JP4923807B2 - PCB mounting structure - Google Patents

Description

  The present invention relates to a printed circuit board mounting structure in which two printed circuit boards facing each other are mounted in a casing.

For example, in a device that is gripped and used by hand, such as a handset of a telephone, there is a limit to increasing the volume in the handset, so that the external dimensions of the built-in printed circuit board are also limited. For this reason, it may not be possible to mount all components on one printed circuit board. In this case, the second printed circuit board is disposed so as to face the first printed circuit board. As the mounting structure of the second printed circuit board, a counterbore hole is provided in one printed circuit board, a through hole is provided in the other printed circuit board, and a positioning pin portion engaged with the counterbore hole is provided at one end. A spacer having a threaded portion at the other end is interposed between two printed circuit boards, and a screw having a through-hole inserted is screwed into the threaded part of the spacer so that the two printed circuit boards are opposed to each other. (See, for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-40914 (paragraphs [0010] to [0012], FIGS. 1 to 3)

  The conventional printed circuit board mounting structure described above has a structure in which a through hole for inserting a screw into the second printed circuit board is provided, so that components can be mounted and wired in the area where the through hole is provided. Therefore, there is a problem that the mounting space for components and the wiring space are reduced.

  The present invention has been made in view of the above-described conventional problems, and an object thereof is to provide a printed circuit board mounting structure in which a mounting space for components and a wiring space are increased.

In order to achieve this object, the present invention includes first and second printed circuit boards provided to face each other in a housing, and a spacer sandwiched between the printed circuit boards, and the first printed circuit board. In a printed circuit board mounting structure in which a substrate is attached to a housing and the second printed circuit board is supported on the first printed circuit board via the spacer, the spacer includes a pair of arm portions facing each other and the arm portions. And a first connecting part that connects the two, and the arm part is provided with elastic holding pieces opposed to each other for holding both side edges of the second printed circuit board , An engaging protrusion that engages with one end of the second printed circuit board is integrally provided on the upper surface of the first connecting portion, and the spacer is fastened to the first printed circuit board and the housing together. .

  According to the first aspect of the present invention, since the second printed circuit board is held by the elastic holding piece of the spacer, there is no need to provide a through hole for inserting a screw into the second printed circuit board. The mounting space and wiring space for components on the printed circuit board 2 can be increased. Moreover, since the number of insertion holes provided in the first printed circuit board can be minimized by fastening the spacer together with the first printed circuit board and the housing, the mounting space for components on the first printed circuit board can be reduced. And the wiring space can be increased.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a plan view showing a state in which a rear case of a handset to which a printed circuit board mounting structure according to the present invention is applied is removed, FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1, and FIG. Fig. 4 is a sectional view taken along the line IV-IV in Fig. 1, Fig. 5 is a sectional view taken along the line VV in Fig. 1, Fig. 6 shows the same spacer, and Fig. 6A is a perspective view seen from the top side. FIG. 7B is a perspective view seen from the bottom side, FIG. 7 shows the same spacer, FIG. 7A is a bottom view, FIG. 7B is a side view, and FIG. FIG. 4D is a plan view.

  4 is composed of a front case 2 and a rear case 3 both of which are formed in a shallow bottom, and the front ends of the front case 2 and the rear case 3 are open to each other. Both cases 2 and 3 are joined so as to be in contact with each other. As shown in FIG. 2, a microphone 6 is provided at one end of the front case 2 corresponding to the transmission hole 5, and a speaker 8 is provided at the other end corresponding to the reception hole 7. .

  Reference numeral 9 denotes a plurality of dial buttons slidably supported in the sliding holes of the front case 2, and reference numeral 10 denotes a plurality of function buttons slidably supported in the sliding holes of the front case 2. Reference numerals 11 and 12 denote studs provided integrally on the bottom of the front case 2, and a first printed circuit board 13 is attached to these studs 11 and 12 by screws 14 and 15.

  Next, a spacer is demonstrated using FIG. 6 and FIG. The spacer 17 is formed in a substantially U shape in plan view by a pair of arm portions 18, 18 facing each other and a first connecting portion 19 that connects the arm portions 18, 18. As shown in FIG. 6B, three pairs of convex portions 18 a that come into contact with the surface of the first printed circuit board 13 are integrally provided on the lower surfaces of the arm portions 18 and 18. Similarly, a pair of convex portions 19 a that are in contact with the surface of the first printed circuit board 13 are integrally projected on the lower surface of the first connecting portion 19.

