JP2011010164A - Portable terminal device - Google Patents

Abstract

The waterproofing of a conventional portable terminal device has either an expensive structure using rubber packing or a structure in which resin is potted on a component or a board, so that the structure is expensive and difficult to repair. Met.
An inexpensive and thin waterproof circuit board can be realized by applying a waterproof resin so as to surround connectors and electrical components on the circuit board and then covering the board with a thin waterproof film. Further, since it is not necessary to pot the top of the connector with a resin, repair is facilitated.
[Selection] Figure 1

Description

  The present invention relates to a waterproof structure in a mobile phone, a wireless terminal, and the like and a manufacturing method thereof.

  As mobile terminal devices such as mobile phones become daily necessities, there are increasing usage scenes where mobile terminals get wet with water, such as kitchens, baths, and rainy outdoors, and waterproof functions are increasingly required.

  Many of the waterproof functions of conventional electrical devices have been realized by a casing structure in which rubber packing such as silicone is sandwiched between the joints (borders) of the upper and lower casings and water does not enter inside.

Alternatively, in order to realize a waterproof structure with a single component, there is a method in which the component is not exposed to water by applying resin (potting) and curing to cover the component mounted in the circuit board or case. there were. (For example, see Patent Documents 1 and 2)
Alternatively, there is a method to achieve waterproofing by sandwiching the front and back of the circuit board between two resin films, pressing and fixing the periphery of the two resin films with heat, etc., and making the circuit board a structure that does not allow water to enter. It was. (For example, see Patent Document 3)

JP 2003-069196 A JP 2005-340232 A JP 2003-086925 A

  A conventional waterproofing method using a casing structure using packing has a complicated and expensive casing structure because it is necessary to prevent water from entering by applying uniform pressure to the packing.

  In addition, since a packing is required on the outer periphery of the casing, the size of the portable terminal has been increased.

  In addition, when a large external force is applied to the housing due to dropping or the like, a gap is formed in the packing, resulting in loss of airtightness and deterioration of waterproofness.

  In addition, the waterproofness may deteriorate due to only small dust on the packing.

  Further, the conventional waterproofing method using potting has the following problems.

  In addition, when the uncured resin is applied to the entire surface of the substrate, it flows out of the substrate, so that a process of removing excess resin is required.

  Further, since the resin applied on the substrate needs to completely cover the component, the height of the resin is higher than the height of the component, and the casing of the mobile terminal device needs to be thick.

  In addition, since the resin applied on the substrate needs to completely cover the parts, it is necessary to increase the amount of the resin applied, and the price of the mobile terminal device is high.

  In addition, in order to transmit an electrical signal or power to the outside of the board, when a cable connector is provided, it is difficult to regenerate (repair) the connector that has been cured by applying resin on the connector.

  In order to solve the above problems, a mobile terminal device of the present invention includes a board on which a connector is mounted, a waterproof resin, a waterproof film, and a cable that transmits an electric signal or power to the outside of the board. In the state where the cable is connected to the connector, the waterproof resin is applied to at least the outer periphery of a specific region on the substrate including the connector, and the waterproof film is bonded to the waterproof resin and the A sealed structure is formed by the outer periphery and the film.

  In addition, the mobile terminal device of the present invention includes a board on which a connector is mounted, a housing for housing the board, a cover for the housing, a waterproof resin, a waterproof film, and an electrical signal or a signal outside the board. A cable for transmitting electric power, the substrate is housed in the housing, and the waterproof resin is applied to an inner periphery of the housing including the connector in a state where the cable is connected to the connector; and The waterproof film is bonded to the waterproof resin to form a sealed structure.

  According to the present invention, a thin waterproof portable terminal device that can be repaired at low cost can be realized.

Schematic of the waterproof circuit board of the portable terminal device of Embodiment 1 of the present invention The figure which shows the manufacturing method of the waterproof circuit board of Embodiment 1 of this invention. Detailed view of waterproof circuit board according to Embodiment 1 of the present invention The figure which shows the manufacturing method of the waterproof circuit board of the portable terminal device of Embodiment 2 of this invention Schematic of the waterproof circuit board of the portable terminal device of Embodiment 3 of the present invention Schematic of the waterproof housing of the mobile terminal device according to the fourth embodiment of the present invention. Schematic diagram of a waterproof casing of a conventional portable terminal device

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view and a plan view of a circuit board to which waterproof measures of the present invention are applied.

