屏蔽層是薄膜開(kāi)關(guān)的組成部分，起以下或更多的作用：

(1)將可能存在的有害靜電安全地釋放，避免敏感的電子元件受損害。

(2)屏蔽的薄膜開(kāi)關(guān)，免受周?chē)h(huán)境的射頻干擾和電磁干擾。

(3)通過(guò)反射或吸收的方式減少或消除射頻干擾和電磁干擾的輻射。

屏蔽層的效力和性能取決于屏蔽層材料的特性和結(jié)構(gòu)，還取決于屏蔽源的頻率和距離。電磁干擾屏蔽通常用于醫(yī)學(xué)設(shè)備、軍事、電信和許多其它的電子設(shè)備。因?yàn)檫@些設(shè)備安裝了新式的輻射和抗干擾部件，屏蔽的重要性也就隨此增加。

我企業(yè)以往應(yīng)用的典型組裝結(jié)構(gòu)如下：

絲印導(dǎo)電銀:通常被印刷在網(wǎng)狀結(jié)構(gòu)的聚脂上，以滿(mǎn)足作業(yè)的特殊要求，此層在面膜層之下。

設(shè)計(jì)考慮因素:

(1)根據(jù)裝配的條件，面膜層材料應(yīng)具有足夠的絕緣，以抵御靜電，如：厚度為125μm的聚脂面膜層應(yīng)可以承受15kV的電壓。

(2)因?yàn)樗鼞?yīng)對(duì)面膜層表面提供足夠的屏蔽，面板邊緣處的薄弱處應(yīng)給予細(xì)致的考慮。即使面膜層的絕緣相當(dāng)良好，面板邊緣附近的靜電也會(huì)干擾面膜層周?chē)?，通過(guò)電路層的邊緣進(jìn)入面板。我廠會(huì)認(rèn)真設(shè)計(jì)以保證避免此類(lèi)現(xiàn)象并對(duì)此進(jìn)行保護(hù)。

(3)我 企業(yè)的技術(shù)人員具有各種壓片經(jīng)驗(yàn)，能夠幫助你解決各種特殊的有關(guān)屏蔽層的困難。

(4)顧客應(yīng)提供一份詳盡的所需屏蔽層的說(shuō)明。一些高技術(shù)要求的屏蔽層價(jià)格比較昂貴，只是在特別需要的時(shí)候才考慮使用。

      注意： 磁場(chǎng)強(qiáng)度的減少由頻率、屏蔽層材料導(dǎo)電率和材料厚度決定。屏蔽材料削弱或減少輻射場(chǎng)能量的等級(jí)與其屏蔽效率（SE）有關(guān)。SE的標(biāo)準(zhǔn)單位為分貝（dB）。它的值為屏蔽前后的電磁場(chǎng)強(qiáng)度的比值。SE的值每增加20分貝，表現(xiàn)為電磁干擾通過(guò)屏蔽物的泄漏值減少十倍。一個(gè)60分貝的屏蔽物減少磁場(chǎng)強(qiáng)度的值為原值的一千分之一（例如，從5伏特/米到5毫伏/米） 。

Introduction EL-erjiguan.htm

The shielding layer is a part of the film switch, which plays the following or more roles:

(1) to release the potential harmful electrostatic safety, to avoid the damage to the sensitive electronic components.

(2) shielding of the film switch, from the surrounding environment of radio frequency interference and electromagnetic interference.

(3) reduction or elimination of radio frequency interference and electromagnetic interference by reflection or absorption.

The effectiveness and performance of the shield depends on the characteristics and structure of the shielding layer, and also depends on the frequency and distance of the shield. Electromagnetic interference shielding is often used in medical equipment, military, telecommunications, and many other electronic devices. Because these devices are equipped with a new type of radiation and interference components, the importance of shielding also increased.

The typical assembly structure that my company used in the past is as follows

Screen printing conductive silver: is normally printed on polyester mesh structure, to meet the special requirements, this layer below the layer mask.

Design considerations:

(1) according to the conditions of assembly, the mask material layer should be with a sufficient insulation, against static electricity, such as thickness of 125 μ m of the polyester film layer should be able to withstand 15kV voltage.

(2) because it should provide sufficient shielding to the surface of the mask layer, the weak points in the edge of the panel should be given careful consideration. Even if the insulation of the mask layer is quite good, the electrostatic near the edge of the panel will interfere with the mask layer. I plant will be carefully designed to ensure that such phenomenon is avoided and to protect.

(3) the technical staff of my company has a variety of tablet experience, can help you to solve a variety of special shielding layer of the difficulties.

(4) the customer shall provide a detailed description of the required shielding layer. Some of the high technical requirements of the shielding layer is more expensive, but only in particular need to consider the use of.

Note: the magnetic field intensity is reduced by the frequency, shielding layer material conductivity and material thickness. Shielding material to weaken or reduce the level of radiation field energy and its shielding efficiency (SE). The standard unit of SE is dB (DB). Its value is the ratio of the electromagnetic field strength before and after shielding. The value of SE is increased by 20 dB, which is ten times as much as the leakage of electromagnetic interference through the shield. A 60 dB shielding to reduce field strength value is the original value of 1000, one (for example, from 5 V / m to 5 mV / M).