Patent Application
20220068575
The present invention relates to an input device, and more particularly to a membrane circuit board for a keyboard device and a manufacturing method thereof.
With the increasing development of science and technology, a variety of electronic devices are designed in views of convenience and user-friendliness. For helping the user well operate the electronic devices, the electronic devices are gradually developed in views of humanization. The common electronic devices include for example mouse devices, keyboard devices, trackball devices, or the like. Via the keyboard device, characters or symbols can be inputted into the computer system directly. As a consequence, most users and most manufacturers of input devices pay much attention to the development of keyboard devices.
The conventional keyboard device usually comprises a base plate, a membrane circuit board, plural scissors-type connecting elements, plural keycaps and plural elastic elements. The scissors-type connecting element is connected between the base plate and the corresponding keycap. Generally, the membrane circuit board comprises three film layers. From top to bottom, these film layers comprise an upper film layer, an insulating spacer layer and a lower film layer. According to the conventional production technology, circuit patterns are firstly printed on the upper film layer and the lower film layer and then the upper film layer, the insulating spacer layer and the lower film layer are combined together.
As known, the membrane circuit board is a very important part within the keyboard device. If the foreign liquid is introduced into the inner portion of the keyboard device, the membrane circuit board is possibly damaged. For solving this problem, the membrane circuit board is designed to meet the high-standard waterproof requirements. Conventionally, a waterproof glue is printed on a periphery region of the membrane circuit board to achieve the effect of sealing the periphery region and preventing moisture from entering the inner portion. However, the process of printing the waterproof glue increases the production cost and is detrimental to the environment.
Therefore, there is a need of providing an improved membrane circuit board and a manufacturing method of the membrane circuit board in order to overcome the above drawbacks.
An object of the present invention provides a membrane circuit board and a manufacturing method of the membrane circuit board. An ultrasonic heat melting device is used to form a waterproof structure on the membrane circuit board. Consequently, the production efficiency is effectively enhanced, and the production cost is reduced.
The other objects and advantages of the present invention will be understood from the disclosed technical features.
In accordance with an aspect of the present invention, a membrane circuit board is provided. The membrane circuit board includes a first film substrate, a second film substrate, an insulating spacer substrate and a waterproof structure. The first circuit layer is installed on the first film substrate. The second film substrate is opposed to the first film substrate. A second circuit layer is installed on the second film substrate. The insulating spacer substrate arranged between the first film substrate and the second film substrate. The first circuit layer is arranged between the first film substrate and the insulating spacer substrate. The second circuit layer is arranged between the second film substrate and the insulating spacer substrate. The waterproof structure includes a first welding layer and a second welding layer. The first welding layer is arranged between the first film substrate and the insulating spacer substrate. The first welding layer is arranged around the first circuit layer. The second welding layer is arranged between the second film substrate and the insulating spacer substrate. The second welding layer is arranged around the second circuit layer.
In an embodiment, the first film substrate has a first positioning opening, the insulating spacer substrate has a second positioning opening, and the second film substrate has a third positioning opening. The first positioning opening, the second positioning opening and the third positioning opening are aligned with each other.
In an embodiment, the first welding layer includes a first welding part and a second welding part, and the second welding layer includes a third welding part and a fourth welding part. The first welding part is arranged around the first circuit layer and the second welding part. The second welding part is arranged around a region between the first positioning opening and the second positioning opening. The third welding part is arranged around the second circuit layer and the fourth welding part. The fourth welding part is arranged around a region between the second positioning opening and the third positioning opening.
In an embodiment, the first welding layer further includes a fifth welding part, and the second welding layer further includes a sixth welding part. The fifth welding part is arranged between the first circuit layer and the first welding part. The fifth welding part is arranged around the first circuit layer and the second welding part. The sixth welding part is arranged between the second circuit layer and the third welding part. The sixth welding part is arranged around the second circuit layer and the fourth welding part.
In an embodiment, after the first film substrate, the insulating spacer substrate and the second film substrate are subjected to an ultrasonic heat melting treatment by an ultrasonic heat melting device, the first welding layer is formed between the first film substrate and the insulating spacer substrate, and the second welding layer is formed between the second film substrate and the insulating spacer substrate.
