JP5019354B2 - Sensor module board connection structure and board connection method - Google Patents

Description

The present invention relates to a sensor module substrate connection structure and a substrate connection method for connecting, for example, a glass substrate on which an ITO (Indium Tin Oxide) electrode is formed to a rigid printed wiring board via a flexible wiring board.

  For example, a multifunctional image forming apparatus called a so-called multifunction peripheral (MFP) having a scanner function, a printing function, a copying function, a network connection function, and the like is used to read characters, images, etc. from a reading object such as a document. It is equipped with a line scanning sensor module that optically reads the information.

  This type of sensor module includes a light source that irradiates a reading target with light. As this light source, an LED light emitting element is widely used. However, in recent years, an attempt has been made to use an organic EL light emitting element as disclosed in Patent Document 1 instead of the LED light emitting element.

  The organic EL light emitting device includes a strip-shaped glass substrate extending in the scanning direction and a light emitting layer formed on the surface of the glass substrate. The light emitting layer emits light by electroluminescence when an electric field is applied, and is electrically connected to an electrode formed on an end portion of the glass substrate.

  The organic EL light emitting element is electrically connected to a rigid printed wiring board. The printed wiring board is made of a hard material that is difficult to bend, such as glass epoxy resin or ceramic. This printed wiring board has electrode pads corresponding to the electrodes of the glass substrate.

When electrically connecting the electrode on the glass substrate and the electrode pad on the printed wiring board, for example, a flexible wiring board as disclosed in Patent Document 2 may be used. The flexible wiring board has a first end connected to the electrode of the glass substrate and a second end connected to the electrode pad of the printed wiring board. The first end of the flexible wiring board and the electrode of the glass substrate, and the second end of the flexible wiring board and the electrode pad of the printed wiring board may be thermocompression bonded with an anisotropic conductive film interposed therebetween, for example. Alternatively, they are joined electrically and mechanically by soldering or the like.
JP 2003-87502 A Japanese Patent Laid-Open No. 3-50871

  The glass substrate of the organic EL light emitting element and the printed wiring board have different thermal expansion coefficients. For this reason, when the glass substrate and the printed wiring board are subjected to external environmental stresses such as temperature and humidity, the printed wiring board expands or contracts more than the glass substrate.

  As a result, even if the flexible wiring board interposed between the glass substrate and the printed wiring board has flexibility, the expansion / contraction difference generated between the printed wiring board and the glass substrate by this flexible wiring board can be reduced. It becomes difficult to absorb quickly.

  Therefore, there is a problem that a large stress is generated in the connection portion between the electrode of the glass substrate and the flexible wiring board and the connection portion between the electrode pad of the printed wiring board and the flexible wiring board, and this causes the connection portion to be easily damaged. .

An object of the present invention is to reliably absorb the expansion / contraction difference generated between the glass substrate and the printed wiring board, and to connect the flexible wiring board and the glass substrate and between the flexible wiring board and the printed wiring board. An object of the present invention is to provide a sensor module substrate connection structure that can prevent breakage of a connection portion.

Another object of the present invention is that a slack portion for absorbing the expansion / contraction difference generated between the glass substrate and the printed wiring board can be easily formed on the flexible wiring board, and there is no difficulty in the process. The object is to obtain a substrate connection method for a sensor module that is easy to work with.

In order to achieve the above object, a substrate connection structure for a sensor module according to an embodiment of the present invention is a rigid structure in which a strip extending in a straight line is formed, and first electrodes are formed at both ends in the longitudinal direction of the mounting surface. A printed wiring board having a length shorter than that of the printed wiring board and mounted on the mounting surface of the printed wiring board. And a third electrode connected to the first electrode of the printed wiring board, and a glass substrate constituting an organic EL light emitting element having a thermal expansion coefficient different from that of the printed wiring board. , and a fourth electrode connected to the second electrode of the glass substrate, provided with a flexible wiring board for electrical connection between the printed circuit board and the glass substrate,
In the flexible wiring board, a freely deformable slack portion that is curved in a direction away from the mounting surface of the printed wiring board is formed between the third electrode and the fourth electrode. It is characterized by that.

