JPS6223478B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an electronic circuit device using a flexible printed wiring board in which a conductive foil is formed on the surface of a flexible base material such as a phenolic resin.

BACKGROUND ART In recent years, in order to miniaturize electronic devices, consideration has been given to using flexible printed wiring boards using thin and flexible flexible base materials for electronic circuits incorporated in the electronic devices.

Flexible printed wiring boards using this flexible base material have a thickness of 0.02 to 0.3 mm, which is extremely thin, and are flexible, so they can be constructed thinly as electronic circuit devices, and can be folded to fit inside equipment. Because it can be incorporated into electronic circuit devices using conventional rigid substrates, the size of the device can be significantly reduced.

The present invention relates to a method of manufacturing an electronic circuit device using such a flexible printed wiring board,
An example of this will be described below with reference to the drawings.

In this embodiment, as shown in FIG. 1, a flexible printed wiring element 4 is used, in which conductive foils 2 and 3 are formed over the entire surface of a strip-shaped flexible base material 1. The ends of are sent out one after another and the element body 4 is formed in the hole drilling process 5.
Guide holes 6, 7 of a constant size are formed at equal intervals on both sides in the longitudinal direction by a press or the like, as well as lead insertion holes 8 for leaded electronic components and small holes 9a, 9b provided for cutting as will be described later. 10a,
10b etc. are formed.

Next, it is sent to an etching process 11 by a sprocket wheel (not shown) or the like that engages with the guide holes 6 and 7, where both the front and back surfaces are etched with a required distance in the longitudinal direction between the guide holes 6 and 7. A first circuit conductive foil 13 is formed on the front side of the frame 12 of the same shape, a second circuit conductive foil 14 is formed on the back side, and a third circuit conductive foil 14 is formed on the outside of the frame 12 and on the front side. Conductive foil 15 is sequentially formed as shown in FIG.

Inside the frame 12 on both the front and back sides, a peripheral foil 16 is provided around the entire circumference at a slight distance from the frame 12.
17 (17 is shown by broken lines in FIGS. 4 and 5), and circuit conductive foils 13 and 14 are formed within these peripheral foils 16 and 17.

The flexible printed wiring element 4 on which the circuit conductive foils 13 to 15 as shown in FIG.
At this point, the leadless electronic component 19 is bonded to the required locations. In this first component mounting step 18, the first circuit conductive foil 13 on the front side and/or the third
The leadless electronic components are attached only to the 15 parts of the circuit conductive foil, and the flexible printed wiring element 4 to which the leadless electronic components 19 are successively connected is sent to the first soldering process 20. .
In the first soldering process 20, as shown in FIG. 3, the front side of the flexible printed wiring element 4 is fed in the direction of the arrow while being dipped in the solder 22 of the solder bath 21, thereby forming a leadless electronic component. 1
9 is soldered 23 to the first circuit conductive foil 13 and the third circuit conductive foil 15.

In this case, the lead insertion hole 8 into which the terminal of the leaded electronic component, switch, or other component is inserted.
are treated in advance to prevent them from being blocked by solder.

Next, the flexible printed wiring element body 4 processed in the first soldering process 20 is sent to a first cutting process 24. This first cutting step 24 is performed by cutting the flexible printed wiring element 4 using a base 25 and a cutter 26.
It is used to partially cut the cutter 26.
is cut into the flexible printed wiring element body 4 to partially cut lines.

Describing the locations where cut lines are formed by the cutter 26, first, the flexible printed wiring element 4
A cutting line 27 for cutting the flexible printed wiring board from the printed circuit board is preset on the flexible substrate 1 exposed between the frame 12 and the peripheral foils 16 and 17, that is, between the frame 12 and the peripheral foils 16 and 17. A first cutting line 28 is formed along the cutting line 27 between the small holes 9a and 9b formed at required locations on the cutting line 27, as shown in FIG. External connection terminal foil 29a, 2 between 10b
A U-shaped second cutting line 30 is formed to surround 9b.

Since the cut lines 28 and 30 are formed by the cutter 26 with an extremely thin cutting edge, even if the cut lines 28 and 30 are formed, there will be no holes in the mouth, and for example, the U-shaped portion will not hang down. It is something that never happens.

The flexible printed wiring element body 4 on which the cutting lines 28 and 30 have been formed is then subjected to a second component mounting step 31.
sent to. In this second component mounting step 31, as shown in FIG. 5, the lead wire of the lead-equipped electronic component 32 is inserted into the lead wire insertion hole 8 from the first circuit conductive foil 13 side on the front side, and the lead wire of the electronic component 32 is inserted into the lead wire insertion hole 8, as shown in FIG. The terminals of the terminal-equipped electronic component 33 are also inserted into the terminal insertion holes 34a and 34b from the front side.

The terminal-equipped electronic component 33 is positioned on the cutting line 28 with its operation piece 33a protruding outward beyond the cutting line 27, and the terminal is attached to the second circuit conductive foil 14 on the back side. Of which 14a, 14
b.

The flexible printed wiring element 4 that has passed the second component mounting process 31 is sent to a second soldering process 34. In this second soldering process 34, the sixth
As shown in the figure, the back side of the flexible printed wiring element 4 is immersed in the solder 36 of the solder tank 35 while being fed in the direction of the arrow. The attached electronic component 33 is soldered 37.

In addition, in the second soldering process 34, the cutting line 28,
30 is not a cutting line where solder can enter, so
There is no possibility that the solder will come out from this cutting line to the front side.

As described above, electronic components are sequentially attached and connected to the first, second, and third circuit conductive foils 13, 14, and 15 formed on the flexible printed wiring element body 4, and the electronic circuits are continuously placed. Finally, in a second cutting step 38, the cutter 39 cuts along the cutting line 27 to obtain two electronic circuit devices 40 and 41, respectively.

In the second cutting process 38, the first cutting process 2
4 is cut by biting the cutter 39 in the same manner as in the first cutting step 24, and this cutting is performed along the cut line 28 formed in the first cutting step 24 and the small holes 9a, 9b. The electronic circuit devices 40 and 41 are separated from the flexible printed wiring element body 4, respectively, to complete the continuous process. FIG. 7 shows electronic circuit devices 40, 41 completed in this manner.

The cut-and-raise piece 42, which can be cut and raised from the base along the U-shaped cut line 30, is soldered to the external terminal 43 by soldering terminal foils 29a and 29b for external connection when assembled into an electronic device, as shown in FIG. By attaching 44, external connection can be easily made as a lead wire, and it can also be folded back and soldered to the first circuit conductive foil 13 or the second circuit conductive foil 14 instead of a jumper wire.

Here, in the flexible printed wiring element 4, tension is applied to the flexible base material 1 when the conductive foils 2 and 3 are attached to the flexible base material, and therefore, when the conductive foils 2 and 3 are removed, the flexible base material Material 1 contracts. On the other hand, when all or even some of the above steps are performed automatically by an automatic machine, it is necessary to reliably run the flexible printed wiring element 4 and reliably position it at a predetermined position. For this reason, in the present invention, the conductive foils 2 and 3 are left around the frame 12 in which the guide holes 6 and 7 are formed to ensure that the shapes of the guide holes 6 and 7 are maintained, thereby ensuring that the sprocket wheels etc. This ensures stable travel and positioning.

On the other hand, peripheral foils 16 and 17 are provided around the electronic circuit device 40 obtained by cutting to prevent dimensional deformation due to shrinkage or elongation and to prevent cracks from occurring when incorporated into electronic equipment. In addition, in the cutting process, if conductive foil is included in the cutter, the wear of the cutting edge will increase, so all cutting lines are set at positions that do not include the conductive foil, and the cutting edge only cuts into the flexible base material 1. I'm trying to disconnect it.

In the above embodiment, the first cutting process 24 was provided after the first soldering process 20, but this first cutting process was performed before that, for example, after the etching process 11.
The same effect can be achieved even if it is provided after the peripheral foil 16, 1.
7 has been described in which both peripheral foils are provided over the entire circumference, but this can be done by providing only one peripheral foil over the entire circumference, or by providing a staggered pattern on the front and back sides and either peripheral foil on the periphery. The same effect can be achieved even if the peripheral foil is provided, and furthermore, this peripheral foil may be provided partially, or may also be used as a conductive foil for a circuit, such as a conductive foil for grounding.

