JP4501668B2 - Surface mounting structure of parts - Google Patents

Description

  The present invention relates to a surface mount structure in which components of different sizes are arranged adjacent to each other on a circuit board.

  As shown in the plan view of FIG. 11, a large electronic component (circuit component) 1 such as a BGA (Ball-Grid-Array), CSP (Chip-Size-Package), or SOP (Small-Outline-Package), For example, a small chip component (circuit component) 2 such as a capacitor component or a coil component may be disposed adjacent to the surface of the circuit board 3.

JP 2002-271096 A JP 2003-347713 A

  When circuit components are arranged adjacent to the circuit board, the setting interval between the adjacently arranged components is the variation in component size due to the manufacturing accuracy of the components, and the components are transported and mounted on the circuit board. The interval takes into account the variation of the component mounting position due to the mounting position accuracy of the component mounting machine. For example, BGA, which is a large component, has an outer dimensional tolerance of about ± 0.2 mm, a small chip component has an outer dimensional tolerance of about ± 0.05 mm, and the mounting position accuracy of the component mounting machine is about 0.05 mm. Therefore, the BGA and the chip component are usually designed to be adjacently arranged with an interval of 0.3 mm or more. As shown in FIG. 11, when a plurality of small chip components 2 are arranged so as to surround the periphery of the BGA (large component) 1, a width of, for example, 0.3 mm or more is always required around the large component 1. A dead space S having d is generated. Since the dead space S reduces the component mounting density of the circuit board, it becomes a cause of hindering miniaturization of the circuit board.

  Incidentally, among the small chip components 2, there is a both-end fixed type component as shown in FIG. That is, land patterns 5 (5A and 5B) for joining small components are formed on the circuit board portions facing the both ends of the chip component 2, respectively. The portions are bonded to the corresponding land patterns 5 (5A, 5B) for bonding small parts by a bonding material 4 such as solder and are surface-mounted on the circuit board 3.

  After such a chip component 2 is placed on the circuit board 3 via the bonding material 4 as shown in FIG. 12A, the bonding material 4 is melted by heating in the reflow process, thereby causing the chip component 2 to move as shown in FIG. As shown in FIG. 13B, the bonding material 4 is bonded and fixed to the circuit board 3, but the both-end-fixed type chip component 2 has a mounting defect due to the tombstone phenomenon as shown in FIG. May occur. The tomb storm phenomenon is a phenomenon in which the chip component 2 is rotated and inverted with one end side as a fulcrum in the reflow process, and is considered to occur as follows. That is, due to the heating in the reflow process, the bonding material 4 on the one end side 2a of the chip component 2 is melted, whereas the bonding material 4 on the other end side 2b of the chip component 2 is not melted. 13A, when the unmelted bonding material 4 and the other end side 2b of the chip component 2 are not bonded, a part of the molten bonding material 4 is a chip. As a result of climbing to the end surface 2a of the component 2 and pulling the end surface 2a of the chip component 2 to the bonding material 4 by the surface tension of the bonding material 4, the other end side 2b of the chip component 2 is lifted, and FIG. As shown in FIG. 2, the chip component 2 is turned upside down with the one end side 2a as a fulcrum.

  The present invention has been made to solve the above-described problems, and the object thereof is to reduce the size of the circuit board and to suppress the occurrence of the tombstorm phenomenon in the component mounting process. The object is to provide a surface mounting structure of a component.

In order to achieve the above object, the present invention has the following configuration as means for solving the above problems. That is, the present invention is a surface mounting structure of a component having a configuration in which components of different sizes are adjacently mounted on a circuit board, and includes a larger component and a smaller component which are arranged adjacent to each other. The circuit board surface portion on which the smaller one of the components is surface-mounted has an end on the side adjacent to the larger component of the smaller component and the larger on the opposite side facing the end . Separate land patterns for joining small parts are formed on the both ends of the part away from the part, and the smaller part is joined to the small part corresponding to the both ends by the joining material. The land pattern on the side closer to the larger part of the land patterns for joining small parts on both ends of the smaller part is bonded to the land pattern for mounting on the circuit board. Is formed to extend from the arrangement area of the smaller part toward the arrangement area of the larger part, and the extension tip side is formed so as to enter the arrangement area of the larger part, or the land The extended tip side of the pattern is formed in contact with or close to the arrangement area of the larger part, and the end of the smaller part adjacent to the larger part and the larger part The distance between adjacent ones is smaller than the surface tension of the bonding material in a state where the bonding material on the land pattern for bonding a small component that is extended toward the arrangement region of the larger component is melted. or a narrow gap to prevent the generation of parts stop engaged with the larger part of the rotary inverted minor components due to is attracted to the larger component side of the tombstone phenomenon, or small It is characterized in that square components is in contact towards parts large.

