JPH0245209B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thin electronic device.

[Prior Art] Conventionally, small electronic devices such as small electronic calculators have a structure in which various electronic components are housed in a device case that combines a pair of upper and lower cases made of synthetic resin. ing.

[Problems to be solved by the invention] In recent years, there has been a tendency for small electronic devices such as small electronic calculators to become thinner, and it is now possible to make small electronic devices as thin as credit cards. It is being considered.

However, as mentioned above, conventional small electronic devices house various electronic components in a device case made of synthetic resin, so in order to make the device thinner, the thickness of the upper and lower resin cases has to be reduced. Making it thinner will weaken the strength of the device,
For this reason, in conventional small electronic devices, the thickness of the case cannot be made very thin, so the thickness of the device cannot be made as thin as that of a credit card. The present invention has been made in view of the above-mentioned circumstances, and its object is to provide a small electronic device.

[Means for Solving the Problems] The small electronic device of the present invention houses an electronic component structure including at least an integrated circuit element and a wiring board in a frame, and each has a sheet member made of a metal plate. Upper and lower covers are adhered to the upper and lower surfaces of the electronic component structure, and the space surrounded by the upper and lower covers at the outer periphery of the frame is filled with an insulating adhesive. be.

[Function] According to the small electronic device of the present invention, since the upper cover of the device and the lower cover of the device, each having a sheet member made of a metal plate, are adhered to the upper and lower surfaces of the electronic component structure, each sheet member made of a metal plate The strength of the metal plate can ensure the strength of the upper and lower surfaces of the device, and as the metal plate sheet member and the electronic component structure are integrated, the strength of the entire device can also be ensured. In addition, since the space surrounded by the outer periphery of the frame housing the electronic component structure, the upper cover, and the lower cover is filled with an insulating adhesive,
The strength of the outer periphery of the device is improved, and the overall device can be made significantly thinner while maintaining sufficient strength.

[Embodiments of the Invention] Examples of the present invention will be described below with reference to drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to a sheet-like small electronic calculator shown in FIGS. 1 to 11.

FIG. 2 shows the external appearance of the sheet-like small electronic calculator, and FIG. 3 shows the disassembled state. In the figure, 1 is an electronic component structure, 2 is an upper cover, and 3 is a lower cover. The electronic component structure 1 is configured by combining a wiring board 11, a semiconductor integrated circuit element 12, an electronic component 13, a display panel 14, and a solar cell 15. The upper cover 2 includes a metal sheet 16 as its main body, a top protection sheet 18, a spacer 17,
and a frame body 19 are laminated. The lower cover 3 is constructed by laminating a metal sheet 20, which is the main body thereof, and a lower surface protection sheet 21. Third
Although not shown in the drawings, reference numeral 4 in FIG. 1 and FIGS. 4 to 6 indicates an adhesive layer made of an insulating adhesive 22. Then, the upper cover 2 is closely laminated on the upper side of the electronic component structure 1, the adhesive layer 4 is provided on the lower side of the electronic component structure 1, and the lower cover 3 is closely laminated on the lower side of the adhesive layer 4. The whole thing is in the form of a thin sheet.

Next, the structure of each part will be described with reference to FIG. 1 and FIGS. 4 to 8. Figure 1 is a cross-sectional view taken along line A-A in Figure 2, Figure 4 is a cross-sectional view taken along line B-B in Figure 2, Figure 5 is a cross-sectional view taken along line C-C in Figure 2, and Figure 6 is a cross-sectional view taken along line B-B in Figure 2.
7 and 8 are cross-sectional views taken along the line D-D in the figure, respectively, and FIGS. 7 and 8 are drawings showing the switch portion, respectively.

