JP2914653B2 - Electronic device and printed circuit board fixing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device and a method for fixing a printed circuit board, and more particularly, to an electronic device equipped with a plurality of printed circuit boards on which electronic components are mounted, and integrating these printed circuit boards in a case. The present invention relates to a method of fixing a printed circuit board to be fixed.

[0002]

2. Description of the Related Art FIGS. 2 and 3 show an example of a conventional electronic device of this type.

In FIG. 1, reference numeral 30 denotes a front case, and a back case 40 is fitted into the front case 30, and a lower substrate 32 and a middle substrate are provided in a space formed by the front case 30 and the back case 40. 34 and the upper substrate 37 are fixedly accommodated.

The front case 30 has a rectangular plate-shaped front part 30.
a and a frame portion 30b extending substantially perpendicularly to the front surface portion 30a, and a step portion 30c is provided at the tip of the frame portion 30b.
Are formed. A substantially cylindrical case fixing boss portion 30d is provided at two opposing positions on the inner side surface of the front portion 30a.
A screw recess 30e is formed on the outer surface of the case fixing boss 30d, and a substantially columnar lower substrate fixing boss 30f is formed at four locations near the corners on the inner surface of the front surface 30a. The lower substrate fixing boss portion 30f has a screw recess 30g formed on the outer surface of the lower substrate fixing boss portion 30f, and four lower portions of the lower substrate fixing boss portion 30f closer to the center are higher than the lower substrate fixing boss portion 30f. A tall middle substrate fixing post 30h is formed to protrude. Post 30h for fixing the middle board
The screw holes 30i are formed in the upper part of each.

The lower substrate 32 has a case fixing boss 30d.
, Two case boss escape holes 32a are formed at locations corresponding to the above, four fixing screw insertion holes 32b are formed corresponding to the lower substrate fixing boss portion 30f, and further penetrate the middle substrate fixing post 30h. Four pillar through holes 32c
A printed wiring (not shown) is formed avoiding the case boss escape hole 32a, the fixing screw insertion hole 32b, and the support column through hole 32c, and an electronic component (not shown) such as an LSI is mounted on both sides. I have.

[0006] Four screw insertion holes 34a are formed near the corners of the middle substrate 34 so as to correspond to the middle substrate fixing columns 30h.

The upper substrate 37 has a case fixing boss 30d.
Two case boss relief holes 37a are formed corresponding to the relay boss screw 41 connected to the lower board fixing boss screw 41, and four case boss relief holes 37a are formed corresponding to the relay boss screw 38 connected to the lower substrate fixing boss portion 30f.
A plurality of screw insertion holes 37b are formed.

The back case 40 has a rectangular plate-shaped main body 40a.
And a frame 4 extending substantially perpendicular to the main body 40a.
0b, and a step portion 40c is formed at the tip of the frame portion 40b. Further, boss screw support portions 40d for fixing one end of the relay boss screw 41 are formed at two places facing the case fixing boss portion 30d.

The front case 30 and the back case 4
When assembling the lower substrate 32, the middle substrate 34, and the upper substrate 37 integrally, the lower substrate 32 is first positioned on the front case 30, and the screw recess 3 of the lower substrate fixing boss 30f is formed.
0g, the lower substrate fixing screw 43 is inserted.
3 and the relay boss screw 38 is arranged corresponding to the lower substrate 3.
2 is fixed to the front case 30 with screws. Next, the middle board 34 is positioned on the middle board fixing support 30h, and the middle board 3 is fixed.
4, the middle substrate fixing screw 44 is screwed into the screw hole 30 i from above to fix the middle substrate 34 to the front case 30.

Next, the screw insertion hole 37b of the upper substrate 37 is aligned with the relay boss screw 38 fixed to the front case 30, and the upper substrate fixing screw 45 is inserted into the screw hole 38a of the relay boss screw 38. The upper substrate 37 is fixed to the front case 30 via the relay boss screw 38. Finally, the case fixing screw 42 is inserted into the screw recess 30 e of the front case 30, the step 30 c and the step 40 c are fitted, and the case is fixed to the relay boss screw 41 fixed to the back case 40. The front case 30 and the back case 40 are integrated by screwing the screws 42 together.