Further, the present invention is a surface mounting structure of a component having a configuration in which components of different sizes are adjacently mounted on the surface of a circuit board, and includes a larger component and a smaller component arranged adjacent to each other. On the circuit board surface where the smaller one of the components is surface-mounted, a separate land pattern for joining small components is formed at both ends of the smaller component in the direction along the larger component. The smaller component has a structure in which both end portions are bonded to the corresponding land pattern for small component bonding by the bonding material and are surface-mounted on the circuit board. Both end portions of the smaller component Each of the land patterns for joining a small part corresponding to each is formed to extend from the smaller part placement area to the larger part placement area, and the extension tip side is larger. Or it is formed enters the arrangement region of the part, or are formed against or in proximity to the arrangement region towards parts of large extension distal end side of the land pattern, the larger the smaller parts The distance between adjacent surfaces of the larger part and the larger part is smaller than the surface tension of the bonding material when the bonding material on the land pattern for bonding small parts is melted. It is a narrow interval to prevent the occurrence of tombstone phenomenon by locking the larger part over to the larger part and stopping it due to being drawn to the larger part side, or the smaller part Another feature is that the part is in contact with the larger part.

Further, the present invention is a surface mounting structure of a component having a configuration in which components of different sizes are adjacently mounted on a circuit board, and includes a larger component and a smaller component arranged adjacent to each other. On the circuit board surface where the smaller component is surface-mounted, separate land patterns for joining small components are formed corresponding to the terminals provided on the smaller component, respectively. The smaller component has a structure in which each terminal is bonded to a corresponding small component land pattern by a bonding material and is surface-mounted on a circuit board. A plurality of components corresponding to each terminal of the smaller component The land pattern closest to the larger part of the land patterns for joining small parts is extended from the arrangement area of the smaller part toward the arrangement area of the larger part. The extension tip side is formed so as to enter the larger component arrangement region, or the land pattern extension tip side is formed in contact with or close to the larger component arrangement region, which is small. The space adjacent to the larger component on the side closest to the larger component of the larger component and the larger component are extended toward the arrangement region of the larger component. The smaller part is attracted to the larger part due to the surface tension of the joining material when the joining material on the land pattern for joining small parts is melted. or a narrow gap to prevent the occurrence of tombstoning phenomenon stop engaged towards parts of large inclination, or, have a well characterized that in contact with the smaller towards parts of the component is large .

  According to the present invention, in the circuit board surface portion on which the smaller component (circuit component such as an electric component or an electronic component) of the larger component and the smaller component arranged adjacent to each other is surface-mounted, Separate land patterns for joining small parts are formed at both ends of the smaller part adjacent to the larger part and the opposite end facing the end. Of the smaller part, the land pattern on the side closer to the larger part of the land patterns for joining small parts on both ends of the smaller part extends toward the larger part's placement area. The following effects can be obtained because of the configuration described above.

  For example, taking into account the component size variation due to the manufacturing accuracy of each of the larger component and the smaller component that are arranged adjacent to each other, the component mounting position variation by the component mounting machine, etc., the larger component And by mounting a smaller component on the circuit board surface with a gap between them and then melting a bonding material such as solder interposed between the component and the land pattern in a reflow process. The smaller component can be displaced closer to the larger component and the smaller component can be placed closer to the larger component. In other words, the land pattern on the side closer to the larger part of the land patterns for joining small parts on both ends of the smaller part is extended toward the larger part. Due to the surface tension of the molten bonding material on the land pattern on the side close to the part, it is possible to draw the smaller part closer to the larger part. For this reason, even if the mounting position of the smaller part with respect to the larger part is the same as the conventional mounting position, the melting on the land pattern for joining the small part that is extended toward the larger part is performed in the reflow process. Depending on the surface tension of the bonding material in the state, the smaller part can be displaced in the direction approaching the larger part, and the distance between the smaller part and the larger part should be narrower than before. Can do. That is, the dead space between the smaller part and the larger part can be reduced. Thereby, it becomes easy to reduce the size of the circuit board.

