HK1082842A - Method for sealing vibrating component with resin - Google Patents

Description

Resin sealing method for vibrating parts

Technical Field

The present invention relates to a method for resin-sealing a vibrating component, which is fixed to a touch panel as a vibration source generating a pressing operation feeling, by sealing the periphery of the vibrating component with resin.

Background

A touch panel input device is also called a digitizer device, and when a stylus or a finger presses an operation area set on a touch panel, detects a pressing operation position in the operation area, and outputs input position data indicating the pressing operation position to a processing device such as a personal computer.

Various touch panel input devices such as the contact type of japanese kokai No. 3-6731 and the resistive type of japanese kokai No. 5-53715 are known as methods for detecting the pressed position, but when the pressing operation is performed by these methods, a clear input operation feeling such as a click feeling when the push button switch is pressed cannot be obtained, and therefore the operator can only know the operation result by a processing device such as a personal computer, but cannot confirm whether the pressing operation to the operation panel has been accepted.

Therefore, the present applicant has developed a touch panel input device that can effectively vibrate a touch panel and transmit a pressing operation feeling to an operator without increasing the size of the entire device by fixing a piezoelectric substrate to the touch panel (see patent document 1).

[ patent document 1] Japanese patent application laid-open No. 2003-122507 (abstract, FIG. 1)

Fig. 7 and 8 show a touch panel input device 100 in which a piezoelectric substrate serving as a vibrating component is used as the touch panel input device 100, and a touch panel is formed by laminating an operation panel 101 and a support substrate 102 with a very small gap therebetween, and an operation region 100A for detecting a pressed position is set in the touch panel. Since the touch panel input device 100 shown in the figure detects the pressed position by the resistance-pressure sensitive method, the opposing upper surfaces of the operation panel 101 and the support substrate 102 are covered with conductor layers 101a and 102a made of a uniform resistive film, and the pair of piezoelectric substrates 120 and 120 are fixed to the back surface of the support substrate 102 around the operation area 100A.

The piezoelectric substrate 120 is in the form of an elongated strip, a pair of drive electrodes 120a and 120b are formed on both the front and back surfaces, and the entire surface of either the front or back surface is fixed to the support substrate 102 of the touch panel with an adhesive or the like. When the pressing operation on the operation area 100A is detected by the contact between the conductor layers 101a and 102a, a driving voltage is applied to the pair of driving electrodes 120A and 120b to vibrate the entire touch panel including the operation panel 101 to which the stretchable piezoelectric substrate 120 is fixed and the support substrate 102, and the operator can confirm the reception of the pressing operation from the vibration.

However, since the driving electrodes 120a and 120b of the piezoelectric substrate 120 are exposed on both the front and back surfaces, aging changes such as oxidation and vulcanization are likely to occur, and short circuits may occur between the electrodes or between the electrodes and other conductors, and therefore the entire piezoelectric substrate is sealed with an insulating resin.

As a resin sealing method for sealing an electronic component with a resin, a sealing method using a dispenser (dispenser) and a screen printing method using a metal mask are known (see patent document 2).

[ patent document 2] Japanese examined patent publication No. 6-95594 (page 3, FIG. 2)

As shown in fig. 9, the sealing method using a dispenser is a method in which a sealing resin 114 is pushed out by a pneumatic dispenser 105, and applied so as to cover the entire periphery of an electronic component 120 to be sealed, and then the sealing resin is heat-cured and fixed to the periphery of the electronic component 120 by a heating furnace to achieve sealing.

In the screen printing method, the sealing resin is considered as screen printing ink and is attached to the periphery of the electronic component, as shown in fig. 10, the base plate 102 on which the electronic component 120 is mounted is covered with a metal mask 112, a through hole 111 slightly larger and deeper than the outline of the electronic component 120 is formed in the metal mask 112 by etching or the like, and the pusher 113 is slid along the surface of the metal mask 112 to fill the sealing resin 114 into the gap between the through hole 111 and the electronic component 120.

Then, the metal mask 112 is removed, and the sealing resin 114 attached to the periphery of the electronic component 120 is cured by heating and fixed to the periphery of the electronic component 120 to be sealed, as in the previous method.