  A connector 2 and an electrical component 3 for connecting the flexible cable 4 are mounted on the circuit board 1. Further, a waterproof resin 6 is applied so as to surround an outer periphery of a region where the connector 2 and the electrical component 3 are mounted, and a resin film 5 having a waterproof function is placed thereon.

  The resin film 5 is a film having a thin waterproof function of several tens to several hundreds of microns made of, for example, PET (polyethylene terephthalate). A resin other than PET may be used as long as it is waterproof.

  The waterproof resin 6 is a curable resin having high waterproof and insulating properties such as a silicone resin. Note that a urethane resin or an epoxy resin may be used as long as it has waterproofness and insulating properties.

  Next, a method for manufacturing a circuit board with this waterproof measure taken will be described.

  2 (1) to 2 (5) show the production method of the present invention.

  First, as shown in FIG. 2 (1), after applying the waterproof resin 6 before curing under the portion where the flexible cable 4 is slightly separated from the connector 2, the flexible cable is placed on the Fill the gap between the circuit boards with waterproof resin. The above is performed with the flexible cable 4 attached to the connector 2.

  Next, waterproof before curing so as to surround the outer periphery of the area of the circuit board including the part where the metal is exposed in the connector, electrical parts and board pattern, including the part where the waterproof cable between the flexible cable and the circuit board is present The resin is applied in a ring shape.

  For application of the waterproof resin, for example, if a dispenser having a structure in which the resin is extruded by air pressure from a thin nozzle is used, it becomes easy to apply the waterproof resin in a linear shape. Although it takes time, it is also possible to apply the waterproof resin to a predetermined place using a method such as spraying, brushing or dipping after masking an area where the waterproof resin is not desired to be applied.

  The viscosity of the waterproof resin before curing should be selected so that it does not flow out of the board or flow to the parts where you do not want to apply the resin, such as connectors. it can.

Since the shape of the waterproof resin before curing can be freely deformed, the application portion of the waterproof resin may include a portion where components are mounted. Since the waterproof resin is insulative, there is no problem even if it contacts parts or circuit patterns.
Next, as shown in FIG. 2 (3), it is placed on the uncured waterproof resin to which the waterproof film 5 is applied, and a sealed space made of the waterproof resin and the waterproof film is formed in the region including the connector and the electrical parts.

  Next, as shown in FIG. 2 (4), the waterproof resin and the film can be brought into close contact with each other by pressurization using the pressure plate 7 from above the waterproof film, and the waterproof resin can be formed thinly. Since the pressure is applied before the waterproof resin is cured, the resin is easily crushed with a low pressure. What is necessary is just to pressurize until the height of waterproof resin becomes the same as the height of the mounting components on a circuit board. Once crushed waterproofing resin is not cured, it will not return, but it may expand or contract by several percent before and after curing, so the height of the waterproofing resin is crushed in advance so that it is slightly lower than the part height. It is desirable.

  Next, as shown in FIG. 2 (5), the waterproof resin is crushed and further cured with the pressure plate removed. Depending on the type of resin, there are types that are cured by being left in the atmosphere and types that are cured by heating or cooling, but any type may be used.

  If the waterproof film is translucent or transparent, the location where the waterproof resin is applied can be confirmed, so that it is easy to inspect whether the waterproof property is secured.

  Moreover, if the waterproof resin is colored and not transparent, the location where the waterproof resin is applied can be more easily confirmed and the inspection can be easily performed.

  FIG. 3 shows a pressurizing method and a cross-sectional view of the substrate after pressurization when it is assumed that the waterproof resin is largely deformed in consideration of expansion at the time of hardening of the waterproof resin. As shown in FIG. 3 (1), the pressure plate 7 has a shape in which only the portion where the resin is applied is thickened so that the height of the resin is lower than the height of the mounted component when the waterproof film is pressed. Can be deformed. FIG. 3 (2) shows a cross-sectional view of the circuit board after curing, and the height of the upper surface of the film above the cured resin (B in the figure) is the height of the upper surface of the film above the connector having the highest mounting component. (A in the figure).

  In other words, the thickness of the substrate to which waterproofing measures have been taken is only increased by the thickness of the film of several tens of microns.

  As described above, it is possible to take a waterproof measure without greatly increasing the thickness of the circuit board including the flexible cable and the connector.

  In addition, the amount of waterproof resin can be reduced as compared with the conventional method of potting resin on the entire surface of the substrate, the material cost can be reduced, and the weight of the portable terminal due to the waterproof resin is small.

  The applied waterproof resin is ring-shaped, and if the sealed space is formed with the waterproof film, the amount of resin and the position accuracy of the waterproof resin applied portion are not required to be very high, so the application work is not required. It is easy and does not take manufacturing man-hours.

  Further, since the waterproof resin is sandwiched between the waterproof film and the circuit board, the waterproof resin before curing does not leak to the outside or adhere to other components.

  Further, when the circuit board is repaired (repaired), the resin film can be peeled off from the waterproof resin. Since the resin film is flexible, it can be easily peeled off from the waterproof resin. Further, since the connector is not covered with the waterproof resin, it can be easily detached from the flexible cable and the connector portion can be easily repaired.

  Moreover, even if bubbles enter the inside of the resin, the waterproof property is not lost because the waterproof resin covers the top of the resin.

  In the above description, an example in which almost the entire surface of the circuit board is waterproofed has been described. However, it may be applied to only a part of the circuit board. It is also possible to apply the same waterproof treatment to both sides of the circuit board.

  Moreover, although the above demonstrated the example of the flexible cable, it is the same also in the case of another coaxial cable.

  FIG. 4 shows a part of the method for manufacturing the waterproof circuit board of the portable terminal device according to the second embodiment, and shows only the waterproof method for the flexible cable portion different from the first embodiment.

  Since other configurations and manufacturing methods are the same as those in the first embodiment, description thereof is omitted.

  First, as shown in FIG. 4 (1), affixing a waterproof tape to a portion of the flexible cable 4 that is slightly away from the connector 2, and then placing the flexible cable on top, the gap between the portion of the flexible cable and the circuit board Fill with waterproof tape. The waterproof tape is adhesive on both sides, so that water does not enter the gap between the flexible cable and the circuit board. The above is performed with the flexible cable 4 attached to the connector 2.

  Next, as shown in FIG. 4 (3), the outer periphery of the area of the circuit board including the portion where the waterproof tape is applied between the flexible cable and the circuit board, and the area where the metal is exposed in the connector, electrical component, or board pattern. A waterproof resin before curing is applied in a ring shape so as to surround. Further, as in the first embodiment, waterproofing is realized by covering the waterproof resin film and forming a sealed space.

  What is different from the first embodiment is a waterproof method between the flexible cable and the circuit board. Since the second embodiment uses a waterproof tape, the manufacturing process can be simplified.

  FIG. 5 shows a configuration diagram of a waterproof circuit board of the mobile terminal device according to the third embodiment.

  A liquid crystal element 9, a camera 10, and an LED 11 are mounted on the circuit board 1, and waterproofing is realized by a waterproof resin and a waterproof film 5 so as to cover them. Since the manufacturing method is the same as that of the first embodiment, description thereof is omitted.

  Since display elements such as liquid crystal elements, LED elements, and EL elements are components that emit light upward with respect to the circuit board, the resin film needs to be transparent. Similarly, since an imaging element such as a camera or an infrared receiving element is a component that receives an optical signal from above with respect to a circuit board, the resin film needs to be transparent.

  For example, by using a transparent PET film, waterproofness can be ensured without losing the functions of the display element and the imaging element.

  Moreover, it becomes easy to test | inspect whether the waterproof resin has adhered on said element by using a waterproof resin opaque.

  FIG. 6 is a configuration diagram of a waterproof circuit board of the mobile terminal device according to the fourth embodiment.

  A connector 2 and an electrical component 3 for connecting the flexible cable 4 are mounted on the circuit board 1. The circuit board 1 is accommodated in the housing 12. The waterproof resin 6 is applied in a ring shape inside the housing 12 so as to surround the outer periphery of the circuit board 1, and the waterproof circuit film 5 is covered thereon, whereby the circuit board becomes a sealed structure and waterproofness can be secured. The cover 13 of the housing 12 is disposed on the resin film 5.

  Since the manufacturing method is the same as that of the first embodiment, the description thereof is omitted. Similar to the first embodiment, this structure can realize a waterproof terminal that is easy to repair and inexpensive.

  The conventional packing structure (sealing structure) using rubber packing is expensive because the casing cover requires a packing frame as shown in FIG. 7, and a certain degree of strength is required to ensure the strength of the cover. Thickness was needed.

  On the other hand, in the structure of FIG. 6, since waterproofness can be ensured by a waterproof film, the cover 13 does not require a packing frame structure, and the cover can be made thin. In addition, since the waterproof film is very thin of about several tens of microns, the portable terminal can be made thinner than the conventional waterproof structure. Furthermore, the cover 13 is made of a metal such as stainless steel, so that both strength and thinness of the portable terminal can be achieved.

  Moreover, it becomes easy to test | inspect whether the waterproof resin has adhered on said element by using a waterproof resin opaque.

  Moreover, by removing the waterproof film, it is easy to attach and detach the cable and repair the board.

  The portable terminal device of the present invention in which a waterproof measure comprising a waterproof resin and a waterproof film is applied to a circuit board is useful as an inexpensive and thin waterproof portable terminal device, and includes a variety of mobile phones, portable games, portable TVs, PDAs, and the like. It can be used for various electronic devices.

DESCRIPTION OF SYMBOLS 1 Circuit board 2 Connector 3 Electrical component 4 Flexible cable 5 Resin film 6 Waterproof resin 7 Pressure plate 8 Waterproof tape 9 Liquid crystal element 10 Camera 11 LED
12 Housing 13 Cover 14 Cover with Frame 15 Rubber Packing 16 Packing Frame

Claims (7)

A board on which a connector is mounted;
Waterproof resin,
Waterproof film,
A cable for transmitting an electrical signal or power to the outside of the substrate,
In a state where the cable is connected to the connector, the waterproof resin is applied to at least an outer periphery of a specific region on the substrate including the connector, and the waterproof film is bonded to the waterproof resin and the outer periphery. A portable terminal device, wherein a sealed structure is formed by the film. The portable terminal device according to claim 1, wherein the waterproof resin is filled between the waterproof film and the substrate at an intersection between the cable and the outer periphery. The portable terminal device according to claim 1, wherein the cable is a flexible substrate. The portable terminal device according to claim 3, wherein the cable, the intersecting portion of the outer periphery, and the substrate are bonded with a waterproof tape having double-sided adhesiveness. Applying a waterproof resin on the component mounted on the substrate or on the outer periphery of the region including the component;
Covering a waterproof film on the waterproof resin;
And a step of pressurizing a portion of the waterproof film where the waterproof resin is in close contact before the waterproof resin is cured to deform the waterproof resin thinly. A board on which components are mounted;
A curable waterproof resin,
A waterproof film,
The waterproof film is tightly covered and covered on the waterproof resin applied on the component mounted on the substrate or the outer periphery of the region including the component, and the outer periphery and the film form a sealed structure,
From the height of the upper surface of the waterproof film above the highest part among the parts in the area where the waterproof film is covered, the height of the upper surface of the waterproof film in the portion in close contact with the waterproof resin A portable terminal device characterized by being low. A board on which a connector is mounted;
A housing for housing the substrate;
A cover of the housing;
Waterproof resin,
Waterproof film,
A cable for transmitting an electrical signal or power to the outside of the substrate,
The waterproof resin is applied to the inner periphery of the casing including the connector in a state where the substrate is accommodated in the casing and the cable is connected to the connector, and the waterproof film is A portable terminal device, wherein a sealed structure is formed by bonding.

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