JP2617696B2 - Electronic component manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for connecting a conductive member of a wiring board to an electrode of an electronic component mounted on a printed board or the like.

[0002]

2. Description of the Related Art In recent years, as home appliances and industrial equipment have become smaller and more portable, it has become necessary to mount electronic components at a high density.

Here, in general, methods for connecting electrodes on various substrates include solder bonding, connection using conductive rubber, and pressure connection using an anisotropic conductive sheet.

[0004] Hereinafter, conventional solder bonding and pressure connection using an anisotropic conductive sheet will be described by taking as an example a connection process between a conductive member of a flexible wiring board and an electrode of a printed board on which electronic components and the like are mounted.

FIG. 13 is a cross-sectional view showing a connection state between a conductive member of a flexible board and an electrode of a printed board by pressure connection using a conventional thermosetting resin having a volume shrinking function. 14b is a cross-sectional view showing a solder connection and a pressure connection using an anisotropic conductive sheet among the electrode connection methods.

As shown in FIG. 13, a flexible wiring board 1 has a conductive member (not shown) provided on a flexible base film 2 via a first adhesive layer 4a. The cover film 3 is provided on the base material with a second adhesive layer 4b interposed therebetween, and is formed by laminating a total of five layers of members. Although not shown, the flexible wiring board 1
A portion of the conductive member which is not covered with the cover film 3 is a lead portion, and when the lead portion and the electrode of the printed circuit board 7 are aligned with each other and pressed against each other, the flexible conductive member A method in which a resin having a volume shrinking function is filled between the substrate 1 and the printed board 7 to form a cured resin layer 9, and the shrinking force strengthens the mechanical connection between the boards and the electrical connection between the electrodes simultaneously. It is.

In the bonding method using solder, as shown in FIG. 14A, the lead portion 6 of the flexible wiring board 1 and the electrode 8 on the printed circuit board 7 are aligned, and a bonding layer 26 made of solder is formed therebetween. Thereby, the mechanical connection between the substrates and the electrical connection between the conductive member and the electrode are simultaneously performed. Usually, copper whose surface is subjected to solder plating is used as the lead 6.

In the pressure welding connection method using an anisotropic conductive sheet, as shown in FIG. 14B, the lead portion 6 of the flexible wiring board 1 and the electrode 8 of the printed circuit board 7 are aligned with each other, and the anisotropic conductive sheet is placed therebetween. The flexible wiring board 1 is pressurized and heated in a state of interposing the adhesive layer 27 to form an adhesive layer 27 and connect the boards together, and at the same time, connect the conductive member and the electrode via the conductive particles 28 in the anisotropic conductive sheet. And are electrically connected.

[0009]

However, each of the above-mentioned conventional connection systems has the following problems.

[0010] In the case of the connection method using the volume contraction force of the thermosetting resin, the connection requires heating, so that the flexible wiring board 1 needs to have heat resistance. Therefore, it is necessary to use polyimide for the cover film 2 and the base film 3, and there is a problem that the material cost is high.

In the case of the joining method using solder, a flux cleaning step is required, and since lead is used,
The impact on the global environment and the human body has become a problem. in addition,
Since the strength itself of the soldering itself is small, a sufficient connection strength between the flexible wiring board 1 and the printed board 7 cannot be obtained. Further, since it is necessary to heat the solder, there is also a problem that the material cost is high as described above.

In the case of a connection system using an anisotropic conductive sheet,
Since the anisotropic conductive sheet is supplied in the form of a sheet, there is a problem that a fillet having high adhesive strength cannot be produced.
Therefore, the peel resistance between the adhesive layer 27 of the anisotropic conductive sheet and the flexible wiring board 1 and the printed board 7 is small, and sufficient connection strength between the flexible wiring board 1 and the printed board 7 is obtained. I can't. Further, since it is necessary to heat the anisotropic conductive sheet, there is a problem that the material cost is increased as described above.

On the other hand, as disclosed in, for example, JP-A-4-82240, in a step of connecting electrodes of two substrates, one substrate is placed on a stage made of a material that can transmit ultraviolet rays. Then, the other substrate is placed with the two electrodes aligned together, and the photocurable adhesive resin filled between the two substrates is irradiated with ultraviolet rays from below to connect the two substrates at room temperature. There is something.

[0014] However, in the above-mentioned publication, the substrate on the lower side is limited to a substrate having a transmittance of ultraviolet rays, so that there is a problem that the application is limited.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a flexible substrate in which a substrate on which an electrode to be connected to a conductive member is mounted has ultraviolet light transmission properties. Even if not, by enabling connection at room temperature with a photocurable adhesive resin, there is no need for a flux cleaning step or lead, and the connection strength between both substrates is high.
It is another object of the present invention to provide a method for manufacturing a versatile electronic component.

[0016]

Means for Solving the Problems To achieve the above object, the means of the first aspect of the present invention is to dispose the base member on the surface of the base member made of a material having ultraviolet transmittance and flexibility. A conductive member extending along the conductive member and a flexible cover member covering a part of the conductive member are laminated, and the main body portion on which the three members are laminated and the cover member of the conductive member are covered. An electronic device that prepares in advance a flexible first substrate configured such that an exposed portion becomes a lead portion and connects the lead portion on the first substrate to an electrode of a second substrate on which elements and the like are mounted. A first step of mounting the second substrate on a stage with the surface on which the electrodes are formed facing upward;
A second step of adhering a photocurable adhesive resin having a volume contraction property to at least one of the substrate and the second substrate, and positioning the lead on the first substrate and the electrodes of the second substrate. A third step of combining the first substrate on the second substrate and using a pressing jig made of a material through which ultraviolet light can pass and having a tip functioning as a pressing surface. A fourth step of pressing the substrate to press the lead portion of the first substrate and the electrode of the second substrate, and allowing the pressing member and the base member of the first substrate to pass through. And a fifth step of irradiating the photocurable adhesive resin with ultraviolet light.

Means taken by the invention of claim 2 is claim 1
In the invention, the second step is performed after the fourth step, and in the second step, a photocurable material is provided around the lead portion of the first substrate and the electrode of the second substrate which are pressed against each other. This is a method of filling an adhesive resin.

Means taken by the invention of claim 3 is claim 1
Alternatively, in the invention according to the second aspect, there is provided a method using a first substrate having a lead portion which has been previously pressurized and plastically deformed so that the height from the surface of the base member becomes substantially uniform.