The electronic component structure 1 will be described. Wiring board 1
1 is a rectangular sheet made of an insulating material and has a thickness of about 220 μm. On the top surface, a plurality of fixed contacts 23, each consisting of a pair of contacts, are arranged in a grid pattern as switch contacts. and a fixed contact 23 and a terminal 2 to be described later on the bottom surface.
A predetermined wiring pattern including lines 4 and 28 is formed. A semiconductor integrated circuit element 12 and electronic components 13 such as chip capacitors and diodes are attached to the lower mounting hole 11a formed in the wiring board 11 by penetrating the upper and lower sides thereof, and these are connected to the wiring pattern of the wiring board 11. be. The display panel 14 consists of a liquid crystal display panel with a thickness of about 550 μm in which liquid crystal is packaged in a film.The liquid crystal is sealed between upper and lower films that serve as upper and lower electrode substrates, and one end 14a of the film is sealed. It has been done.
The display panel 14 is disposed on one side of the wiring board 11 on the same plane. As shown in FIG. 1, terminals 24 formed on the lower surface of the wiring board 11 and terminals 25 formed on the lower surface of the upper electrode substrate of the display panel 14 are connected by a flexible film 27 having wiring 26 made of conductive adhesive. and terminal 2
4 and 25 and the wiring 26 are bonded together by heating and pressing. The solar cell 15 has a thickness of about 180 μm and is made by forming an amorphous silicon thin film on the upper surface of a substrate made of stainless steel, and is arranged on one side of the wiring board 11 in the same plane as the display panel 14. . As shown in FIG. 4, terminals 28 formed on the lower surface of the wiring board 11 and terminals 29 formed on the upper surface of the substrate of the solar cell 15 are connected by a flexible film 31 having wiring 30 made of conductive adhesive. 30 and terminals 28, 29 are bonded together by heating and pressing. In this case, the wiring 30 is formed on the opposite side of the flexible film 31 so as not to shoot against the substrate side of the solar cell 15,
Through hole 31 at terminal 29 part of solar cell 15
A wiring 30 is led out to the solar cell 15 side through a and is electrically connected to the terminal 29. In this way, the electronic component structure 1 is constructed by arranging each component in a plane and electrically connecting them to each other, and the semiconductor integrated circuit element 12 operates using the solar cell 15 as a power source and the input signal from the fixed contact 23. A display signal is output to the display panel 14, and the calculation result is displayed.