  Also, the land pattern for joining small parts on the side closer to the larger part has a larger area than the land pattern for joining small parts on the side farther from the larger part. Make the bonding material formation area on the land pattern for joining small parts closer to the part larger than the formation area of the joining material on the land pattern for joining small parts away from the larger part. Can do. As a result, the surface tension of the bonding material in the molten state on the land pattern for joining small parts on the side closer to the larger part is melted on the land pattern for joining small parts on the side away from the larger part. The surface tension of the bonding material in the molten state on the land pattern for bonding small parts closer to the larger part can be made stronger than the surface tension of the bonding material in the state, and the smaller part becomes the larger part. Therefore, the smaller component can be placed closer to the larger component.

  Further, in the circuit board surface portion on which the smaller component is surface-mounted, a separate land pattern for joining small components is formed at each end portion of the smaller component along the larger component. In this case, the land pattern for joining small parts corresponding to both end portions of the smaller part is provided with a configuration in which each of the land patterns extends toward the arrangement area of the larger part. For example, considering the component size variation due to the manufacturing accuracy of the larger component and the smaller component adjacent to each other and the variation in the component mounting position by the component mounting machine, the larger component After each component and the smaller component are mounted on the circuit board surface, the bonding material between the component and the land pattern is melted in the reflow process. And can be displaced toward the larger part of the smaller parts, the distance between the larger part of the smaller parts may be narrower than the prior art. That is, the dead space is reduced, and the circuit board can be easily downsized.

  Furthermore, even when a plurality of terminals are formed on the smaller component, the land pattern for joining small components individually corresponding to each terminal of the smaller component is closest to the larger component. By providing a structure in which the land pattern is extended toward the arrangement region of the larger part, the smaller part is changed to the larger part by the surface tension of the bonding material in the reflow process in the same manner as described above. It can be displaced and placed close to the larger component, and the dead space between the smaller component and the larger component can be reduced, and the circuit board can be reduced in size.

  Further, according to the present invention, the distance between the larger part and the smaller part is smaller than the surface tension of the joining material when the joining material on the land pattern for joining the small parts is melted. This is a narrow interval that prevents the rotation of the smaller component from being turned over, overturning, or tilting due to the component being pulled toward the larger component. In other words, since the interval between the larger component and the smaller component is a narrow interval that can prevent the occurrence of the tomb storm phenomenon, mounting failure of the smaller component due to the tomb storm phenomenon occurs. Can be suppressed.

  Furthermore, in the formation area of the land pattern for joining small parts that is extended toward the arrangement area of the larger part, it enters the part closer to the larger part or the arrangement area of the larger part. In the reflow process, the surface tension of the bonding material in the molten state on the land pattern for joining small parts is added to the melted state formed in the through hole. Since the surface tension of the conductive material is increased and the surface tension is enhanced, and the smaller part can be drawn with the increased surface tension, the smaller part is brought closer to the larger part and surface mounted. Thus, the circuit board can be further reduced in size.

  In the case where a plurality of smaller parts are arranged so as to surround the periphery of the larger part, in the conventional structure, it is a dead dead so as to surround the periphery of the larger part. Whereas there is space, by providing a configuration unique to the present invention, it is possible to effectively reduce the dead space around the larger component.

  Embodiments according to the present invention will be described below with reference to the drawings. In the description of this embodiment, the same components as those in the conventional example are denoted by the same reference numerals, and duplicate descriptions of the common portions are omitted.

  FIG. 1 is a schematic plan view showing the surface mounting structure of a component according to the first embodiment. In the surface mounting structure of the component according to the first embodiment, a large circuit component 1 such as a large plastic package component (for example, BGA, CSP, SOP) is surface-mounted on the circuit board 3, and the large component 1 A plurality of small chip components (for example, circuit components such as capacitor components, coil components, and filter components) 2 are surface-mounted on a circuit board 3 so as to surround the periphery of the circuit board 3.