In the case of the dispenser sealing method, since the sealing resin 114 is pushed out from the fine nozzle, the sealing resin 114 having a low viscosity is used, and once applied to the surface of the plate-shaped piezoelectric substrate 120, the shape thereof cannot be maintained until it is cured by heating, and thus, there is a problem that the edge portion of the plate-shaped electronic component such as the piezoelectric substrate 120 is exposed and cannot be completely sealed. Furthermore, the resin should be attached to the entire periphery of each 1 electronic component 120 without omission, which makes the process complicated and difficult to automate.

However, although the screen printing method is suitable for mass production because the metal mask 112 can be reused and all electronic components mounted on the base plate 102 can be resin-sealed at the same time, and is also suitable for automation because the process is simple, the following problems arise when the vibrating components such as the piezoelectric substrate 120 of the touch panel input device 100 are used as resin-sealing devices as they are.

That is, although the piezoelectric substrate 120 fixed to the touch panel (the operation panel 101 or the support substrate 102) is fixed between the operation area 100A and the periphery of the touch panel 101 or 102 so as not to hinder the detection of the pressing operation position, the piezoelectric substrate 120 is required to be fixed within a very limited width by enlarging the operation area 100A in order to facilitate the pressing operation (in the case where the operation area 100A is transparent and the display inside thereof needs to be viewed, the operation area is required to be more clearly) in the touch panels 101 and 102 whose size is limited by the installation space or the miniaturization requirement. On the other hand, in order to generate large vibration more effectively, the piezoelectric substrate 120 should be as large as possible within a limited mounting width, and as a result, as shown in fig. 8, when the piezoelectric substrate 120 having a width of 2mm is mounted, the distance d between the piezoelectric substrate 120 and the operation region 100A is only about 0.5 mm.

Even if there is a large space for arrangement, when the vibration component 120 is sealed with resin, if the sealed resin is thick, the vibration of the vibration component 120 itself is limited, and the vibration cannot be effectively generated, so that the thickness of the seal needs to be reduced.

In resin sealing such a piezoelectric substrate 120 by screen printing, the narrow gap d is set to be the thickness limit of the sealing resin 114, and in fig. 10, the gap between the through hole 111 of the metal mask 112 and the piezoelectric substrate 120 is set to a width of the gap d (for example, 0.5mm) or less.

On the other hand, since at least the flat surface of the piezoelectric substrate 120 needs to be covered with the sealing resin 114, the height of the through hole 111 needs to be higher than that of the piezoelectric substrate 120 (for example, by 1mm), and even if the sealing resin 114 needs to be filled into the gap by the pusher 113, the touch panel 102 having a narrow and deep gap cannot be filled, and the piezoelectric substrate 120 cannot be completely sealed as a whole.

In view of this problem, if the sealing resin 114 having a low viscosity is used and the resin inflow pressure (filling pressure) generated by the pusher 113 is increased to fill the gap, the sealing resin 114 can reach the touch panel 102, but if the resin inflow pressure generated by the pusher 113 is increased to fill the gap, the sealing resin 114 adhering to the flat surface side (upper surface side) of the piezoelectric substrate 120 is also wiped off, and a part of the flat surface is exposed. Further, if the viscosity of the sealing resin 114 is reduced, the sealing resin cannot maintain its shape until it is heated and cured in a heating furnace after adhering to the surface of the piezoelectric substrate 120, and adheres to the operation region 100A side, or the edge portion is exposed, and complete sealing cannot be achieved.

Disclosure of Invention

The present invention has been made in view of the above problems, and an object thereof is to provide a resin sealing method for a vibrating part suitable for mass production, in which the vibrating part can be completely covered with a thin-layer sealing resin.

In order to achieve the above object, a method of resin-sealing a vibrating component of a touch panel input device according to claim 1 is a method of resin-sealing a vibrating component of a touch panel input device that vibrates a vibrating component fixed to a touch panel around an operation area and generates a pressing operation feeling to be transmitted to an operator when a pressing operation to the operation area is detected,

(a) covering a touch panel with a metal mask plate, wherein a deep through hole slightly larger than the outline of a vibrating part is formed in a portion corresponding to a portion where the vibrating part is fixed to the touch panel, and a resin inflow space is formed between the vibrating part and the through hole, (b) sliding a pusher along the metal mask plate, filling a sealing resin having thixotropy, thermosetting properties, and insulation properties into the resin inflow space through the through hole, (c) removing the metal mask plate, heating and curing the sealing resin attached to the periphery of the vibrating part, and covering the periphery of the vibrating part with the cured sealing resin.

