, one or a plurality of dummy chip components are mounted so as to disperse the external force applied from at least the above-described direction. For example, one dummy chip component is mounted so as to be adjacent to the chip component. Alternatively, two dummy chip components are mounted so as to sandwich the chip component. Alternatively, the three dummy chip components are mounted so as to form a triangle including the chip components inside. When one or more dummy chip components are mounted in this manner, the external force applied as described above is applied not only to the chip components but also to the dummy chip components. That is, the applied external force is dispersed. Therefore, according to the printed circuit board according to the present embodiment, the chip component can withstand a strong external force as compared with the case where the dummy chip component is not mounted, thereby improving the mechanical strength of the mounted chip component. It will be.

  In one aspect of the printed circuit board according to the present embodiment, the plurality of dummy chip components are mounted facing each other so as to sandwich the mounted chip component.

  According to this aspect, since the mounted chip component is protected by the plurality of dummy chip components, the mechanical strength of the mounted chip component is substantially improved.

  In another aspect of the printed circuit board according to the present embodiment, in the direction in which the mechanical strength of the mounted chip component is relatively weak, the end surface of the dummy chip component is more than the end surface of the chip component. Located near the object to which the external force is applied.

  According to this aspect, even if an object such as a jig enters from a direction in which the strength is relatively weak with respect to the mounted chip component, the end surface of the dummy chip component comes before the end surface of the chip component. The object will arrive. Therefore, it is difficult to apply an external force directly to the chip component, and the possibility that the chip component is peeled off is further reduced.

  In another aspect of the printed circuit board according to this embodiment, in addition to the mechanical strength of the mounted chip component, the mechanical strength of the mounted dummy chip component also has anisotropy, and the mounting The dummy chip component so that the direction in which the mechanical strength related to the chip component to be mounted is relatively weak and the direction in which the mechanical strength related to the mounted dummy chip component is relatively strong are along each other Is implemented.

  According to this aspect, for example, each of the mounted chip component and the plurality of dummy chip components is bonded to the printed circuit board at two points (hereinafter, these points are also referred to as “bonding points”). Therefore, the mechanical strength of these parts is anisotropic. Therefore, the dummy chip component is mounted so that the direction in which the strength related to the mounted chip component is relatively weak and the direction in which the strength related to the mounted dummy chip component is relatively strong are along each other. Therefore, even if an external force is applied from a direction where the strength related to the mounted chip component is relatively weak, the external force can be received in a direction where the strength related to the mounted dummy chip component is relatively strong. That is, it is possible to effectively supplement the mechanical strength weakness of the mounted chip component.

  In another aspect of the printed circuit board according to this embodiment, the interval between the plurality of dummy chip components to be mounted is smaller than the width of the object to which the external force is applied.

  According to this aspect, the plurality of dummy chip components to be mounted prevents entry of an object that applies external force. Therefore, it is difficult to apply an external force directly to the chip component, and the possibility that the chip component is peeled off is further reduced.

  In another aspect of the printed circuit board according to the present embodiment, the printed circuit board further includes connection means for electrically connecting at least one set of the plurality of mounted dummy chip components.

  According to this aspect, at least one set of the plurality of dummy chip components to be mounted is electrically connected by the connecting means including, for example, wiring. Therefore, it is possible to avoid a plurality of mounted dummy chip components from being in a so-called electrically floating state. In other words, a plurality of dummy chip components to be mounted can be electrically stabilized.

  In another aspect of the printed circuit board according to the present embodiment, the printed circuit board further includes grounding means for grounding the connected at least one set.

  According to this aspect, at least one set connected is grounded to the reference voltage or ground. Therefore, the plurality of dummy chip components to be mounted can be further stabilized electrically.

  In another aspect of the printed circuit board according to this embodiment, the dummy chip component is a conductor having a resistance value lower than a predetermined resistance value.

  According to this aspect, since the dummy chip component not only protects the chip component but also functions as a part of the wiring, that is, as a jumper, it is very convenient in practice. Here, the “predetermined resistance value” is an upper limit value of a resistance value that allows the dummy chip component to function suitably as a jumper, in other words, a resistance value that avoids unnecessary energy loss as much as possible. It is good to obtain in advance.

  In another aspect of the printed circuit board according to the present embodiment, the chip component is mounted directly on the printed circuit board.