  In the first embodiment, as shown in the enlarged plan view of the chip component placement region in FIGS. 2A to 2C, the chip component (that is, the larger component 1 adjacent to the chip component is small). On the circuit board surface portion on which the smaller one of the two components 2 is surface-mounted, both end portions of the chip component 2 (in other words, the large component 1 (the larger component adjacently disposed) 1 and 2 (the larger part of the smaller parts 2) and the opposite end 2B opposite to the end 2A, both ends 2A and 2B. Are formed with separate land patterns 8 (8A, 8B) for joining small components. Of these land patterns 8A and 8B for joining small parts, the land pattern 8A closer to the large part 1 is formed to extend toward the area where the large part 1 is disposed. In the first embodiment, the land pattern 8A is extended. As shown in FIG. 2 (a), the distal end side is formed so as to enter the arrangement area of the large component 1, or as shown in FIG. 2 (b), the extended distal end side is provided with the large component 1. It is formed in contact with the region, or, as shown in FIG.

  Further, the land pattern 8A on the side close to the large-sized component 1 has a point S formed on the side opposite to the extension forming side as described above. Further, in the first embodiment, the land pattern 8A on the side close to the large component 1 has a larger area than the land pattern 8B on the side remote from the large component 1, and the bonding material on the land pattern 8A 4 is wider than the formation area of the bonding material 4 on the land pattern 8B. Note that all of the land patterns 8A corresponding to the respective chip components 2 arranged so as to surround the large component 1 may have the same form, or one or more of all the chip components 2 may be formed. The land pattern 8A corresponding to the predetermined chip component 2 is formed in the form shown in FIG. 2A, for example, and the rest is formed in the form shown in FIG. It does not have to be a form.

  The chip component 2 is surface-mounted on the circuit board 3 by bonding both end portions thereof to the corresponding land patterns 8A and 8B with a bonding material such as solder. In the first embodiment, the distance d between the large component 1 and the chip component 2 is narrow enough to avoid the occurrence of the tombstorm phenomenon during the component mounting process as described below.

  For example, in the step of surface mounting the chip component 2 on the circuit board 3, as shown in FIG. 3A, the circuit board 3 on which the land patterns 8A and 8B are formed is prepared. In the circuit board 3, respective conveyance areas for the large component 1 and the chip component 2 are determined in advance. The distance between the transfer area of the large component 1 and the transfer area of the chip component 2 takes into account variations in the outer size due to the manufacturing accuracy of the large component 1 and the chip component 2 and the mounting position accuracy of the component mounting machine. However, the intervals are as narrow as possible. Both land patterns 8A and 8B for joining small components are formed in the conveyance area of each chip component 2 set as described above.

  A chip component 2 is conveyed to a set conveyance area on the circuit board 3 as described above by using a component mounting machine, and the chip component 2 is formed into a land pattern as shown in FIG. It mounts on 8A and 8B through the bonding material 4. FIG. 4A is a plan view showing an example of the positional relationship between the chip component 2 and the land pattern 8 (8A, 8B) at this time. In the first embodiment, when the chip component 2 is transported and placed in the transport region set on the circuit board 3, one end of the chip component 2 is placed on the pointed portion S in the land pattern 8A on the side close to the large component 1. The land pattern 8A is formed so that the sides are overlapped.

  Thereafter, the circuit board 3 on which the large component 1 and the chip component 2 are placed is passed through a reflow furnace. Thereby, the bonding material 4 is heated and melted. In the first embodiment, the formation area of the bonding material 4 on the land pattern 8A on the side close to the large component 1 is larger than the formation area of the bonding material 4 on the land pattern 8B on the side remote from the large component 1. Because of the wide configuration, the bonding material 4 on the land pattern 8A has a higher surface tension in the molten state than the bonding material 4 on the land pattern 8B. For this reason, when the bonding material 4 is in a molten state in the reflow process, as shown in FIGS. 3B and 4B, the molten state on the land pattern 8A on the side close to the large component 1 is obtained. Due to the surface tension of the bonding material 4, the chip component 2 is attracted in a direction approaching the large component 1.

  Thus, when the chip component 2 is displaced by the surface tension of the bonding material 4, a tomb storm phenomenon is likely to occur. In this first embodiment, the distance between the large component 1 and the chip component 2. When the chip component 2 is drawn to the large component 1 side due to the surface tension of the molten bonding material 4, the large component 1 side of the chip component 2 is shown in the model diagram of FIG. Even if it is going to rotate upside down around the end 2A of the chip, the end surface of the chip component 2 on the large component 1 side is locked to the side surface of the large component 1 so that a tomstorm phenomenon can be prevented from occurring. . Thereby, the rotation inversion resulting from the tomb storm phenomenon of the chip component 2 is avoided, and the occurrence rate of mounting defects can be greatly reduced.

