JP7010481B2 - Connection structure between rigid circuit board and flexible circuit board - Google Patents

Description

The present invention relates to a connection structure between a rigid circuit board and a flexible circuit board.

Conventionally, as a structure for connecting an electric signal output from a circuit board constituting various electronic components such as a rotary electronic component and a slide electronic component to a connector, for example, the techniques described in Patent Document 1 and Patent Document 2 have been used. be.

In Patent Document 1, a pattern forming portion (13) of a flexible substrate (10) is insert-molded in a case (40) for an electronic component constituting a rotary electronic component, and a drawer portion (17) of the flexible substrate (11) is formed. ) Is pulled out from the electronic component case (40), and a terminal pattern (25) for connecting a connector is formed at the tip thereof.

Further, in Patent Document 2, the connection circuit pattern (69) provided near one end of the flexible circuit board (60) constituting the operation plate (1) and the rigid circuit board (90) arranged below the connection circuit pattern (69) are provided. The connection circuit pattern (69) is contacted with the connection circuit pattern (93), and the contact portion is repelled by the elastic member (120) installed on the upper surface side of the flexible circuit board (60). , (93) are connected, thereby electrically connecting to a connector (110) installed on the lower surface side of the rigid circuit board (90).

Further, conventionally, when the flexible circuit board has solder heat resistance, there is also a method of connecting by using solder or the like instead of the elastic member.

Japanese Patent Application Laid-Open No. 2003-174266 Japanese Unexamined Patent Publication No. 2010-118195

However, the above-mentioned conventional example has the following problems.
When a material having a low melting point such as a polyethylene terephthalate (PET) film is used as the synthetic resin film (11) constituting the flexible substrate (10) shown in the above cited document 1, it is formed on the synthetic resin film (11). The resulting resistor pattern (21) cannot be fired at a high temperature, and therefore, when a rotary electronic component using this resistor pattern (21) is placed in a high temperature environment, its resistance value changes. There was a risk that it would end up. On the other hand, when a polyimide (PI) film having high heat resistance is used as the synthetic resin film (11) in order to solve this problem, the material cost becomes high.

As shown in the above cited document 2, when the flexible circuit board (60) and the rigid circuit board (90) in which the connector (110) is installed are connected by using the elastic member (120), the elastic member (120) is connected. ) Will increase the number of parts and increase the cost. In addition, the assembly work becomes complicated.

In addition, when connecting using solder instead of the elastic member, not only the soldering process is required and it takes time, but also a PI film with high heat resistance must be used, so the material cost. Will be high.

The present invention has been made in view of the above points, and an object thereof is to obtain a stable electric output even in a high temperature environment, to have a small number of parts, to be easy to manufacture, and to increase the cost. It is an object of the present invention to provide a connection structure between a rigid circuit board and a flexible circuit board.

The present invention is a connection structure of a rigid circuit board and a flexible circuit board for connecting a connection pattern of a flexible circuit board to a connection pattern of the rigid circuit board, wherein the connection pattern of the rigid circuit board and the connection pattern of the flexible circuit board are connected. And are joined to each other, and the joined portion is sealed by a molded body formed by molding a molten resin, and a recess leading to the flexible circuit board is further formed on the side surface of the molded body on the side where the flexible circuit board is pulled out. The recess is characterized in that it is provided at a position overlapping the circuit pattern derived from the connection pattern of the flexible circuit board when projected from the upper surface or the lower surface of the joined portion .
According to the present invention, the circuit pattern provided on the rigid circuit board and the circuit pattern provided on the flexible circuit board can be easily and surely connected with a small number of parts, and the cost can be reduced. You can also do it.
At this time, if various electronic components such as rotary electronic components and slide-type electronic components are configured by using the above-mentioned rigid circuit board (if it is a rigid circuit board for various electronic components), a resistor provided on the rigid circuit board is provided. Since various circuit patterns such as body patterns can be easily fired at a high temperature, stable electrical output can be obtained even in a high temperature environment.
Further, the flexible circuit board pulled out from the side surface of the molded body bends toward the front and back directions of the flexible circuit board at the side portion pulled out from the side surface of the molded body, but at that time, when the flexible circuit board bends at an acute angle, There is a risk of damage such as cracks in the circuit pattern on the flexible circuit board in the bent portion. However, according to the present invention, when the flexible circuit board is bent on the side surface of the molded body, the bending is performed in the space in front of the recess in the portion where the recess is provided, so that the bending is not an acute angle and an arc is formed. It becomes the drawn bend. Since the circuit pattern of the flexible circuit board is provided so as to overlap the recesses, damage to the circuit pattern can be easily and surely prevented.