The thixotropic sealing resin has a low viscosity in a flowing step of moving the pusher on the metal mask plate and filling the resin inflow space, and can be filled to the deepest part of the narrow resin inflow space even when filling is performed with a low resin inflow pressure. Further, the thixotropic sealing resin increases in viscosity after the metal mask is removed and the flow is stopped, so that the sealing resin can maintain the shape of the sealing resin adhering to the periphery of the vibrating component.

With the invention according to claim 1, since the reusable metal mask is used and the sealing resin can be attached to the vibrating component by a simple process, the method is convenient for automation and suitable for mass production of the resin-sealed vibrating component.

Further, since the sealing resin can be filled into the narrow resin inflow space with a low resin inflow pressure, the sealing resin on the plane of the vibrating component is not wiped off by the pusher, and the entire vibrating component can be completely covered even with a thin layer of the sealing resin. Therefore, the sealing resin does not restrict the vibration of the vibrating component itself, and resin sealing can be performed even for the vibrating component with a limited arrangement space.

Further, since the sealing resin adhering to the periphery of the vibrating component can maintain its shape before the heat curing step, it does not flow around the vibrating component, and the corners of the vibrating component are not exposed, and the entire vibrating component can be completely covered. Therefore, the surface of the vibrating component does not come into contact with the outside air, and deterioration due to aging can be prevented.

Drawings

Fig. 1 is a perspective view showing the arrangement relationship between the piezoelectric substrate 120 fixed to the touch panel 102 and the metal mask 1.

Fig. 2 shows a process of covering the touch panel with the metal mask 1, in which (a) is a longitudinal sectional view cut along the width direction of the through-hole 3, and (b) is a longitudinal sectional view partially omitted cut along the longitudinal direction of the through-hole 3.

Fig. 3 shows a filling process for reducing the resin inflow pressure by the pusher 5 and filling the sealing resin 3 into the remaining gap of the resin inflow space 4, wherein (a) is a vertical cross-sectional view taken along the width direction of the through-hole 3 and rearward in the sliding direction of the pusher 5, and (b) is a vertical cross-sectional view partially omitted and cut along the length direction of the through-hole 3.

Fig. 4 shows a state of filling the sealing resin 3 after the filling step is completed, in which (a) is a vertical cross-sectional view taken along the width direction of the through-hole 3, and (b) is a vertical cross-sectional view partially omitted along the longitudinal direction of the through-hole 3.

Fig. 5 shows a process of pulling up the metal mask blank 1 in the vertical direction, in which (a) is a longitudinal sectional view cut along the width direction of the through-hole 3, and (b) is a longitudinal sectional view partially omitted from the cut along the longitudinal direction of the through-hole 3.

Fig. 6 shows a step of separating the sealing resin 3 on the metal mask blank 1 from the piezoelectric substrate 120, in which (a) is a vertical cross-sectional view cut along the width direction of the through-hole 3, and (b) is a vertical cross-sectional view partially omitted cut along the longitudinal direction of the through-hole 3.

Fig. 7 is an exploded perspective view of the touch panel input device 100.

Fig. 8 is a rear view of the touch panel 102 to which the piezoelectric substrate 120 is fixed.

Fig. 9 is a perspective view of a sealing method using the conventional dispenser 105.

Fig. 10 is a longitudinal sectional view of a conventional screen printing method.

Detailed description of the preferred embodiments

A method for resin sealing a vibrating component according to an embodiment of the present invention will be described below with reference to fig. 1 to 6. Fig. 1 to 6 show an example of a method of resin-sealing a piezoelectric substrate 120 used as a vibrating component in the touch panel input device 100 shown in fig. 7 and 8, fig. 1 is a perspective view showing an arrangement relationship between the piezoelectric substrate 120 fixed to the touch panel 102 and the metal mask 1, and fig. 2 to 6 are explanatory views of respective steps of resin-sealing the vibrating component 120.