  When the bonding material 4 is disposed on the land patterns 8A and 8B for bonding small parts, the bonding material 4 may be formed on the entire surface of the land patterns 8A and 8B. In consideration of the self-alignment operation, the land patterns 8A and 8B may be formed only on predetermined portions. For example, the bonding material 4 may be partially formed on the land pattern 8A as shown in FIG. 4C, and the bonding material 4 may be formed on the entire surface of the land pattern 8B.

  In the first embodiment, the land pattern 8A on the side close to the large component 1 among the land patterns 8A and 8B for joining the small component on both ends of the chip component 2 is directed toward the area where the large component 1 is disposed. Therefore, the self-alignment in which the chip component 2 is drawn closer to the large component 1 by the surface tension of the molten bonding material 4 by heating on the land pattern 8A and placed close to the large component 1 is performed. Can be done. The land pattern 8B on the side far from the large component 1 may be bonded to the end portion 2B of the chip component 2 through the bonding material 4 in a state where the chip component 2 is arranged close to the large component 1 by such self-alignment. Therefore, the land pattern 8B far from the large component 1 is formed at a position closer to the large component 1 than the land pattern 5B far from the conventional large component 1 as shown in the model diagram of FIG. be able to. As described above, since the land pattern 8B can be formed close to the large component 1, an area effective for component mounting and pattern layout on the circuit board 3 can be increased.

  A gap of 50 μm or more is formed between the large component 1 and the circuit board 3 by, for example, solder balls. For this reason, as shown in the schematic cross-sectional view of FIG. 3B, the fillet of the bonding material 4 can be satisfactorily formed also in the land pattern 8 </ b> A portion that has entered the arrangement region of the large component 1. it can.

  The second embodiment will be described below. In the description of the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and duplicate descriptions of common portions are omitted.

  In the second embodiment, as shown in FIG. 7A, the chip component 2 is disposed on the circuit board 3 in the region where the chip component 2 extends along the two end portions 2 </ b> A and 2 </ b> B in the direction along the large component 1. In addition, land patterns 10 (10A, 10B) for joining small parts are formed. Each of the land patterns 10A and 10B is formed to extend from the arrangement region of the chip component 2 toward the large component 1. In addition, in the example shown in FIG. 7, the extension tip side of each of the land patterns 10A and 10B is formed so as to enter the arrangement area of the large-sized component 1, but the extension is the same as in the first embodiment. The front end side is formed in contact with the arrangement area of the large-sized component 1 instead of entering the arrangement area of the large-sized component 1 or is disposed close to the arrangement area of the large-sized component 1. It is good also as a structure.

  In the second embodiment, the land patterns 10A and 10B are configured to extend from the arrangement area of the chip component 2 toward the arrangement area of the large-size component 1, and thus the first embodiment example. Similarly to the above, in the step of surface mounting the chip component 2 on the circuit board 3, after the chip component 2 is mounted at a predetermined mounting position as shown in FIG. It is possible to perform self-alignment in which the chip component 2 is drawn toward the large component 1 side by the surface tension of the bonding material 4 in the molten state. During the self-alignment operation, as shown in the model diagram of FIG. 8, the molten bonding material 4 crawls up from the bottom surface side to the side surface of the chip component 2, and the side surface of the chip component 2 is caused by the surface tension of the bonding material 4. In this second embodiment, the distance between the large component 1 and the chip component 2 is such that the side surface of the chip component 2 is large even if the chip component 2 is about to roll over to the large component 1 side. The gap is narrow so that it can be locked to the side surface of the component 1 to prevent the chip component 2 from rolling over.

  Configurations other than those described above are the same as in the first embodiment.

  The third embodiment will be described below. In the description of the third embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals, and duplicate descriptions of the common portions are omitted.

  In the third embodiment, in addition to the configurations of the first and second embodiments, land patterns 8A and 10 (10A, 10B) for joining small components that are extended toward the large component 1 are formed. 9 (a) and 9 (b), a through hole 12 is formed near the large component as shown by the solid line, or the large component 1 is disposed as shown by the dotted line. A through hole 12 is formed in the protruding portion.

  The fourth embodiment will be described below. In the description of the fourth embodiment, the same components as those in the first to third embodiments are denoted by the same reference numerals, and duplicate descriptions of the common portions are omitted.

