JP2001223465A - Connection method of printed-wiring board and connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve connection reliability and to reduce manufacturing costs. SOLUTION: A land 13a of a conductive pattern 13 that is formed on the connection surface of a flexible printed-wiring board 5 using thermoplastic resin as an insulating board material is electrically connected to a land 11a of a conductive pattern 11 that is formed on the connection surface of a rigid printed-wiring board 2 via solder 14. At this time, the conductive patterns 11 and 13 that are placed at a place, where the printed-wiring board 2 is connected to the printed-wiring board 5, are sealed by the thermoplastic resin composing the flexible printed-wiring board. In addition, the flexible printed-wiring board 5 has a region where the conductive pattern 13 is not formed at the connection surface tip, and the thermoplastic resin of the region is allowed to adhere to the connection surface of the rigid printed-wiring board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a structure for connecting printed wiring boards.

[0002]

2. Description of the Related Art Conventionally, a connection structure using an anisotropic conductive resin material has been known as a connection structure for a printed wiring board (Japanese Patent Laid-Open No. 9-8453). This means that an anisotropically conductive thermoplastic resin 52 is provided between the conductor pattern forming surface of the first printed wiring board 50 and the conductor pattern forming surface of the second printed wiring board 51 as shown in FIG. It is arranged and melts the thermoplastic resin 52 by pressure and ultrasonic waves. As a result, the space between the lands 50a and 50b is narrowed, and the two are electrically connected.

[0003] "Introduction to high-density flexible substrates"
On page 100 of (Numakura Kenshi, published by Nikkan Kogyo Shimbun), a method of connecting a hard printed board and a flexible board by solder fusion is described. According to this connection method, as shown in FIG. 10, the land 60a of the conductor pattern of the hard printed board 60 and the land 61a of the conductor pattern of the flexible board 61 are connected by solder 62. Further, the flexible board 61 is bonded to the hard printed board 60 via an adhesive 63.

[0004]

However, in the connection structure shown in FIG. 9, the printed wiring board 50,
It is necessary to print on the surface of the printed wiring board 51 or to place an anisotropic conductive resin film on the surface of the printed wiring boards 50 and 51. For this reason, the number of steps for obtaining the connection structure increases, which causes an increase in manufacturing cost. In addition, with the anisotropic conductive resin material 52 interposed, the printed wiring board 5
Since the surfaces 0 and 51 are connected to face each other, voids are easily generated at the bonding interface between the resin material 52 and the printed wiring boards 50 and 51, and the reliability is poor.

In the connection structure shown in FIG. 10, the flexible substrate 6 is used to secure the insulation reliability of the connection location.
After the connection of 1, the end of the flexible substrate 61 needs to be covered with a protective insulating film or the like, which again causes a problem that the number of manufacturing steps increases.

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a connection method and a connection structure for a printed wiring board, which are capable of improving connection reliability and reducing manufacturing costs. Aim.

[0007]

According to a first aspect of the present invention, there is provided a method for connecting a printed wiring board to a connecting surface of a first printed wiring board using a thermoplastic resin as an insulating substrate material, except for a leading end of the connecting surface. Forming a conductor pattern including a land as a connection terminal in a region; a land of the conductor pattern formed on a connection surface of the first printed wiring board; and a conductor pattern formed on a connection surface of the second printed wiring board. And arranging the lands so as to overlap with each other, and heating a connection point between the first printed wiring board and the second printed wiring board to a temperature equal to or higher than a glass transition temperature of the thermoplastic resin and applying pressure to the site. In addition, the land of the first printed wiring board and the land of the second printed wiring board are electrically connected, and the first printed wiring board is structured. Softening and deforming the thermoplastic resin to be adhered to the connecting surface of the second printed wiring board, and sealing the conductive pattern at the connecting portion with the thermoplastic resin. Have.

As described above, without using an anisotropic conductive film or the like, it is possible to use the deformability due to the change of the first printed wiring board itself and to seal the connection portion together with the terminal connection with resin, so that the manufacturing cost is reduced. Can be reduced. Further, a region where a conductor pattern is not formed is provided at the end of the connection surface of the first printed wiring board, and the end of the connection surface is brought into close contact with the connection surface of the second printed wiring board. The conductor pattern can be sealed.

According to a seventh aspect of the present invention, in the method of connecting a printed wiring board, a conductive pattern including lands as connection terminals is formed on a connection surface of the first printed wiring board using a thermoplastic resin as an insulating substrate material. Excluding the land of the conductive pattern, covering the conductive pattern with a protective film, and forming the protective film also near the end of the connection surface of the first printed wiring board; Arranging a land of the conductor pattern formed on the first printed wiring board and a land of the conductor pattern formed on the connection surface of the second printed wiring board with a connection material interposed therebetween; A connection point between the wiring board and the second printed wiring board is heated to a temperature equal to or higher than the glass transition temperature of the thermoplastic resin, and a pressure is applied to the connection point, whereby the first Wherein the land of the printed wiring board second
Is electrically connected to the land of the printed wiring board via the connection material, and the thermoplastic resin constituting the first printed wiring board is softened and deformed, and the conductor pattern at the connection portion is formed of the thermoplastic resin. Sealing, wherein a protective film formed at an end of the connection surface of the first printed wiring board blocks the flow of the connection material to the outside of the connection surface.

Accordingly, even if the amount of the connection material between the lands of the first and second printed wiring boards is excessive and flows when the two printed wiring boards are connected, the connection surface end of the first printed wiring board can be used. Since the protective film formed on the substrate blocks the flow, the insulation reliability at the connection point can be improved.

Further, in the method for connecting a printed wiring board according to the present invention, a conductive pattern including lands as connection terminals is formed on a connection surface of the first printed wiring board using a thermoplastic resin as an insulating substrate material. Forming and removing the land of the conductor pattern, when covering the conductor pattern with a protective film, at the end of the protective film,
Forming a convex portion so as to expose the surface of the first printed wiring board on both sides thereof while covering the conductive pattern; and forming a convex portion at a position separated by a predetermined distance from the tip of the connection surface of the second printed wiring board. Forming a conductive pattern including a land as a connection terminal on a second printed wiring board so that an end of the conductive pattern is terminated;
The land of the conductor pattern formed on the printed wiring board is overlapped with the land of the conductor pattern formed on the connection surface of the second printed wiring board, and the exposed surface of the first printed wiring board is Arranging the printed circuit board so as to face the front end of the connection surface of the printed circuit board, and heating a connection portion between the first printed circuit board and the second printed circuit board to a temperature equal to or higher than the glass transition temperature of the thermoplastic resin. And applying pressure to the portion,
Electrically connecting the land of the printed wiring board and the land of the second printed wiring board via the connection material, and softening and deforming the thermoplastic resin constituting the first printed wiring board; A step in which the portion of the thermoplastic resin of the first printed wiring board exposed from the protective film adheres to the tip of the connection surface of the second printed wiring board and seals the conductive pattern at the connection location with the thermoplastic resin; And characterized in that:

Thus, it is possible to improve the adhesive strength at the end of the second printed wiring board where the stress is applied most at the connection point between the first printed wiring board and the second printed wiring board. Furthermore, since the conductor pattern of the first printed wiring board located at the tip of the second printed wiring board is sealed so as to be surrounded by the thermoplastic resin and the second printed wiring board, the resin sealing is performed. Can be improved in reliability.

The printed wiring board connection structure according to claims 18, 24, and 31 is obtained by the printed wiring board connection method according to claims 1, 7, and 14, respectively. Is almost the same as the above.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a part of an electronic apparatus according to the first embodiment. Inside the electronic device, a rigid printed wiring board 1 and a rigid printed wiring board 2 are supported. Various electronic components are mounted on the rigid printed wiring board 1, and FIG. 1 shows a state where the IC 3 of the DIP package is mounted via the pins 3a. Similarly, various electronic components 4 are mounted on the rigid printed wiring board 2. As a material of the insulating substrate 10 of the rigid printed wiring boards 1 and 2, for example, a glass cloth base epoxy resin can be used.

A flexible printed wiring board 5 is connected between the ends of the rigid printed wiring board 1 and the rigid printed wiring board 2 which are horizontally arranged vertically to establish electrical continuity between them. As a material of the insulating substrate 12 of the flexible printed wiring board 5, 65 to 3 of polyetheretherketone (PEEK) resin is used.
5% by weight and a polyetherimide (PEI) resin of 35 to
A thermoplastic resin (@PEEK) containing 65% by weight is used. ＠PEEK is a thermoplastic resin that softens at a temperature equal to or higher than the glass transition temperature.

FIG. 2 is an enlarged view showing a connection portion between the rigid printed wiring board 2 and the flexible printed wiring board 5.

A plurality of conductor patterns 11 are formed on the upper surface of the rigid printed wiring board 2, and a land 11a is formed at an end of the conductor pattern 11 which terminates at a predetermined distance from an end of the board. This land 11a
A solder 14 is applied as a connection material on the top. A plurality of conductor patterns 13 are also formed on the surface of the flexible printed circuit board 5 corresponding to the conductor patterns 11 on the rigid printed circuit board 2, and lands 13a as connection terminals are formed at their ends. I have. These conductor patterns 11 and 13 are made of copper.

At the connection point between the rigid printed wiring board 2 and the flexible printed wiring board 5, the land 11a of the conductor pattern 11 and the land 13a of the conductor pattern 13
a is connected by the solder 14 and the glass epoxy resin 10 forming the rigid printed circuit board 2.
And Flexible Printed Wiring Board 5 @ PEE
K12 is bonded between the conductor patterns 11 and 13 by deformation of the PEEK12. Further, the glass epoxy resin 10 at the end of the rigid printed wiring board 2 is bonded to a solder resist 16 formed on the flexible printed wiring board 5 so as to cover the conductor pattern 13 other than the land 13a. Also, at the end of the flexible printed wiring board 5 ＠
Is bonded to a solder resist 15 formed on the rigid printed wiring board 2 so as to cover the conductor pattern 11 other than the land 11a. Therefore, the conductor pattern 1
The electrically conductive portions 1 and 13 are resin-sealed by the #PEEK 12 of the flexible printed wiring board 5.

FIG. 3A is a side view of the flexible printed wiring board 5, and FIG.
FIG. 2 shows a plan view when viewed from below. As shown in FIGS. 3A and 3B, the conductor pattern 13 has a plurality of wirings extending in parallel with the longitudinal direction of the flexible printed wiring board 5, and ends thereof function as lands 13a as connection terminals. Except for the land 13a, the conductor pattern 13 is covered with a solder resist 16 as a protective film.

The land 13a of the conductor pattern 13 is formed at a position separated from the tip of the connection surface of the printed wiring board 5 by a predetermined distance.
It consists only of EEK12. Among the plurality of wirings, the wirings located at both ends are also formed at positions separated by a predetermined distance from the side end surface of the PEEK12.
2 is securely sealed when it softens and deforms.

Next, a method of connecting the flexible printed circuit board 5 as the first printed circuit board and the rigid printed circuit board 2 as the second printed circuit board will be described with reference to FIG.

First, as shown in FIG. 4A, a conductor pattern 11 is formed on an insulating substrate 10 of a rigid printed wiring board 2. At this time, the conductor pattern 11 is not formed at the end of the connection surface of the rigid printed wiring board 2, and the glass epoxy resin 10 is exposed at the end of the rigid printed wiring board 2. Thereafter, the end of the rigid printed wiring board 2 where the conductor pattern 11 is not formed, the land 11 portion of the conductor pattern 11, and the land 1
Except for one space, a solder resist 15 is formed, and the conductor pattern 11 is covered with the solder resist 15.
Further, a solder paste 14 is applied to the land 11 a of the conductor pattern 11. When the solder 14 is formed, the land 11a may be plated with solder,
Solder coating may be performed. In this example, the solder 14
Eutectic solder of tin-lead is used, and its melting point (melting temperature) is 183 ° C.

A flux or a hydrocarbon compound such as alkane is applied to the solder 14 in order to ensure its wettability. In particular, when a hydrocarbon compound such as an alkane is applied, it is preferable to apply it not only to the solder 14 but also to the entire superposed surface of both substrates. In this case, if the alkane is heated above the boiling point of the alkane with the alkane interposed between the rigid printed wiring board 2 and the flexible printed wiring board 5, the alkane enters the surface of the PEEK12. As a result, on the surface of @ PEEK12,
A dispersion layer in which the alkane is dispersed is formed. This dispersion layer has a lower elastic modulus than the intrinsic elastic modulus of PEEK12. That is, by forming the dispersion layer on the surface, the adhesion to the layer to be adhered is strengthened.
2 can improve the adhesiveness.

Then, as shown in FIG. 4B, a conductor pattern 13 is formed on the flexible printed circuit board 5 so as to correspond to the conductor pattern 11 on the rigid printed circuit board 2.
To form Also at this time, the conductor pattern 13 is not formed at the end of the connection surface of the flexible printed wiring board 5. Then, the solder resist 16 is formed except for the tip of the flexible printed wiring board 5, the land 13a of the conductor pattern 13, and the space between the lands 13a.
The flexible printed circuit board 5 thus formed is aligned with the rigid printed circuit board 2 and overlapped.

Next, as shown in FIG. 4C, the connection portion where the rigid printed wiring board 2 and the flexible printed wiring board 5 are overlapped is heated while being pressed by the thermocompression bonding tool 21. At this time, the glass transition temperature of the PEEK 12 is 150 ° C. to 230 ° C.
Means that the connection point is higher than the melting temperature of the solder 14 and ΔPE
Pressure is applied to the site while heating to a temperature equal to or higher than the glass transition temperature of EK12. For example, the heating temperature is 240 ° C. to 300 ° C., and the heating and pressurizing are continued for 5 seconds to 15 seconds. In this embodiment, a pulse heat type thermocompression bonding tool 21 is used.

By this heating, the solder 14 is melted and the connection between the lands 11a and 13a of the conductor patterns 11 and 13 is performed, while the PEEK 12 constituting the insulating substrate of the flexible printed wiring board 5 is softened and deformed. The lands 11a and 13a and the conductor patterns 11 and 13 at the connection points are sealed with resin.

Here, in the present embodiment, the conductor pattern 13 is not formed at the tip of the flexible printed wiring board 5, and the flexible printed wiring board 5 has a portion consisting of only the PEEK12.
The tip made of the PEEK12 is the conductor pattern 1
3 can be supplied with a sufficient resin.

That is, as shown in FIG. 10, in the conventional flexible printed wiring board, since the conductor pattern is formed up to the end, there is a possibility that the conductor pattern is exposed at the end. For example, a configuration such as providing an insulating film for use was adopted.

On the other hand, in the present invention, a thermoplastic resin is used as a material of the insulating substrate of the flexible printed wiring board 5, and the resin sealing of the connection portion is performed by utilizing the fluidity of the thermoplastic resin. In particular, since a portion consisting of only the PEEK 12 is provided at the end of the flexible printed wiring board 5, the conductor pattern 13 can be reliably prevented from being exposed.

The PEEK 12 constituting the insulating substrate of the flexible printed wiring board 5 is softened and deformed when heated above the glass transition temperature.
In its softened state, it firmly adheres to glass epoxy resin and solder resist. For this reason, the adhesive which has been conventionally used for connecting the rigid printed wiring board and the flexible printed wiring board can be omitted in this example.

As described above, in the present embodiment, the resin sealing can be performed simultaneously with the terminal connection by utilizing the meltability of the substrate itself, so that the manufacturing cost can be reduced. Also,
When the PEEK 12 of the flexible printed wiring board 5 softens, the air flows between the rigid printed wiring board 2 and the flexible printed wiring board 5 in the direction of the rigid printed wiring board 2 while pushing away the air existing between the rigid printed wiring board 2 and the flexible printed wiring board 5. For this reason, compared with the case where a film or the like is sandwiched between the two substrates in advance, voids are less likely to be formed, and the reliability of the connection portion can be improved.

Second Embodiment Next, a second embodiment of the present invention will be described.
An embodiment will be described with reference to the drawings.

The connection method and connection structure between the rigid printed wiring board 2 and the flexible printed wiring board 105 according to the second embodiment are common to those according to the first embodiment in many cases. Detailed description is omitted, and different parts are mainly described.

The structure of the flexible printed wiring board 105 in the second embodiment is such that a solder resist 16a is also provided at the tip of the board as shown in FIGS. This is the most different point from the flexible printed circuit board 5.

Here, the solder 14 formed on the land 11a of the conductor pattern 11 on the rigid printed wiring board 2
Is excessive, when the thermocompression bonding tool 21 presses and heats the overlapping portion of the rigid printed wiring board 2 and the flexible printed wiring board 5, the molten solder 14 is removed from the flexible printed wiring board 10.
5 may protrude from the tip. That is, the solder 14
Is excessive, when the solder 14 is melted, the conductor pattern 1 of the flexible printed wiring board 5 is removed.
3, and in the worst case, it protrudes from the front end of the flexible printed wiring board 105.

For this reason, in this embodiment, as shown in FIGS. 5A and 5B, a solder resist 16a is provided at the end of the connection surface of the flexible printed wiring board 105. The solder resist 16a blocks the flow of the solder 14 even when an excessive amount of the solder 14 is given to the land 11a of the conductor pattern 11 even if an excessive amount of the solder 14 is given to the land 11a of the conductor pattern 11. For this reason, as shown in FIG. 6, when the flexible printed wiring board 105 and the rigid printed wiring board 2 are joined by the thermocompression bonding tool 21, the solder 14
Can be reliably prevented from protruding from the front end portion, and it is possible to ensure the insulation of the connection portion.

In the example shown in FIG. 5, the conductor pattern 13 made of copper is extended to the tip of the flexible printed wiring board 105, and a solder resist 16a is formed so as to cover the conductor pattern 13 at the tip. I have. However, the conductor pattern 13 does not need to be provided up to the front end of the substrate, and may be terminated before reaching the front end of the substrate, as in the first embodiment. In this case, the solder resist 16a may be formed directly on the PEEK 12, which is an insulating substrate of the flexible printed wiring board 105. In this manner, the conductor pattern 13 can be formed when the PEEK 12 is softened and deformed.
Is more preferable because there is no risk of being exposed to the outside.

The solder resist may be formed not only at the tip of the connection surface but also at both ends parallel to the longitudinal direction of the flexible printed wiring board 105. This makes it possible to prevent the solder from protruding in all directions.

(Third Embodiment) Next, a third embodiment of the present invention will be described.
An embodiment will be described with reference to the drawings.

The connection method and the connection structure between the rigid printed wiring board 2 and the flexible printed wiring board 205 according to the third embodiment are often the same as those according to the first embodiment. Detailed description is omitted, and different parts are mainly described.

In the third embodiment, as shown in FIG. 7A and FIG.
5 at the end of the solder resist 216, the conductor pattern 13 is covered.
The most different point from the flexible printed circuit board 5 in the first embodiment is that a plurality of convex portions 216a are formed in accordance with the conductor pattern 13 so as to expose the EEK 12.

The solder resist 216 is composed of, for example, a modified epoxy resin as a main component, and further includes a filler, an organic solvent, a curing agent, and the like. After the solder resist 216 is provided on the flexible printed circuit board 205, if the solder resist 216 is bonded to the glass epoxy resin which is the material of the insulating substrate 10 of the rigid printed circuit board 2 by applying pressure and heat, both of them have thermosetting properties. Therefore, the bonding strength is not sufficient.

For this reason, in the present embodiment, in the flexible printed wiring board 205, the adjacent conductor patterns 13
The solder resist 21 is removed by removing the solder resist in between.
The end of No. 6 was made uneven, and the PEEK12 thermoplastic resin was exposed in the concave part.

As shown in FIG. 8, the rigid printed wiring board 2 connected to the flexible printed wiring board 205 has a region where neither the conductor pattern 11 nor the solder resist 15 is formed at the end of the connection surface. That is, before connection with the flexible printed wiring board 205, the glass epoxy resin, which is the material of the insulating substrate 10 of the rigid printed wiring board 2, is exposed in the region of the distal end portion.

Then, as described above, the PEPE12 exposed at the concave portion of the solder resist 216
Is aligned with the glass epoxy resin 10 at the tip of the rigid printed wiring board 2. That is, @PEEK
The tip of the concave portion of the solder resist 216 that exposes 12 is positioned so as to be located inside the end surface of the rigid printed wiring board 2.

The exposed #PEEK 12 is softened and deformed and flows toward the rigid printed circuit board 2 when the joint is pressed and heated by the thermocompression bonding tool 21. Then, the softened #PEEK 12 adheres tightly to the glass epoxy resin 10 of the rigid printed circuit board 2, so that both are firmly joined.

As a result, it is possible to improve the bonding strength on the heel side of the bonding portion of the flexible printed circuit board 205 where the stress is most applied. Further, on the heel side of the joint portion of the flexible printed board 205,
Since the PEEK 12 reaches the surface of the rigid printed circuit board 2 and is strongly bonded to the glass epoxy resin 10,
The glass epoxy resin 10 and the ＠PEEK 12 surround the conductor pattern 13 on the heel side of the joint. Thereby, the resin sealing of the conductor pattern 13 on the heel side of the joint can be more complete.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, but can be implemented with various modifications.

For example, in the above-described embodiment, in the electrical connection between the rigid printed circuit board and the flexible printed circuit board, the connection between the terminals by soldering is performed by utilizing the thermoplastic property of the substrate material of the flexible printed circuit board. At the same time, resin sealing around the terminals was performed simultaneously. However, in connecting the first printed wiring board and the second printed wiring board, both or one of them may be a flexible printed wiring board using a thermoplastic resin.

When a rigid printed wiring board is used, a ceramic substrate or a metal base substrate other than the resin substrate may be used as the insulating substrate.

As the insulating resin material of the flexible printed circuit board, polyetherimide (PEI) or polyetheretherketone (PEEK) alone can be used in addition to the above-mentioned ＠PEEK. Further, polyethylene naphthalate (PEN) or polyethylene terephthalate (PET) may be used as an insulating resin material of the flexible printed wiring board.
Alternatively, as an insulating substrate of a flexible printed wiring board, PEEK, PEI, PEN,
PET having a structure in which at least one layer made of a thermoplastic resin material is laminated may be used. At the time of lamination, the polyimide substrate and the layer made of a thermoplastic resin material can be bonded to each other using, for example, an adhesive. The polyimide substrate has a coefficient of thermal expansion of about 15 to 20 ppm,
Since the coefficient of thermal expansion is close to that of copper (17 to 20 ppm), which is often used as wiring, peeling, warpage of the flexible printed wiring board, and the like can be prevented.

In the above-described example, the solder 14 is connected to the land 11 a of the conductor pattern 11 of the rigid printed circuit board 2.
However, it may be provided on the land 13a of the conductor pattern 13 on the flexible printed wiring board side. Also, solder may be provided on both lands 11a and 13a. Further, the lands (terminals) of both printed wiring boards may be joined using a conductive adhesive, or the lands may be brought into direct contact. Furthermore, the shape of the land in the conductor pattern may be any of a square land, a round land, and a deformed land.

Further, in the above-described first and second embodiments, the conductor pattern 13 is covered with a coverlay made of the above-mentioned thermoplastic material instead of the solder resists 16 and 16a of the flexible printed wiring boards 5 and 105. Is also good. As described above, a solder resist containing a modified epoxy resin as a main component has insufficient bonding strength with an epoxy resin as a substrate material of a rigid printed wiring board and a solder resist of the same component formed on the substrate. However, by covering the conductor pattern 13 of the flexible printed wiring boards 5 and 105 with a coverlay made of the above-described thermoplastic material (＠PEEK, PEEK, PEI, PEN, PET), this coverlay can be used as a rigid printed wiring board. It tightly adheres to an epoxy resin as a substrate material or a solder resist formed on the substrate, and can greatly improve the bonding strength between the two wiring substrates. In addition, this coverlay comes into close contact with the epoxy resin at the tip of the rigid printed circuit board,
It is possible to more reliably perform the resin sealing of the electrical connection portions of both wiring boards.

The solder resist 15 formed on the conductor pattern 11 of the rigid printed wiring board 2 may be a cover lay made of the above-mentioned thermoplastic resin.

[Brief description of the drawings]

FIG. 1 is an exemplary perspective view illustrating a part of an electronic apparatus according to an embodiment.

FIG. 2 is a cross-sectional view illustrating a connection portion according to the first embodiment.

FIG. 3 is a side view and a plan view of a flexible printed circuit board.

FIG. 4 is a cross-sectional view for explaining a manufacturing method.

FIG. 5 is a side view and a plan view of a flexible printed circuit board according to a second embodiment.

FIG. 6 is a cross-sectional view illustrating a connection portion according to the second embodiment.

FIG. 7 is a side view and a plan view of a flexible printed circuit board according to a third embodiment.

FIG. 8 is a cross-sectional view illustrating a connection portion according to a third embodiment.

FIG. 9 is a cross-sectional view for explaining a conventional technique.

FIG. 10 is a cross-sectional view for explaining a conventional technique.

[Explanation of symbols]

2 ... rigid printed wiring board, 5 ... flexible printed wiring board, 11 conductor patterns, 11a ... land, 1
3 ... conductor pattern, 13 a ... land, 14 ... solder, 15
... Solder resist, 16 ... Solder resist

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kenzo Hirano 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside Denso Corporation (72) Inventor Toshihiro Miya 1-1-1, Showa-cho, Kariya City, Aichi Prefecture Denso Corporation (72) Inventor Yuji Teramae 1-1-1, Showa-cho, Kariya-shi, Aichi, Japan Denso Co., Ltd. (72) Inventor Tomohiro Yokochi 1-1-1, Showa-cho, Kariya-shi, Aichi F-term (reference) 5E344 AA02 BB04 BB10 BB11 CC23 DD02 DD10 EE17

Claims (34)

[Claims] 1. A step of forming a conductor pattern including lands as connection terminals in a region other than a front end portion of a connection surface on a connection surface of a first printed wiring board using a thermoplastic resin as an insulating substrate material; Placing the land of the conductor pattern formed on the connection surface of the first printed wiring board and the land of the conductor pattern formed on the connection surface of the second printed wiring board in an overlapping manner; The connection between the first printed wiring board and the second printed wiring board is heated to a temperature equal to or higher than the glass transition temperature of the thermoplastic resin, and a pressure is applied to the connected part, so that the land of the first printed wiring board and the second printed While electrically connecting the land of the wiring board, the thermoplastic resin constituting the first printed wiring board is softened and deformed, and the Connection method of the printed wiring board, characterized in that the conductor pattern in the connection point with adhering the fat in connection surface of the second printed circuit board and a step of sealing with a thermoplastic resin. 2. A protection film is formed on the conductor pattern of the first printed wiring board except for the land, and the land is also removed on the conductor pattern of the second printed wiring board. The method for connecting a printed wiring board according to claim 1, wherein the protection film is formed by pressing. 3. The method according to claim 2, wherein a front end portion of the connection surface of the first printed wiring board is in close contact with a protective film formed on a conductor pattern of the second printed wiring board. Connection method of printed wiring board. 4. The conductor pattern on the second printed circuit board is formed such that the conductor pattern terminates at a position separated by a predetermined distance from the front end of the connection surface, and the connection without the conductor pattern is formed. 4. The method for connecting a printed wiring board according to claim 2, wherein a front end of the surface is brought into close contact with a protective film formed on the conductor pattern of the first printed wiring board. 5. The printed wiring according to claim 2, wherein the protective film formed on the conductor pattern of the first printed wiring board is formed of a thermoplastic resin material. Board connection method. 6. The conductive pattern according to claim 1, wherein each of the conductor patterns of the first and second printed wiring boards has a plurality of wirings and lands connected to the wirings. Connection method of printed wiring board. 7. A step of forming a conductor pattern including a land as a connection terminal on a connection surface of a first printed wiring board using a thermoplastic resin as an insulating substrate material, except for a land of the conductor pattern. with coating the conductive pattern in the protective film, the first a step of also forming the protective layer in the vicinity of connecting surface end portion of the printed circuit board, said first printed wiring lands of the conductive pattern formed on the substrate And arranging a land of the conductive pattern formed on the connection surface of the second printed wiring board with a connection material interposed therebetween, and connecting the first printed wiring board and the second printed wiring board. A portion is heated to a temperature equal to or higher than the glass transition temperature of the thermoplastic resin, and pressure is applied to the portion, so that the land of the first printed wiring board and the second printed wiring are The land of the substrate is electrically connected via the connection material, the thermoplastic resin constituting the first printed wiring board is softened and deformed, and the conductive pattern at the connection location is sealed with the thermoplastic resin. Formed on the end of the connection surface of the first printed wiring board
A method for connecting a printed wiring board, wherein the protective film blocks the flow of the connection material to the outside of the connection surface. 8. The method according to claim 1, wherein the thermoplastic resin at an end of the connection surface of the first printed wiring board is softened and deformed so as to cover a protective film formed near the end of the connection surface. 8. The method for connecting a printed wiring board according to 7. 9. The method of connecting a printed wiring board according to claim 7, wherein a protective film is formed also on the conductor pattern of the second printed wiring board except for the lands. 10. The thermoplastic resin at the end of the connection surface of the first printed wiring board is softened and deformed so as to cover the protective film, and the softened and deformed thermoplastic resin is applied to the second printed circuit board. 10. The method for connecting a printed wiring board according to claim 9, wherein the method is in close contact with a protective film formed on a conductor pattern of the wiring board. 11. The conductor pattern on the second printed wiring board is formed such that the conductor pattern terminates at a position separated by a predetermined distance from the front end of the connection surface, and the conductor pattern is not formed. The method for connecting a printed wiring board according to any one of claims 7 to 10, wherein a front end of the connection surface is in close contact with a protective film formed on a conductor pattern of the first printed wiring board. 12. The printed wiring according to claim 7, wherein the protective film formed on the conductor pattern of the first printed wiring board is formed of a thermoplastic resin material. Board connection method. 13. The printed circuit board according to claim 7, wherein each of the conductor patterns of the first and second printed wiring boards has a plurality of wirings and lands connected to the wirings. Connection method of printed wiring board. 14. A step of forming a conductor pattern including a land as a connection terminal on a connection surface of a first printed wiring board using a thermoplastic resin as an insulating substrate material, except for a land of the conductor pattern. When the conductive pattern is covered with the protective film, a convex portion is formed at an end of the protective film so as to expose the surface of the first printed wiring board on both sides while covering the conductive pattern. A conductor pattern including a land as a connection terminal in a second position so that an end of the conductor pattern is terminated at a position separated by a predetermined distance from a front end of the connection surface of the second printed wiring board.
Forming a land of the conductive pattern formed on the first printed wiring board and a land of the conductive pattern formed on the connection surface of the second printed wiring board; Arranging the first printed wiring board so that the surface of the first printed wiring board faces the front end of the connection surface of the second printed wiring board; and connecting the first printed wiring board to the second printed wiring board. A portion is heated to a temperature equal to or higher than the glass transition temperature of the thermoplastic resin, and pressure is applied to the portion, so that the land of the first printed wiring board and the land of the second printed wiring board are interposed via the connection material. To electrically connect the first printed wiring board, and to soften and deform the thermoplastic resin forming the first printed wiring board, thereby forming the first printed wiring in a portion exposed from the protective film. And a step of sealing the conductive pattern at the connection point with the thermoplastic resin while the thermoplastic resin of the plate is in close contact with the connection surface tip of the second printed wiring board. Connection method. 15. The connection pattern of the first printed wiring board, wherein the conductor pattern is formed so as to terminate at a position separated by a predetermined distance from a front end portion of the connection surface, and a thermoplastic resin at a front end portion of the connection surface. The method for connecting a printed wiring board according to claim 14, wherein the contact is in close contact with a connection surface of the second printed wiring board. 16. The method for connecting a printed wiring board according to claim 14, wherein a protective film is formed also on the conductor pattern of the second printed wiring board except for the lands. 17. The conductive pattern of the first and second printed wiring boards has a plurality of wirings and lands connected to the wirings, respectively.
17. The method for connecting a printed wiring board according to any one of claims 16 to 16. 18. A land of a conductor pattern formed on a connection surface of a first printed wiring board using a thermoplastic resin as an insulating substrate material, and a land of a conductor pattern formed on a connection surface of a second printed wiring board. Is a connection structure of a printed wiring board which is electrically connected, wherein a conductor pattern at a connection point between the first printed wiring board and the second printed wiring board constitutes the first printed wiring board. The first printed wiring board has an area where a conductor pattern is not formed at the end of the connection surface thereof, and the thermoplastic resin in the area is filled with the second resin. A connection structure for a printed wiring board, which is in close contact with the connection surface of the printed wiring board. 19. A protective film is formed on the conductor pattern of the first printed wiring board except for the lands,
19. The connection structure for a printed wiring board according to claim 18, wherein a protective film is formed also on the conductor pattern of the second printed wiring board except for the lands. 20. The device according to claim 19, wherein a front end portion of the connection surface of the first printed wiring board is in close contact with a protective film formed on a conductor pattern of the second printed wiring board. Connection structure of printed wiring board. 21. The conductor pattern on the second printed circuit board is formed such that the conductor pattern terminates at a position separated by a predetermined distance from the tip of the connection surface, and the connection without the conductor pattern is formed. The front end of the surface is in close contact with a protective film formed on a conductor pattern of the first printed wiring board.
0. The printed wiring board connection structure according to 0. 22. The printed wiring according to claim 18, wherein the protective film formed on the conductor pattern of the first printed wiring board is formed of a thermoplastic resin material. Board connection structure. 23. The conductive pattern of each of the first and second printed wiring boards has a plurality of wirings and lands connected to the wirings, respectively.
23. The connection structure for a printed wiring board according to any one of claims to 22. 24. A land of a conductor pattern formed on a connection surface of a first printed wiring board using a thermoplastic resin as an insulating substrate material, and a land of a conductor pattern formed on a connection surface of a second printed wiring board. Is a connection structure of a printed wiring board electrically connected, wherein the lands of the first and second printed wiring boards are electrically connected via a connection material;
A conductor pattern at a connection point between the printed wiring board and the second printed wiring board is sealed with a thermoplastic resin constituting the first printed wiring board, and the first printed wiring board is A connection structure for a printed circuit board, comprising: a protection film near an end of the connection surface, wherein the protection film blocks the flow of the connection material to the outside of the connection surface. 25. The method according to claim 24, wherein the thermoplastic resin at the end of the connection surface of the first printed wiring board is softened and deformed so as to cover a protective film formed at the end of the connection surface. The connection structure of the printed wiring board as described. 26. The printed wiring board connection structure according to claim 21, wherein a protective film is formed also on the conductor pattern of the second printed wiring board except for the lands. 27. The thermoplastic resin at the end of the connection surface of the first printed wiring board is softened and deformed so as to cover the protective film, so that the softened and deformed thermoplastic resin is applied to the second printed circuit board. 27. The connection structure for a printed wiring board according to claim 26, wherein the connection structure is adhered to a protective film formed on the conductor pattern of the wiring board. 28. The conductor pattern on the second printed wiring board is formed such that the conductor pattern terminates at a position separated by a predetermined distance from the tip of the connection surface, and the conductor pattern is not formed. 26. The connection surface tip portion is in close contact with a protective film formed on a conductor pattern of the first printed wiring board.
28. The connection structure for a printed wiring board according to any one of claims to 27. 29. The printed wiring according to claim 24, wherein the protective film formed on the conductor pattern of the first printed wiring board is formed of a thermoplastic resin material. Board connection structure. 30. The conductor pattern of each of the first and second printed wiring boards has a plurality of wirings and lands connected to the wirings, respectively.
30. The connection structure for a printed wiring board according to any one of claims to 29. 31. A land of a conductor pattern formed on a connection surface of a first printed wiring board using a thermoplastic resin as a material of an insulating substrate, and a land of a conductor pattern formed on a connection surface of a second printed wiring board. Is a connection structure of a printed wiring board electrically connected to the first printed wiring board, wherein a protective film covering the conductive pattern is provided except for a land of the conductive pattern, and an end of the protective film is provided. The portion is formed in a convex shape so as to expose the surface of the first printed wiring board on both sides thereof while covering the conductive pattern, and the conductor pattern of the second printed wiring board is formed at an end thereof. The first portion of the first printed wiring board exposed from the protective film is formed of a thermoplastic resin. The grease is brought into close contact with the front end of the connection surface of the second printed wiring board, and the conductor pattern at the connection point between the first printed wiring board and the second printed wiring board is replaced with the first printed wiring board. A connection structure for a printed wiring board, characterized by being sealed with a thermoplastic resin constituting the board. 32. On the connection surface of the first printed wiring board, the conductor pattern is formed so as to terminate at a position separated by a predetermined distance from a front end portion of the connection surface, and a thermoplastic resin at the front end portion of the connection surface. 32. The connection structure for a printed wiring board according to claim 31, wherein a contact is closely attached to a connection surface of the second printed wiring board. 33. The printed wiring board connection structure according to claim 31, wherein a protective film is formed also on the conductor pattern of the second printed wiring board except for the lands. 34. The conductor pattern of each of the first and second printed wiring boards has a plurality of wirings and lands connected to the wirings, respectively.
34. The connection structure for a printed wiring board according to any one of claims to 33.