The upper cover 2 will be described. The metal sheet 16, which is the main body of the upper cover, is made of a metal plate, for example, a stainless steel plate, with a thickness of about 100 μm, and has a rectangular shape corresponding to the entire frame 19. This metal sheet 16 also serves as a contact sheet, and a plurality of contact springs 32 having the shape shown in FIG. 7 are arranged in a grid pattern facing the fixed contacts 23 of the wiring board 11 and etched. The display panel 1 is formed by
4 and the solar cell 15, the display window 33 and the battery window 3
4 is formed by an etching process, and a plurality of relief recesses 35 corresponding to the integrated circuit element 12 and the electronic component 13 are formed on the lower surface by a half-etching process. A movable contact 36 is provided on the lower center surface of each contact spring 32 by printing carbon paint, respectively, as an operation section for inputting input to the fixed contact 23. In addition, metal sheet 1
A recess 34a is formed in the battery window 34 of No. 6 to allow the wiring 30 of the flexible film 31 to escape. The spacer 17 maintains the distance between the metal sheet 16, which also serves as a contact sheet, and the wiring board 11, and is made of a transparent polyester film with a thickness of about 50 μm, and has a rectangular shape corresponding to the size of the wiring board 11. I am doing it. The spacer 17 has a wiring board 11
A plurality of contact holes 37 are formed in a grid pattern at positions facing each of the fixed contacts 23, and a plurality of escape holes 38 are formed corresponding to the integrated circuit element 12 and each electronic component 13. In addition, this spacer 1
A transparent insulating adhesive 43 having a thickness of approximately 25 μm is applied in advance to the upper and lower surfaces of each member 7 . The thickness of the frame 19
It is made of a metal plate, for example, a stainless steel plate, with a diameter of about 400μ, has a size that surrounds the electronic component structure 1, and has a protrusion 19a that partitions between the display panel 14 and the solar cell 15, and is rectangular as a whole. It forms a frame. As shown in FIGS. 5 and 6, contact pieces 39 are cut upwardly at appropriate locations on the frame 19 for electrostatic shielding.
A contact piece 39b is formed with a portion a facing downward. The upper surface protection sheet 18 is the metal sheet 16
This protects the top surface of the metal sheet 1 and is made of a transparent polyester film approximately 50μ thick.
It has a rectangular shape slightly larger than 6. This protective sheet 18 includes the display transparent portion 40 of the display panel 14.
Opaque printing is applied to the entire lower surface of the solar cell 15 except for the light-receiving portion 41 of the metal sheet 1.
Printing 42 for displaying input items for switch contacts is printed corresponding to each contact spring 32 of 6. Furthermore, a transparent insulating adhesive 43 having a thickness of approximately 25 μm is applied to the entire lower surface of the upper surface protection sheet 18. Then, the spacer 17 is connected to the electronic component structure 1.
The spacer 1 is placed on the upper surface of the wiring board 11.
7 is bonded to the wiring board 11 by an insulating adhesive 43 applied to the lower surface of the metal sheet 1.
6 is arranged on the upper surface of the spacer 17.
The spacer 17 is bonded to the spacer 17 by an insulating adhesive 43 applied to the upper surface of the spacer 17 . Further, the upper surface protection sheet 18 is placed on the upper surface of the metal sheet 16, and is adhered to the metal sheet 16 by a transparent insulating adhesive 43 applied to the lower surface of this upper surface protection sheet 18. Further, the frame 19 is arranged below the metal sheet 16 to surround the electronic component structure 1 and the spacer 17, and is bonded to the lower surface of the metal sheet 16 via an adhesive 43. Therefore, as shown in FIG. 4, the metal sheet 1
6 each contact spring 32 and each contact hole 3 of spacer 17
7 are vertically opposed and overlapping each other, and each contact spring 32
Each movable contact 36 is connected to each contact hole 37 of the spacer 17.
It is located above and faces each of the fixed contacts 23 of the wiring board 11 via. Each item of the display print 42 on the top protection sheet 18 is located above each contact spring 32. This constitutes a switch. The contact spring 32 of the metal sheet 16 is normally in a horizontal state due to the spring force as shown in FIG. When the display print 42 portion of the top protection sheet 18 is pressed down, the contact spring 32 of the metal sheet 16 also bends downward against the spring force and enters the contact hole 37 of the spacer 17.
The movable contact 36 contacts the fixed contact 23 of the wiring board 11. Therefore, the pair of contacts of the fixed contact 23 are electrically connected to each other. In addition, as shown in FIG.
The display windows 33 of the display panel 14 are stacked vertically, and the upper part of the display panel 14 is fitted into the display windows 33, so that its display surface faces a transparent display see-through section 40. Therefore, the display on the display panel 14 can be read from the outside via the display see-through section 40. Note that the upper surface of the display panel 14 is adhered to the upper surface protection sheet 18 with a transparent insulating adhesive 43. Also, the fourth
As shown in the figure, the light receiving section 41 of the protective sheet 18 and the battery window 34 of the metal sheet 16 are vertically overlapped, and the solar cell 15 is fitted into the battery window 34 so that the battery element faces the transparent light receiving section 41. are doing. Therefore, the solar cell 15 can receive external light via the light receiving section 41. Note that the solar cell 15 is adhered to the protective sheet 18 via a transparent insulating adhesive 43. As shown in FIG. 1, the relief recesses 35 of the metal sheet 16 and the relief holes 38 of the spacer 17 overlap vertically, and the integrated circuit element 1 mounted on the wiring board 11
2 and the escape hole 38 where the upper part of each electronic component 13 faces each other.
and is fitted into the escape recess 35. Note that the integrated circuit element 12 and the electronic component 13 are electrically insulated from the metal sheet 16 by a layer of insulating adhesive 43. In this way, the upper cover 2 is laminated in close contact with the entire upper surface of the electronic component structure 1.
In this embodiment, a frame 1 is used as a part of the upper cover 2.
9 is provided, and this frame body 19 holds the electronic component structure 1 from the periphery.

