JP5467589B2 - Electronic circuit components and electronic equipment - Google Patents

Description

  The present invention relates to an electronic circuit component on which printed wiring is formed, and an electronic apparatus including the electronic circuit component.

  Conventionally, as described in, for example, Patent Document 1 below, many portable electronic devices in which an electronic circuit board is housed in a housing have been provided. The electronic circuit board has a configuration in which, for example, printed wiring is formed on the surface of a glass epoxy board and electronic components are surface-mounted. In such portable electronic devices, there is a strong demand for weight reduction and thickness reduction. For example, a casing is formed of a plastic material that is lighter than metal, and an electronic circuit board is reduced in thickness and weight.

JP-A-11-298169

  By the way, as a technique for reducing the thickness and weight of an electronic circuit board, an electronic component such as a silicon chip is embedded in a board (mounted body) made of a plastic material such as polycarbonate by insert molding or the like, and a printed wiring formed on the board is formed. A method of extending the end portion to the connection terminal of the electronic component and connecting it can be considered. As a result, the electronic circuit board is made thinner and lighter than when electronic components are surface-mounted.

  However, when an electronic component is embedded in a plastic substrate, a gap occurs at the boundary between the plastic substrate and the electronic component due to the difference in thermal expansion coefficient between the plastic substrate and the electronic component when a temperature change such as a temperature test occurs. There is a risk of disconnection in the printed wiring straddling the boundary portion.

  The present invention has been made in consideration of the above-described conventional problems, and an object of the present invention is to provide an electronic circuit component and an electronic device that can prevent disconnection of a printed wiring in a configuration in which the electronic component is embedded in a mounted body. It is said.

An electronic circuit component according to the present invention is an electronic circuit component in which a printed wiring is formed on a surface of a resin mount, and the electronic component is electrically connected to the printed wiring on the mount There are embedded, the terminal surface of the connection terminal is provided with electronic components, the being exposed to the surface side of the mounting body, the boundary portion of at least the electronic component and the mounted object, the On the terminal surface of the electronic component and on the surface of the mounted body, the electronic component is disposed between the terminal surface of the electronic component and the surface of the mounted body and bonded to the electronic component and the mounted body, respectively. The printed wiring is wired on the adhesive layer and adhered to the adhesive layer, the mounted body is a housing of an electronic device, and the adhesive layer is extends in a strip along the boundary, the Printed wiring is characterized in that it is wired so as to intersect the extending direction of the adhesive layer across over said adhesive layer.

Due to these characteristics, when a temperature change occurs, even if a gap occurs at the boundary between the mounted body and the electronic component due to the difference in thermal expansion coefficient between the mounted body and the electronic component, the mounted body and the electronic component The thermal expansion difference is absorbed by the adhesive layer, and the printed wiring adhered to the adhesive layer is held by the adhesive layer.
Further, by assembling the housing, an electronic circuit composed of printed wiring and electronic components can be formed without accommodating an electronic circuit board or the like.

In the electronic circuit component according to the present invention, the printed wiring is connected to the connection terminal from the surface of the mounted body through the adhesive layer , and the adhesive layer is a terminal surface of the electronic component. A step is formed on the upper surface and the surface of the mounted body, and a portion of the printed wiring that is bonded to the adhesive layer is curved or bent along the surface of the adhesive layer. .

In the electronic circuit component according to the present invention, the mounted body is preferably formed of a resin having a thermal expansion coefficient equivalent to that of the electronic component.
Thereby, even if a temperature change arises, the difference of the thermal expansion of a to-be-mounted body and an electronic component can be suppressed small.

In the electronic circuit component according to the present invention, the terminal surface of the electronic component and the surface of the mounted body are preferably flush with each other.
As a result, when the adhesive layer and the printed wiring are formed at the boundary portion between the electronic component and the mounted body, the adhesive layer can be formed by various methods, and the operation of forming the adhesive layer is facilitated. .

In the electronic circuit component according to the present invention, it is preferable that the adhesive layer is made of an adhesive applied to at least a boundary portion between the electronic component and the mounted body.
Thereby, the adhesive layer is securely bonded to the boundary portion between the electronic component and the mounted body.

In addition, an electronic apparatus according to the present invention includes the above-described electronic circuit component.
With such a feature, an electronic circuit is formed in the electronic device by assembling the electronic circuit component.

  According to the electronic circuit component and the electronic device according to the present invention, the difference in thermal expansion between the mounted body and the electronic component is absorbed by the adhesive layer, and the printed wiring bonded to the adhesive layer is held by the adhesive layer. Therefore, disconnection of the printed wiring can be prevented.