  In the fourth embodiment, an example of the surface mounting structure of a component when a three-terminal type chip component 2 as shown in the model diagram of FIG. In the fourth embodiment, the circuit board 3 is connected to a separate small component corresponding to the arrangement position of each terminal 13 (13A to 13C) provided in the three-terminal type chip component 2. Land patterns 14 (14A to 14C) are formed. Among these land patterns 14A to 14C, at least the land pattern 14B closest to the large-sized component 1 is formed to extend toward the large-sized component 1, and the extended tip side is arranged as shown in FIG. It is formed so as to enter the region, is formed in contact with the region where the large component 1 is disposed, or is formed close to the region where the large component 1 is disposed.

  Also in the fourth embodiment, like the first to third embodiments, after the chip component 2 is mounted on the setting mounting position of the circuit board 3 by the mounting machine, the bonding material 4 is applied in the reflow process. By melting, the chip component 2 is drawn toward the large component 1 by the surface tension of the bonding material 4. In the fourth embodiment, the distance between the large component 1 and the chip component 2 is a narrow interval that can prevent the occurrence of the tomb storm phenomenon when the chip component 2 is pulled toward the large component 1 in this way. Yes.

  In addition, this invention is not limited to the form of each 1st-4th embodiment, Various embodiment can be taken. For example, the shape of the land patterns 8, 10, and 14 for small component bonding is not limited to the illustrated example, and the self-alignment operation of the chip component 2 by the surface tension of the bonding material 4 on the land pattern or bonding Considering the bonding strength of the material 4 to the chip component 2 and the like, the shape and size may be appropriate.

  In each of the first to third embodiments, the example in which the plurality of chip components 2 arranged adjacent to the periphery of the large component 1 are all fixed at both ends is shown. Furthermore, both-end-fixed type chip parts 2 and multi-terminal type chip parts 2 having three or more terminals as shown in the fourth embodiment, for example, are mixedly arranged around the large-sized part 1. Even in such a case, the dead space around the large component 1 can be reduced by applying the configuration of the present invention, and the chip component 2 around the large component 1 is caused by the tomb storm phenomenon. Mounting defects can be reduced.

  Furthermore, although the example in which the plurality of chip parts 2 are arranged so as to surround the periphery of the large-sized part 1 has been shown, the large-sized part is also provided when the chip part 2 is not disposed so as to surround the periphery of the large-sized part 1. If 1 and the chip component 2 are adjacently arranged, the present invention can be applied.

  Further, in each of the first to fourth embodiments, a minute gap is formed between the large component 1 and the chip component 2. For example, the surface of the bonding material 4 in a molten state is used. The chip component 2 may be attracted to the large component 1 by tension and the chip component 2 may be in contact with the large component 1.

  Furthermore, in the fourth embodiment, the three-terminal type chip component 2 has been described as an example. However, even when the multi-terminal type chip component 2 having four or more terminals is disposed adjacent to the large component 1, By applying the configuration of the embodiment, it is possible to construct a surface mounting structure of a component that can obtain the same effect as described above. Furthermore, in addition to the configuration of the fourth embodiment, a through hole is formed in a portion near the large component 1 or a portion entering the large component 1 in the land pattern extended toward the arrangement region of the large component 1. It may be provided.

It is a typical top view showing surface mounting structure of parts of the example of the 1st embodiment. It is a figure for demonstrating the form example of the land pattern for small component joining which comprises the surface mounting structure of the component of 1st Embodiment. It is a figure for demonstrating an example of the process of carrying out the surface mounting of the chip components which comprise 1st Embodiment in a circuit board. FIG. 4 is a view for explaining an example of a process of surface-mounting the chip component constituting the first embodiment on a circuit board together with FIG. 3. It is a figure for demonstrating one of the effects acquired from the structure of 1st Embodiment. It is a figure for demonstrating another effect obtained from the structure of the example of 1st Embodiment. It is a figure for demonstrating the surface mounting structure of the components of the example of 2nd Embodiment. It is a figure for demonstrating one of the effects acquired from the structure of 2nd Embodiment. It is a figure for demonstrating the example of 3rd Embodiment. It is a figure for demonstrating the example of 4th Embodiment. It is a figure for demonstrating one prior art example of the surface mounting structure of components. It is a figure for demonstrating an example of the process of surface-mounting components on a circuit board. It is a figure for demonstrating a tombstorm phenomenon.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Large component 2 Chip component 3 Circuit board 4 Bonding material 8, 10, 14 Land pattern for small component bonding