The adhesive layer 4 will be described. The adhesive layer 4 is formed of an acrylic or epoxy two-component insulating adhesive 22. The adhesive 22 is applied to the entire lower surface of the wiring board 11 in the electronic component assembly 1, and is filled to cover the integrated circuit element 12 protruding from the lower surface of the wiring board 11 and the lower part of each electronic component 13. 22 is filled to cover the lower part of the display panel 14, and is also filled to fill the space on the lower side of the solar cell 15. Furthermore, the adhesive 22 surrounds the entire outer periphery of the frame 19 in the upper cover 2 and protects the protective sheet 18 of the upper cover 2 and the protective sheet 21 of the lower cover 3.
It is filled in between. In this way, the adhesive layer 4 is formed by filling the entire lower surface of the electronic component structure 1 with the adhesive 22 in a layered manner.
Each component is bonded and fixed from below, and irregularities of each component on the lower side of the electronic component structure 1, that is, variations in height of each component are absorbed.
If a case structure constituting the device case is provided below the electronic component structure 1 instead of the adhesive layer 4, the structure will be complicated in order to fix the electronic component structure 1, and the electronic component structure will be It is difficult to absorb the irregularities of each component of the electronic component structure 1, and it is especially difficult to absorb the irregularities when an error occurs in the mounting dimensions of the components of the electronic component structure 1 or the thickness of the component itself during assembly. On the other hand, since the adhesive layer 4 of this embodiment has fluidity, it can absorb the unevenness of each component of the electronic component structure 1 while reliably fixing each component, especially when attaching each component during assembly. It can flexibly absorb errors in dimensions and thickness of the parts themselves. Furthermore, in this embodiment, since the adhesive 22 adheres and fixes the outer periphery of the frame 19 between the protective sheets 18 and 21, it is possible to increase the strength of the sheet-like small electronic calculator. The appearance can be improved by covering the laminated seams of each component on the outer periphery with the adhesive 22.

The lower cover 3 will be described. The metal sheet 20, which is the main body of the upper cover 3, is made of a metal plate, for example, a stainless steel plate, with a thickness of about 100 μm, and has a rectangular shape with the same size as the frame 19 of the upper cover 2. The lower surface protection sheet 21 is formed of a transparent polyester film with a thickness of about 25 μm, and the metal sheet 2
It has a rectangular shape slightly larger than zero, and a transparent insulating adhesive 43 with a thickness of about 25 μm is applied to the upper surface side. The metal sheet 20 is placed overlappingly on the lower surface of the adhesive layer 4 and fixed by adhesive.
An insulating adhesive 43 is applied to the upper surface of the metal sheet 20 at a portion facing each component of the electronic component structure 1 in order to insulate the metal sheet 20 from each component. The lower surface protection sheet 21 is overlaid and adhesively fixed to the lower surface of the metal sheet 20 via an adhesive 43. In this case, the adhesive 22 flows and catches the lower cover 3, so
The lower cover 3 can be set parallel to the upper cover 2 with high accuracy at a required spacing position, and the spacing (thickness dimension) with respect to the upper cover 2 can be freely adjusted at the manufacturing stage. The metal sheet 20 supports the adhesive layer 4 from below, and the bottom protection sheet 21 protects the bottom surface of the metal sheet 20. For example, decorative printing is printed on the top surface of the bottom protection sheet 21. being done.

In this sheet-like small electronic calculator, the contact sheet 16, the frame 19, and the support sheet 20 are made of metal plates, such as stainless steel plates, so that the entire computer has high mechanical strength and rigidity. Also, the overall thickness of this sheet-like small electronic calculator is
It is 800μ.

Furthermore, the sheet-like small electronic calculator of this embodiment is provided with electrostatic shielding measures. That is, as shown in FIG.
6, and as shown in FIG.
The downward contact piece 39b formed on the lower cover 3
is in contact with the upper surface of the metal sheet 20. Therefore, since the metal sheet 16 located on the upper side and the metal sheet 20 located on the lower side are electrically connected at the same potential via the metal frame 19, the influence of static electricity from the outside is This prevents any damage to the semiconductor integrated circuit elements 12 on the substrate 11.