In an embodiment, the membrane circuit board further includes an anti-slip structure. The anti-slip structure is installed on a surface of the first film substrate away from the insulating spacer substrate, or the anti-slip structure is installed on a surface of the second film substrate away from the insulating spacer substrate.
In accordance with another aspect of the present invention, a manufacturing method of a membrane circuit board is provided. The manufacturing method includes the following steps. Firstly, a first film substrate is provided. A first circuit layer is formed on the first film substrate. Then, an insulating spacer substrate is provided. Then, a second film substrate is provided. A second circuit layer is formed on the second film substrate. Then, an ultrasonic heat melting treatment is performed on the first film substrate, the insulating spacer substrate and the second film substrate. Consequently, a waterproof structure is formed. The waterproof structure includes a first welding layer and a second welding layer. The first welding layer is arranged between the first film substrate and the insulating spacer substrate. The second welding layer is arranged between the second film substrate and the insulating spacer substrate. The first welding layer is arranged around the first circuit layer, and the second welding layer is arranged around the second circuit layer.
In an embodiment, the insulating spacer substrate and the second film substrate, the manufacturing method further includes the following steps before the ultrasonic heat melting treatment is performed on the first film substrate. Firstly, a positioning treatment is performed on the first film substrate, the insulating spacer substrate and the second film substrate. Secondly, a correcting treatment is performed on the first film substrate, the insulating spacer substrate and the second film substrate.
In an embodiment, the positioning treatment, the correcting treatment and the ultrasonic heat melting treatment are performed in an ultrasonic heat melting device.
In an embodiment, the ultrasonic heat melting device includes a first roller device, a correcting device and a second roller device. The positioning treatment is performed on the first film substrate, the insulating spacer substrate and the second film substrate by the first roller device. The correcting treatment is performed on the first film substrate, the insulating spacer substrate and the second film substrate by the correcting device. The ultrasonic heat melting treatment is performed on the first film substrate, the insulating spacer substrate and the second film substrate by the second roller device.
From the above descriptions, the present invention provides a membrane circuit board and a manufacturing method of the membrane circuit board. After a first film substrate, an insulating spacer substrate and a second film substrate of the membrane circuit board are subjected to an ultrasonic heat melting treatment, the first film substrate, the insulating spacer substrate and the second film substrate are combined as a waterproof structure. That is, a first welding layer is formed between the first film substrate and the insulating spacer substrate and arranged around the first circuit layer, and the second welding layer is formed between the second film substrate and the insulating spacer substrate and arranged around the second circuit layer. The first circuit layer and the second welding layer have the function of sealing the membrane circuit board while effectively preventing moisture from entering the internal circuit layers of the membrane circuit board through the space between the film substrates. The manufacturing method of the present invention can produce the membrane circuit board at the increased production efficiency and the reduced production cost. Since the waterproof glue is not used, the manufacturing method of the present invention is environmentally friendly.
The above objects and advantages of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which:
Please refer to
A first circuit layer 15 is installed on the first film substrate 11. The first film substrate 11 and the second film substrate 12 are opposed to each other. A second circuit layer 16 is installed on the second film substrate 12. The insulating spacer substrate 13 is arranged between the first film substrate 11 and the second film substrate 12. The first circuit layer 15 is arranged between the first film substrate 11 and the insulating spacer substrate 13. The second circuit layer 16 is arranged between the second film substrate 12 and the insulating spacer substrate 13. The waterproof structure 14 comprises a first welding layer 141 and a second welding layer 142. The first welding layer 141 is arranged between the first film substrate 11 and the insulating spacer substrate 13. Moreover, the first welding layer 141 is arranged around the first circuit layer 15. The second welding layer 142 is arranged between the second film substrate 12 and the insulating spacer substrate 13. Moreover, the second welding layer 142 is arranged around the second circuit layer 16.
Preferably but not exclusively, the first film substrate 11 and the second film substrate 12 are polyester (PET) film substrates. Preferably but not exclusively, the first circuit layer 15 and the second circuit layer 16 are respectively printed on the surfaces of the first film substrate 11 and the second film substrate 12 according to the designated circuit patterns. The membrane circuit board 1 is installed on an external keyboard of a desktop computer (e.g., a keyboard with a PS2 interface or a keyboard with a USB interface) or a built-in keyboard of a notebook computer or a laptop computer. The applications of the membrane circuit board 1 are not restricted. That is, the concepts of the membrane circuit board 1 can be applied to any appropriate electronic product that uses the membrane circuit board 1 as the signal input interface.
The other detailed structure of the membrane circuit board will be described as follows.
Please refer to
Please refer to
Please refer to
As shown in
The following aspects should be specially described. After the first film substrate 11, the insulating spacer substrate 13 and the second film substrate 12 are subjected to an ultrasonic heat melting treatment, the waterproof structure is produced. That is, the first welding layer 141 is formed between the first film substrate 11 and the insulating spacer substrate 13, and the second welding layer 142 is formed between the second film substrate 12 and the insulating spacer substrate 13. The operating principles of the ultrasonic heat melting treatment will be described as follows. Firstly, a sound generator generates a high-frequency signal. Then, a welding head fixed on the ultrasonic heat melting treatment is directly contacted with a plate workpiece made of plastic material (e.g., PET). The high-frequency vibration causes the molecules in the plate workpiece to undergo the violent friction and generate the local high temperature. When the temperature is higher than the melting point of the plastic material, the plastic material is molten. When the molten plastic material is cooled down, the molten plastic material is re-solidified and bonded together to achieve a welding effect. In an embodiment, the welding head of the ultrasonic heat melting treatment is a roller-shaped welding head.
As shown in
A method of manufacturing a membrane circuit board of the present invention will be described as follows.
Firstly, in a step S1, a first film substrate 11 is provided. A first circuit layer 15 is formed on the first film substrate 11.
In a step S2, an insulating spacer substrate 13 is provided.
In a step S3, a second film substrate 12 is provided. A second circuit layer 16 is formed on the second film substrate 12.
In a step S4, the first film substrate 11, the insulating spacer substrate 13 and the second film substrate 12 are subjected to an initial positioning treatment. Consequently, the first film substrate 11, the insulating spacer substrate 13 and the second film substrate 12 are initially aligned with each other.
In a step S5, the first film substrate 11, the insulating spacer substrate 13 and the second film substrate 12 are subjected to a correcting treatment. Consequently, the relative positions between the first film substrate 11, the insulating spacer substrate 13 and the second film substrate 12 are finely tuned, and the alignment between these components is more precise.
In a step S6, the first film substrate 11, the insulating spacer substrate 13 and the second film substrate 12 are subjected to an ultrasonic heat melting treatment. Consequently, a waterproof structure 14 is formed. The waterproof structure 14 comprises a first welding layer 141 and a second welding layer 142. The first welding layer 141 is arranged between the first film substrate 11 and the insulating spacer substrate 13. The second welding layer 142 is arranged between the second film substrate 12 and the insulating spacer substrate 13. Moreover, the first welding layer 141 is arranged around the first circuit layer 15, and the second welding layer 142 is arranged around the second circuit layer 16.
From the above descriptions, the present invention provides a membrane circuit board and a manufacturing method of the membrane circuit board. After a first film substrate, an insulating spacer substrate and a second film substrate of the membrane circuit board are subjected to an ultrasonic heat melting treatment, the first film substrate, the insulating spacer substrate and the second film substrate are combined as a waterproof structure. That is, a first welding layer is formed between the first film substrate and the insulating spacer substrate and arranged around the first circuit layer, and the second welding layer is formed between the second film substrate and the insulating spacer substrate and arranged around the second circuit layer. The first circuit layer and the second welding layer have the function of sealing the membrane circuit board while effectively preventing moisture from entering the internal circuit layers of the membrane circuit board through the space between the film substrates. The manufacturing method of the present invention can produce the membrane circuit board at the increased production efficiency and the reduced production cost. Since the waterproof glue is not used, the manufacturing method of the present invention is environmentally friendly.
While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202010876186.2 | Aug 2020 | CN | national |