[0011]

The above-mentioned conventional electronic equipment and printed circuit board fixing method have the following problems.

That is, many screws (four lower substrate fixing screws 43 and four middle substrate fixing screws 43) are used to fix the lower substrate 32, the middle substrate 34, and the upper substrate 37, and to integrate the front case 30 and the rear case 40. Fixing screw 44, four upper board fixing screws 45, and 2
Since the case fixing screws 42) are used, the number of screw tightening steps is large, and the assembly takes time.

The lower substrate 32 is provided with two case boss escape holes 32a, four fixing screw insertion holes 32b, and four support through holes 32c, so that the mounting area of electronic components and printed wiring are provided. The area that can be used for electronic devices is small, which is disadvantageous for downsizing and multifunctional electronic devices.
In addition, there is a problem in that the layout of the printed wiring is more restricted, and it takes time to design.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and can greatly reduce the number of assembling steps, and can greatly increase the area where electronic components can be mounted on a printed circuit board and the area where printed wiring can be performed. It is an object of the present invention to provide an electronic device and a method for fixing a printed circuit board, which can advantageously reduce the size and multifunctionality of the electronic device and increase the degree of freedom in pattern design.

[0015]

In order to achieve the above object, an electronic device according to the present invention is an electronic device in which a plurality of printed boards on which electronic components are mounted are fixed in a case. A support rib for supporting the outer peripheral portion of the lower board, and a support for supporting the middle board and fixing a holder for connecting a plurality of printed boards are formed in the front case, and the support is made to penetrate the lower board. A through hole is formed, a through hole for screwing is formed at four corners of the middle substrate, an insertion hole for inserting the holder and a locking portion for locking the holder are formed on the upper substrate, The holder includes a holding piece of the lower substrate, a holding portion of the middle substrate, a screw insertion hole formed in the holding portion, a forked portion, a locking groove into which the locking portion of the upper substrate is fitted, and a fixing piece of the back case. , And a screw hole formed in the fixing piece Are both composed of an elastic material, it is characterized in that a plurality of screw insertion holes, and the lower substrate holding ribs are formed in the back casing.

According to the above electronic apparatus, the number of through holes formed in the lower substrate is greatly reduced from, for example, 10 to four, and the number of through holes formed in the upper substrate is reduced, for example, from six to two. can do. Therefore, the area in which the electronic components can be mounted and the area in which the printed wiring can be printed on the printed circuit board can be significantly increased.

Further, according to the method of fixing a printed circuit board in an electronic device according to the present invention, a plurality of boards on which electronic parts are mounted are provided.
In electronic equipment that fixes the printed circuit board in the case,
In the method of fixing a printed circuit board, a step of passing a support formed on a front case through a through hole formed on a lower board and supporting the lower board with a receiving rib formed on the front case ; The holder is positioned over the middle substrate and screwed in place.
Pressing the lower substrate by the pressed holding pieces and fixing the middle substrate to the upper surface of the support , formed on the upper substrate
The fixing piece formed in the holder through the insertion hole,
An engaging portion formed on the upper substrate is formed on the holder.
Step locking groove to be fitted engaging the said substrate on the holder has, and performs alignment between the back casing and the table case, the fixed by inserting the screw into the screw insertion hole of the back casing The screw is screwed into one of the screw holes, the back case is fixed to the holder, and the back case is formed in the back case.
And a step of holding down the lower substrate by a lower substrate holding rib to achieve overall integration.

According to the method for fixing a printed circuit board in the above-mentioned electronic equipment, for example, the conventional process of 14 screw tightening steps can be reduced to 6 screw tightening steps. It is possible to reduce the cost and reduce the cost.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an electronic apparatus and a method for fixing a printed circuit board according to the present invention will be described below with reference to the drawings. FIG. 1 is an exploded partial cross-sectional perspective view showing an electronic apparatus according to an embodiment. In FIG. 1, reference numeral 10 denotes a front case. The front case 10 has a rectangular plate-shaped front part 10a.
And a frame portion 10b extending substantially perpendicularly to the front surface portion 10a. At predetermined eight locations on the inner peripheral portion of the inner surface of the front surface portion 10a, there are formed quadrangular prisms for supporting the lower substrate 12. A small receiving rib 10c is formed to protrude. A column 10d having a substantially columnar shape for fixing the middle substrate 14 is formed protrudingly in the vicinity of the square portion slightly inside the position where the receiving rib 10c is formed, and a screw hole (not shown) is formed above the column 10d. ) Is formed.