As shown in fig. 1, a touch panel (support substrate) 102 on the back surface of the touch panel input device 100 is formed in a rectangular plate shape, and an operation area 100A for detecting a pressing operation position is set in the center thereof. The touch panel 102 is formed of a transparent material, and an operator can perform a pressing operation while looking at a display screen of a display device (not shown) disposed therebelow through the operation region 100A. The thin, long plate-like piezoelectric substrate 120 is fixed from the back surface of the touch panel 102, and is disposed in the gap between the operation region 100A and the periphery of the touch panel 102 so as not to obstruct the view of the operator looking at the display screen of the display device. In the present embodiment, a pair of piezoelectric substrates 120, 120 are fixed along the periphery of the touch panel 102 in the longitudinal direction, respectively.

The metal mask 1 is a metal plate made of a metal material such as aluminum or stainless steel, and is formed in a rectangular plate shape larger than the outer shape of the touch panel 102 so as to cover the entire back surface of the touch panel 102. The metal mask 1 has a through hole 2 formed at a position corresponding to the fixed position of the piezoelectric substrate 120. As shown in fig. 2(a) and (b), the through hole 2 is composed of a small hole portion 2a and an enlarged diameter portion 2b, the small hole portion 2a has a cross-sectional shape similar to and slightly larger than a projected shape of the piezoelectric substrate 120 in a vertical direction (a direction orthogonal to the rear surface of the touch panel), the enlarged diameter portion 2b is continuous with a step portion at the upper end of the small hole portion 2b, and the entire height of the through hole 2 is slightly higher than the height of the piezoelectric substrate 120.

The through hole 2 having the stepped portion is formed by forming a small hole portion 2a and an enlarged diameter portion 2b in 2 metal plates by, for example, etching treatment, and then overlapping the 2 metal plates with 1 metal mask 1. When the touch panel 102 is covered with the metal mask 1 formed in this manner, the entire piezoelectric substrate 120 is accommodated in the through hole 2, and a resin inflow space 4 into which the sealing resin 3 is filled is formed between the inner surface of the through hole 2 and the piezoelectric substrate 120 (see fig. 2(a) and (b)).

In order to prevent the sealing resin 3 adhering to the side surface of the piezoelectric substrate 120 from protruding from the operation region 100A, the interval of the resin inflow space 4, particularly the interval between the piezoelectric substrate 120 and the small hole portion 2a, is set to be equal to or smaller than the gap d between the operation region 100A and the piezoelectric substrate 120, and is set to 0.5mm equal to the gap d. And when the height of the piezoelectric substrate 120 is 0.7mm, the height of the through-hole 2 is set to be 1mm higher than it.

The sealing resin 3 filled in the resin inflow space 4 is a synthetic resin having at least insulating properties, thixotropy, and thermosetting properties, and an epoxy resin having these properties is used here. Since the entire surface of the piezoelectric substrate 120 exposed by the one set of driving electrodes 120a and 120b is covered, short circuit between these electrodes is avoided, and since heating is performed after filling and curing is achieved around the piezoelectric substrate 120, insulation and thermosetting of the sealing resin 3 are required. The thixotropic property (thixocopy) is a property that viscosity decreases during flowing and returns to an original high-viscosity state when static, and is required to be easily filled into the resin inflow space 4 and to maintain its shape after filling and before the heat curing step, as described below.

Further, it is preferable that the sealing resin 3 has a low shrinkage rate at the time of heat curing, has a certain elasticity after heat curing, that is, has a small elastic coefficient, and can be heat cured at a low temperature. The low shrinkage rate at the time of thermal curing is required because the sealing resin 3 adheres to the wiring patterns (120 c, 120d, 120e, and 120f in fig. 2) drawn out from the piezoelectric substrate 120 at the time of filling the resin inflow space 4, and if the shrinkage rate is high, these wiring patterns are drawn in at the time of thermal curing, and the patterns are peeled off or cut. The reason why the elasticity is required is not to restrict the deformation of the piezoelectric substrate 120 which becomes a vibration generation source after hardening. On the other hand, low-temperature curing is required because the piezoelectric substrate 120 deteriorates if high temperature is applied for curing.

As shown in fig. 1, the sealing resin 3 is carried on one end of the metal mask 1 in a flowing state, and is filled into the resin inflow space 4 of the through-hole 2 by using a pusher 5 and a screen printing method. The pusher 5 may be made of any material as long as it can push the sealing resin to the resin inflow space 4, and here, a rubber pusher 5 is used, a part of which can enter the through hole 4 from the surface of the metal mask 1, and the inflow pressure of the resin to the resin inflow space can be increased.