Means taken by the invention of claim 4 is claim 1
Alternatively, in the fourth aspect, in the fourth step, at least one side surface and a direction in which ultraviolet light travels inside the pressing jig are inclined at substantially the same angle with respect to a normal direction of the pressing surface. This is a method using a pressing jig configured as described above.

Means taken by the invention of claim 5 is claim 1
Alternatively, in the invention of the second aspect, the fourth step is a method using a pressing jig composed of a number of optical fibers bundled together and configured such that the tip end surface of each optical fiber is a pressing surface.

Means taken by the invention of claim 6 is that of claim 5
In the fourth aspect, in the fourth step, a pressing jig configured such that a direction of an optical axis of the optical fiber is inclined by a predetermined angle with respect to a normal direction of a pressing surface of the pressing jig is provided. This is the method used.

Means taken by the invention of claim 7 is claim 1
Alternatively, in the invention according to the second aspect, a first substrate is provided in which at least one groove extending from a front end surface of the lead portion to a side surface of the conductive member is formed at a front end portion of the lead portion.

Means taken by the invention of claim 8 is that of claim 7
The method according to the first aspect of the invention uses a first substrate in which the width of the groove is smaller than the width of the remaining lead.

Means taken by the invention of claim 9 is claim 1
Alternatively, in the invention according to the second aspect, a first substrate having a plurality of leads is prepared, and the above steps are performed between the respective leads of the first substrate and the respective electrodes of the plurality of second substrates. is there.

In a tenth aspect of the present invention, in the first or second aspect, an opening is provided in a portion of the stage below the electrode, and a high-pressure gas connected to the opening is provided. A tank is provided, and in the fourth step, a high-pressure gas from a high-pressure gas tank is introduced into the opening at the time of pressurization by the pressurizing jig, and the pressurizing jig is applied to the second substrate. This is a method of applying a pressure that opposes the pressure of.

According to an eleventh aspect of the present invention, in the tenth aspect, an elastic film is formed on the opening of the stage, and in the fourth step, when the high-pressure gas is introduced, In this method, a pressure against the pressure of the pressing jig is applied to the second substrate by expanding the coating.

According to a twelfth aspect of the present invention, in the third aspect of the invention, a first adhesive layer is interposed between the base member and the conductive member, and the conductive member and the cover are provided. A second substrate is provided with a second adhesive layer interposed between the first substrate and a notch formed by notching a part of the cover member from a side surface. In the second step, the notch is formed in the notch. The photocurable adhesive resin is also adhered to the exposed first adhesive layer on the first substrate, and in the fifth step, the photocurable adhesive resin adhered to the cutout portion of the cover member is also irradiated with ultraviolet rays. Is the way.

According to a thirteenth aspect of the present invention, in the twelfth aspect, the second step includes the step of including the first adhesive layer exposed at the notch and a cover member around the first adhesive layer. This is a method of attaching a photocurable adhesive resin to a wide area.

According to a fourteenth aspect of the present invention, in the third aspect of the present invention, at least a part of the notch is formed on a surface of the base member of the first substrate facing the first conductive member. The method further comprises the step of attaching a reinforcing plate to a region straddling a portion covered with the cover film adjacent to the notch.

In a preferred embodiment of the present invention, a conductive member extending along the base member and a cover member covering a part of the conductive member are laminated on the surface of the base member made of glass. A first substrate is prepared in advance, in which a main body portion on which the three members are stacked and a portion of the conductive member that is exposed without being covered by the cover member is a lead portion, and a conductive member on the first substrate is prepared. As a method of manufacturing an electronic component connected to an electrode of a second substrate on which elements and the like are mounted, a first step of mounting the second substrate on a stage with the surface on which the electrodes are formed facing upward, A second step of adhering a photocurable adhesive resin having a volume contraction property to at least one of the first substrate and the second substrate; and a step of connecting the lead portion of the conductive member on the first substrate to the second substrate. The above electrodes on the substrate A third step of arranging the first substrate on the second substrate and placing the first substrate on the second substrate, the third substrate comprising a material capable of transmitting ultraviolet light, and having a tip functioning as a substantially flat pressing surface and at least one side surface; And a pressing jig configured such that a direction in which ultraviolet light travels inside the pressing jig is inclined at substantially the same angle with respect to a normal direction of the pressing surface, and the first substrate is A fourth step of pressing the lead portion of the first substrate and the electrode of the second substrate under pressure, and allowing the pressure jig and the base member of the first substrate to permeate through an adhesive resin. And a fifth step of irradiating the substrate with ultraviolet light.

According to a sixteenth aspect of the present invention, in the fifteenth aspect of the present invention, in the fourth step, a plurality of optical fibers bundled with each other are formed so that the front end surface of each optical fiber becomes a pressing surface. This is a method using a configured pressure jig.

[0032] The invention according to claim 17 is the invention according to claim 15 or 16, wherein an opening is provided in a portion of the stage below the electrode, and a high-pressure gas connected to the opening is provided. A tank is provided, and in the fourth step, a high-pressure gas from a high-pressure gas tank is introduced into the opening at the time of pressurization by the pressurizing jig, and the pressurizing jig is applied to the second substrate. This is a method of applying a pressure that opposes the pressure of.

The means of the invention of claim 18 is that, in the invention of claim 17, an elastic film is formed on the opening of the stage, and in the fourth step, when the high-pressure gas is introduced, In this method, a pressure against the pressure of the pressing jig is applied to the second substrate by expanding the coating.

[0034]

According to the above arrangement, the following effects are achieved for each claim.

According to the first aspect of the present invention, since the pressing jig and the first substrate have ultraviolet transmittance, the photocurable adhesive resin can be cured at room temperature even if the second substrate does not have ultraviolet transmittance. It is possible to do. Therefore, the use of the flexible wiring board is expanded, and the base member and the cover member of the first substrate functioning as the flexible wiring board can be made of inexpensive materials. For example, it is not necessary to use expensive polyimide having excellent heat resistance as a material of the base member and the cover member, and for example, it is possible to use inexpensive polyester or the like.