It is typical sectional drawing of the electronic circuit component for demonstrating embodiment of the electronic circuit component which concerns on this invention. It is a perspective view showing the connection part of the electronic component and printed wiring for demonstrating embodiment of the electronic circuit component which concerns on this invention. It is a perspective view showing the connection part of the electronic component and printed wiring for demonstrating the reference form of the electronic circuit component which concerns on this invention. It is typical sectional drawing of the electronic circuit component for demonstrating the reference form of the electronic circuit component which concerns on this invention. It is typical sectional drawing of the electronic circuit component for demonstrating other embodiment of the electronic circuit component which concerns on this invention. It is sectional drawing which represented typically the movement of the electronic timepiece for demonstrating embodiment of the electronic device which concerns on this invention.

  Embodiments of an electronic circuit component and an electronic device according to the present invention will be described below with reference to the drawings.

[Electronic circuit components]
First, an embodiment of an electronic circuit component according to the present invention will be described with reference to FIGS.
FIG. 1 is a cross-sectional view schematically showing an example of an electronic circuit component according to the present invention, and FIG. 2 is an enlarged perspective view showing a connecting portion between an electronic component 2 and a printed wiring 3 described later.

  As shown in FIGS. 1 and 2, the electronic circuit component 1 has a printed wiring 3 formed on the surface of a resin mount 5 and the electronic component 2 is embedded in the mount 5 by insert molding or the like. Consisting of

The mounted body 5 is, for example, a casing of an electronic device (for example, a base plate or a train wheel receiver in the case of an electronic timepiece), and the printed wiring 3 is directly formed on the surface of the casing. The mounted body 5 is made of a resin having a thermal expansion coefficient equivalent to that of the electronic component 2. For example, in the case of the electronic component 2 made of silicon, the thermal expansion coefficient of the electronic component 2 is about 3 × 10e ⁻⁶ / ° C. Therefore, the mounted body 5 is formed of a liquid crystal polymer having a value close to this thermal expansion coefficient. In addition to the liquid crystal polymer, polycarbonate, ABS resin (a thermoplastic resin composed of three components of acrylonitrile-butadiene-styrene), polyacetal (POM), or the like can be used as the material of the mounted body 5.

  The electronic component 2 is an electronic component such as a silicon chip, and forms an electronic circuit 4 by being electrically connected to the printed wiring 3. A plurality of connection terminals 20 for electrical connection are formed on the upper surface (terminal surface 21) of the electronic component 2. Further, the terminal surface 21 of the electronic component 2 is formed flush with the surface of the mounted body 5 (the surface on which the printed wiring 3 is formed) and is exposed on the surface side of the mounted body 5.

  An adhesive layer 6 made of, for example, an ultraviolet (UV) curable resin is formed at a boundary portion between the electronic component 2 and the mounted body 5 described above. The adhesive layer 6 is disposed between the terminal surface 21 of the electronic component 2 and the surface of the mounted body 5, and is adhered to the terminal surface 21 of the electronic component 2 and the surface of the mounted body 5. ing. The adhesive layer 6 is extended in a strip shape along the boundary portion described above. That is, the adhesive layer 6 is formed in a rectangular ring shape along the outer edge of the terminal surface 21 of the electronic component 2. The adhesive layer 6 is made of an adhesive such as a UV adhesive applied to the boundary portion between the electronic component 2 and the mounted body 5, and the terminal surface 21 and the mounted surface of the electronic component 2 by inkjet printing or screen printing. It is formed by printing on the surface of the body 5. The adhesive layer 6 has elasticity that can be elastically deformed in accordance with the relative displacement between the electronic component 2 and the mounted body 5 due to a difference in thermal expansion, and is electrically insulative so that adjacent printed wirings 3 are not short-circuited. It is made of a polymer material having Further, the adhesive layer 6 has a breaking strain larger than that of the printed wiring 6, and has a breaking strain that does not break even if the electronic component 2 and the mounted body 5 are displaced relative to each other due to a difference in thermal expansion.

  The printed wiring 3 is a film-like wiring having conductivity, and is made of a conductive paste such as silver nano paste. The printed wiring 3 is formed by printing on the surface of the mounted body 5 by, for example, ink jet printing or screen printing, and is adhered to the surface of the mounted body 5. The printed wiring 3 extends from the surface of the mounted body 5 to the connection terminal 20 of the electronic component 2 through the adhesive layer 6 described above. That is, the printed wiring 3 extends from the surface of the mounted body 5 to the connection terminal 20 across the adhesive layer 6. The end of the printed wiring 3 is bonded to the connection terminal 20 of the electronic component 2 described above, and is electrically connected to the connection terminal 20. In addition, a portion of the printed wiring 3 that is bonded to the adhesive layer 6, that is, a portion that straddles the adhesive layer 6 (hereinafter, the straddling portion 30) is curved along the surface of the adhesive layer 6.

