薄膜开关

是集按键功能、指示元件、仪器面板为一体的一种新型电子按键操作系统。

由面板、夹层胶、上电路、隔片层、下电路和背胶层六部分组成按下薄膜开关，上电路的触点向下变形，与下电路的极板接触导通，手指松开后，上电路触点反弹回来，电路断开，回路触发一个信号。薄膜开关结构严谨，外形美观，密封性好。具有防潮湿，使用寿命长等特点。广泛应用于电子通讯、电子测量的仪器，工业控制，医疗设备，汽车工业，智能玩具，家用电器等领域。

薄膜开关装置中有许多种不同形式和结构的按键。按键的基本性能例如行程、操作力和机械寿命主要由按键类型和材料决定。薄膜开关包括单片线路开关和双片线路开关。

通常，薄膜开关上的按键只是用色彩来表达键体的位置、形状和大小。这样，只能凭操作者的视觉来识别操作的准确性，由于没有适当的反馈信息表明手指是否按在了开关的有效范围使开关动作， 因而影响了对整机监控的自信和操作的速度。一种使开关键体微微凸起，略高于面板，构成立体形状的薄膜开关，称为立体键开关。立体键不仅能准确地给定键体的范围，提高辨认速度，使操作者的触觉比较敏感，同时还增进了产品外观的装饰效果.开关可以按特性分为以下列出的三种主要触觉结构：

1、金属弹片按键：

金属弹片按键采用成形的金属弹片，布置在开关结构的内部。弹片上带有按钮接头，用于形成电气回路。
优点：(1)此结构具有良好的触觉性能。
(2)高温状态下使用寿命仍旧很长。
缺点：(1)用于柔软的面板时，若面板在凸起区域弯曲则面板可能被损坏。
(2)此结构最好用于印刷电路板或刚性面板。
2、聚脂按键:
聚脂按键是在薄膜开关结构中的线路层轧出凸起的按键，此结构非常耐用，行程比金属弹片按键要小一些。在一些应用中，聚脂按键可以被轧到面膜层，此种方式可以减少薄膜开关的总层数。按键的操作力与材料厚度、按键直径和按键凸起高度有关。
优点：(1)非常耐用
 (2)可以很好地使用数百万次
3、无感按键:
无手感开关没有触感，此种操作面板通常采用其它方式表示开关的动作状态。
优点：(1)使用寿命长(可以使用上百万次)。
(2)有效面积大。 

(3)在所有的开关形式中价格最低点击放大

缺点：(1)没有手感。

 (2)若面膜层有凸起，此时推荐不采用此种开关。

It is a new type of electronic key operating system integrating key function, indicating element and instrument panel.

The membrane switch is composed of a panel, a sandwich glue, an upper circuit, a spacer layer, a lower circuit and a back glue layer. The contact point of the upper circuit deforms downward and contacts and conducts with the polar plate of the lower circuit. After the finger is released, the contact point of the upper circuit bounces back, the circuit is disconnected, and the loop triggers a signal. The membrane switch has rigorous structure, beautiful appearance and good sealing performance. It has the characteristics of moisture prevention and long service life. Widely used in electronic communication, electronic measuring instruments, industrial control, medical equipment, automobile industry, intelligent toys, household

There are a number of different forms and structures in the thin film switch device. The basic properties such as travel, operating force and mechanical life are mainly determined by the key type and material. Thin film switch includes single chip circuit switch and double circuit switch.

In general, the buttons on the film switch simply use color to express the position, shape, and size of the key. In this way, can only rely on the operator's visual to identify the operating accuracy, due to the lack of appropriate feedback information indicates that the fingers to the switch of the effective range of the switching action, thus affecting the confidence of the whole monitoring and operation speed. A key body is slightly raised, slightly higher than the panel, constitute a three-dimensional shape of the film switch, known as the three-dimensional key switch. Stereo key can not only accurately set the scope of the key body, improve the recognition speed, so that the operator's sense of touch is more sensitive, but also enhance the decorative effect of the product appearance.

The switch can be divided into three main tactile structures listed below:

Metal shrapnel keys:

Metal shrapnel button with metal shrapnel forming, disposed in the internal structure of the switch. Shrapnel with button connector for forming electric circuit.

Advantages: (1) this structure has a good sense of touch.

(2) the service life of high temperature is still very long.

Disadvantages: (1) when used in a soft panel, if the panel in the convex area of the panel may be damaged.

(2) the structure is best used for printed circuit boards or rigid panels.

Polyester buttons:

Polyester button is in the thin film switch circuit structure layer rolled convex keys, this structure is very durable, travel than metal shrapnel keys to some small. In some applications, polyester keys can be rolled into the mask layer, it can reduce the total number of membrane switch. The operating force of the key is related to the thickness of the material, the diameter of the key and the height of the button.

Advantages: (1) very durable

(2) millions of times can be used very well

No sense keys:

No touch switch is not touch, this operation panel usually uses other means to express the switch state of action.

Advantages: (1) long service life (can be used on a million).

(2) the effective area.

(3) in all the switches in the form of the lowest price Click to enlarge

Disadvantages: (1) no feel.

(2) if the mask layer is raised, this switch is not recommended at this time.