Furthermore, in the sensor module board connection method according to the present invention, the first electrode is formed between the first electrode formed on the mounting surface of the printed wiring board and the second electrode formed on the glass substrate. Electrically connecting using a flexible wiring board having a third electrode corresponding to the fourth electrode and a fourth electrode corresponding to the second electrode,
And it said fourth electrode of said of said glass substrate second electrode and the flexible wiring board connected to each other, placing the flexible wiring board in which the glass substrate is connected to the top of the mounting surface of the printed circuit board as well as location, the linear member is interposed across between said third electrode and the fourth electrode of the flexible circuit board between the flexible wiring board and the mounting surface, the flexible wiring board by connecting the a and the first electrode of the third electrode and the printed circuit board to each other, the portion corresponding to the linear body of the flexible wiring board in an arc shape in a direction away from the mounting surface Curving and finally pulling out the linear body from between the flexible wiring board and the mounting surface, so that the third electrode and the fourth electrode of the flexible wiring board That of forming a slack portion that can be freely deformed in the intermediate portion is characterized.

  According to the present invention, when a difference in expansion / contraction occurs between the glass substrate and the printed wiring board due to the difference in thermal expansion coefficient between the two, the slack portion of the flexible wiring board depends on the expansion / contraction direction. By freely deforming, the expansion / contraction difference generated between the glass substrate and the printed wiring board is absorbed.

  For this reason, the stress which generate | occur | produces in the connection part of a glass substrate and a flexible wiring board and the connection part of a printed wiring board and a flexible wiring board can be reduced, and the failure | damage of a connection part can be avoided.

  Further, the slack portion of the flexible wiring board is formed in the flexible wiring board in the final process of connecting the flexible wiring board to which the glass substrate is connected to the printed wiring board. For this reason, a dedicated process for forming the slack portion is not required, and the slack portion can be easily and reliably formed without any unreasonable process.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 9 in which the first embodiment is applied to a contact sensor module.

  FIG. 1 discloses a contact sensor module 1 used in a multifunctional image forming apparatus called, for example, a multifunction peripheral (MFP). The contact sensor module 1 is for optically reading information such as characters and images from a reading object such as a document, and is installed below a conveyance path for conveying the reading object.

  The contact sensor module 1 has a housing 2 made of synthetic resin. The housing 2 has an elongated bar shape extending in the scanning direction. As shown in FIG. 2, a first recess 3 is formed on the upper surface of the housing 2. The first recess 3 extends in the longitudinal direction of the housing 2. The first recess 3 has an opening 4 that opens to the upper surface of the housing 2 and a bottom surface 5 that faces the opening 4. The opening 4 is closed by a transparent glass plate 6.

  A second recess 7 is formed on the bottom surface of the housing 2. The second recess 7 extends in the longitudinal direction of the housing 2. The second recess 7 communicates with the first recess 3 through a communication hole 8 formed inside the housing 2. The communication hole 8 is located at the center along the width direction of the housing 2 and extends in the longitudinal direction of the housing 2.

  A lens unit 9 is held inside the communication hole 8. The lens unit 9 extends in the longitudinal direction of the housing 2, and its upper end protrudes into the first recess 3. The lens unit 9 has a central axis O1 that stands up perpendicular to the scanning direction.

  A sensor substrate 10 is attached to the second recess 7. The sensor substrate 10 extends in the longitudinal direction of the housing 2 so as to close the second recess 7. A plurality of CCD image sensors 11 are mounted on the upper surface of the sensor substrate 10. The CCD image sensors 11 are arranged in a line at intervals in the longitudinal direction of the housing 2 and are positioned on the central axis O <b> 1 of the lens unit 9.

  The first recess 3 of the housing 2 accommodates an EL light source unit 15 as shown in FIG. The EL light source unit 15 of the present embodiment includes a rigid printed wiring board 16, a pair of organic EL light emitting elements 17 and 18, and four flexible wiring boards 19.

  The printed wiring board 16 is made of a hard material that is difficult to bend, such as glass epoxy resin or ceramic. The printed wiring board 16 has a pair of EL support portions 21a and 21b.

  As shown in FIG. 5, the EL support portions 21 a and 21 b have a strip shape extending in a straight line in the longitudinal direction of the housing 2 along the scanning direction. Each of the EL support portions 21a and 21b has a first end portion 22 located at one end along the longitudinal direction and a second end portion 23 located at the other end along the longitudinal direction.

  The first end portion 22 of one EL support portion 21a and the first end portion 22 of the other EL support portion 21b are connected to each other via a bridge portion 24 shown in FIG. Similarly, the second end portion 23 of one EL support portion 21a and the second end portion 23 of the other EL support portion 21b are connected to each other via another bridge portion 25. For this reason, the EL support portions 21a and 21b of the printed wiring board 16 are arranged in parallel with a space between each other.

  As shown in FIG. 5, each EL support portion 21 a, 21 b has a first surface 27 as a mounting surface and a second surface 28 located on the opposite side of the first surface 27. A pair of first electrodes 29 are formed on the first surface 27 at positions corresponding to the first end 22 and the second end 23, respectively. As shown in FIG. 3, the first electrode 29 is arranged in the width direction of the EL support portions 21a and 21b at the first end portion 22 and the second end portion 23, and the EL support portions 21a and 21b Separated in the longitudinal direction. For this reason, each of the EL support portions 21a and 21b has four first electrodes 29.

  Further, the second surfaces 28 of the EL support portions 21a and 21b are fixed to the bottom surface 5 of the first recess 3 via the metal plate 30 shown in FIG. With this fixing, the lens unit 9 is inserted between the EL support portions 21 a and 21 b of the printed wiring board 16.

  The organic EL light emitting elements 17 and 18 are mounted on the first surfaces 27 of the EL support portions 21a and 21b. The organic EL light emitting elements 17 and 18 each include a transparent glass substrate 31 and a light emitting layer 32. The glass substrate 31 has an elongated strip shape extending in the scanning direction. The glass substrate 31 has a first end portion 33 located at one end along the longitudinal direction and a second end portion 34 located at the other end along the longitudinal direction.

  A pair of second electrodes 36 are respectively formed on the first and second end portions 33 and 34 of the glass substrate 31. The second electrode 36 is an ITO (Indium Tin Oxide) electrode made of, for example, an oxide film of indium and tin, and is arranged in the width direction of the glass substrate 31 and the first surface 27 of the printed wiring board 16. Facing each other.

  The light emitting layer 32 is formed on the upper surface of the glass substrate 31 and extends in the longitudinal direction of the glass substrate 31. The light emitting layer 32 emits light by electroluminescence when an electric field is applied, and one end and the other end along the longitudinal direction are electrically connected to the second electrode 36. For this reason, the light emitting layer 32 is given an electric field by applying a voltage to the both ends of the longitudinal direction, and the light emitting layer 32 light-emits uniformly along a longitudinal direction. In other words, the luminance distribution of the light emitting layer 32 is uniform along the scanning direction.

  The glass substrate 31 of the organic EL light emitting elements 17 and 18 is bonded to the first surfaces 27 of the EL support portions 21a and 21b via, for example, a double-sided adhesive tape 37. By this adhesion, the organic EL light emitting elements 17 and 18 are integrated with the printed wiring board 16 and are arranged in two rows with the lens unit 9 interposed therebetween.

  Further, in a state where the organic EL light emitting elements 17 and 18 are bonded to the EL support portions 21a and 21b of the printed wiring board 16, the glass substrate 31 of the organic EL light emitting elements 17 and 18 is separated in the longitudinal direction of the EL support portions 21a and 21b. Between the first electrodes 29. As a result, the first electrode 29 of the printed wiring board 16 and the second electrode 36 of the organic EL light emitting elements 17 and 18 are adjacent to each other along the longitudinal direction of the organic EL light emitting elements 17 and 18.