  Further, as shown in FIG. 6A, a pair of convex portions 18b that come into contact with the surface of a second printed circuit board 23, which will be described later, are integrally projected on the upper surfaces of the arm portions 18, 18. Similarly, on the upper surface of the first connecting portion 19, a pair of convex portions 19 b that are in contact with the surface of the second printed circuit board 23 are integrally projected. In addition, a pair of engaging protrusions 19c and 19c that are engaged with one end 23a (see FIG. 2) of the second printed circuit board 23 are integrally provided on the upper surface of the first connecting portion 19.

  As shown in FIG. 6A, the arms 18 and 18 are provided with claws 20 a and 20 a that engage with both side edges of the second print 23 at the tip, and hold the second printed circuit board 23. A pair of elastic holding pieces 20, 20 facing each other are erected integrally. When the spacer 17 is attached to the front case 2 as will be described later, the elastic holding pieces 20 are engaged with the inner wall 2a of the front case 2 as shown in FIG. A rib 20b as an engaging portion for preventing the elastic deformation is integrally projected.

  Reference numeral 21 denotes a second connecting portion for connecting the central portions of the arm portions 18, 18, and the lower surface 21 a is longer than the lower surface 19 d of the first connecting portion 19 as shown in FIG. The upper surface 21 b is formed higher than the upper surface 19 e of the first connecting portion 19 by a length δ. That is, the thickness t of the second connecting portion 21 is such that the first and second printed circuit boards are mounted when the first and second printed circuit boards 13 and 23 are mounted in the handset 1 as will be described later. The surface of 13 and 23 is formed by the thickness which does not contact the upper surface of the 2nd connection part 21, and lower surface 21a, 21b.

  At both ends of the first connecting portion 19 of the spacer 17, as shown in FIG. 6A, support portions 22 and 22 having an insertion hole 22 a at the center are formed. As shown in FIG. 3B, a positioning convex portion 22b is provided around the insertion hole 22a on the back surface side of the support portion 22, and the positioning convex portion 22b is as shown in FIG. Is fitted into the insertion hole 13 a of the first printed circuit board 13.

  In FIG. 2, reference numeral 23 denotes a second printed circuit board on which a connector 25 that is electrically connected to a connector 24 mounted on the first printed circuit board 13 is mounted. Reference numeral 26 denotes a stud integrally provided upright at the bottom of the front case 2, and one end of the second printed circuit board 23 is attached to the stud 26 with a screw 27. In FIG. 3, reference numeral 28 denotes a stud that is integrally provided on the bottom of the front case 2, and the spacer 17 is fastened together with the first printed board 13 to the stud 28 by a fastening screw 29.

  Next, a method for mounting a printed circuit board in the printed circuit board mounting structure configured as described above will be described. First, the first printed circuit board 13 is attached to the studs 11 and 12 with screws 14 and 15 as shown in FIG. Next, the second printed circuit board 23 is lowered from above the spacer 17 shown in FIG. 6A, and the elastic holding pieces 20 and 20 are elastically deformed by the both side edges of the second printed circuit board 23 while the second printed circuit board 23 is elastically deformed. The printed circuit board 23 is placed on the arm portions 18 and 18.

  Both side edges of the second printed circuit board 23 placed on the arm portions 18, 18 are engaged with the claws 20 a, 20 a of the elastic holding piece 20 and are held by the spacer 17. In this state, the second printed circuit board 23 is slid on the arm portions 18, 18, and the one end 23 a is engaged with the engagement protrusion 19 c of the spacer 17, whereby the second printed circuit board 20 is against the spacer 17. Is positioned at a predetermined position.

  The connector 24 of the first printed circuit board 13 and the connector of the second printed circuit board 23 are fitted into the insertion holes 13a of the first printed circuit board 13 as shown in FIG. 25 is electrically connected, and the spacer 17 is placed on the first printed circuit board 13. This electrical connection is performed by providing the spacer 17 with a positioning convex portion 22b that fits into the insertion hole 13a of the first printed circuit board 13, so that the connector 24 and the second printed circuit board 13 of the first printed circuit board 13 are fitted. Since it can carry out in the state with which the board | substrate 23 and the connector 25 were positioned, workability | operativity improves.

  Further, by fitting the positioning convex portion 22b of the spacer 17 into the insertion hole 13a of the first printed circuit board 13, the second printed circuit board 23 is positioned at a predetermined position with respect to the spacer 17 as described above. Therefore, the second printed circuit board 23 is positioned with respect to the stud 26. For this reason, the work of attaching the second printed circuit board 23 to the stud 26 with the screw 27 is facilitated.