  Next, a method for manufacturing the electronic circuit component 1 having the above-described configuration will be described.

  First, the electronic component 2 is embedded in the mounted body 5. More specifically, when the mounted body 5 is molded, the electronic component 2 is disposed inside the mold, and the mounted body 5 is insert-molded using the electronic component 2 as an insert. At this time, the electronic component 2 is held at a predetermined position so that the terminal surface 21 of the electronic component 2 is exposed to the surface side of the mounted body 5 and is flush with the surface of the mounted body 5.

  Next, the adhesive layer 6 is disposed at the boundary portion between the surface of the mounted body 5 and the terminal surface 21 of the electronic component 2. More specifically, the adhesive is applied by inkjet printing or the like along the boundary line between the surface of the mounted body 5 and the terminal surface 21 of the electronic component 2, and the surface of the mounted body 5 and the terminal surface of the electronic component 2. The adhesive layer 6 straddling the area 21 is formed in a band shape along the boundary portion. Thereby, the polymeric material (adhesive) which forms the contact bonding layer 6 is suppressed to a small quantity. Moreover, since the above-described adhesive layer 6 is formed by applying an adhesive, the adhesive layer 6 is securely bonded to the surface of the mounted body 5 and the terminal surface 21 of the electronic component 2. Furthermore, since the terminal surface 21 of the electronic component 2 and the surface of the mounted body 5 are flush with each other, the adhesive layer 6 is easily formed as compared with the case where there is a step at the boundary portion, and inkjet printing is performed. The adhesive layer 6 can be formed by various methods such as screen printing.

Next, the printed wiring 3 is formed on the surface of the mounted body 5. More specifically, the printed wiring 3 is formed by printing a conductive paste on the surface of the mount 5 by inkjet printing or screen printing. At this time, the printed wiring 3 extends from the surface of the mounted body 5 through the adhesive layer 6 to the connection terminal 20 of the electronic component 2, and the end of the printed wiring 3 is on the connection terminal 20. It is glued. As a result, the printed wiring 3 is electrically connected to the connection terminal 20 of the electronic component 2. Furthermore, since the terminal surface 21 of the electronic component 2 and the surface of the mounted body 5 are flush with each other, the printed wiring 3 can be formed by various methods such as inkjet printing and screen printing.
Thus, the electronic circuit component 1 is completed.

  According to the electronic circuit component 1 having the above-described configuration, the difference in thermal expansion between the mounted body 5 and the electronic component 2 is absorbed by the adhesive layer 6 and the printed wiring 3 bonded to the adhesive layer 6 is bonded to the adhesive layer. Therefore, the disconnection of the printed wiring 3 can be prevented.

  In addition, since the mounted body 5 is a casing of an electronic device, an electronic device including the printed wiring 3 and the electronic component 2 can be obtained without assembling the electronic circuit board by assembling the casing and manufacturing the electronic device. A circuit 4 is formed. Therefore, the electronic circuit board can be omitted, the cost can be reduced, and the electronic device can be downsized.

  Further, the printed wiring 3 is connected to the connection terminal 20 from the surface of the mounted body 5 through the adhesive layer 6, and the extending portion 30 of the printed wiring 3 adhered to the adhesive layer 6 extends along the surface of the adhesive layer 6. Even if a gap is generated at the boundary between the mounted body 5 and the electronic component 2 due to the difference in thermal expansion coefficient between the mounted body 5 and the electronic component 2, the straddling portion 30 of the printed wiring 3 is By becoming straight from the curved state, the difference in thermal expansion between the mounted body 5 and the electronic component 2 is absorbed. Thereby, disconnection of the printed wiring 3 can be reliably prevented.

  Further, if the mounted body 5 is formed of a resin having the same thermal expansion coefficient as that of the electronic component 2, even if a temperature change occurs, the difference in thermal expansion between the mounted body 5 and the electronic component 2 is kept small. Therefore, disconnection of the printed wiring 3 can be more reliably prevented.