According to the second aspect of the present invention, since the photocurable adhesive resin does not adhere between the surfaces of the first substrate and the second substrate that are in contact with the electrodes, the photocurable adhesive resin is not attached. There is no need to extrude. Therefore, even if the press-contact force in the fourth step is small, the electrical connection between the two is reliably performed. Therefore, adverse effects on the second substrate itself, elements mounted on the second substrate, and the like are avoided.

According to the third aspect of the present invention, in the fourth step, the lead portion is plastically deformed by pressure in advance,
Since the height of each part of the lead portion from the base member is substantially uniform, the lead portion and the electrode are reliably electrically connected even if the pressing force is small. Therefore, adverse effects on the second substrate itself, elements mounted on the second substrate, and the like are avoided.

According to the fourth or sixth aspect of the present invention, the interference between the equipment above the stage on which the second substrate is installed and the pressing jig is avoided, and the alignment between the lead and the electrode is also confirmed. It will be easier.

According to the invention of claim 5 or 16, since the attenuation of the intensity of the ultraviolet light passing through the pressure jig formed of the optical fiber is extremely small, stronger ultraviolet light is applied to the photocurable adhesive resin. Therefore, the time required for curing the photocurable adhesive resin is reduced, and the productivity is improved.

According to the seventh or eighth aspect of the present invention, since the volume-shrinking force of the photocurable adhesive resin acts not only at both ends of the lead but also at the groove, the compressive stress acting between the lead and the electrode increases. The electrical connection between the lead portion and the electrode is further strengthened.

According to the ninth aspect of the present invention, the electrodes of the second substrate on which different types of elements are mounted are electrically connected to each other via the conductive member of the first substrate. Therefore, the use of the flexible wiring board is further expanded.

According to the tenth, tenth, seventeenth, or eighteenth aspect, even when an element or the like is mounted on a surface of the second substrate opposite to the surface on which the electrodes are formed, the opening of the stage can be formed. By burying the element and the like, the connection between the first substrate and the second substrate is performed without applying the pressing force of the pressing jig to the element and the like. Therefore, the reliability of the manufactured electronic component is improved.

According to the twelfth aspect of the present invention, in the notch, an adhesive force acts between the first adhesive layer of the first substrate and the photocurable adhesive resin instead of the cover member. Therefore, an adhesive force higher than the adhesive force between the cover member generally formed of a plastic film and the photocurable adhesive resin is obtained, and the connection strength between the first substrate and the second substrate is improved.

According to the thirteenth aspect, even when the first substrate is bent in the vicinity of the notch, the first substrate is bent in the region including the cover member. There is no sharp bend. Therefore, a favorable connection state between the first substrate and the second substrate can be obtained without causing damage to the cover member, an increase in the resistance value of the conductive member, and the like.

According to the fourteenth aspect, even when the first substrate is bent in the vicinity of the notch, the generation of the sharply bent portion is prevented by the reinforcing plate. Therefore, a favorable connection state between the first substrate and the second substrate can be obtained without causing breakage of the base member or increase in the resistance value of the conductive member.

According to the fifteenth aspect of the invention, the use of the first substrate having the base member made of a glass substrate is expanded similarly to the above-mentioned flexible wiring substrate.
In addition, since the pressing jig is inclined from the normal direction of the pressing surface, interference between the equipment above the stage and the pressing jig is avoided, and the pressing force acts obliquely during pressing. Therefore, the impact force on the glass substrate is reduced, and damage to the glass substrate and the like are prevented.

[0047]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(First Embodiment) As shown in FIG. 1, a flexible wiring board 1 (first wiring board) used in this embodiment includes a base film 2 (base member) and a cover film 3 (cover member). And three conductive members 5 are formed via two first and second adhesive layers 4a and 4b. Although only the structure near the end is shown in the figure, the flexible conductive member 1 has a constant width and extends for a predetermined length, and when attached to a printed circuit board or the like, it is bent at a part thereof. In many cases, plastic bending deformation is possible. In particular, in the present embodiment, the base film 2 and the cover film 3, which are the main components of the flexible wiring board 1, are made of a material having not only flexibility but also transmitting ultraviolet rays, for example, polyester.

Each of the conductive members 5 extends in parallel with each other in the longitudinal direction of the flexible wiring board 1, and at the leading end where connection with the electrodes on the printed circuit board is made, as shown in FIG. The conductive member 5 has a portion that is not covered by the cover film 3, and this portion corresponds to the lead 6.
It is. Further, a groove 12 is formed at a distal end portion of the lead 6 by cutting a predetermined length from the distal end surface of the lead 6 in the longitudinal direction of the flexible conductive member. This groove 1
The width of 2 is larger than the width of the remaining portion of the lead 6 divided by the groove 12, but smaller than the interval between the three leads 6.

As will be described later, as shown in FIG. 4, the cover film 3 is attached to the flexible wiring board 1 at a part of the base film 2 on the side outside the conductive member 5 as shown in FIG. A notch 14 is formed as a notch, and as described later, by providing the notch 14, the connection strength between the flexible wiring board 1 and the printed board 7 is improved.

Next, steps for connecting the flexible wiring board 1 to a printed board 7 such as an electronic component or a wiring board will be described with reference to FIGS. 2A to 2E.

First, as shown in FIG. 2A, the printed circuit board 7 such as an electronic component having an electrode 8 or a wiring board is opposed to the flexible wiring board 1. At this time, the printed circuit board 7 is placed on a stage (not shown) with the electrodes 8 facing upward, and the flexible wiring board 1 is held above the printed circuit board 7 with the leads 6 facing downward. Then, a light-curing adhesive resin 9 having insulating properties and volume shrinkage is applied to a wide portion including the surface of the printed board 7 and the surface of the electrode 8, and the lead 6 of the flexible board 1 and the electrode 8 of the printed board 7 are Align. Note that the photocurable adhesive resin 9 may be applied to the flexible wiring board 1 side.

Next, as shown in FIG. 2B, the leads 6 of the flexible wiring board 1 are mounted on the electrodes 8 of the printed circuit board 7. At this time, the lead 6 and the electrode 8 of the printed circuit board 7
The photo-curable adhesive resin 9 is interposed between the spaces (and the cutouts 14).

Next, as shown in FIG. 2C, the lead 6 is pressed by a pressing jig 10 made of a material having ultraviolet transparency such as quartz glass, and the lead 6 is pressed against the electrode 8 of the printed circuit board 7. I do. At this time, the photocurable adhesive resin 9 interposed between the lead 6 and the electrode 8 is extruded by a pressing force, and the lead 6 and the electrode 8 are electrically connected.