  When the organic EL light emitting elements 17 and 18 emit light, the light from the organic EL light emitting elements 17 and 18 is applied to the reading object on the transport path through the glass plate 6. The light applied to the reading object is reflected by the reading object and then guided to the image sensor 11 through the lens unit 9. The image sensor 11 outputs a signal having a level corresponding to the amount of received light. Thereby, information such as characters and images on the reading object is optically read.

  As shown in FIG. 5, the flexible wiring board 19 is for electrically connecting the organic EL light emitting elements 17 and 18 and the printed wiring board 16. Each flexible wiring board 19 has an insulating film 38 having flexibility such as polyester or polyimide. A third electrode 39 and a fourth electrode 40 are formed on the insulating film 38. The third electrode 39 and the fourth electrode 40 are electrically connected through a conductor pattern 41 shown in FIG.

  When the organic EL light-emitting elements 17 and 18 are placed on the first surfaces 27 of the EL support portions 21a and 21b, the insulating film 38 is connected to the first electrode 29 of the printed wiring board 16 and the organic EL light-emitting elements 17 and 17. It has a length dimension so as to straddle between the 18 second electrodes 36.

  The third electrode 39 corresponds to the first electrode 29 of the printed wiring board 16 and is located at one end of the insulating film 38. The fourth electrode 40 corresponds to the second electrode 36 of the glass substrate 31 and is located at the other end of the insulating film 38.

  The fourth electrode 40 of the flexible wiring board 19 and the second electrode 36 of the glass substrate 31 are thermocompression bonded with an anisotropic conductive film 42 interposed therebetween. Similarly, the first electrode 29 of the printed wiring board 16 and the third electrode 39 of the flexible wiring board 19 are thermocompression bonded to each other with another anisotropic conductive film 43 interposed therebetween.

  Therefore, the flexible wiring board 19 electrically connects the first electrode 29 and the third electrode 39 and the second electrode 36 and the fourth electrode 40 on the first surface 27 of the printed wiring board 16. Mechanically connected.

  As shown in FIGS. 3 and 5, the flexible wiring board 19 has a slack portion 45 at an intermediate portion located between the third electrode 39 and the fourth electrode 40. The slack portion 45 is configured by bending the insulating film 38 so as to be curved in an arc shape in a direction away from the first surface 27 of the printed wiring board 16.

  As a result, a space 46 is secured between the slack portion 45 and the first surface 27 of the printed wiring board 16. Due to the presence of the space 46, the slack portion 45 can be freely elastically deformed in an arbitrary direction.

  The diameter D of the circular arc drawn by the slack portion 45 depends on the thickness of the organic EL light-emitting elements 17 and 18, but is desirably 0.2 mm to 0.4 mm, particularly 0.3 mm. That is, when the diameter D is less than 0.2 mm, the degree of curvature of the slack portion 45 is insufficient, and the deformation amount of the slack portion 45 is insufficient.

  On the contrary, when the diameter D exceeds 0.5 mm, the top of the slack portion 45 protrudes above the organic EL light emitting elements 17 and 18, and the slack portion 45 is interposed between the organic EL light emitting elements 17 and 18 and the glass plate 6. A space to accommodate For this reason, the housing 2 is increased in size, which is not preferable when the contact sensor module 1 is made compact.

  As shown in FIG. 5, the connection portion between the second electrode 36 of the glass substrate 31 and the fourth electrode 40 of the flexible wiring board 19 is covered with a moisture-proof material 47. Similarly, the connection portion between the first electrode 29 of the printed wiring board 16 and the third electrode 39 of the flexible wiring board 19 is covered with another moisture-proof material 48.

  As the moisture-proof materials 47 and 48, for example, acrylate radical polymerization type epoxy-modified acrylate, urethane-modified acrylate, silicone-modified acrylate, silicon-based or epoxy-cation polymerization-type acrylic ultraviolet-curing synthetic resin is used.