  Further, the terminal surface 21 of the electronic component 2 and the surface of the mounted body 5 are flush with each other, so that the adhesive layer 6 and the printed wiring 3 can be formed by various methods, and the adhesive layer 6 and the printed layer 5 can be printed. Since the work of forming the wiring 3 is facilitated, the productivity of the electronic circuit component 1 can be prevented from being lowered.

  Further, the adhesive layer 6 is made of an adhesive applied to the terminal surface 21 of the electronic component 2 and the surface of the mounted body 5, and is surely provided at the boundary portion between the terminal surface 21 of the electronic component 2 and the surface of the mounted body 5. Therefore, the adhesion failure of the adhesive layer 6 to the mounted body 5 and the electronic component 2 can be prevented, and the disconnection of the printed wiring 3 can be surely prevented.

Further, the adhesive layer 6 is extended in a band shape along the boundary portion between the terminal surface 21 of the electronic component 2 and the surface of the mounted body 5, and the material (adhesive) for forming the adhesive layer 6 is small. Since it can be suppressed, the material cost of the adhesive layer 6 can be kept low and the economic efficiency can be improved.
Moreover, since the above-mentioned adhesive layer 6 is made of a polymer material having electrical insulation, the printed wirings 3 are not electrically short-circuited via the adhesive layer 6 and a short circuit in the electronic circuit 4 is prevented. Can do.

As mentioned above, although the embodiment of the electronic circuit component according to the present invention has been described, the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist thereof.
In the reference form shown in FIG. 3, the adhesive layer 6 </ b> A made of a polymer material having electrical insulation is formed over the entire terminal surface 21 of the electronic component 2 . In this case, an opening 60 is formed in the adhesive layer 6 </ b> A at the portion of the connection terminal 20 of the electronic component 2, and the connection terminal 20 is exposed from the opening 60. In addition, after forming the adhesive layer 6A, the above-described opening 60 may be formed by drilling with a laser or the like, or before forming the adhesive layer 6A, a mask is installed in the opening 60 portion to form the adhesive layer 6A. Then, the mask 60 may be removed to form the opening 60 described above.

  As described above, according to the configuration in which the adhesive layer 6A is formed on the entire terminal surface 21 of the electronic component 2, it is only necessary to apply an adhesive by screen printing or the like, and there is no need for fine positional accuracy and the like. The forming operation is easy. As a result, the productivity of the electronic circuit component 1 can be improved. Further, since the adhesive layer 6A is made of a polymer material having electrical insulation, the printed wirings 3 are not electrically short-circuited via the adhesive layer 6A, and a short circuit in the electronic circuit 4 can be prevented.

In the reference form shown in FIG. 4, the adhesive layer 6 </ b> B is formed not only on the terminal surface 21 of the electronic component 2 but also on the entire surface of the mounted body 5 .
As another reference form, there is a configuration in which an adhesive layer is formed only at a location where the printed wiring 3 passes in a boundary portion between the terminal surface 21 of the electronic component 2 and the surface of the mounted body 5 . That is, as another reference mode, there is a configuration in which a plurality of adhesive layers are intermittently disposed along a boundary portion between the terminal surface 21 of the electronic component 2 and the surface of the mounted body 5 .

  Further, in the above-described embodiment, the electronic component 2 is embedded in the mounted body 5 by insert molding. However, as shown in FIG. 5, the present invention is arranged inside the recess 50 formed in the mounted body 5A. A configuration in which the electronic component 2 is fitted to each other via an adhesive may be used. More specifically, after the electronic component 2 is arranged inside the recess 50, when the adhesive layer 6 is formed by applying an adhesive at the boundary between the terminal surface 21 of the electronic component 2 and the surface of the mounted body 5, An adhesive is filled between the side surface of the electronic component 2 and the inner peripheral surface of the recess 50. Thereby, the electronic component 2 arrange | positioned in the recessed part 50 is fixed with an adhesive agent.

  In the above-described embodiment, the adhesive layer 6 is formed of an adhesive, but the present invention is an adhesive made of an adhesive tape that can be attached to the surface of the mounted body 5 or the terminal surface 21 of the electronic component 2. It may be a layer, and may be an adhesive layer having other configurations.

[Electronics]
Next, an embodiment of an electronic apparatus according to the present invention will be described with reference to FIG.
FIG. 6 is a cross-sectional view schematically showing a movement of an electronic timepiece 100 which is an example of the electronic apparatus according to the invention.

  As shown in FIG. 6, an electronic timepiece 100 includes a train wheel receiver 107, a ground plate 105 attached to the train wheel receiver 107 in an overlapping manner (corresponding to a mounted body in the present invention), and an IC attached to the ground plate 105. A chip 102 (corresponding to an electronic component in the present invention) and a train wheel 108 that is rotatably supported between the main plate 105 and the train wheel support 107 are provided.