Next, a method of manufacturing a sheet-like small electronic calculator having the above-mentioned configuration will be explained. First, in the electronic component structure 1, the integrated circuit element 12 and each electronic component 13 are mounted on the wiring board 11 with its surface (top surface) as a reference position, and the display panel 14 and the solar cell 1 are mounted.
5 is connected to the wiring board 11 using flexible films 27 and 31 and assembled. The upper cover 2 is made by adhesively fixing the frame 19 to the lower surface of the metal sheet 16 using an adhesive 43 using a heating and pressing method, and then attaching the upper protective sheet 18 to the upper surface of the metal sheet 16 using an adhesive 43.
3, and is assembled by adhesion and fixation by heating and pressing. Then, the electronic component structure 1 and the metal sheet 1
6 and a laminate of the upper surface protection sheet 18 are stacked on top of each other with the spacer 17 in between.
7. Adhesive fixation is performed by heating and pressing via adhesive 43 applied to both surfaces. In this case, the surface side of the upper surface protection sheet 18 is used as a reference surface for bonding. As a result, the upper cover 2 and the electronic component assembly 1 are assembled, and the upper surface side of the upper cover 2 becomes a flat surface.
Note that the lower side of the electronic component structure 1 has an uneven state in which each component protrudes (see FIGS. 9 and 10). Next, as shown in FIG.
A stacked body of the electronic component structure 1 and the electronic component structure 1 is arranged with the upper cover 2 facing down, and the back side of the electronic component structure 1 is positioned on the top side. Electronic component structure 1 on the upper side
Apply adhesive 2 to the top and outer periphery of the laminate on the back side of the laminate.
Fill 2. Since this adhesive 22 has fluidity, it easily enters the recesses between the parts on the back side of the electronic component structure 11 and covers and embeds the convex parts of each component, so that the electronic component structure 11 The adhesive layer 4 is formed by absorbing the irregularities and dimensional variations of the parts on the back side of the adhesive. Next, the lower cover 3 is manufactured by bonding and fixing the metal sheet 20 and the protective sheet 21 to each other via the adhesive 43 by heating and pressing, and as shown in FIG. 10, the lower cover 3 is placed on the adhesive 22. Pressure is applied from above to fix it to the adhesive 22. The lower cover 3 is made parallel to the upper cover 2 and rolled down to a position where the total thickness is 800μ. In this case, since the adhesive 22 is pressed by the lower cover 3 and flows toward the outer circumference, the lower cover 3 can be lowered to a preset height position. Therefore, the upper cover 2 and the lower cover 3
can be arranged in parallel with high precision, and the thickness between the upper cover 2 and lower cover 3 can be set with high precision with respect to the design value. Note that the excess adhesive 22 flows between the protective sheet 19 of the upper cover 2 and the protective sheet 21 of the lower sheet 3 and protrudes to the outer periphery. Next, as shown in FIGS. 10 and 11, the outer periphery of both the protective sheets 18, 21 and the adhesive 22 between the protective sheets 18, 21 is cut into the final shape shown by the broken line. For this cutting, both protective sheets 18 and 21 are previously formed to be larger than the final shape during the manufacturing stage. After cutting into the final shape, the adhesive 22 present between both protective sheets 19 and 21 is applied to the upper and lower metal contact sheets 1.
6, 20 and the outer periphery of the frame 19 can be hidden, and the periphery of the sheet-like small electronic calculator can be made to look like resin in combination with the resin contact sheets 18, 21.

That is, the sheet-like small electronic calculator of the above embodiment has an upper cover 2 which is mainly made of a metal sheet 16 and has a metal frame 19 adhered to its lower surface, and a lower cover 3 which is mainly made of a metal sheet 20. An electronic component structure that constitutes a case body of a computer, and has a display panel 14 and a solar cell 15 connected to a wiring board 11 on which an integrated circuit element 12 and an electronic component 13 are attached between the upper cover 2 and the lower cover 3. At the same time, the metal sheet 16 constituting the upper cover 2 is adhered to the upper surface of the wiring board 11 of the electronic component assembly 1 via a spacer 17 using an adhesive 43 applied to the upper and lower surfaces of the spacer 17. Furthermore, a metal sheet 20 constituting the lower cover 3 is placed on the lower surfaces of the wiring board 11, display panel 14, and solar cell 15 of the electronic component structure 1, and an adhesive layer 4 made of an insulating adhesive 22 and the upper surface of the metal sheet 20 According to this sheet-like small electronic calculator, there are upper covers 2 on the upper and lower surfaces respectively.
Since there is a metal sheet 16 constituting the computer and a metal sheet 20 constituting the lower cover 3, the upper and lower metal sheets 16 and 20 can ensure the strength of the upper and lower surfaces of the computer. Since the sheets 16 and 20 are adhered to the electronic component structure 1 with insulating adhesives 43 and 22, respectively, the metal sheets 16 and 20 that constitute the upper cover 2 and the lower cover 3 of the computer and the electronic component structure are Since the strength of the entire computer can be ensured by integrating it with the body 1, it is possible to significantly reduce the thickness while ensuring sufficient strength.