  Next, a procedure for electrically connecting the EL support portions 21a and 21b of the printed wiring board 16 and the organic EL light emitting elements 17 and 18 will be described as a representative of one organic EL light emitting element 17 side.

  As shown in FIG. 6, the flexible wiring board 19 maintains a flat shape before being connected to the printed wiring board 16 or the glass substrate 31.

  First, the second electrode 36 positioned at the first end 33 of the glass substrate 31 and the fourth electrode 40 of the flexible wiring board 19 are opposed to each other with the anisotropic conductive film 42 interposed therebetween. In this state, the glass substrate 31 and the flexible wiring board 19 are pressurized in a direction approaching each other, the anisotropic conductive film 42 is sandwiched between the second electrode 36 and the fourth electrode 40, and the flexible wiring board 19. Heat using a welding tool. As a result, the second electrode 36 and the fourth electrode 40 are thermocompression bonded via the adhesive film of the anisotropic conductive film 42, and the flexible wiring board 19 is bonded to the first end 33 of the glass substrate 31. The

  Next, the second electrode 36 positioned at the second end 34 of the glass substrate 31 and the fourth electrode 40 of the flexible wiring board 19 are thermocompression bonded in the same procedure as described above. Thereby, the flexible wiring board 19 is joined to the first and second end portions 33 and 34 of the glass substrate 31.

  Thereafter, a moisture-proof material 47 is applied to a portion of the connecting portion between the second electrode 36 and the fourth electrode 40 that enters between the glass substrate 31 and the printed wiring board 16 and dried.

  Next, the glass substrate 31 to which the flexible wiring board 19 is bonded is bonded to the first surface 27 of the EL support portion 21a. Subsequently, the third electrode 39 of the flexible wiring board 19 joined to the first end portion 33 of the glass substrate 31 and the first electrode 29 of the EL support portion 21a are interposed with the anisotropic conductive film 43 therebetween. Opposite to each other.

  In this state, the EL support portion 21a and the flexible wiring board 19 are pressurized in a direction approaching each other, the anisotropic conductive film 43 is sandwiched between the first electrode 29 and the third electrode 39, and the flexible wiring board 19 is heated using a welding tool. As a result, the first electrode 29 and the third electrode 39 are thermocompression bonded via the adhesive film of the anisotropic conductive film 43, and the flexible wiring board 19 is bonded to the first end 22 of the EL support portion 21a. Is done.

  When sandwiching the anisotropic conductive film 43 between the first electrode 29 and the third electrode 39, as shown in FIG. 7, the intermediate portion of the flexible wiring board 19 and the first surface 27 of the EL support portion 21a. A piano wire 51 having a diameter of 0.3 mm is interposed between the two. The piano wire 51 is an example of a wire member and crosses between the third electrode 39 and the fourth electrode 40.

  In the state where the first electrode 29 and the third electrode 39 are joined due to the presence of the piano wire 51, the insulating film 38 of the flexible wiring board 19 bypasses the piano wire 51 as shown in FIG. Curved in an arc.

  Next, also at the second end portion 34 of the glass substrate 31, the flexible wiring board 19 is joined to the second end portion 23 of the EL support portion 21a in the same procedure as described above, and the insulation of the flexible wiring board 19 is also performed. The film 38 is curved in an arc shape along the piano wire 51.

  When the adhesive film of the anisotropic conductive film 43 is cured, the piano wire 51 is pulled out from between the EL support portion 21 a and the flexible wiring board 19. As a result, as shown in FIG. 9, a slack portion 45 that is curved in an arc shape toward the upper side of the EL support portion 21 a is formed in the intermediate portion of the flexible wiring board 19. At the same time, a space 46 that allows free deformation of the slack portion 45 is formed between the slack portion 45 and the EL support portion 21a.

  Thereafter, the moisture-proof material 47 is applied again to the portion of the connecting portion between the second electrode 36 and the fourth electrode 40 that has been thermocompression bonded first and exposed to the outer periphery of the glass substrate 31 from the moisture-proof material 47. ,dry. Thereby, the connection portion between the second electrode 36 and the fourth electrode 40 is completely covered with the moisture-proof material 47.

  Finally, a moisture-proof material 48 is applied and cured so as to cover the joint between the first electrode 29 and the third electrode 39. Thereby, the connection work of the organic EL light emitting element 17 to the EL support portion 21a is completed.

  According to such a contact type sensor module 1, the glass substrate 31 of the organic EL light emitting elements 17 and 18 and the printed wiring board 16 on which the glass substrate 31 is mounted have different thermal expansion coefficients. When the temperature of the EL light source unit 15 rises due to the thermal effect of the self-heating of the organic EL light-emitting elements 17 and 18, the elongation amount due to the thermal expansion of the printed wiring board 16 greatly exceeds the elongation amount of the glass substrate 31.

  In particular, the first and second end portions 33 and 34 of the glass substrate 31 are connected to the printed wiring board 16 via the flexible wiring board 19, respectively. Receive the accompanying pulling force.

  In the first embodiment, since the slack portion 45 is formed in the intermediate portion of the flexible wiring board 19, when the flexible wiring board 19 receives a tensile force, the slack portion 45 follows the acting direction of the pulling force. Then, it is deformed freely and absorbs the tensile force applied to the flexible wiring board 19.

  For this reason, the stress which arises in the junction part of the 1st electrode 29 and the 3rd electrode 39, and the connection part of the 2nd electrode 36 and the 4th electrode 40 can be reduced.

  Further, as in the first embodiment, the first electrode 29 and the third electrode 39, and the second electrode 36 and the fourth electrode 40 are heated via the anisotropic conductive films 42 and 43. In the connection method in which pressure bonding is performed, when moisture enters the connection portion between the electrodes, moisture becomes one factor that promotes peeling of the connection portion.

  However, in the first embodiment, the joint between the first electrode 29 and the third electrode 39 is covered with the moisture-proof material 48 and the connection between the second electrode 36 and the fourth electrode 40 is performed. The part is covered with a moisture-proof material 47. For this reason, it is possible to prevent moisture from entering the connecting portion between the electrodes, and it is difficult for the connecting portion to be peeled off.

  Accordingly, in addition to reducing the stress generated in the connecting portion, it is possible to surely avoid the breakage of the connecting portion, and there is an advantage that the reliability of the electrical connection between the glass substrate 31 and the printed wiring board 16 is improved. is there.

  The inventor conducted a reliability acceleration test including a thermal shock test and a high-temperature and high-humidity storage test in the EL light source unit 15 having the above-described configuration, and examined whether or not the connection portion was broken.

(1) As a condition of the thermal shock test, the operation of cooling the EL light source unit 15 at −30 ° C. for 30 minutes and heating at 70 ° C. for 30 minutes was defined as one cycle, and this operation was repeated 300 times.

(2) As conditions for the high temperature and high humidity storage test, the EL light source unit 15 was stored in an environment of 60 ° C. and 90% RH for 1000 hours.

  As a result, in the EL light source unit 15 in which the slack portion 45 is formed in the intermediate portion of the flexible wiring board 19 and the connection portions between the electrodes are covered with the moisture-proof materials 47 and 48, the connection portions did not break.

  On the other hand, in the case of an EL light source unit in which the flexible wiring board having no slack portion 45 and the moisture-proof material are omitted, in the thermal shock test, the connection portion between the electrodes is destroyed before reaching 100 cycles, and the high temperature In the wet test, it was confirmed that the connection between the electrodes was broken within 200 hours.

  Therefore, by forming the slack portion 45 on the flexible wiring board 19 and covering the connection portion between the electrodes with the moisture-proof materials 47 and 48, it is possible to effectively prevent the breakage of the connection portion.

  Furthermore, according to the connection method according to the first embodiment, the slack portion 45 of the flexible wiring board 19 connects the third electrode 39 of the flexible wiring board 19 to the first electrode 29 of the printed wiring board 16. On the way, it is formed on the insulating film 38 of the flexible wiring board 19.

  In other words, the slack portion 45 can be formed by a simple operation of placing the insulating film 38 along the piano wire 51, and an independent work process for forming the slack portion 45 is not necessary. Therefore, workability does not occur and the workability is improved.

  The present invention is not limited to the first embodiment described above, and various modifications can be made without departing from the spirit of the invention.

FIG. 10 discloses a reference example relevant to the present invention. This reference example is different from the first embodiment in the bent shape of the flexible wiring board 19 and the structure of the connecting portion between the flexible wiring board 19 and the printed wiring board 16. Other configurations of the EL light source unit 15 are basically the same as those in the first embodiment. For this reason, in the reference example , the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 10, the first electrode 29 of the printed wiring board 16 is formed on the second surface 28 located on the opposite side of the glass substrate 31. The flexible wiring board 19 that connects the first electrode 29 of the printed wiring board 16 and the second electrode 36 of the glass substrate 31 passes through the outside of the outer peripheral edge of the printed wiring board 16 and the first surface of the printed wiring board 16. 27 and a bent portion 60 straddling the second surface 28. The bent portion 60 is curved in an arc shape, and a gap 61 that allows free deformation of the bent portion 60 is formed between the inner surface of the bent portion 60 and the outer peripheral edge portion of the printed wiring board 16. .

In the reference example , since the end portion of the flexible wiring board 19 wraps around the second surface 28 from the first surface 27 of the printed wiring board 16, the third electrode 39 of the flexible wiring board 19 is printed by thermocompression bonding. When connecting to the first electrode 29 of the wiring board 16, the portion of the flexible wiring board 19 that is wired along the first surface 27 becomes an obstacle, and the printed wiring board 16 is opposite to the first electrode 29. It becomes difficult to support from the side.

  Therefore, when the first electrode 29 is formed on the second surface 28 of the printed wiring board 16, it is desirable that the third electrode 39 of the flexible wiring board 19 is soldered to the first electrode 29. Furthermore, soldering may be omitted by replacing the third electrode with the connector 39 and replacing the first electrode 29 with a connector receptacle into which the connector can be fitted.

According to such a reference example, when the flexible wiring board 19 receives a tensile force due to a difference in thermal expansion between the printed wiring board 16 and the glass substrate 31, the bending portion 60 freely follows the direction of the tensile force. It deforms and absorbs the tensile force accompanying the thermal expansion difference applied to the flexible wiring board 19.

  Therefore, similarly to the first embodiment, the stress generated in the connection portion between the first electrode 29 and the third electrode 39 and the connection portion between the second electrode 36 and the fourth electrode 40 is reduced. can do.

  Furthermore, in the first embodiment, when the flexible wiring board is connected to the printed wiring board, the slack portion is formed in the flexible wiring board, but the present invention is not limited to this. For example, a slack portion that is curved in an arc shape may be formed in the middle of the flexible wiring board in advance, and the flexible wiring board having this slack portion may be connected to both the glass substrate and the printed wiring board.

1 is a perspective view of a contact sensor module according to a first embodiment of the present invention. 1 is a cross-sectional view of a contact sensor module according to a first embodiment of the present invention. The top view of the contact | adherence type | mold sensor module which expands and shows the connection part of a printed wiring board and an organic electroluminescent light emitting element in the 1st Embodiment of this invention. The top view of the EL light source unit which concerns on the 1st Embodiment of this invention. Sectional drawing of the EL light source unit which concerns on the 1st Embodiment of this invention. Sectional drawing which shows the state which made the 1st electrode of the glass substrate and the 3rd electrode of the flexible wiring board mutually oppose on both sides of an anisotropic conductive film in the 1st Embodiment of this invention. Sectional drawing which shows the positional relationship of the flexible wiring board at the time of connecting the flexible wiring board which joined the glass substrate to a printed wiring board in the 1st Embodiment of this invention, a printed wiring board, and a piano wire. Sectional drawing which shows the state which interposed the piano wire between the flexible wiring board and the printed wiring board in the 1st Embodiment of this invention. Sectional drawing which shows the state which pulled out the piano wire and formed the slack part in the middle of the flexible wiring board in the 1st Embodiment of this invention. Sectional drawing of the EL light source unit which concerns on the reference example relevant to this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 16 ... Printed wiring board, 17, 18 ... Organic EL light emitting element, 19 ... Flexible wiring board, 27 ... Mounting surface (1st surface), 29 ... 1st electrode, 31 ... Glass substrate, 36 ... 2nd electrode 39 ... 3rd electrode, 40 ... 4th electrode, 45 ... slack part, 51 ... wire member (piano wire).

Claims (6)

A rigid printed wiring board in which a first electrode is formed on both ends in the longitudinal direction of the mounting surface in a strip shape extending in a straight line ,
The printed wiring board is mounted on the mounting surface of the printed wiring board with a length shorter than that of the printed wiring board, and second electrodes are formed on the mounting surface side surfaces of the printed wiring board at both ends in the longitudinal direction. And a glass substrate constituting an organic EL light emitting element having a thermal expansion coefficient different from that of the printed wiring board,
A third electrode connected to the first electrode of the printed wiring board; and a fourth electrode connected to the second electrode of the glass substrate , the printed wiring board and the glass substrate. A flexible wiring board that electrically connects between and
A sensor module board connection structure comprising:
In the flexible wiring board, a freely deformable slack portion that is curved in a direction away from the mounting surface of the printed wiring board is formed between the third electrode and the fourth electrode. board connection structure of the sensor module, characterized in that. 2. The first electrode and the third electrode according to claim 1, wherein the second electrode and the fourth electrode are thermocompression bonded to each other with an anisotropic conductive film interposed therebetween. Is a substrate connection structure for a sensor module, characterized in that they are thermocompression bonded to each other with another anisotropic conductive film interposed therebetween. 2. The sensor module substrate connection structure according to claim 1, wherein the slack portion is curved in an arc shape, and a diameter of the arc drawn by the slack portion is 0.2 to 0.4 mm. . Between the first electrode formed on the mounting surface of the printed wiring board and the second electrode formed on the glass substrate, the third electrode corresponding to the first electrode and the second electrode are provided. A sensor module substrate connection method for electrically connecting using a flexible wiring board having a corresponding fourth electrode,
Connecting the second electrode of the glass substrate and the fourth electrode of the flexible wiring board to each other;
The flexible wiring board connected to the glass substrate is placed on the mounting surface of the printed wiring board, and the third electrode of the flexible wiring board is interposed between the flexible wiring board and the mounting surface. And a linear body so as to cross between the fourth electrode and the fourth electrode,
A direction in which the portion of the flexible wiring board corresponding to the linear body is moved away from the mounting surface by connecting the third electrode of the flexible wiring board and the first electrode of the printed wiring board to each other. Curved in an arc shape,
Finally, by pulling out the linear body from between the flexible wiring board and the mounting surface, the flexible wiring board can be freely deformed into an intermediate portion between the third electrode and the fourth electrode. A method for connecting a substrate of a sensor module, comprising: 5. The method according to claim 4, wherein the second electrode and the fourth electrode are thermocompression bonded to each other with an anisotropic conductive film interposed therebetween, and the first electrode and the third electrode Is a substrate connection method for a sensor module, characterized in that the other anisotropic conductive film is sandwiched between them and they are thermocompression bonded together. 6. The printed circuit board according to claim 5, wherein after connecting the second electrode of the glass substrate and the fourth electrode of the flexible wiring board, a part of a connection portion of these electrodes is covered with a moisture-proof material, After connecting the first electrode of the wiring board and the third electrode of the flexible wiring board, the part of the connecting portion between the second electrode and the fourth electrode that is detached from the moisture-proof material is again used. A method for connecting a substrate of a sensor module, wherein the substrate is coated with a moisture-proof material.

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