  On the surface (outer surface) of the ground plate 105, the IC chip 102 is embedded with the terminal surface 121 exposed, and a printed wiring 103 made of a conductive paste such as silver nano paste is formed. The printed wiring 103 is electrically connected to a crystal resonator (not shown) and the like, and is also electrically connected to the connection terminal 120 of the IC chip 102. Further, an adhesive layer 106 in which the IC chip 102 is disposed between the terminal surface 121 and the surface of the ground plate 105 is formed at the boundary portion between the terminal surface 121 of the IC chip 102 and the surface of the ground plate 105. The printed wiring 103 is extended from the surface of the ground plate 105 to the connection terminal 120 of the IC chip 102 through the adhesive layer 106. The above-described adhesive layer 106 has a configuration similar to that of the above-described adhesive layer 6.

  In the electronic timepiece 100 described above, the electronic circuit 104 including the IC chip 102 and the printed wiring 103 is formed on the base plate 105. Therefore, the electronic circuit board is not required, and the electronic timepiece 100 can be reduced in thickness and weight. . Further, since the IC chip 102 is embedded in the ground plate 105, the ground plate 101 with an electronic circuit (corresponding to the electronic circuit component in the present invention) composed of the ground plate 105, the IC chip 102, the printed wiring 103, and the like is made thin. As a result, the electronic timepiece 100 can be thinned. Furthermore, since the adhesive layer 106 can prevent the printed wiring 103 from being disconnected due to the difference in thermal expansion between the IC chip 102 and the ground plane 105, the heat resistance of the electronic timepiece 100 can be improved.

As mentioned above, although the embodiment of the electronic device according to the present invention has been described, the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist thereof.
For example, the electronic device according to the present invention may be other than the electronic timepiece 100, and may be an electronic device such as a mobile phone, a portable digital music player, a notebook personal computer, a digital camera, or an electronic notebook.

  In the above-described embodiment, the printed wiring 103 is formed on the base plate 105 and the IC chip 102 is embedded. However, in the present invention, the printed wiring 103 is formed on the train wheel bridge 107 and the IC is embedded. The chip 102 may be embedded.

DESCRIPTION OF SYMBOLS 1 Electronic circuit component 2 Electronic component 3 Printed wiring 4 Electronic circuit 5 Mounted body 6 Adhesive layer 20 Connection terminal 21 Terminal surface 100 Electronic timepiece (electronic device)
101 Grounding board with electronic circuit (electronic circuit parts)
102 IC chip (electronic component)
103 Printed wiring 105 Ground plate (mounted body)
106 Adhesive layer 120 Connection terminal 121 Terminal surface

Claims (6)

An electronic circuit component in which printed wiring is formed on the surface of a resin mount,
In the mounted body, an electronic component electrically connected to the printed wiring is embedded,
The terminal surface provided with the connection terminal of the electronic component is exposed on the surface side of the mounted body,
At least at the boundary between the electronic component and the mounted body, on the terminal surface of the electronic component and on the surface of the mounted body, between the terminal surface of the electronic component and the surface of the mounted body. An adhesive layer that is disposed across and bonded to the electronic component and the mounted body is formed,
The printed wiring is wired on the adhesive layer and bonded to the adhesive layer,
The mounted body is a housing of an electronic device,
The adhesive layer extends in a band shape along the boundary portion,
The electronic circuit component , wherein the printed wiring is wired so as to cross over the adhesive layer and intersect the extending direction of the adhesive layer . The electronic circuit component according to claim 1,
The printed wiring is connected to the connection terminal through the adhesive layer from the surface of the mounted body,
The adhesive layer forms a step on the terminal surface of the electronic component and the surface of the mounted body,
A part of the printed wiring bonded to the adhesive layer is bent or bent along the surface of the adhesive layer. The electronic circuit component according to claim 1 or 2,
The electronic circuit component, wherein the mounted body is made of a resin having a thermal expansion coefficient equivalent to that of the electronic component. In the electronic circuit component according to any one of claims 1 to 3,
An electronic circuit component, wherein a terminal surface of the electronic component and a surface of the mounted body are flush with each other. In the electronic circuit component according to any one of claims 1 to 4,
The electronic circuit component, wherein the adhesive layer is made of an adhesive applied to at least a boundary portion between the electronic component and the mounted body.   An electronic apparatus comprising the electronic circuit component according to any one of claims 1 to 5.

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