The photocurable adhesive resin 9 is used as the pressing jig 10
Teflon coating or the like is applied to at least the vicinity of the pressing surface of the pressing jig 10 so as not to adhere to the surface.

Next, as shown in FIG.
In addition, the photocurable adhesive resin 9 filled between the substrates is irradiated with the ultraviolet light transmitted through the base film 2 to cure the photocurable adhesive resin 9. Thereby, the flexible wiring board 1
And the printed circuit board 7 are mechanically connected.

Next, as shown in FIG.
Is released, and the connection process ends. Even when the pressure is removed, the lead 6 of the flexible board 1 and the printed board 7
The electrode 8 is pressed into contact with the electrode 8 so that the electrical connection is more firmly maintained.

Therefore, in this embodiment, since the photocurable adhesive resin is used, the connection between the flexible wiring board 1 and the printed board 7 can be performed at room temperature without heating. Therefore, it is not necessary to use an expensive material such as polyimide having high heat resistance as a material for forming the base film 2 and the cover film 3 of the flexible wiring board 1, and it is possible to use inexpensive polyester. Further, since no solder is used, there is an effect that neither lead nor a washing step is required.

In particular, in this embodiment, since the pressing jig 10 having an ultraviolet ray transmitting property is used, the ultraviolet ray can be irradiated from the flexible wiring board 1 side. Therefore, the material forming the second wiring board is not limited to, for example, glass having ultraviolet transmittance. This allows
The flexible wiring board 1 can be connected to an opaque substrate such as a printed board at normal temperature, and the use of the flexible wiring board 1 can be expanded while reducing the cost.

As the photo-curable adhesive resin 9 used in the present invention, there are ultraviolet-curable epoxy, silicone, acrylic and the like. Also, Au, Cu, S is applied to the surface of the electrode 8 of the printed circuit board 7 or the surface of the lead 6 of the flexible wiring board 1.
Plating of n, Ni, solder and the like are performed.

Next, the groove 12 is formed in the lead 6 in this embodiment.
The function and effect of the formation of will be described with reference to FIG. FIG. 3 is an enlarged view of a part of FIG.

As shown in FIG. 3, when the photocurable adhesive resin 9 is cured, a concave portion 11 corresponding to the volume contraction force is generated in a region located between the adjacent leads 6 of the base film 2. A compressive stress is generated between the lead 6 and the electrode 8 by the contraction force. In addition, in this embodiment, since the groove 6 is provided in the lead 6, a concave portion 13 corresponding to the volume contraction force of the photocurable adhesive resin 9 is also generated in the groove 12, and the lead contraction force is generated by this volume contraction force. A compressive stress is generated between the electrode 6 and the electrode 8. That is, when considering the tip of one lead 6, there are column-shaped urging members that generate a compressive stress between the lead and the electrode at a total of four places including both ends and two intermediate places. Therefore, by forming the groove 12 at the tip of the lead 6 as in the present embodiment, the electrical connection between the lead and the electrode can be more firmly held. Further, as described later, the adhesive force between the photocurable adhesive resin 9 and the first adhesive layer 4a on the base film 2 acts on the groove 12, and the adhesive force is applied to the lead 6 as described later. Is larger than the adhesive force of the photocurable adhesive resin 9 to the resin. As a result, the reliability of the connection between the two substrates can be greatly improved.

In this embodiment, since the width of the groove 12 is smaller than the width of each remaining portion of the lead 6, the area of the remaining portion of the lead 6 is sufficiently large, and the electric resistance at the tip of the lead 6 is reduced. There is no danger of rising.

At this time, since the interval between the leads 6 is larger than the width of the groove 12, the depth d1
Is larger than the depth d2 of the concave portion 13. That is,
The compressive stress between the lead and the electrode due to the volume contraction force of the photocurable adhesive resin between the adjacent leads 6 is reduced by the groove 12.
Is larger than the compressive stress of the portion.

Next, as shown in FIG. 4, the operation and effect when the cutout portion 14 is provided on the side of the conductive member 5 of the cover film 3 in the flexible wiring board 1 will be described. 5A and 5B show a state in a connecting step (step shown in FIG. 2B) between the flexible wiring board 1 and the printed board 7, and show a cross-sectional state of both boards corresponding to a cross-section taken along line VV in FIG. . As shown in FIG. 5A, the photocurable adhesive resin 9 filled in the cutouts 14 connects the first adhesive layer 4a and the printed circuit board 7. The adhesive strength between the adhesive layer 4 and the substrate 7 at the notch portion 14 is significantly higher than the adhesive strength between the cover film 3 made of polyester and the printed circuit board 7.

Specifically, the adhesive force between the first adhesive layer 4a and the photo-curable adhesive resin 9 is usually about 200 g / g.
mm or more is obtained.

When the notch 14 is formed in the flexible substrate 1, in the step shown in FIG. 2A, the photocurable adhesive resin 9 is applied to the wide area including the cover film 3 around the notch 14. It is preferable to apply it to the surface. The reason will be described below.

For example, when the photo-curable adhesive resin 9 is not sufficiently filled in the entire cutout portion 14 as in the conventional connection process shown in FIG. 13, the radius of curvature of the bend becomes small, and the bend is caused. State. For this reason, the base film 2 is damaged, and although not shown in FIG. 13, the conductive member 5 near the bent portion also bends with a small radius of curvature. There is a possibility that the resistance value of the conductive member 5 may increase.

However, as shown in FIG. 5A, when the photocurable adhesive resin 9 is filled over a wider area than the notch 14, even if the flexible wiring board 1 is bent, the notch 1
Since the boundary between the cover film 4 and the cover film 3 is covered with the photocurable adhesive resin 9, the boundary is not bent. Therefore,
The effect of not causing damage to the base film 2 or increasing the resistance value of the conductive member 5 can be exhibited.