Further, in addition to the above features, the present invention is characterized in that the connection pattern of the rigid circuit board and the connection pattern of the flexible circuit board are joined via a conductive material having adhesiveness.
By using the conductive material having adhesiveness, the connection pattern of the rigid circuit board and the connection pattern of the flexible circuit board can be more reliably connected.

According to the present invention, stable electrical output can be obtained even in a high temperature environment, the number of parts is small, manufacturing work is easy, and cost can be reduced.

It is a perspective view which looked at the case 1 for an electronic component with a drawer part from the upper side. It is a perspective view which looked at the case 1 for an electronic component with a drawer part from the lower side. It is an enlarged perspective view of the main part which looked at the part which pulled out the flexible circuit board 80 from the case 10 for an electronic component, and looked at from the upper side. FIG. 3 is an enlarged perspective view of a main part of a portion in which a flexible circuit board 80 is pulled out from a case 10 for electronic components as viewed from below. It is an exploded perspective view of the case 1 for an electronic component with a drawer part seen from the upper side. It is an exploded perspective view of the case 1 for an electronic component with a drawer part seen from the lower side. An enlarged schematic cross-sectional view (enlarged in the AA line portion of FIG. 3) showing an enlarged periphery of the connection portion between the rigid circuit board 20 sandwiched and stored in the first and second molds A1 and A2 and the flexible circuit board 80. Schematic cross-sectional view). It is an operation explanatory drawing of the recesses 53a, 53b, 53c.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 and 2 are perspective views of an electronic component case 1 with a drawer configured using the present invention as viewed from above or below, and FIGS. 3 and 4 are flexible circuit boards from the electronic component case 10 respectively. Enlarged perspective view of the main part when the part where 80 is pulled out is seen from the upper side or the lower side, and FIGS. Each member cannot be disassembled, and the case 50 shows a solid state in which space due to other parts to be insert-molded is omitted).

As shown in these figures, the electronic component case 1 with a drawer includes a rigid circuit board (hard circuit board for various electronic components) 20 and a case (molded body) 50 constituting the electronic component case 10, and a flexible circuit. It is configured to include a substrate 80. In the following description, the "top" or "front" refers to the direction in which the surface of the rigid circuit board 20 on which the resistor pattern 25 or the like described below is formed is viewed from the opposite surface side, and is the opposite of the "bottom". It shall refer to the direction.

As shown in FIGS. 5 and 6, the rigid circuit board 20 has a substantially rectangular flat plate-shaped and long insulating rigid substrate 21 on the upper surface thereof, a linear conductor pattern 23, and the conductor pattern. A single linear resistor pattern 25 arranged parallel to the 23 is formed, and a plurality (three) connection patterns are formed in the vicinity of the outer periphery of one of the shorter surfaces of the upper surface of the hard substrate 21. 27, 29, 31 are formed, one end of the conductor pattern 23 and the connection pattern 27 are connected by a drawer pattern 33, and one end of the resistor pattern 25 and the connection pattern 29 are connected to the drawer pattern 35. The other end of the resistor pattern 25 and the connection pattern 31 are connected by a drawer pattern 37. In the outer periphery located between the connection patterns 27, 29, 31, two grooves 38, 39 are formed by cutting out the outer periphery in a concave shape. Further, a recess 41 cut out in a semicircular shape is formed at a position on the root side of the connection patterns 27 and 31 on both the left and right sides along the longitudinal direction of the hard substrate 21. Further, a positioning portion 43 formed of small holes penetrating is formed at a predetermined position of the hard substrate 21.

The case 50 is an integrally molded product obtained by molding a synthetic resin into a substantially rectangular shape, and has a bottom portion 51 formed on the entire lower surface of the hard circuit board 20 and a side wall portion 51a formed on a portion surrounding the outer periphery of the hard circuit board 20. , 51b, 51c, 51d. The conductor pattern 23 and the resistor pattern 25 on the upper surface of the rigid circuit board 20 are exposed on the upper surface of the case 50. The upper and lower portions of the flexible circuit board 80 are sandwiched and fixed by the case 50 in a state where the lower surface of the one end side portion thereof is in contact with and connected to the upper surface of the one end side portion of the rigid circuit board 20. Three recesses 53a, 53b, 53c extending from the upper surface of the side wall portion 51a to the flexible circuit board 80 are formed on the outer peripheral side surface of the side wall portion 51a on the side where the flexible circuit board 80 of the case 50 is pulled out. As shown in FIG. 3, each of the recesses 53a, 53b, 53c has the following circuit pattern 83 of the flexible circuit board 80 when the joint portion between the rigid circuit board 20 and the flexible circuit board 80 is projected from the upper surface or the lower surface thereof. It is provided at a location overlapping with 85 and 87.

Further, a cover mounting recess 55 for inserting a pair of claws of a cover (not shown) is formed from the outer peripheral side surfaces of the left and right side wall portions 51b and 51d along the longitudinal direction of the case 50 to the bottom surface of the bottom portion 51. The cover (not shown) is formed so as to cover the upper surface of the case 50. Further, at the positions corresponding to the connection patterns 27, 29, 31 of the rigid circuit board 20 on the bottom 51 of the case 50, three recesses 57 formed of small holes leading to the bottom surface of the rigid circuit board 20 are formed.

The flexible circuit board 80 is formed on the lower surface of the flexible substrate 81 in which a flexible insulating synthetic resin film (for example, PET film, polyphenylene sulfide [PPS] film, etc.) is formed in a substantially strip shape, as shown in FIG. As shown, a plurality of (three) drawing circuit patterns 83, 85, and 87 are formed in a substantially linear and parallel manner. A plurality (three) connection patterns 89, 91, 93 are formed on the lower surface of the flexible substrate 81 in the vicinity of the tip end side on the hard substrate 21 side at predetermined intervals along the tip end side. These connection patterns 89, 91, and 93 are connected to one end of each of the circuit patterns 83, 85, 87, respectively. These connection patterns 89, 91, and 93 are provided at positions facing each of the connection patterns 27, 29, and 31 of the rigid circuit board 20, respectively. On the other hand, a plurality of (three) connector connection patterns 95, 97, 99 are formed in the portion of the flexible substrate 81 near the tip side opposite to the hard board 21 at predetermined intervals along the tip side. Has been done. These connector connection patterns 95, 97, 99 are connected to one end of each of the circuit patterns 83, 85, 87, respectively.

Resin insertion holes 101 and 103 made of substantially rectangular small holes are formed at positions between the connection patterns 89, 91 and 93 of the flexible circuit board 80. Further, at both outer positions of the connection patterns 89, 91, 93 (both corner positions of the flexible substrate 81), a pair of rectangular overhanging portions 105, 107 projecting outward from both the left and right sides of the flexible substrate 81. , And the overhanging portions 105 and 107 are formed with resin insertion portions 109 and 111 having small holes. Further, positioning portions 113 and 115 composed of two through holes are formed at predetermined positions of the flexible circuit board 80. Further, a reinforcing plate 117 is attached to the opposite surface of the flexible circuit board 80 provided with the connector connection patterns 95, 97, 99.

Next, a method of manufacturing the case 1 for electronic parts with a drawer portion will be described. That is, in order to manufacture the case 1 for electronic components with a drawer portion, as shown in FIG. 7, the rigid circuit board 20 and the flexible circuit board 80 are sandwiched and stored in the first and second molds A1 and A2. .. At this time, the connection patterns 27, 29, 31 provided on the rigid circuit board 20 and the connection patterns 89, 91, 93 provided on the flexible circuit board 80 are attached to the conductive adhesives 117, 119, 121, respectively (FIGS. 5 and 5). 6) to join and bond. As the conductive adhesives 117, 119, 121, for example, silver paste is used.

At this time, as shown in FIG. 7, the positioning pin A11 provided in the first mold A1 is inserted into the positioning portion 43 provided on the rigid circuit board 20, and the positioning portion 113 provided on the flexible circuit board 80. The positioning pin A13 provided in the first mold A1 is inserted into the 115 (only 113 is shown in FIG. 7) and positioned. Further, the first and second molds A1 and A2 form a cavity C in the shape of the case 50. Further, on the side of the first mold A1, a resin injection portion C13 that opens into the cavity C is provided. Further, the portion provided with the connection patterns 27, 29, 31 of the rigid circuit board 20 and the portion provided with the connection patterns 89, 91, 93 of the flexible circuit board 80 are mainly the substrate pressing portions provided in the first mold A1. It is pressed by A15 and the substrate pressing portion A21 provided on the second circuit board A2, and is sandwiched and pressure-welded. The substrate pressing portions A15 are provided at three locations in the width direction, and these three recesses 53a, 53b, and 53c of the case 50 are formed. Further, the substrate pressing portions A21 are also provided at three locations in the width direction, whereby the three recesses 57 of the case 50 are formed. At this time, the groove portions 38 and 39 provided in the hard circuit board 20 face each of the resin insertion holes 101 and 103 provided in the flexible circuit board 80, and the recesses 41 provided in the hard circuit board 20. , 41 face each of the resin insertion portions 109 and 111 provided on the flexible circuit board 80.

Then, the cavity C is filled with the molten resin from the resin injection portion C13 and solidified, and then the first and second molds A1 and A2 are removed to complete the electronic component 1 with a drawer portion. Since the resin injection portion C13 is located opposite to the opposite surface side of the portion of the flexible circuit board 80 where the connection pattern 91 is provided, the pressure of the injected molten resin is the connection patterns 89, 91, 93. Acts as a force for pressing the connection patterns 27, 29, 31 of the rigid circuit board 20, thereby further improving the connection strength between the connection patterns 27, 29, 31 and the connection patterns 89, 91, 93. It is needless to say that the above manufacturing procedure is an example thereof, and manufacturing may be performed using various other different manufacturing procedures.

According to the electronic component 1 with a drawer portion, the connection patterns 27, 29, 31 of the rigid circuit board 20 and the connection patterns 89, 91, 93 of the flexible circuit board 80 are bonded to each other, and the bonded portions are formed of molten resin. Since it is configured to be sealed by the case (molded body) 50 according to the above, the circuit patterns 23, 25, 33, 35, 37 provided on the rigid circuit board 20 and the circuit patterns 83, 85 provided on the flexible circuit board 80 , 87 can be easily and surely connected with a small number of parts, and the cost can be reduced. Further, since the electronic component (case 10 for electronic component) is configured by using the hard circuit board 20, various circuit patterns such as the resistor pattern 25 provided on the hard circuit board 20 can be easily fired at a high temperature. Can be done. Therefore, stable electrical output can be obtained even when the electronic component (the electronic component case 10 or the electronic component (sliding electronic component) configured by using the electronic component case 10) is placed in a high temperature environment. can.

Further, in the electronic component 1 with a drawer portion, the connection patterns 27, 29, 31 of the rigid circuit board 20 and the connection patterns 89, 91, 93 of the flexible circuit board 80 are made of a conductive adhesive material (conductive property). Material) Since they are joined via 117, 119, 121, the connection patterns 27, 29, 31 of the rigid circuit board 20 and the connection patterns 89, 91, 93 of the flexible circuit board 80 are more reliably connected. be able to.

Further, the electronic component 1 with a drawer portion has recesses 53a, 53b, 53c leading to the flexible substrate 80 (upper surface thereof) on the side surface (side surface on the outer peripheral side of the side wall portion 51a) on the side where the flexible circuit board 80 of the case 50 is pulled out. The recesses 53a, 53b, 53c are further formed from the connection patterns 89, 91, 93 of the flexible circuit board 80 when the joint portion between the rigid circuit board 20 and the flexible circuit board 80 is projected from the upper surface or the lower surface thereof. Since it is provided at a position overlapping with the derived circuit patterns 83, 85, 87, damage to the circuit patterns 83, 85, 87 can be easily and surely prevented. That is, the flexible circuit board 80 pulled out from the side surface of the case 50 faces the front and back directions of the flexible circuit board 80 at the portion of the side H1 (see FIG. 8) without the recesses 53a, 53b, 53c pulled out from the side surface of the case 50. However, if the flexible circuit board 80 is bent at an acute angle at that time, the circuit pattern on the flexible circuit board 80 in the bent portion may be damaged such as cracks. However, according to the electronic component 1 with a drawer portion, when the flexible circuit board 80 is bent on the side surface of the case 50, the bending is in front of the recesses 53a, 53b, 53c in the portion where the recesses 53a, 53b, 53c are provided. Since it is performed in the space H2, it does not bend at an acute angle, but bends in an arc. Since the circuit patterns 83, 85, 87 of the flexible circuit board 80 are provided so as to overlap the recesses 53a, 53b, 53c, damage to these circuit patterns 83, 85, 87 can be easily and surely prevented. You can.

Further, the molded body as the case 50 penetrates the resin insertion holes 101 and 103 provided in the flexible circuit board 80 and the grooves 38 and 39 provided in the rigid circuit board 20 vertically, and also penetrates the flexible circuit board vertically. Since the resin insertion portions 109 and 111 provided in the 80 and the recesses 41 and 41 provided in the rigid circuit board 20 penetrate vertically, the rigid circuit board 20, the case 50, and the flexible circuit board 80 are fixed (connected). ) Can be performed more reliably. Further, by locating the overhanging portions 105 and 107 provided on the flexible circuit board 80 in the case 50, the pull-out strength of the flexible circuit board 80 from the case 50 can be further strengthened.

Further, as described above, the molded body constituting the case 50 penetrates the resin insertion holes 101 and 103 of the flexible circuit board 80 and the grooves 38 and 39 of the hard circuit board 20 vertically, whereby the hard circuit board is formed. The joint portions of the connection patterns 27, 29, 31 of 20 and the connection portions 89, 91, 93 of the flexible circuit board 80 are partitioned by the molded body for each joint portion. Therefore, it is possible to reliably prevent a short circuit between the joint portions.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications may be made within the scope of claims and the technical ideas described in the specification and drawings. It is possible. It should be noted that any shape, structure or material not directly described in the specification or drawings is within the scope of the technical idea of the present invention as long as the action and effect of the present invention are exhibited. For example, in the above embodiment, an example in which the present invention is applied to a case 1 for an electronic component with a drawer for a slide-type electronic component is shown, but for example, a case for an electronic component with a drawer for a rotary electronic component, etc. It may be applied to electronic components with drawers used for various other purposes. Further, in the above embodiment, a case for electronic parts is used as a molded body for sealing the joint portion where the connection pattern of the rigid circuit board and the connection pattern of the flexible circuit board are joined, but the case other than the case for electronic parts is used. The joint portion may be sealed by using various molded bodies (for example, a molded body used only for sealing the joint portion). Further, in the above embodiment, the recess formed on the side surface of the case on the side where the flexible circuit board is pulled out is provided on the upper surface side of the flexible circuit board, but conversely, it may be provided on the lower surface side of the flexible circuit board. May be provided on both the upper surface side and the lower surface side of the flexible circuit board. In addition, the above description and the embodiments shown in each figure can be combined with each other as long as there is no contradiction in the purpose, configuration, and the like. Further, the above description and the description contents of each figure can be independent embodiments even if they are a part thereof, and the embodiment of the present invention is one embodiment in which the above description and each figure are combined. Not limited to.

1 Case for electronic parts with drawer 10 Case for electronic parts 20 Rigid circuit board 23 Conductor pattern (circuit pattern)
25 Resistance pattern (circuit pattern)
27, 29, 31 Connection pattern 40 Case (molded body)
53a, 53b, 53c Recessed 80 Flexible circuit board 83,85,87 Circuit pattern 89,91,93 Connection pattern 117,119,121 Conductive adhesive (conductive material)

Claims (2)

It is a connection structure of a rigid circuit board and a flexible circuit board that connects the connection pattern of the flexible circuit board to the connection pattern of the rigid circuit board.
The connection pattern of the hard circuit board and the connection pattern of the flexible circuit board are joined to each other, and the joined portion is sealed by a molded body formed by molding a molten resin .
A recess leading to the flexible circuit board is formed on the side surface of the molded product on the side where the flexible circuit board is pulled out.
Further, the concave portion is provided at a position where it overlaps with the circuit pattern derived from the connection pattern of the flexible circuit board when projected from the upper surface or the lower surface of the joined portion. Board connection structure. The connection structure between the rigid circuit board and the flexible circuit board according to claim 1.
A connection structure between a rigid circuit board and a flexible circuit board, wherein the connection pattern of the rigid circuit board and the connection pattern of the flexible circuit board are joined via a conductive material having adhesiveness.

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