Next, a second embodiment of the present invention will be described with reference to FIG. This second embodiment is applied to a sheet-like small electronic calculator like the first embodiment described above, and the same parts in FIG. 12 as in FIGS. 1 and 3 are given the same reference numerals and explained. omitted.

In this second embodiment, the adhesive 22 of the adhesive layer 4 is provided between the electronic component structure 1 and the lower cover 3, and the adhesive 22 of the adhesive layer 4 is provided between the metal sheet 16 of the upper cover 2 and the metal sheet 20 of the lower cover 3. The outer periphery of the frame 19 is surrounded and filled. In this case, the strength of the outer periphery is improved.

In the above embodiment, the upper cover 2 has a structure in which the upper protective sheet 18, the spacer, and the frame 19 are adhered to the metal sheet 16, and the lower cover 3
has a structure in which a lower surface protection sheet 18 is adhered to a metal sheet 20, but the upper cover 2 and lower cover 3 are limited to the above embodiments as long as they are composed of sheet members made of metal plates. Alternatively, the frame body 19 may be formed integrally with a metal sheet. Further, the present invention is not limited to sheet-like small electronic calculators, but can be widely applied to other small electronic devices, and furthermore, the present invention can also be applied to electronic component structures.
It is sufficient if it includes at least an integrated circuit element and a wiring board.

[Effects of the Invention] According to the small electronic device of the present invention, the strength of the upper and lower surfaces of the device is ensured by the upper cover of the device and the lower cover of the device having the metal plate sheet member, and the upper and lower covers and the electronic The strength of the entire device is ensured because the component components are integrated by adhesive, and the space surrounded by the outer periphery of the frame housing the electronic component components, the upper cover, and the lower cover is filled. Since the adhesive improves the strength of the outer periphery of the device, it is possible to significantly reduce the thickness of the device while ensuring sufficient strength for the entire device.

[Brief explanation of drawings]

1 to 11 show a first embodiment of the present invention, in which FIG. 1 is a sectional view taken along line A-A in FIG. 2, and FIG. 2 is an external view showing a sheet-like small electronic calculator. , Figure 3 is an exploded perspective view, Figure 4 is Figure 2B-
5 is a sectional view taken along the line C-C in FIG. 2, FIG. 6 is a sectional view taken along the line D-D in FIG. 2, and FIG. 7 shows the contact spring of the contact sheet. 8 is a sectional view of the switch section showing the operating state of the switch, FIGS. 9 and 10 are explanatory diagrams showing the manufacturing process of the sheet-like small electronic calculator, and FIG.
The figure is a perspective view showing a semi-finished product of a sheet-like small electronic calculator. FIG. 12 is a sectional view of a sheet-like small electronic calculator showing a second embodiment of the present invention. 1...Electronic component component, 2...Top cover, 3
... lower cover, 4 ... adhesive layer, 11 ... wiring board, 12 ... integrated circuit element, 13 ... semiconductor component, 14 ... display panel, 15 ... solar cell, 1
6...Metal sheet, 17...Spacer, 18...
Top protection sheet, 19... Frame, 20... Metal sheet, 21... Bottom protection sheet, 22... Adhesive, 23... Fixed contact, 32... Contact spring, 33
... Display window, 34 ... Battery window, 36 ... Movable contact, 40 ... Display transparent section, 41 ... Light receiving section, 43
...Insulating adhesive.

Claims (1)

[Claims] 1 An electronic component structure including at least an integrated circuit element and a wiring board is housed in a frame, and
An upper cover of the device and a lower cover of the device each having a sheet member made of a metal plate, each having an outer periphery larger than that of the frame, are adhered to the upper and lower surfaces of the electronic component structure, and the outer periphery of the frame is A small electronic device characterized in that a space surrounded by the upper and lower covers of the unit is filled with an insulating adhesive.