  According to this aspect, the mechanical strength of the chip component to be mounted is weak compared to the case where the chip component is mounted with a terminal. Under such disadvantageous circumstances, the benefits of improving mechanical strength can be truly enjoyed. However, it is not intended to prevent the provision of the dummy chip component when mounted with terminals.

  As described above, according to the printed circuit board of the present embodiment, since the dummy chip component is provided, the mechanical strength of the mounted chip component can be improved.

  The operation and other advantages of the present embodiment will be clarified from the examples described below.

  Embodiments of the present invention will be described below with reference to the drawings.

(1) First Example A configuration of a printed circuit board according to a first example and its operation and effect will be described with reference to FIGS.

  First, the configuration of the printed circuit board according to this embodiment will be described with reference to FIG. FIG. 1 is a top view conceptually showing the basic structure of the printed circuit board according to the first embodiment of the present invention.

  As shown in FIG. 1, a printed circuit board 1 according to this embodiment is, for example, a surface-mount type printed circuit board, and includes a substrate unit 11, wirings 21 and 22, and land units 31, 32, 33, 34, 35, and 36. Is provided.

  The substrate unit 11 is an insulating substrate such as glass epoxy.

  The wirings 21 and 22 are copper foil patterns formed on the surface of the substrate unit 11 and having a line width of 0.15 mm, for example. The wiring pattern is formed by etching a copper foil formed on an insulating plate according to a predetermined pattern formed by printing.

  The land portions 31, 32, 33, 34, 35, and 36 are so-called receptacles for mounting various electronic components such as chip components or dummy chip components on the substrate portion 11, and are formed on the substrate portion 11, for example. It is the copper foil with which an opening part and the circumference | surroundings of the opening part are equipped. The intervals between the land portions 31 and 32, the intervals between the land portions 33 and 34, and the intervals between the land portions 35 and 36 are the intervals between the electrodes of the chip component 41, the interval between the electrodes of the dummy chip component 51 shown in FIG. The distance between the electrodes of the dummy chip component 52 is substantially equal to each other.

  Since the printed circuit board 1 is configured as shown in FIG. 1, the chip component 41 and the dummy chip components 51 and 52 can be arranged as shown in FIG. FIG. 2 is a top view and a cross-sectional view conceptually showing a state in which chip components are mounted on the printed circuit board according to the first embodiment.

  In FIG. 2, a chip component 41 is an electrical functional element such as a thermistor capable of detecting the temperature of a laser accompanied by heat generation, and the output as the element is sent to a control device (not shown) via wirings 21 and 22. Communicated. The size of the vertical and horizontal height is, for example, 1.0 [mm] × 0.5 [mm] × 0.5 [mm]. This size may vary with advances in miniaturization technology.

  The dummy chip components 51 and 52 may have the same outer shape as the chip component 41, but the height in the Z direction is preferably higher than that of the chip component 41 from the viewpoint of the protection function. As long as the electrical function and the mechanical strength can be ensured, it is not necessary to be the same as the chip component 41.

  Then, two electrodes (not shown) provided on the bottom surface of the chip component 41 are soldered to the land portions 31 and 32, respectively. Similarly, the dummy chips 51 and 52 are soldered with the electrodes and the corresponding land portions.

  The manner in which the jig 61 is pressed against the chip component 41 mounted as shown in FIG. 2 will be described with reference to FIG. FIG. 3 is a top view conceptually showing how the jig is pressed against the chip component mounted on the printed board according to the first embodiment.

  In FIG. 3, the jig 61 is an example of an “object to which an external force is applied” according to the present invention, and is, for example, tweezers used in an assembly process, and presses the mounted chip component 41 to apply an external force. Therefore, it becomes a factor that peels off the mounted chip component 41.

  The width w <b> 2 is the width of the jig 61 and is a value that naturally changes depending on the type of the jig 61. When the jig 61 is tweezers, for example, the width w2 of the jig 61 is 2.0 [mm].

  The interval w1 is the interval between the dummy chip components 51 and 52. When the dummy chip components 51 and 52 are mounted facing each other so as to sandwich the chip component 41 to be mounted, the chip component of the jig 61 is used. It is the course width to 41.