Claims (6)

A surface-mount structure of a component having a configuration in which components of different sizes are adjacently mounted on a circuit board, and the smaller one of a larger component and a smaller component adjacent to each other On the circuit board surface portion where the component is surface-mounted, the end of the smaller component adjacent to the larger component and the end away from the larger component on the opposite side facing the end The land pattern for joining small parts is formed in the part on both end sides with the part, and the smaller part is joined to the land pattern for joining small parts corresponding to each end part by the joining material. The land pattern on the side close to the larger part of the land patterns for joining small parts on both ends of the smaller part is the surface part of the smaller part. It is formed so as to extend from the installation area toward the arrangement area of the larger part, and the extension tip side is formed so as to enter the arrangement area of the larger part, or the extension tip side of the land pattern is larger. is formed by or in proximity to contact the arrangement region of the component, and the ends of adjacent to the larger part of the smaller part of the side, each other adjacent distance between the larger part of the larger In the state where the bonding material on the land pattern for bonding small parts that is formed to extend toward the part mounting area is melted, the smaller part is closer to the larger part. or a narrow gap to prevent the occurrence of attraction is greater towards the tombstone phenomenon stop engaged with the part of the rotation inverted towards parts of small due to, or, the smaller part towards the large Surface mounting structure of the component, characterized in that in contact with the goods.   2. The component according to claim 1, wherein the land pattern for joining small components closer to the larger component has a larger area than the land pattern for joining smaller components on the side farther from the larger component. Surface mount structure. A surface-mount structure of a component having a configuration in which components of different sizes are adjacently mounted on a circuit board, and the smaller one of a larger component and a smaller component adjacent to each other On the surface of the circuit board where the components are surface-mounted, separate land patterns for joining small components are formed on both ends of the smaller component along the larger component. These parts are configured to be mounted on the surface of the circuit board by bonding their both ends to the corresponding land pattern for bonding small parts by the bonding material, and the small parts corresponding to both ends of the smaller part respectively. Each of the bonding land patterns is formed to extend from the arrangement area of the smaller part toward the arrangement area of the larger part, and the extension tip side thereof is arranged in the arrangement area of the larger part. Or it is formed of silicon, or its being formed or in proximity to contact with arrangement region of the part of the extension tip towards the side is larger land pattern, the side along the larger part of the smaller parts and surface, the mutually adjacent spacing between the larger parts, towards parts of the smaller parts of the surface tension of the bonding material in a state where the bonding material on the land pattern for small component bonding is melted is greater Narrow spacing to prevent the occurrence of tombstone phenomenon by locking the roll-over of the smaller part caused by being pulled to the side to the larger part , or the smaller part is larger A surface mounting structure of a component characterized by being in contact with the component. A surface-mount structure of a component having a configuration in which components of different sizes are adjacently mounted on a circuit board, and the smaller one of a larger component and a smaller component adjacent to each other On the circuit board surface portion where the component is surface-mounted, a separate land pattern for joining small components is formed corresponding to each of a plurality of terminals provided on the smaller component. Each terminal is bonded to a corresponding land pattern for small component bonding by a bonding material and is surface-mounted on a circuit board. For bonding a plurality of small components corresponding to each terminal of a smaller component The land pattern closest to the larger part of the land pattern is formed to extend from the area where the smaller part is arranged toward the area where the larger part is arranged, and the extension tip side is large. Or is formed enters the arrangement region of have how components, or its being formed or in proximity to contact with arrangement region of the part of the extension tip towards the side is larger land pattern, the smaller part of the The space between the surface facing the larger component on the side closest to the larger component and the larger component is adjacent to the larger component. The slope of the smaller part caused by the smaller part being pulled toward the larger part due to the surface tension of the joining material when the joining material on the land pattern for joining the parts is molten is larger. A surface mounting structure for a component, characterized in that it has a narrow interval to prevent the occurrence of a tombstone phenomenon by being locked to the component, or the smaller component is in contact with the larger component.   Land in the land pattern formation area for joining small parts extended toward the area where the larger parts are arranged. Enter the area closer to the larger parts or the area where the larger parts are arranged. The surface mounting structure for a component according to any one of claims 1 to 4, wherein a through hole is formed in the portion.   6. The component surface mounting structure according to claim 1, wherein a plurality of smaller components are arranged so as to surround the periphery of the larger component.

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