Lower substrate 12 arranged on receiving rib 10c
Has four through holes 12 for penetrating the column 10d.
a is formed near the square.

The middle substrate 14 is supported on the upper surface of the column 10d. A through hole 14a for inserting a screw 24 is formed in the vicinity of the square portion of the middle substrate 14, and these four screws 24 are The middle substrate 14 and the holder 15 are fixed to the column 10d by being screwed into the screw holes formed on the upper part of the column 10d.

The holder 15 comprises a support 10d and a back case 20.
The upper substrate 17 is pressed down and the upper substrate 17 is locked, and is formed using an elastic phosphor bronze plate or the like. Holder 1
5 has a forked portion 15a, a holding piece 15d for holding down the lower substrate 12 is formed at a lower portion of both ends of the forked portion 15a, and a holding portion 15b for holding down the middle substrate 14 is provided above the holding piece 15d. It is extended and the screw 2 is
4 is formed with a screw insertion hole 15c. A locking groove 1 for locking the upper substrate 17 above the forked portion 15a.
5e is formed, and a fixing piece 15f is formed above the locking groove 15e so as to extend in a direction perpendicular to the forked portion 15a, and a screw hole for screwing the screw 22 is formed in the center of the fixing piece 15f. 15g are formed, and the fixing piece 15f and the locking groove 15 are formed.
The distance e has a function as a spacer for keeping the distance between the upper substrate 17 and the back case 20.

The upper substrate 17 is formed with two insertion holes 17a through which the fixing pieces 15f are inserted, and the base of the insertion hole 17a becomes narrower so that a locking portion 17b for locking the locking groove 15e is formed. It has become.

The back case 20 is a main body 2 having a rectangular plate shape.
0a and a frame portion 20b extending substantially perpendicular to the main body 20a, and a step portion 20c is formed at the tip of the frame portion 20b. 15g screw hole in body 20a
A screw insertion hole 20d is formed at two places facing the screw insertion hole, and a recess 20e for accommodating the head of the screw 22 is formed around the screw insertion hole 20d. Eight holding ribs 20f are formed on the inner surface of the main body 20a so as to correspond to the receiving ribs 10c, so that the lower substrate 12 can be sandwiched between the receiving ribs 10c and the holding ribs 20f.

The front case 10 and the back case 2
When assembling the lower substrate 12, the middle substrate 14, the holder 15, and the upper substrate 17 integrally, first, the pillars 10d are inserted into the through holes 12a to position the lower substrate 12 on the front case 10.
Through which the receiving rib 10c is positioned at the outer peripheral end of the lower substrate 12. Next, the through hole 14 of the middle substrate 14 is
a, the middle substrate 14 is supported on the upper surface of the column 10d, the holders 15 are arranged at both ends of the middle substrate 14, and four screws 24 are respectively inserted into the screw insertion holes 15c and the through holes 14d.
a, and screwed into the screw hole formed in the upper part of the support 10d to simultaneously connect the middle substrate 14 and the holder 15 to the support 1d.
Fixed to 0d. By this fixation, the lower substrate 12 also holds the holding piece 1
5d, the receiving rib 10c is pressed toward the receiving case 10c.
Fixed to Next, in order to lock the upper substrate 17 in the locking groove 15e, the fixing piece 15f is inserted through the insertion hole 17a, and locked in the locking groove 15e in the locking portion 17b. At this time, the elasticity of the holder 15 is used to push the holder 15 slightly outward, and the stress of the pushing is released when the locking groove 15e is locked in the locking portion 17b. By doing so, the upper substrate 17 can be firmly fixed between the holders 15 by utilizing the elasticity of the holders 15.