  Particularly in the present embodiment, the mechanical strength of the chip component 41 to be mounted has anisotropy. Here, it is assumed that at least mechanical strength is applied to the chip component 41 to be mounted by a jig 61 from a relatively weak direction. At this time, if it is left unprotected, the chip component 41 to be mounted may be peeled off. Therefore, dummy chip components 51 and 52 are mounted so as to disperse the external force.

  More specifically, the chip component 41 is soldered at two points, and regarding the mechanical strength of the chip component 41 to be mounted, the direction along the straight line connecting the two points (that is, the chip component 41 of the chip component 41). It is considered that the strength in the direction intersecting with the straight line connecting the two points (that is, the short side direction of the chip component 41) is weaker than the strength in the long side direction).

  Therefore, the dummy chip components 51 and 52 are mounted facing each other so as to sandwich the chip component 41 to be mounted so as to disperse the external force applied from the short side direction of the chip component 41. Therefore, even if the jig 61 enters the chip component 41 from the Y-axis direction, the external force by the jig 61 can be dispersed not only by the chip component 41 but also by the dummy chip components 51 and 52. .

  In addition, at this time, in the short side direction of the chip component 41, the end surfaces of the dummy chip components 51 and 52 are positioned closer to the jig 61 that applies external force than the end surface of the chip component 41. Therefore, even if the jig 61 enters the chip component 41 from the Y-axis direction, it reaches the end surfaces of the dummy chip components 51 and 52 before the end surface of the chip component 41. That is, it is difficult for an external force to be directly applied to the chip component 41, and the possibility that the chip component 41 is peeled off is further reduced.

  In addition, in addition to the mechanical strength of the chip component 41 to be mounted, if the mechanical strength of the dummy chip components 51 and 52 to be mounted is also anisotropic, the chip component 41 to be mounted The direction in which the mechanical strength is relatively weak (that is, the short side direction of the chip component 41) and the direction in which the mechanical strength related to the mounted dummy chip components 51 and 52 is relatively strong (that is, the dummy chip component). The dummy chip components 51 and 52 are mounted so that the long side directions of the 51 and 52 are along each other. Therefore, the weak point on the mechanical strength of the chip component 41 to be mounted can be effectively supplemented.

  In addition, the interval w1 between the dummy chip components 51 and 52 is smaller than the width w2 of the jig 61 for applying an external force. Accordingly, since the jig 61 is prevented from entering, the possibility that the chip component 41 is peeled is further reduced.

  In addition, the chip component 41 typically does not have a terminal, and is directly attached to the land portions 31 and 32 by solder. However, according to the present embodiment, since the dummy chip parts 51 and 52 are further provided around the chip part 41, it is possible to truly enjoy the benefit of improving the mechanical strength of the chip part 41.

  As described above, according to the printed circuit board 1 according to this embodiment, since the dummy chip components 51 and 52 are provided, the mechanical strength of the mounted chip component 41 can be preferably improved.

(2) Second Example The configuration of a printed circuit board according to a second example and the operation and effect thereof will be described with reference to FIGS. FIG. 4 is a top view conceptually showing the basic structure of the printed circuit board according to the second embodiment. FIG. 5 is a top view and a cross-sectional view conceptually showing a state in which chip components are mounted on a printed circuit board according to the second embodiment. In addition, the same code | symbol is attached | subjected to the same thing as the structure included in the already demonstrated figure, and the description is abbreviate | omitted suitably.

  4 and 5, the wiring 23 is an example of the “connecting unit” according to the present invention, and electrically connects the dummy chip components 51 and 52 to be mounted. Therefore, it is possible to avoid the so-called electrically floating state of the dummy chip parts 53 and 54 to be mounted and the land portions 33, 34, 35 and 36 for mounting these dummy chip parts.

  In addition, the wiring 24 and the ground 7 are examples of the “grounding means” according to the present invention. Specifically, the dummy chip parts 53 and 54 connected by the wiring 23 and the land portions 33, 34, 35 and 36 for mounting these dummy chip parts are connected to the ground 7, that is, the reference voltage or the ground by the wiring 24. Grounded. Therefore, electrical stabilization can be further achieved.

  The dummy chip parts 53 and 54 are examples of the “dummy chip parts” according to the present invention, and are conductors having a resistance value lower than a predetermined resistance value. This resistance value is typically 0 [Ω]. Therefore, it not only protects the chip component 41 but also functions as a jumper that jumps over the wiring 21 and electrically connects the wiring 23 and the wiring 24, which is very convenient in practice.