Next, as shown in FIG. 5B, the effect of the case where the reinforcing plate 15 is provided on the back surface of the area extending over the cutout portion 14 and the cover film 3 in the flexible wiring board 1 will be described. In this example, a reinforcing plate 15 is provided on a surface of the base film 2 opposite to the surface on which the cover film 3 is laminated, in a region corresponding to a region straddling the cutout portion 14 and a region where the cover film exists. ing. When such a reinforcing plate 15 is provided, even when the photocurable adhesive resin 9 is not sufficiently filled in the cutout portion 14, the curvature radius of the bent portion can be maintained large, and as shown in FIG. The flexible wiring board 1 does not bend. Therefore, by providing the reinforcing plate 15,
The peel strength of the flexible wiring board 1 from the printed board 7 can be improved.

The reinforcing plate 15 may be attached to the flexible wiring board 1 before performing the connecting step, or may be attached during the connecting step.

Next, a specific example of a shape other than the shape shown in FIG. 2 of the pressing jig will be described.

As shown in FIG. 6A, when the inside of the pressing jig 10 is inclined with respect to the direction in which the ultraviolet rays travel, that is, the pressing jig 10 itself is inclined with respect to the normal direction of the tip end surface of the pressing jig 10. Interference with members above the pressing jig 10 can be avoided. For example, even when a member such as a protective cover attached to the apparatus exists above the stage on which the printed circuit board is mounted, interference between the protective cover and the pressing jig 10 may be caused. In addition, a connection process between the printed board 7 and the flexible wiring board 1 can be performed. Also,
Even when the state of alignment between the printed circuit board 7 and the flexible wiring board 1 is visually checked from above,
The checking operation is not hindered by the pressing jig 10.
Therefore, the connection accuracy can be improved.

However, the lower side surface of the side surface of the pressing jig 10 need not be formed along the traveling direction of the ultraviolet rays. For example, as shown in FIG. 6B, the upper part of the lower side surface may be vertical, and only the lower part may be inclined with respect to the normal direction of the pressing surface 16 of the pressing jig 10.

FIGS. 7A and 7B show a case where the pressing jig 10 is constituted by a plurality of optical fibers 17 bundled together and the distal end surface of the optical fiber 17 is the pressing surface 16 of the pressing jig 10. The structure of is shown. By using the optical fiber 17 as the pressing jig 10, it is possible to irradiate the photo-curable adhesive resin 9 with ultraviolet light of high illuminance.
The time required for curing the photocurable adhesive resin 9 is short,
There is an effect that productivity is improved. As shown in FIG. 7A, the entire optical fiber 17 may be linear and inclined with respect to the normal direction of the pressing surface 16, but the upper portion of the optical fiber 17 is vertical and the lower portion is the pressing surface 16 as shown in FIG. May be inclined with respect to the normal direction of.

Next, FIG. 8A shows a state in the connecting step when a part of the tip end surface of the pressing jig 10 is the pressing surface 16. FIG. 8B is a diagram illustrating a state in the connection step when the distal end of the pressing jig 10 has a stepped shape and a part of the distal end is the pressing surface 16. FIG.
As shown in a, at the tip of the pressing jig 10, a pressing surface at the foremost end has a shape protruding from the surroundings, so that a region wider than the pressing region can be irradiated with ultraviolet rays. The use of the pressing jig 10 having the configuration as shown in FIGS. 8A and 8B has an effect of curing the photocurable adhesive resin 9 protruding from the flexible wiring board 1.

(Second Embodiment) Next, a second embodiment will be described with reference to FIGS. 9A to 9F. In this embodiment, different kinds of substrate electrodes such as a printed circuit board, a semiconductor element, and an electronic component inside an electronic device, for example, an electrode of a semiconductor element and an electrode of a printed circuit board can be connected via the flexible wiring board 1.

As shown in FIG. 9A, a semiconductor substrate 18 on which a semiconductor element having an electrode 8a is mounted is placed on a stage (not shown) with the electrode 8a facing upward, and has a first seed 6a at one end. The flexible wiring board 1 having the second lead 6b at the other end is held with the first lead 6a facing downward, and the photocurable adhesive resin 9 is applied around the electrode 8a of the semiconductor substrate 18. In this state, the first lead 6a of the flexible wiring board 1 and the electrode 8a of the semiconductor substrate 18 are aligned.

Next, as shown in FIG.
a is mounted on the electrode 8 a of the semiconductor substrate 18. At this time, the photocurable adhesive resin 9 is interposed over the entire area around the first lead 6a and the electrode 8a of the semiconductor substrate 18.

Next, as shown in FIG.
By pressing the first lead 6a, the first lead 6a and the electrode 8a of the semiconductor substrate 18 are pressed against each other. Further, as shown in FIG. 9D, the ultraviolet light transmitted through the pressing jig 10 and the base film 2 is applied between the two substrates. Irradiate the photo-curable adhesive resin 9 filled in the resin to cure the photo-curable adhesive resin 9.

Next, as shown in FIG.
Is released, and the connection between the flexible wiring board 1 and the semiconductor substrate 18 is completed.

The above connection process is the same as that of the first embodiment shown in FIG.
This is basically the same as the connection process described with reference to FIGS. That is, the first lead 6a and the electrode 8a of the semiconductor substrate 18 are pressed against each other by the volume shrinkage force caused by the curing of the photocurable adhesive resin 9, and the connection between them is firmly maintained.

In this embodiment, as shown in FIG. 9F, the second lead 6b at the other end of the flexible wiring board 1 and the electrode 8b of the printed circuit board 7 are the same as those shown in FIGS. 9A to 9E. A process is performed to connect both substrates.

Alternatively, the connecting step between the semiconductor substrate 18 and the flexible wiring board 1 and the connecting step between the printed board 7 and the flexible wiring board 1 can be performed simultaneously. In that case, the time required for the process can be reduced.

As described above, in the present embodiment, the electronic components and the electrodes of each substrate, such as the electrodes 8a of the semiconductor element mounted on the semiconductor substrate 18 and the electrodes 8b of the printed circuit board 7, are connected to each other by a flexible method. Electrical connection can be made via the wiring board 1. In this case, as in the first embodiment, by forming the pressing jig 10 from a material having a transparency to ultraviolet light, it is possible to further reduce the cost of the material forming the flexible wiring board by normal temperature connection, and furthermore, The use can be expanded. Note that FIG.
9D, the direction of the ultraviolet light transmitted through the inside of the pressing jig 10 is parallel to the normal of the pressing surface of the pressing jig. It goes without saying that the direction of the ultraviolet light passing through the inside of the tool may be inclined with respect to the normal to the pressing surface.

Third Embodiment Next, a third embodiment will be described with reference to FIGS. 10A to 10E.

The flexible wiring board 1 may have the structure described in the first embodiment, but in this embodiment,
The lead 6 is plastically deformed by pressurization in advance.

First, as shown in FIG. 10A, the leads 6 of the flexible wiring board 1 are mounted on the electrodes 8 of the printed circuit board 7. At this time, unlike the first and second embodiments, the photocurable adhesive resin is not yet applied.

Next, as shown in FIG.
The lead 6 is pressurized by 0, and the lead 6 and the electrode 8 are pressed against each other. By this step, the lead 6 and the electrode 8 are electrically connected.

Next, as shown in FIG. 10C, a space between the flexible wiring board 1 and the printed circuit board 7 is filled with a photocurable adhesive resin 9 so that the light around the area where the lead 6 and the electrode 8 are pressed against each other is filled. Fill with curable adhesive resin 9.

Next, as shown in FIG.
The photocurable adhesive resin 9 is irradiated with the ultraviolet light transmitted through the base film 2 and the photocurable adhesive resin 9 to cure the photocurable adhesive resin 9.

Next, as shown in FIG.
The pressurization by 0 is released, thereby terminating the connection between the two substrates. The pressure contact function between the lead and the electrode due to the volume contraction force of the photocurable adhesive resin 9 is the same as in each of the above embodiments.

In this embodiment, the lead 6 and the electrode 8 are pressed against each other and then filled with the photocurable adhesive resin 9.
The photocurable adhesive resin 9 does not enter between the contact surfaces between the electrode and the electrode 8. Therefore, as a first effect, the lead 6 and the electrode 8
It is not necessary to extrude the photocurable adhesive resin 9 by pressurization during this period, so that electrical connection can be obtained with a low pressing force. Therefore, the printed circuit board 7 is hardly damaged by the pressure. The second effect is that the lead 6 and the electrode 8 are provided only by the absence of the photocurable adhesive resin 9 between the lead 6 and the electrode 8.
Since the contact area increases, the contact resistance value decreases. Therefore, due to the above two effects, the reliability of the connection is further improved.

In this embodiment, the leads 6 of the flexible wiring board 1 are plastically deformed by pressurization before the connection step is performed, so that the following effects are obtained. That is, the surface of the lead 6 has fine irregularities, and in order for the lead 6 and the electrode 8 to be electrically connected,
The unevenness on the surface of the lead 6 is flattened by pressing,
It is necessary to increase the contact area between the electrode and the electrode 8. On the other hand, in the case where the lead 6 has been plastically deformed by pressurization in advance, the unevenness on the surface is flattened.
When the lead 6 and the electrode 8 are pressed against each other in the step shown in FIG. 2B, a pressing force enough to plastically deform the lead 6 is not required. Therefore, an electrical connection can be obtained with a low pressing force, and there is an effect that the printed circuit board is not damaged by the pressurization.

(Fourth Embodiment) Next, a fourth embodiment will be described with reference to FIGS. 11A to 11C. This embodiment is particularly suitable when the electronic component 19 is mounted on the surface of the printed circuit board 7 opposite to the surface on which the electrodes 8 are formed, as shown in FIG. 11A.

As shown in FIG. 11A, the printed circuit board 7 is mounted on the stage 20. An opening 21 is formed in a region of the stage 20 located below the electrode 8 of the printed circuit board 7. An electronic component 19 is mounted on the lower surface of the printed circuit board 7 in the figure, and the electronic component 19 is buried in the opening 19
The electronic component 19 does not come into contact with the supporting surface of the electronic component 19. The opening 21 is connected to the cavity 22 inside the stage 20. The cavity 22 is connected to a high-pressure gas tank 24 via a high-pressure gas supply valve 23,
Further, it is connected to the outside air via an exhaust valve 25. In addition,
An elastic film may be stretched over the opening 21.

Then, as shown in FIG. 11A, a photocurable adhesive resin 9 is applied to the vicinity of the electrode 8 on the printed circuit board 7, the lead 6 and the electrode 8 are aligned, and the lead 6 is placed on the electrode 8. Mount.

Next, as shown in FIG.
The lead 6 is pressurized by 0, and the lead 6 and the electrode 8 are pressed against each other. At this time, the high-pressure gas supply valve 23 is simultaneously opened, and high-pressure gas is introduced into the cavity 22 from the high-pressure gas tank 24,
By setting the cavity 22 in a high pressure state, a pressure against the pressing force of the pressing jig 10 is applied to the printed circuit board 7.

When an elastic film is stretched over the opening 21, the elastic film expands, so that a pressure against the pressing force of the pressing jig 10 is applied to the printed circuit board 7. (Not shown).

Then, in the state shown in FIG. 11B, the light transmitted through the pressing jig 10 and the base film 2 is applied to the photocurable adhesive resin 9 interposed between the substrates, and
To cure.

Next, as shown in FIG. 11C, the exhaust valve 25 is opened at the same time when the pressurization is removed, and the high-pressure gas supply valve 2 is opened.
3 is closed to bring the cavity 21 to atmospheric pressure. This allows
The connection process ends.

Next, the operation and effect of the stage 20 having the opening 21 in this embodiment will be described. The stage 20 has no opening 21 and the printed circuit board 7
Of the electronic component 1 on the surface opposite to the surface on which the electrodes 8 are provided.
9 is mounted, when the lead 6 and the electrode 8 are pressed against each other by the pressing jig 10, the electronic component 20 is sandwiched between the printed circuit board 7 and the stage 20.
The pressure concentrates on zero. And electronic component 1
There is a possibility that troubles such as the 9 being detached from the printed circuit board 7 or being damaged may occur.

However, in this embodiment, since the opening 21 is provided in the stage 20, the electronic component 19 is
No contact is made with 0, and the above-described problem does not occur. Also,
In order to apply pressure against the pressing force of the pressing jig 10 to the printed circuit board 7 by setting the cavity 22 in a high pressure state,
The printed board 7 does not bend and the deformation of the printed board 7 can be prevented.

(Fifth Embodiment) Next, a fifth embodiment will be described with reference to FIGS. 12A and 12B.

FIG. 12A shows a case where a substrate having a conductive member 35 on a glass substrate 32 is used instead of the flexible wiring substrate, and the conductive member 35 of this substrate is electrically connected to the electrode 8 on the printed circuit board 7. It is a figure showing the state of each member in the case of doing. Ultraviolet rays are applied to the photocurable resin 9 via the pressing jig 10 and the glass substrate 32, and the mechanical connection between the two substrates and the conductive member 35 are made using the volume shrinkage of the photocurable adhesive resin 9. And electrical connection between the electrode 8 and
This is the same as the above embodiments.

In this embodiment, in this case, the direction of the ultraviolet light passing through both sides of the pressing jig 10 and the inside of the pressing jig 10 is defined with respect to the normal direction of the tip end surface of the pressing jig 10. Leaning. With such a method, it is possible to avoid interference with other devices and to accurately confirm the alignment between the conductive member 35 and the electrode 8. The pressing jig 10
Is applied from an oblique direction, so that the impact force on the glass substrate 32 at the time of pressing is reduced, and the glass substrate 3
2 can be prevented.

FIG. 12B shows a state in which a bump 36 is further formed on a conductive member 35 on a glass substrate 32 and the bump 36 and the electrode 8 of the printed circuit board 7 are electrically connected. It is a figure showing a state. Further, in the present embodiment, the width of the pressing jig 10 is made larger than the width of the glass substrate 32 so that the photocurable adhesive resin 9 protruding from the glass substrate 32 is surely cured.

[0108]

As described above, according to the invention of each claim, the following effects are exhibited.

According to the first aspect of the present invention, it is possible to reduce the cost of the flexible wiring board and expand the application.

According to the second or third aspect of the present invention, the connection between the conductive member and the electrode can be reliably performed while reducing the pressure contact force at the time of press-connecting the electrode. Improvement can be achieved.

According to the fourth or sixth aspect of the present invention, it is possible to avoid interference between devices above the stage on which the second substrate is installed and the pressing jig, and to confirm the alignment between the lead and the electrode. It can be facilitated.

According to the fifth or sixteenth aspect of the present invention, productivity can be improved by shortening the time required for curing the photocurable adhesive resin.

According to the seventh or eighth aspect of the present invention, the lead
By increasing the compressive stress acting between the electrodes, the electrical connection between the lead portion and the electrodes can be strengthened.

According to the ninth aspect of the present invention, the use of the flexible wiring board can be expanded to the electrical connection between different kinds of elements and the like.

According to the tenth, eleventh, seventeenth, and eighteenth aspects of the present invention, even when an element or the like is mounted on the surface of the second substrate opposite to the surface on which the electrode is formed, the element or the like can be used. The first substrate-the second substrate
The connection between the substrates can be performed, and thus, the reliability of the manufactured electronic component can be improved.

According to the twelfth aspect, the connection strength between the first substrate and the second substrate can be improved.

According to the thirteenth or fourteenth aspect of the present invention, the first
The connection strength between the substrate and the second substrate can be improved, and the cover member in the first substrate can be prevented from being damaged and the resistance value of the conductive member can be prevented from increasing.

According to the fifteenth aspect of the present invention, the use of the first substrate having the glass substrate as a base member is expanded, interference between devices above the stage and the pressing jig is prevented, and the glass at the time of pressing is used. It is possible to reduce the impact force on the substrate.

[Brief description of the drawings]

FIG. 1 is a perspective view of a flexible wiring board according to a first embodiment.

FIG. 2 is a cross-sectional view showing a change of each member in a connection step of the first embodiment.

FIG. 3 is a cross-sectional view showing a connection state of a flexible wiring board and a printed board at a lead end portion.

FIG. 4 is a perspective view of a flexible wiring board provided with notches.

FIG. 5 is a cross-sectional view showing a relationship between a state in which a cutout portion is filled with a photocurable adhesive resin and a state of a bent portion of a flexible wiring board.

FIG. 6 is a cross-sectional view showing a connection state between the two substrates when a pressing jig having a side surface inclined with respect to the normal direction of the front end surface is used.

FIG. 7 is a cross-sectional view showing a connection state between both substrates when a pressing jig in which optical fibers are bundled is used.

FIG. 8 is a cross-sectional view showing a connection state of both substrates by a pressing jig having an ultraviolet irradiation area wider than a pressing surface.

FIG. 9 is a cross-sectional view showing a change in the state of each member in a connection step of the second embodiment.

FIG. 10 is a cross-sectional view showing a change in the state of each member in a connection step of the third embodiment.

FIG. 11 is a cross-sectional view showing a change in the state of each member in a connection step of the fourth embodiment.

FIG. 12 is a sectional view showing a state of each member at the time of press contact connection of the fifth embodiment.

FIG. 13 is a cross-sectional view showing a state of each member at the time of connection using a conventional photocurable adhesive resin.

FIG. 14 is a cross-sectional view showing a state of each member at the time of connection with a conventional solder and anisotropic conductive adhesive.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flexible wiring board 2 Base film 3 Cover film 4 Adhesive layer 5 Conductive member 6 Lead 7 Printed circuit board 8 Electrode 9 Photocurable adhesive resin 10 Pressing jig 11 Concave part 12 Groove part 13 Concave part 14 Notch part 15 Reinforcement plate 16 Addition Compression surface 17 Optical fiber 18 Semiconductor substrate 19 Electronic component 20 Stage 21 Opening 22 Cavity 23 High-pressure gas supply valve 24 High-pressure gas tank 25 Exhaust valve

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kazunari Nishihara 1006 Kazuma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-3-268388 (JP, A) JP-A-5 −218636 (JP, A)

Claims (18)

(57) [Claims] 1. A conductive member extending along a base member on a surface of a base member made of a material having transparency and flexibility of ultraviolet rays, and a flexible cover for covering a part of the conductive member. A flexible first substrate configured such that a main body portion on which the three members are laminated and a portion of the conductive member that is not covered with the cover member and is exposed serves as a lead portion. A method of manufacturing an electronic component, comprising: connecting a lead portion on the first substrate to an electrode of a second substrate on which an element or the like is mounted, wherein the surface on which the electrode is formed faces upward, A first step of mounting the substrate on a stage; and a second step of attaching a photo-curable adhesive resin having volumetric shrinkability to at least one of the first substrate and the second substrate.
And a third step of aligning the lead portion on the first substrate and the electrode of the second substrate so that the first substrate is superposed on the second substrate, and ultraviolet rays can be transmitted. A pressing jig made of a suitable material and having a tip functioning as a pressing surface, pressurizes the first substrate, and press-contacts the lead portion of the first substrate with the electrode of the second substrate. And a fifth step of irradiating the photocurable adhesive resin with ultraviolet rays through the pressure jig and the base member of the first substrate. Production method. 2. The method for manufacturing an electronic component according to claim 1, wherein the second step is performed after the fourth step, and the second step is a lead portion of the pressed first substrate. And a photocurable adhesive resin around the electrodes of the second substrate. 3. The method for manufacturing an electronic component according to claim 1, wherein a first substrate having a lead portion which is pre-pressed and plastically deformed so that the height from the surface of the base member becomes substantially uniform is used. A method of manufacturing an electronic component, comprising: 4. The method for manufacturing an electronic component according to claim 1, wherein in the fourth step, at least one side surface and a direction in which ultraviolet rays travel inside the pressing jig correspond to the pressing surface. A method for manufacturing an electronic component, comprising using a pressure jig configured to be inclined at substantially the same angle with respect to a normal direction. 5. The method of manufacturing an electronic component according to claim 1, wherein in the fourth step, a large number of optical fibers bundled with each other are formed, and a tip surface of each optical fiber is a pressing surface. A method of manufacturing an electronic component, comprising using a pressing jig. 6. The method of manufacturing an electronic component according to claim 5, wherein in the fourth step, the direction of the optical axis of the optical fiber is at a predetermined angle with respect to the normal direction of the pressing surface of the pressing jig. A method for manufacturing an electronic component, comprising using a pressure jig configured to be inclined. 7. The method for manufacturing an electronic component according to claim 1, wherein at least one groove extending in parallel with a side surface of the conductive member from a tip surface of the lead portion is formed at a tip portion of the lead portion. A method for manufacturing an electronic component, comprising using a first substrate according to claim 1. 8. The method of manufacturing an electronic component according to claim 7, wherein the first substrate is used in which the width of the groove is smaller than the width of the remaining lead portion. . 9. The method of manufacturing an electronic component according to claim 1, wherein a first conductive member having a plurality of lead portions is prepared, and the lead portions of the first substrate and a plurality of the second substrates are provided. A method for manufacturing an electronic component, comprising performing the above steps with each of the electrodes. 10. The method of manufacturing an electronic component according to claim 1, wherein an opening is provided in a portion of the stage below the electrode, and a high pressure gas tank connected to the opening is provided. In the fourth step, the high-pressure gas from the high-pressure gas tank is introduced into the opening at the time of pressurization by the pressurizing jig, and the second substrate is pressed against the pressure of the pressurizing jig. A method for manufacturing an electronic component, comprising applying a pressure to the electronic component. 11. The method for manufacturing an electronic component according to claim 10, wherein an elastic film is formed on the opening of the stage, and the film is expanded when the high-pressure gas is introduced in the fourth step. A method of applying a pressure against the pressure of the pressing jig to the second substrate. 12. The method of manufacturing an electronic component according to claim 3, wherein a first adhesive layer is provided between the base member and the conductive member, and the first adhesive layer is provided between the conductive member and the conductive member. Second
An adhesive layer is provided, and a first substrate having a notch formed by notching a part of the cover member from a side surface is used. In the second step, the first substrate on the notch is exposed. An electronic component characterized in that a photocurable adhesive resin is adhered also to the first adhesive layer, and in the fifth step, the photocurable adhesive resin adhered to the cutout portion of the cover member is also irradiated with ultraviolet rays. Manufacturing method. 13. The method of manufacturing an electronic component according to claim 12, wherein in the second step, light is applied to a wider area including the first adhesive layer exposed in the cutout and a cover member around the first adhesive layer. A method for manufacturing an electronic component, comprising applying a curable adhesive resin. 14. The method of manufacturing an electronic component according to claim 3, wherein in the fourth step, at least a notch is formed on a surface of the base member of the first substrate facing the first conductive member. A method of manufacturing an electronic component, further comprising the step of attaching a reinforcing plate to a region extending over a part and a portion covered with a cover film adjacent to a notch. 15. A main body in which a conductive member extending along the base member and a cover member covering a part of the conductive member are laminated on a surface of a base member made of glass, and the three members are laminated. A first substrate is prepared in advance where a portion and an exposed portion of the conductive member that are not covered by the cover member become a lead portion, and the lead portion on the first substrate is provided on the second substrate on which elements and the like are mounted. A method for manufacturing an electronic component to be connected to an electrode, comprising: a first step of mounting the second substrate on a stage with a surface on which the electrode is formed facing upward; and a step of mounting the first substrate and the second substrate. Secondly, a photo-curable adhesive resin having volumetric shrinkage is attached to at least one of the substrates.
And a step of overlaying the first substrate on the second substrate by aligning the lead portion of the conductive member on the first substrate with the electrode of the second substrate. And a tip made of a material through which ultraviolet light can pass, the tip of which functions as a substantially flat pressing surface, and at least one side surface and a direction in which ultraviolet light travels inside the pressing jig are normal to the pressing surface. A pressure jig configured to be inclined at substantially the same angle with respect to the direction is used to pressurize the first substrate so that the lead portion of the first substrate and the electrode of the second substrate are separated from each other. A fourth step of pressing, and a fifth step of irradiating the adhesive resin with ultraviolet light through the pressure jig and the base member of the first substrate. Method. 16. The method for manufacturing an electronic component according to claim 15, wherein in the fourth step, a plurality of optical fibers bundled together are formed, and a tip surface of each optical fiber is configured as a pressing surface. A method of manufacturing an electronic component, characterized by using a pressure jig. 17. The method for manufacturing an electronic component according to claim 15, wherein an opening is provided at a portion of the stage below the electrode, and a high-pressure gas tank connected to the opening is provided. In the fourth step, the high-pressure gas from the high-pressure gas tank is introduced into the opening during pressurization by the pressurizing jig so that the pressure of the pressurizing jig is prevented against the second substrate. A method of manufacturing an electronic component, which comprises applying a pressure to be applied. 18. The method for manufacturing an electronic component according to claim 17, wherein an elastic film is formed on the opening of the stage, and the film is expanded when the high-pressure gas is introduced in the fourth step. A method of applying a pressure against the pressure of the pressing jig to the second substrate.