Next, the screw insertion hole 20d of the back case 20 is aligned with the screw hole 15g of the fixing piece 15f.
2 is screwed into the screw hole 15g while being inserted through the screw insertion hole 20d, and the back case 20 is fixed to the holder 15. At this time, the step 20c fits inside the frame 10b,
By pressing the lower substrate 12 toward the rib 10c side by the holding rib 20f, the lower substrate 12 can be more firmly fixed,
The back case 20 can be fixed to the front case 10 via the holder 15. Further, by screwing the back case 20 and the holder 15, the bending of the holder 15 is regulated, and the upper substrate 17 can be securely fixed to the holder 15.

In the electronic device described above, the lower substrate 12
Only four of the through holes 12a for inserting the support post 10d are formed in the support rib 10c and the holding rib 2c.
0f is located at a position on the outer peripheral edge of the lower substrate 12 where there is no hindrance to mounting of electronic components and printed wiring,
This is significantly different from the conventional lower substrate 32 in which as many as ten through-holes are formed as shown in FIG. 2, and the area in which electronic components can be mounted and the area in which print wiring can be performed can be greatly increased.
The number of through holes formed in the upper substrate 17 can be greatly reduced from the conventional six to two through holes 12a.
As in the case of 2, the area in which electronic components can be mounted and the area in which print wiring can be performed can be greatly increased. Therefore, it is possible to advantageously reduce the size and multifunction of the electronic device, and to greatly increase the degree of freedom in pattern design.

According to the method of fixing a printed circuit board in an electronic device described above, the front case 10, the rear case 20, the lower substrate 12,
All the assembly of the middle board 14 and the upper board 17 is completed, so that the number of assembling steps can be greatly reduced as compared with the conventional case which requires, for example, 14 screwing steps.

In the above embodiment, the printed circuit board is 3
Although the number of printed circuit boards has been described by way of example, the number of printed circuit boards is not limited to three, and may be, for example, four. 15e may be formed to lock the printed circuit board.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view, partly in section, showing an electronic apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating an example of a conventional electronic device.

FIG. 3 is a partial cross-sectional exploded perspective view showing an example of a conventional electronic device.

[Explanation of symbols]

 Reference Signs List 10 front case 10c receiving rib 10d support 12 lower substrate 12a through hole 14 middle substrate 14a through hole 15 holder 15a forked part 15b holding part 15c screw insertion hole 15d holding piece 15e locking groove 15f fixing piece 15g screw hole 17 upper board 17a insertion Hole 17b Locking portion 20 Back case 20d Screw insertion hole 20f Holding rib 22, 24 Screw

Claims (2)

(57) [Claims] 1. An electronic device in which a plurality of printed boards on which electronic components are mounted are fixed in a case, wherein a front case supports a receiving rib for supporting an outer peripheral portion of a lower board; A pillar for fixing a holder connecting the two printed boards is formed, a through hole is formed in the lower board to penetrate the pillar, and a through hole for screwing is formed in four corners of the middle board. An insertion hole for inserting the holder and an engagement portion for engaging the holder are formed on the upper substrate, and the holder is formed on a holding piece of the lower substrate, a holding portion of the middle substrate, and the holding portion. The rear case has a screw insertion hole, a forked portion, a locking groove in which the locking portion of the upper substrate is fitted, a fixing piece of the back case, and a screw hole formed in the fixing piece, and is made of an elastic material. Has several screw insertion holes,
And the lower substrate holding rib is formed. 2. A plurality of prints on which electronic components are mounted.
Printed board for electronic equipment that fixes the board in the case
In the method of fixing a plate, a step in which a support formed in a front case is penetrated through a through hole formed in a lower substrate , and the lower substrate is supported by a receiving rib formed in the front case ; The substrate is placed on the upper surface of the support, the holder is positioned and screwed from above the middle substrate, and the lower substrate is pressed by a holding piece formed on the holder , and the middle substrate is pressed. Fixing the support to the upper surface of the support, inserting a fixing piece formed in the holder into an insertion hole formed in the upper substrate, and fixing the locking portion formed in the upper substrate to the
A step of fitting the upper substrate to the holder by fitting it into a locking groove formed in the holder, and aligning the back case with the front case, and inserting a screw into the screw insertion hole of the back case. Then, the screw is screwed into the screw hole of the fixing piece, the back case is fixed to the holder, and the lower substrate is pressed down by the lower substrate pressing rib formed on the back case, so that the whole substrate is integrated. A method for fixing a printed circuit board in an electronic device, the method including: