JPH08116145A - Connection structure and connection method of rigid substrate and flexible substrate - Google Patents

Abstract

PURPOSE: To improve connection strength between a rigid substrate and a flexible substrate, to miniaturize a connection part and to reduce connection defective. CONSTITUTION: The title structure has a solder connection part 22 formed by soldering connection leads 16, 13 formed in opposite surfaces of a rigid substrate 11 and a flexible substrate 10, a through hole 18 which is provided to an area near both sides holding the solder connection part 22 between and passes through the rigid substrate 11 and the flexible substrate 10 in thickness direction thereof and a fastener 24 which is inserted and fixed to the through hole 18 and fastens the rigid substrate 11 and the flexible substrate 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connecting structure and a connecting method for a rigid printed board and a flexible printed board incorporated in an electronic device.

[0002]

2. Description of the Related Art In recent years, with the demand for miniaturization of electronic devices such as personal computers and word processors, the need for high-density mounting of electronic components has increased. As a technology that meets such needs, stacking multiple rigid printed circuit boards (rigid printed circuit boards) on which electronic components are mounted and incorporating them in electronic devices in this state makes effective use of space. There is a way to do.

A flexible printed circuit board (flexible printed circuit board) is generally used as a component for connecting the plurality of rigid printed circuit boards to each other.

In this flexible printed circuit board, a connecting lead for electrically connecting the rigid printed circuit boards is formed on the surface of a flexible thin film using a flexible insulating substrate. is there.

Reference numeral 1 in FIG. 6 denotes a flexible printed circuit board. The characteristic of this flexible printed circuit board 1 is that the rigid printed circuit boards 2 and 2 are connected to each other as shown in FIG. Connection can be realized, and incorrect wiring can be prevented and wiring work can be rationalized.

However, due to the recent demand for high-density mounting, the pitch of the connecting lead of the rigid printed circuit board 2 and the connecting lead of the flexible printed circuit board 1 connected to the rigid printed circuit board 2 becomes narrower and narrower. There is a tendency.

When soldering connecting leads provided at a narrow pitch, the joint width per lead becomes very narrow. Therefore, when an external force such as a tensile force is applied, the solder connecting portion May easily break.

Therefore, conventionally, as shown in FIGS. 7A and 7B, the connecting lead 3 of the rigid printed board 2 and the connecting lead 4 of the flexible printed board 1 are soldered. A double-sided adhesive sheet 6 for fixing the rigid printed circuit board 2 and the flexible printed circuit board 1 to each other is disposed inside the formed portion (solder connecting portion 5) to reinforce the solder connecting portion. There is.

[0009]

The conventional connection structure between the rigid printed circuit board 2 and the flexible printed circuit board 1 described above has the following problems to be solved. First, as described above, the double-sided adhesive sheet 6
Or even when using a thermocompression sheet for reinforcement,
If each rigid printed circuit board 2 is heavy, there is a possibility that “displacement” or “peel” may occur at the connection part when an external force due to handling in the manufacturing process of the product, particularly an external force in the twisting direction is applied. However, there is a demand for further improvement in connection strength.

Secondly, in the case of reinforcement using the double-sided adhesive sheet 6 and the like, an area of approximately the same size as the area for soldering is required in order to attach them. , It may be an obstacle to high-density mounting.

Thirdly, since the double-sided adhesive sheet 6 and the solder connecting portion 5 are slightly separated from each other, the double-sided adhesive tape 6 is provided.
Even if peeling does not occur on the adhesive surface of the
It is considered that only the solder is broken, and the solder connection portion 5 may not be sufficiently reinforced.

Fifth, the flexible printed board 1
In order to connect the rigid printed circuit board 2 with the rigid printed circuit board 2, two kinds of tools are prepared: a tool for softening the thermocompression bonding sheet 6 and a tool for melting the solder material 5. Alternatively, it is necessary to sequentially move one tool to two places, which may complicate the apparatus and reduce workability.

Sixth, if there is a connection failure, the flexible printed circuit board 1 is replaced with the rigid printed circuit board 2.
However, in the above-mentioned configuration, the repairability is poor, and when reconnecting the two after repairing, it is necessary to wash the remaining residue of the sticky sheet 6 that has stuck. However, there are cases in which it is difficult to handle.

The present invention has been made in view of the above circumstances, and when connecting a rigid substrate and a flexible substrate, it is possible to improve the connection strength, reduce the size of the connection portion, and reduce the connection failure. An object of the present invention is to provide a connecting structure and a connecting method for a substrate and a flexible substrate.

[0015]

A first means of the present invention is, in a connection structure of a rigid board and a flexible board for connecting the rigid board and the flexible board, to the surfaces of the rigid board and the flexible board which face each other. A solder connecting portion formed by soldering the formed connecting leads together, and a through hole provided in the vicinity of the solder connecting portion and penetrating the rigid board and the flexible board in the thickness direction thereof, A connecting structure for a rigid board and a flexible board, comprising: a fastener that is inserted into the through hole and that fastens the rigid board and the flexible board.

A second means is the connecting structure of the rigid board and the flexible board of the first means, wherein the through holes are provided in the vicinity of both sides sandwiching the solder connecting portion. .

A third means is the connection structure of the rigid board and the flexible board of the first means, wherein the fastener has a cylindrical portion having an outer diameter slightly smaller than an inner diameter of the through hole, It has an intermediate member inserted into the through hole and a shaft portion, and the outer diameter of the intermediate member is expanded by press-fitting the shaft portion into the cylindrical portion of the intermediate member inserted into the through hole. And a center member for fitting the cylindrical portion with the inner surface of the through hole.

A fourth means is a connection method for connecting a rigid board and a flexible board, wherein the through holes provided in the rigid board and the through holes provided in the flexible board are aligned with each other and a positioning pin is inserted into them. The step of aligning the rigid board and the flexible board, and soldering the connecting leads formed on the opposing surfaces of the aligned rigid board and flexible board by soldering. The method is characterized by including a step and a step of fastening the rigid board and the flexible board by inserting a fastener into the through hole.

A fifth means is a connecting structure for connecting a rigid board and a flexible board, wherein the connecting boards provided on the surfaces of the rigid board and the flexible board facing each other are connected to each other. It is characterized in that it has a solder connecting portion connected by soldering and an adhesive filled around the solder connecting portion and for adhering the rigid substrate and the flexible substrate to each other.

A sixth means is the connection structure of the rigid board and the flexible board of the fifth means, wherein the adhesive is previously attached to a connecting lead of either the rigid board or the flexible board. The thermocompression-bonded sheet is softened, and the softening temperature is below the melting temperature of the solder.

A seventh means is a connecting method for connecting a rigid substrate and a flexible substrate, wherein a connecting lead provided on the rigid substrate and a connecting lead provided on the flexible substrate are opposed to each other. And the flexible board and the rigid board are driven in a direction in which they are relatively close to each other, and are supplied to the thermocompression-bonding sheet attached to the connecting board of the flexible board and the connecting board of the rigid board. Bonding is performed by bringing the soldered material in contact with the solder material at a predetermined pressure and heating the thermocompression-bonding sheet and the solder material from the rigid board side, and the thermocompression-bonding sheet being softened at a predetermined temperature. When it becomes an agent and fills the periphery of the solder material and the solder material melts, the heating is terminated and the connection part is cooled to solder the connecting leads together and the rigid. It is characterized in that a step of performing an adhesive plate and the flexible substrate.

[0022]

According to the first to fourth means, the solder connection portion is reinforced by the fastener, so that the area required for the connection portion can be made small and the connection can be made firmly. According to the fifth to seventh means, by filling the periphery of the solder connection portion with an adhesive and reinforcing the solder connection portion with this adhesive, the area required for connection can be made small and strong connection can be performed. .

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Reference numeral 10 in FIG. 3 denotes a flexible printed circuit board. This flexible printed circuit board 10 has a thickness of 60.
Flexible film 12 of μm to 100 μm made of polyimide
On one surface (lower surface in the figure) of the film 12, a plurality of connecting leads 13 for the entire length in the width direction of the film 12 are provided, for example, 0.3 mm
It is formed at a pitch.

In FIG. 3, only one end of the flexible printed board 10 is shown, and the other end is not shown because it has the same structure as this one end. Both ends of the flexible printed circuit board 10 in the width direction (only one end is shown) serve as connection parts 14 connected to the rigid printed circuit board. Through holes 15 are formed on both sides of the connecting portion 14 so as to sandwich the plurality of connecting leads 13 in the thickness direction of the flexible printed circuit board 10.

Next, the rigid printed board 11 will be described. The rigid printed circuit board 2 is a rigid flat printed circuit board having a thickness of 0.5 mm to 2 mm, for example. This rigid printed circuit board 11 is shown in FIG.
Although only one end thereof is shown, a wiring pattern of a predetermined shape is formed on the surface of the other end side (not shown) of the rigid printed board 11 so that various electronic components can be surface-mounted. .

At one end of the rigid printed board 11, a plurality of connecting leads 16 led out from the wiring pattern are connected to the connecting lead 13 provided on the flexible printed board. It is provided at the same pitch as.

A pair of through holes 18 are provided on both sides of the connecting lead 16 in the same manner as the flexible printed circuit board 10. The through holes 15 and 18 provided in the rigid printed circuit board 2 and the flexible printed circuit board 10 are formed so as to communicate with each other when the connecting leads 13 and 16 are positioned to face each other.

Next, a method of connecting the rigid printed circuit board 2 having the above-mentioned configuration and the flexible printed circuit board 10 will be described. FIG. 3 shows that the rigid printed circuit board 11 and the flexible printed circuit board 10 are aligned with each other, and the connecting lead 1 is provided on them.
This is a positioning and soldering mechanism that connects 3 and 16 by soldering.

This mechanism is based on the rigid printed circuit board 1 described above.
1 has a back-up 19 for supporting the back surface of 1. The backup 19 includes a support surface 19a for supporting the rigid printed circuit board 2 and also supports the support surface 19a.
From the above, an insertion pin 20 to be inserted into the through hole 18 provided in the rigid printed circuit board 2 is projected.

Above the backup 19, a soldering tool 21 for soldering the rigid printed board 2 supported by the backup 19 by pressing and heating the connecting portion of the flexible printed board 10 is provided. ing.

The soldering tool 21 has a pressing surface 21a capable of collectively pressing the entire joint 14 of the flexible printed circuit board 10 and heats the tool 21 to a predetermined temperature. A heating heater (not shown) for keeping heat is provided.

The tool 21 is driven in a direction in which it comes in contact with and separates from the rigid printed circuit board 11 and the flexible printed circuit board 10 held by the backup 19, that is, in the vertical direction.

Next, the operation of aligning and soldering the rigid printed circuit board 11 and the flexible printed circuit board 10 using this apparatus will be described. First,
The rigid printed circuit board 11 is backed up 19
Set to. The rigid printed circuit board 11 is supported on the supporting surface 19 a of the backup 19 by inserting the pair of through holes 18 onto the insertion pins 20.

A solder material 22 for joining is previously supplied to the tip of the connecting lead 16 of the rigid printed board 11 by a method such as screen printing or plating.

Next, the flexible printed board 1
0 indicates that the connecting portion 14 is connected to the rigid printed circuit board 11
The through hole 15 and the insertion pin 2
It is set in the backup 19 while being extrapolated to 0.

As a result, the rigid printed circuit board 1 is
1 and the flexible printed circuit board 10 are supported on the support surface 19a of the backup 19, and the connecting leads 13 and 16 provided on them are positioned to face each other.

Then, in this state, the soldering tool 21 descends to press the connecting portion 14 of the flexible printed circuit board 10 against the rigid printed circuit board 11 and heat it to a predetermined temperature.

As a result, the rigid printed circuit board 1 is
Solder material 2 supplied to the tip of the connecting lead 16 of No. 1
2 melts, and the connecting lead 16 of the rigid printed board 11 and the connecting lead 13 of the flexible printed board 10 are joined together by soldering. Hereinafter, each soldering part is referred to as a solder connecting part 22.

When the rigid printed circuit board 11 and the flexible printed circuit board 10 are soldered, the rigid printed circuit board 11 and the flexible printed circuit board 10 in this state are backed up by the backup 19.
Taken from.

Then, the through holes 15 and 18 of the rigid printed board 11 and the flexible printed board 10 are formed.
A fastener made of plastic as shown in FIG. 24 is fitted in the inside, and the fastener 24 mechanically connects the both.

The fastener 24 includes a head portion 25a and a shaft portion 25.
and a middle member 26 which is externally inserted on the lower end side of the shaft portion 25b of the center member 25 and which is interposed between the center member 25 and the inner walls of the through holes 15 and 18.

The intermediate member 26 has the through holes 15, 1
8 is formed in a tubular shape having an outer diameter slightly smaller than the inner diameter of 8, and has a flange portion 26a formed at the upper end portion with a diameter larger than the inner diameters of the through holes 15 and 18, and at the lower end portion. A slit 26a is provided along the axial direction. The inner diameter of the intermediate member 26 is such that the shaft portion 25 of the central member 25 faces toward the portion where the slit 26b is provided.
The diameter is smaller than that of b.

The fastener 24 has the center member 25 after the intermediate member 26 is inserted into the through holes 15 and 18.
Is set by pushing into the intermediate member 26.
As a result, the intermediate member 26 is expanded by the shaft portion 25b of the central member 25 and fixed to the rigid printed circuit board 11 and the flexible printed circuit board 10.

Further, the lower end portion of the intermediate member 26 projecting from the lower surface of the rigid board 11 widens as shown in the figure, and thus the widened portion and the upper end flange portion 26a.
(In the figure, it is covered by the head of the central member) and the rigid substrate 11 and the flexible substrate 10
Are sandwiched in the thickness direction.

As a result, the intermediate member 26 is effectively prevented from coming off the through holes 15 and 18, and the rigid printed circuit board 11 and the flexible printed circuit board 1 are also prevented.
0 is firmly fastened.

Therefore, the rigid printed circuit board 1
1 and the flexible printed circuit board 10 are electrically and mechanically connected to each other by the solder connection portion 22 and the fastening by the fastener 24.

In this way, one end of the flexible printed circuit board 10 has two rigid printed circuit boards 11.
If it is connected to one of the rigid printed circuit boards 10, the other end of the flexible printed circuit board 10 is also connected to the other rigid printed circuit board 10 in the same manner.

When the two rigid printed circuit boards 11 are connected by the flexible printed circuit board 10, one rigid printed circuit board 11 is connected to the other rigid printed circuit board 1 at this flexible printed circuit board 10.
By folding back about 1 by about 180 °, the rigid printed circuit board 11 can be arranged three-dimensionally as in the conventional example. (Refer to FIG. 6) According to such a configuration, there are the effects described below.

First, the connection by the fastener 24 is different from the connection by the adhesive sheet 6 shown in the conventional example, by engaging the intermediate member 26 with the rigid printed board 11 and the flexible printed board 10. Since they are connected to each other, unless the shaft portion 25b or the intermediate member 26 is broken, no displacement or peeling occurs, and the reliability is high.

Second, the double-sided adhesive sheet 6 as in the conventional example.
Since it is not necessary to provide a special area for, the device can be downsized accordingly. Thirdly, since the through holes 15 and 18 for inserting the fastener 24 are used for aligning the rigid printed circuit board 11 and the flexible printed circuit board 10, the through holes 15 and 1 are
8 can be aligned, and at the same time, the rigid printed circuit board and the flexible printed circuit board can be positioned.

The fastener 24 can be inserted into the through holes 15 and 18 with one touch without requiring any special tool. Therefore, the connecting work itself between the rigid printed circuit board 11 and the flexible printed circuit board 10 is simplified and facilitated as compared with the conventional case.

Fourthly, when a connection failure is found and the necessity of repair arises, a special tool is used to make the center member 25.
The fastener 24 can be removed from the through holes 15 and 18 by pushing the lower end protruding portion of the shaft portion 25b upward and pushing it upward from the intermediate member 26.

Therefore, the rigid printed circuit board 1
Removing the flexible printed circuit board 10 from 1,
That is, even when repair is required, this repair can be easily performed, and since there is no residue of the adhesive or the like, handling at the time of repair becomes easy.

The fastener 24 can be easily attached to the center member 2 when a special tool is used as described above.
5 and the intermediate member 26 can be separated, but if the flexible printed circuit board 11 and the flexible printed circuit board 10 are simply pulled in the direction in which the flexible printed circuit board 10 is peeled from the rigid printed circuit board 11, the rigid printed circuit board 11 and the flexible printed circuit board 10 can be separated from each other. Since it is sandwiched by the flange portion 26a of 26 and the lower end portion, they cannot be separated.

Therefore, it is possible to realize a connection structure in which the normal bonding strength is strong but the repair can be easily performed. Next, a second embodiment of the present invention will be described. The same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The flexible printed circuit board 10 'and the rigid printed circuit board 11' of the second embodiment are as shown in FIG. 5, and unlike the first embodiment, the connecting portion 1 is provided.
No through holes (15 and 18 shown in FIG. 3) were formed in the 4 training.

Next, a method of connecting the rigid printed circuit board 11 'and the flexible printed circuit board 10' in the second embodiment will be described. FIG. 4A shows a state in which the connecting portion 14 of the flexible printed circuit board 10 'is opposed to the rigid printed circuit board 11'.

Similar to the first embodiment, connecting leads 13 and 16 are formed on the flexible printed circuit board 10 'and the rigid printed circuit board 11' at a predetermined pitch. The solder material 22 is attached to the tip of the connecting lead 16 provided on the rigid printed circuit board 11 '.
Is supplied in advance.

The rigid printed circuit board 11 'is held on the backup 19' as shown in FIG. 4B with the connecting portion facing upward. Note that this backup 19 'does not include a positioning pin, unlike the backup 19 of the first embodiment.

The flexible printed circuit board 10 is also provided.
A strip-shaped thermocompression-bonding sheet 30 extending over all of the connecting leads 13 is attached to the tip of the connecting lead 13 of No. '. This thermocompression-bonding sheet 30 is, for example, about 150 ° C.
It has the property of completely softening in the vicinity to become an adhesive, and its softening temperature is the melting point of the solder material 22 (for example, 180 ° C.).
It is set lower than.

Next, the flexible printed circuit board 1
The connecting lead 13 of 0'and the connecting lead 16 of the rigid printed circuit board 11 'are precisely aligned.
This alignment may be performed by, for example, recognizing the alignment marks provided on the rigid printed circuit board 11 'and the flexible printed circuit board 10' by image recognition, or by connecting the leads 13 and 16 to each other. You may go by recognizing directly.

If such an alignment is made,
As shown in FIG. 4 (c), the flexible printed circuit board 10 'is pressed against the rigid printed circuit board 11' and heated by using a thermocompression bonding tool 31.

When the thermocompression bonding tool 31 comes into contact with the flexible printed circuit board 10 ', the heat conduction of the thermocompression bonding sheet 30 is heated, and the adhesive 30' is completely softened at about 150.degree. Becomes This adhesive 30 '
By being pressurized, as shown in FIG. 4 (d), in addition to wrapping around the solder material 22, the connecting lead 1
3 and 16 and the connecting leads 13 and 16 are extruded to fill this portion.

On the other hand, while the solder material 22 is still in the cured state, it breaks through the adhesive 30 'existing in the corresponding portion, and the connecting lead of the flexible printed circuit board 10' is released.
It directly contacts the terminal 13.

Further, as the heating by the thermocompression bonding tool 31 progresses, the solder material 22 begins to melt from around 180 ° C., and the connecting lead 13 for connecting the rigid printed circuit board 11 ′ and the flexible printed circuit board 10 ′. , 16 are soldered together.

After that, by cooling this connecting portion to 150 ° C. or lower, the molten solder material 22 and the adhesive 30 'are solidified, and the connection is completed. In addition, this cooling is
The operation may be performed while the pressure applied by the tool 31 is maintained, or after the tool 31 is raised.

In this way, the rigid printed circuit board 1 having two flexible printed circuit boards 10 'at one end
If connected to one of the 1's, in the same way,
The other end of the flexible printed circuit board 10 'is also connected to the other rigid printed circuit board 11'.

When the two rigid printed circuit boards 11 'are connected by the flexible printed circuit board 10', one rigid printed circuit board 11 'is connected to the other rigid printed circuit board 11' in this flexible printed circuit board 10 part. By folding back about 180 °, the rigid printed circuit board 11 ′ can be arranged three-dimensionally as in the conventional example. (Refer to FIG. 6) According to such a configuration, there are the effects described below.

First, in this embodiment, the conventional example (see FIG. 7) is used.
Unlike (b)), as shown in FIG.
2 is directly reinforced by the adhesive 30 'filled around the solder connection portion 22.

That is, since the reinforcement portion and the solder connection portion 22 are not separated from each other, the reinforcement of the solder connection portion 22 becomes stronger and the breakage of the solder connection portion 22 can be effectively prevented.

Second, since the reinforcement can be performed in the soldering area, it is not necessary to provide a special reinforcement area as in the conventional example, and the size of the apparatus can be reduced.
Thirdly, connecting leads 13 and 16 provided at a narrow pitch.
When connecting between, the solder material 22 supplied to the adjacent connecting leads 16 may come into contact with each other to cause a solder bridge which causes a short.

However, in this embodiment, before the solder material 22 is melted, the adjacent connecting lead 16 and lead 1 are connected.
Since the adhesive 30 'is filled between them and plays the role of a dam, there is an effect that solder bridges can be effectively prevented.

Therefore, there is an effect that a good connection with few defects can be performed. Fourthly, when the connection leads 13 and 16 provided at a narrow pitch are connected to each other, migration is likely to occur due to the outside air. However, in the case of this embodiment, the periphery of the solder material 22 is The adhesive 30 'filled in the above-described structure serves as a protective coat for shutting off the outside air.

As a result, there is an effect that a highly reliable connection with less migration can be performed. It should be noted that the present invention is not limited to the above-mentioned one embodiment, and can be variously modified without changing the gist of the invention.

For example, in the above first and second embodiments, 2
The rigid printed circuit boards 11 are connected by the flexible printed circuit board 10. However, the number of rigid printed circuit boards 11 is not limited to this, and three rigid printed circuit boards 11 are connected to each other by using the flexible printed circuit boards 10 provided in a three-pronged (Y-shaped) shape. May be connected.

Further, the structure may be such that two rigid printed boards are connected by two flexible printed boards. Furthermore, this flexible printed circuit board 10
As a module manufactured by using, three or more rigid printed circuit boards 11 ... Are connected in series using a plurality of flexible printed circuit boards 10, and they are bent and stacked in a bellows shape. good.

In the first embodiment, the fastener shown in FIG. 24 was used as the most suitable fastener, but the fastener is not limited to this and may be a simple rivet.

Although the number of the fasteners 24 is two,
One or two or more fasteners may be further provided on the intermediate portion to make three or more fasteners. Also, in the second embodiment, in the connecting step, the solder material 22 is supplied to the connecting lead 16 side provided on the rigid printed circuit board 11 'to connect the flexible printed circuit board 10' with the connecting material. Although the thermocompression-bonding sheet 30 is attached to the lead 13 side, it is not limited to this.

The thermocompression-bonding sheet 30 is not provided on the connecting lead 13 of the flexible printed circuit board 10 ', but is overlaid on the solder material 22 supplied to the connecting lead 16 of the rigid printed circuit board 11'. Alternatively, the thermocompression-bonding sheet 30 may be attached.

Even if the rigid printed circuit board 11 and the flexible printed circuit board are connected in this state,
The adhesive 30 ′ can be filled around the solder connecting portion 22, and the solder connecting portion 22 can be reinforced.

[0081]

As described above, according to the present invention, a rigid board connecting lead and a flexible board connecting lead are provided.
A solder connection portion with the solder, a through hole that is provided in the vicinity of the solder connection portion and penetrates the rigid board and the flexible board in the thickness direction thereof, and is inserted into the through hole, and the rigid board and It is reinforced with a fastener for fastening a flexible substrate.

Secondly, the solder connection portion is reinforced by an adhesive agent filled around the solder connection portion. With such a configuration, it is possible to improve the connection strength between the rigid board and the flexible board, reduce the size of the connection portion, and reduce the connection failure.

[Brief description of drawings]

FIG. 1A is a perspective view showing a first embodiment of the present invention, and FIG. 1B is a longitudinal sectional view of the same.

FIG. 2A is a perspective view showing a fastening step of the fastener, and FIG. 2B is a vertical sectional view showing the same.

FIG. 3 is a perspective view showing a soldering process.

4A to 4D are process diagrams showing a second embodiment.

FIG. 5 is a perspective view showing a connecting portion as well.

FIG. 6 is an overall perspective view showing a connection between a general rigid board and a flexible board.

7A is a vertical cross-sectional view showing a conventional example, and FIG.
Also a perspective view.

[Explanation of symbols]

10 ... Flexible printed circuit board (flexible circuit board), 11 ... Rigid printed circuit board (rigid circuit board),
13 ... Connection lead, 15 ... Through hole, 16 ... Connection lead
Reference numeral 18 ... Through hole, 20 ... Positioning pin, 22 ... Solder connecting portion, 24 ... Fastener, 25 ... Central member, 25b ... Shaft portion, 26 ... Intermediate member, 30 ... Thermocompression bonding sheet, 30 ′ ... Adhesive Agent.

Claims (7)

[Claims] 1. A connection structure for connecting a rigid board and a flexible board to a rigid board and a flexible board, wherein connecting leads formed on the surfaces of the rigid board and the flexible board facing each other are soldered together. And a through hole that is provided in the vicinity of the solder connecting portion and that penetrates the rigid board and the flexible board in the thickness direction thereof, and is inserted into the through hole, and is connected to the rigid board and the flexible board. A connecting structure for a rigid substrate and a flexible substrate, comprising a fastener for fastening the substrate. 2. The connection structure between a rigid board and a flexible board according to claim 1, wherein the through holes are provided in the vicinity of both sides of the solder connection part. Construction. 3. The connection structure between a rigid board and a flexible board according to claim 1, wherein the fastener has a cylindrical portion having an outer diameter slightly smaller than an inner diameter of the through hole, and is inserted into the through hole. It has an intermediate member to be attached and a shaft, and the shaft is press-fitted into the cylindrical part of the intermediate member inserted into the through hole to expand the outer diameter of the intermediate member and A connecting structure for a rigid substrate and a flexible substrate, comprising: a central member that is fitted to the inner surface of the through hole. 4. A connection method for connecting a rigid board and a flexible board, wherein the through holes provided in the rigid board and the through holes provided in the flexible board are aligned with each other, and a positioning pin is inserted into them. A step of aligning the rigid board and the flexible board; a soldering step of connecting the connecting leads formed on the opposed surfaces of the aligned rigid board and the flexible board by soldering; A method of connecting a rigid substrate and a flexible substrate, comprising a fastening step of fastening the rigid substrate and the flexible substrate by inserting a fastener into the through hole. 5. A connection structure between a rigid board and a flexible board for connecting the rigid board and the flexible board, wherein the connecting leads provided on the surfaces of the rigid board and the flexible board facing each other are connected by soldering. A connection structure between a rigid board and a flexible board, comprising: a solder connection part formed by the above; and an adhesive that fills the periphery of the solder connection part and bonds the rigid board and the flexible board together. 6. The connection structure for a rigid board and a flexible board according to claim 5, wherein the adhesive is thermocompression-bonded in advance to a connecting lead of either the rigid board or the flexible board. A connection structure between a rigid substrate and a flexible substrate, wherein the sheet is softened and the softening temperature is equal to or lower than the melting temperature of the solder. 7. A connecting method for connecting a rigid board and a flexible board, wherein a connecting lead provided on the rigid board and a connecting lead provided on the flexible board are opposed to each other; The flexible board is connected to the flexible board by driving the board and the rigid board in a relatively close direction.
The thermocompression-bonded sheet adhered to the solder and the solder material supplied to the rigid board connecting lead are brought into contact with each other at a predetermined pressure, and the thermocompression-bonded sheet and the solder material are applied from the rigid board side. And the thermocompression-bonding sheet is softened at a predetermined temperature to become an adhesive, fill the periphery of the solder material, and melt the solder material, the heating is terminated and the connection portion is cooled. The method for connecting a rigid board and a flexible board, comprising the steps of: soldering the connecting leads together and adhering the rigid board to the flexible board.