The steps of sealing the piezoelectric substrate 120 with the sealing resin 3 using the metal mask blank 1 and the pressing body 5 will be described below with reference to fig. 2 to 6.

First, the touch panel 102 is provided with the piezoelectric substrate 120 on the side of the slide table of the screen printer, not shown, and the metal mask 1 having the through hole 2 is superimposed on the touch panel 102 so as to cover the touch panel 102, as shown in fig. 2. In the superposed state, the resin inflow space 4 is formed between the piezoelectric substrate 120 and the through-hole 2. The distance between the periphery of the piezoelectric substrate 120 and the resin inflow space 4 of the small diameter portion 2a is 0.5mm, and the height of the piezoelectric substrate 120 is smaller than the through hole 20 and larger than the small diameter portion 2a, and slightly protrudes from the small diameter portion 2 a.

Then, the pusher 5 is slid along the surface of the metal mask 1, and the sealing resin 3 loaded on the metal mask 1 is filled into the resin inflow space 4. As shown in fig. 3, the pushing body 5 is pushed to slide along the surface of the metal mask 1, and the resin inflow pressure by the pushing body 5 is increased to fill the sealing resin 3 into the resin inflow space 4. As a result, the sealing resin 3 fills the entire resin inflow space 4 including the void on the front surface side of the piezoelectric substrate 120 without any void (see fig. 4(a) (b)).

Then, as shown in fig. 5, the metal mask 1 is pulled up in the vertical direction until the viscous sealing resin 3 is completely separated from the piezoelectric substrate 120 as shown in fig. 6. Thus, the sealing resin 3 is adhered to the entire circumference of the piezoelectric substrate 120 with a uniform thickness of approximately 0.5 mm.

The piezoelectric substrate 120 having the sealing resin 3 attached thereto is moved into a high-temperature furnace at about 100 ℃ in units of the touch panel 102, and the sealing resin 3 is thermally cured and fixed. Since the sealing resin 3 attached to the piezoelectric substrate 120 is in a static state before the thermal curing, the original high viscosity state can be restored and the shape thereof can be maintained. Therefore, the piezoelectric substrate 120 does not sag along the side surface thereof, and the shape thereof can be maintained in a state of completely covering the entire circumference of the piezoelectric substrate 120 even if the piezoelectric substrate is a thin layer of 0.5 mm.

The piezoelectric substrate 120 sealed with the thermosetting sealing resin 3 is prevented from being in contact with the outside air, deterioration due to aging is prevented, and short-circuiting with other parts is prevented because the electrodes are covered with the insulating sealing resin 3.

In the above-described embodiments, the vibrating component may not be a piezoelectric substrate as long as it is a vibration source fixed to the touch panel. The touch panel input device can use any detection method, and when 2 operation panels (plates) are stacked as in the present embodiment, the touch panel may be the upper operation panel 101.

The sliding direction of the pusher 5 in the filling step is not limited to the longitudinal direction of the through-hole.

(possibility of Industrial use)

The present invention is applicable to a resin sealing method for resin-sealing a vibrating component fixed to a touch panel.

Claims (1)

1. A resin sealing method for resin sealing a vibrating component (120) of a touch panel input device (100), wherein the touch panel input device (100) vibrates the vibrating component (120) fixed to a touch panel (102) around an operation area (100A) and generates a pressing operation feeling transmitted to an operator when detecting a pressing operation on the operation area (100A),

(a) covering the touch panel (102) with a metal mask (1), forming a deep through hole (2) slightly larger than the outline of the vibrating part (120) at a portion corresponding to a portion where the vibrating part (120) is fixed to the touch panel (102) in the metal mask (1), and forming a resin inflow space (4) between the vibrating part (120) and the through hole (2),

(b) a pushing body (5) is slid along the metal mask (1), a sealing resin (3) having thixotropy, thermosetting property and insulation property is filled into the resin inflow space (4) through the through hole (2),

(c) after removing the metal mask (1), the sealing resin (3) adhered to the periphery of the vibrating part is heated and hardened,

the periphery of the vibrating part is covered with a hardened sealing resin (3).