  As described above, according to the printed circuit board 1 according to the present embodiment, the wiring 23, the wiring 24, the ground 7, and the dummy chip parts 53 and 54 are provided. It is possible to suitably improve the mechanical strength.

(3) Third Example A configuration of a printed circuit board according to a third example and its function and effect will be described with reference to FIG. FIG. 6 is a top view conceptually showing how the jig is pressed against the chip component mounted on the printed board according to the third embodiment. In addition, the same code | symbol is attached | subjected to the same thing as the structure included in the already demonstrated figure, and the description is abbreviate | omitted suitably.

  In FIG. 6, dummy chip components 55 and 56 are mounted at substantially intermediate positions in the X-axis direction of the dummy chip components 53 and 54, and wirings 231, 232, and 233 are mounted to electrically connect them. ing. At this time, the interval w3 between the dummy chip components 54 and 56 is narrower than the interval w1 shown in FIG. Therefore, the entry of the jig 62 having a width smaller than that of the jig 61 shown in FIG. 3 (that is, the width w2 of the jig 61> the width w4 of the jig 62) can be suitably prevented.

  As mentioned above, according to the printed circuit board 1 which concerns on a present Example, various shapes and arrangement | positioning of a dummy chip component are assumed, and it can enjoy various accompanying benefits in connection with it.

  That is, the present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit or idea of the invention that can be read from the claims and the entire specification. The substrate is also included in the technical scope of the present invention.

It is a top view which shows notionally the basic composition of the printed circuit board based on 1st Example of this invention. It is the upper side figure and sectional view which show notionally a mode that a chip component is mounted in the printed circuit board based on 1st Example. It is a top view which shows notionally a mode that a jig | tool is pressed with respect to the chip component mounted in a printed circuit board based on 1st Example. It is a top view which shows notionally the basic composition of the printed circuit board based on 2nd Example. It is the top view and sectional drawing which show notionally a mode that a chip component is mounted in the printed circuit board based on 2nd Example. It is a top view which shows notionally a mode that a jig | tool is pressed with respect to the chip component mounted in a printed circuit board based on 3rd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printed circuit board 11 Board | substrate part 21,22 Wiring 31,32,33,34,35,36 Land part 41 Chip component 51,52 Dummy chip component 61 Jig w2 Jig 61 width w1 Dummy chip components 51,52 space | interval 23, 24 Wiring 7 Ground 53, 54 Dummy chip 55, 56 Dummy chip parts 231, 232, 233 Wiring 62 Jig w3 Dummy chip parts 54, 56 interval w4 Jig 62 width

Claims (9)

A printed circuit board for mounting chip components,
The mechanical strength of the mounted chip component is anisotropic,
One or a plurality of dummy chip components mounted so as to disperse an external force applied at least from a direction in which the mechanical strength is relatively weak with respect to the mounted chip components. substrate. The printed circuit board according to claim 1, wherein the plurality of dummy chip components are mounted to face each other so as to sandwich the mounted chip component. In the direction in which the mechanical strength of the mounted chip component is relatively weak, the end surface of the dummy chip component is positioned closer to the object to which the external force is applied than the end surface of the chip component. The printed circuit board according to claim 2. In addition to the mechanical strength of the mounted chip component, the mechanical strength of the mounted dummy chip component also has anisotropy,
A direction in which the mechanical strength of the mounted chip component is relatively weak,
The direction in which the mechanical strength of the mounted dummy chip component is relatively strong,
The printed circuit board according to claim 2, wherein the dummy chip parts are mounted along each other. The printed circuit board according to claim 2, wherein an interval between the plurality of mounted dummy chip components is smaller than a width of an object to which the external force is applied. 6. The printed circuit board according to claim 1, further comprising a connection unit that electrically connects at least one set of the plurality of mounted dummy chip components. 7. The printed circuit board according to claim 6, further comprising a grounding unit that grounds at least one set of the connected units. The printed circuit board according to claim 7, wherein the dummy chip component is a conductor having a resistance value lower than a predetermined resistance value. The printed circuit board according to claim 1, wherein the chip component is mounted directly on the printed circuit board.

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