Further, like the electronic circuit device 40, the electronic circuit device 41 may also have a circuit conductive foil formed on the peripheral edge foil or the back surface.

Furthermore, in the above embodiment, the circuit conductive foils 13 and 14 are formed on both sides using the flexible printed wiring element 4 provided with the conductive foils 2 and 3 on both sides, but in this case only one side is conductive. A circuit conductive foil is formed on only one side of a flexible printed wiring element having foil, and the lead wire of an electronic component with a lead is inserted from the back side where the conductive foil is not provided, and the terminal of an electronic component with a terminal is inserted. In this case, leadless electronic components are held by adhesive etc. on the conductive foil for circuits on the surface.
The same effect can be obtained even if the terminals of electronic components are inserted from the back side and soldered all at once using the dip method.

In addition, in the case of this single-sided conductive foil, the peripheral foil is provided only on one side.

The present invention provides an electronic circuit device in which an electronic component is attached and connected to a circuit conductive foil formed on a flexible printed wiring element as described above, and then separated by cutting to obtain an electronic circuit device, in which the electronic component is placed on a preset cutting line. If the electronic component is to be located in the area, before installing the electronic component, a cutting line is formed in advance at the part where the electronic component is located, and after the electronic component is connected by soldering etc., it is separated by cutting on the cutting line excluding the cutting line. According to this, even if operating pieces such as switches and external connection terminals protrude from the outer periphery of the flexible printed wiring board, it can be easily separated as a flexible printed wiring board. be.

For this reason, it is especially easy to incorporate this as an electronic circuit device into an electronic device such as an ultra-compact tape recorder or radio, and at the same time, to easily protrude a switch operation piece or an external connection terminal from the operation section of the device. This greatly simplifies the assembly work.

Moreover, the cutting line cut by the cutter in the first and second cutting steps is set on the inside of the frame made of conductive foil, excluding the conductive foil, reducing wear on the cutting edge when cutting with the cutter. In addition, the cutting line in the first and second cutting steps is made by cutting two lines that are placed in advance on the cutting line and are located outside the width of the electronic component to be attached so as to straddle the cutting line. By making the small hole the boundary between the first cut and the second cut, it is possible to perform the cut even if the positions of the cut lines are slightly shifted, and the occurrence of cracks can be prevented. It has great industrial potential.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the steps of an embodiment of the present invention;
Figure 2 is a perspective view showing the conductive foil for circuits formed in sequence, Figure 3 is a schematic diagram showing the soldering state in the first soldering process, and Figure 4 is the main part with cut lines formed. Top view, Figure 5 is a top view of the main part with electronic components with leads and terminals installed, Figure 6 is the second
FIG. 7 is a schematic top view of the manufactured electronic circuit device, and FIG. 8 is a schematic side view showing the external connection state of the device. 1... Flexible base material, 2, 3... Conductive foil,
4...Flexible printed wiring element, 9a, 9b...
... Small hole, 12 ... Frame, 13, 14, 15 ... Conductive foil for circuit, 24 ... First cutting step, 27 ... Cutting line, 28 ... Cutting line, 33 ... Electronic component with terminal,
34...Second soldering process, 38...Second cutting process.

Claims (1)

[Claims] 1. In the process of sequentially forming circuit conductive foil surrounded by a frame by etching on a band-shaped flexible printed wiring element in which conductive foil is provided over at least one entire surface of a flexible base material, the conductive foil inside the frame is etched. A cutting line for cutting the flexible printed wiring board is set in advance on the flexible substrate excluding the board, and in the first cutting step, the cutting line is set outside the width of the electronic component to be attached so as to straddle the cutting line. A cutting line is partially cut between the two small holes provided on the cutting line, and an electronic component is placed on the cutting line and connected to the circuit conductive foil, and then a second cutting process is performed. A method of manufacturing an electronic circuit device, comprising manufacturing an electronic circuit device separated from the flexible printed wiring element body by cutting along a cutting line other than the cutting line.