  Further, the spacer 17 and the first printed circuit board 13 are fastened to the stud 28 together with the fastening screw 29 as shown in FIG. Thus, by fastening the spacer 17 and the first printed circuit board 13 together with the stud 28, it is not necessary to provide a dedicated stud for attaching the spacer 17 to the front case 2. For this reason, by providing a dedicated stud, it becomes unnecessary to provide a hole or a notch in the first printed circuit board 13, thereby increasing the mounting space and wiring space for components on the first printed circuit board 13. Can be made.

  In this state, the arm portion 18 of the spacer 17 and the convex portions 18a and 19a of the first connecting portion 19 are in contact with the first printed circuit board 13, so that the entire surfaces of the arm portion 18 and the first connecting portion 19 are the first. No printed circuit board 13 is contacted. For this reason, since wiring can be provided or a component can be mounted in this non-contact region, the mounting space and wiring space for the component on the first printed circuit board 13 can be increased.

  Similarly, when the arm portion 18 of the spacer 17 and the convex portions 18b and 19b of the first connecting portion 19 are in contact with the second printed circuit board 23, the entire surfaces of the arm portion 18 and the first connecting portion 19 are second. The printed circuit board 23 is not touched. For this reason, since wiring can be provided in this non-contact area | region and components can be mounted, the mounting space and wiring space of the components in the 2nd printed circuit board 23 can be increased.

  Moreover, since the 2nd connection part 21 is formed so that it may not contact the surface of the 1st and 2nd printed circuit boards 13 and 23 mounted in the handset 1, wiring may be wired to this non-contact area | region. Since it can be provided or components can be mounted, the mounting space and wiring space of the components on the first and second printed boards 13 and 23 can be increased.

  Further, by attaching the spacer 17 to the front case 2, the rib 20 b of the elastic holding piece 20 is engaged with the inner wall 2 a of the front case 2 as shown in FIG. 4 to prevent elastic deformation of the elastic holding piece 20. The second printed circuit board 23 is prevented from falling off the spacer 17 due to impact or the like.

  In the present embodiment, the spacers 17 are provided with convex portions 18a, 18b, 19a, 19b that are in contact with both surfaces of the first and second printed circuit boards 13, 23, but if necessary, Alternatively, a convex portion that contacts one of the printed circuit boards may be provided, and it is not always necessary to provide the convex portion that contacts both surfaces of the first and second printed circuit boards 13 and 23.

It is a top view which shows the state which removed the rear case of the handset which applied the mounting structure of the printed circuit board which concerns on this invention. It is the II-II sectional view taken on the line in FIG. It is the III-III sectional view taken on the line in FIG. It is the IV-IV sectional view taken on the line in FIG. It is the VV sectional view taken on the line in FIG. The spacer in the mounting structure of the printed circuit board which concerns on this invention is shown, The figure (A) is the perspective view seen from the upper surface side, The figure (B) is the perspective view seen from the bottom face side. The spacer in the mounting structure of the printed circuit board which concerns on this invention is shown, The figure (A) is a bottom view, The figure (B) is a side view, The figure (C) is a rear view, The figure (D) is a top view. is there.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Handset, 2 ... Front case, 3 ... Rear case, 13 ... 1st printed circuit board, 17 ... Spacer, 18 ... Arm part, 18a, 18b, 19a, 19b ... Convex part, 19c ... Engagement protrusion, 19 DESCRIPTION OF SYMBOLS 1st connection part, 20 ... Elastic holding piece, 21 ... 2nd connection part, 23 ... 2nd printed circuit board, 29 ... Screw for co-fastening.

Claims (1)

A first printed circuit board and a second printed circuit board provided in the housing so as to face each other; a spacer sandwiched between the printed circuit boards; and the first printed circuit board is attached to the housing, and the second printed circuit board In a printed circuit board mounting structure for supporting a substrate on the first printed circuit board via the spacer,
The spacer is formed in a U shape in a plan view by a pair of arm portions facing each other and a first connecting portion that connects these arm portions, and each of the both side edges of the second printed circuit board is formed on the arm portion. The elastic holding pieces facing each other are erected , and an engaging protrusion for engaging one end of the second printed circuit board is integrally provided on the upper surface of the first connecting portion, and the spacer A printed circuit board mounting structure characterized by being fastened together with a first printed circuit board and a housing.

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