1291853 1 _ 九、發明說明： 【發明所屬之技術領域】 本發明涉及一種降低電磁干擾之屏蔽裝置，尤指一種 降低印刷電路板之電磁干擾之屏蔽裝置。 【先前技術】 電磁干擾（Electro Magnetic Interference，EMI)係目前 電子産業中存在之一大問題，隨著積體電路之頻率愈來愈 高，其内部傳輸導線、電源或印刷電路板上具有較高工作 頻率之電子元件都會對外發散出電磁波，而使得其他元件 受到干擾，影響正常之工作運作，因此從業者十分重視在 ，降低電磁干擾上之設計。印刷電路板係整個電子系統正常 工作之基礎，在印刷電路板佈局開始時就做好防治電磁干 擾之工作，係建構高可靠度電子系統之首要任務。 在設計印刷電路板時，有時除了設計接地層來降低電 磁干擾外，通常盡可能在印刷電路板外層之可利用空間鋪 設接地銅猪以增加接地面積，進而透過減小某些接地回路 阻抗來降低電磁干擾，或者在印刷電路板易産生電磁輻射 之區域設置金屬屏蔽罩來降低電磁干擾。但往往由於印刷 電路板之走線錯综複雜或其他原因，可利用之空間非常有 | 限’印刷電路板上某些易産生電磁輪射之區域很難鎖設面 積較大之接地銅箔或設置金屬屏蔽罩，故此區域之電磁輻 射得不到有效抑制，從而引起電磁干擾。 因是，實有必要對習知之降低電磁干擾之屏蔽裝置進 行改良，以消除上述缺失。 【發明内容】 鑒於以上内容，有必要提供一種降低電磁干擾之屏蔽 裝置，用以降低印刷電路板上之電磁干擾。 一種降低電磁干擾之屏蔽裝置，其用於降低印刷電路 板上之電磁干擾，該降低電磁干擾之屏蔽裝置包括複數設 置於該印刷電路板上之裸露導電接地部、一絕緣片及一導 5 1291853 I片哕二fr電接地部均與該印刷電路板内接地點導 片具有等導電接地部開設複數通孔，該導電 一導雷姑面，该絕緣片固定於該印刷電路板上且該每 固定該,裸露在該絕緣片外’該導電片 觸。、。亥、、‘邑、，彖片上且該導電面與該等導電接地部相互接 支術，在印刷電路板易産生電磁輻射之區 如^6置數¥笔接地部，並將該等導電接地部與一導電片 妯’除了可增加印刷電路板之接地面積來減小芊此接 ==外’也在該區域上形成了良好之屏蔽以 攸而有效的降低了印刷電路板之電磁干擾。 【實施方式】 ，一併參閱第一圖至第三圖，本發明降低電磁干擾之 二置之較佳實施方式用於降低印刷電路板1〇〇(如電 月^機板）上之電磁干擾，區域110爲印刷電路板100易産 ifΐ輕射之區域’該區域110由於走線（圖未示）複雜或 二原因，很難用鋪設面積較大之接地銅箔或設置金屬屏 敝罩之方式來降低電磁干擾。 該降低電磁干擾之屏蔽裝置包括複數設置於該區域 之適^位置之裸露導電接地部11卜一絕緣片200及一 ，，片300’本實施_方式中，該等導電接地部m爲銅箔， 该絕緣片200爲絕緣貼布或絕緣貼紙，該導電片3〇〇 電貼布或導電貼紙。 ” 其中每一導電接地部1U均與該印刷電路板1〇〇内之 接地點（圖未示）導通，該等導電接地部1U之數量、大小 可根^該區域110之可利用空間而定，該等導電接地部U1 之數量愈多、尺寸愈大，則防電磁干擾之效果就愈好。 ^該絕緣片200之尺寸大小滿足可以覆蓋該區域110， 該絕緣片+ 200對應該等導電接地部ιη開設複數通孔 210，本實施方式中，該絕緣片2〇〇與該區域n〇尺寸大 I291853 以"ί:!:通孔210之尺寸大小均與其對應之導電 ^導電片300之-面形成-導電面，該導電片3〇〇之 面之尺寸大小滿足可以覆蓋該等通孔210,本實施方 式中，該導電▲片300與絕緣片200之尺寸大小一致。' 印刷四圖及第五圖’該絕緣片_固定於該 =^板U)〇之區域H0上且該等導電接地部iu均透 通孔210裸露在該絕緣片外，除該等導電接地 ^覆i裸露在絕緣片細外該區域11G均被該絕緣片200 =導電片300之導電面貼於該絕緣片2〇〇 ,, 八中母裸硌在5亥絕緣片200外之導電接 地邛111均與該導電面之間達到良好之接觸。 由於該等導電接地部U1均與該導電片3〇〇 带 觸’域該等導電接地部111外該i域 中之非接地電路之間發上使： nf之導電面相當於該印刷電路板100之-個接地 面，廷樣就增加了該印刷電路板100之接 小了該區域110内某些接地回路之接地阻抗二= 地阻抗偏高而引起之電磁干擾。同時，由於該導電片300 ，導電面，於，區域11。之上’這就對該區域11G形成了 良好之屏蔽保護作用，進而防止了該區域110 ♦ 輕射可能對印刷電路板_中之其他電路造成之干ϋ 效的降低了印刷電路板1 00之電磁干擾。 μΪ上=述，本發明符合發明專利要件，爰依法提出專 凡熟悉本案技藝之人士，在爰依本發明精神所作之^效^; 飾或變化，皆應涵蓋於以下之申請專利範圍内。 少 1291853 【圖式簡單說明】 第一圖係本發明降低電磁干擾之屏蔽裝置之較佳實施 方式之導電接地部設置在印刷電路板上之示意 圖。 第二圖係本發明降低電磁干擾之屏蔽裝置之較佳實施 方式之絕緣片示意圖。 第三圖係本發明降低電磁干擾之屏蔽裝置之較佳實施 . 方式之導電片不意圖。 第四圖係本發明降低電磁干擾之屏蔽裝置之較佳實施 方式之絕緣片固定於印刷電路板上之示意圖。 • 第五圖係本發明降低電磁干擾之屏蔽裝置之較佳實施 方式之導電片固定於絕緣片上之示意圖。 【主要元件符號說明】1291853 1 _ IX DESCRIPTION OF THE INVENTION: TECHNICAL FIELD The present invention relates to a shielding device for reducing electromagnetic interference, and more particularly to a shielding device for reducing electromagnetic interference of a printed circuit board. [Prior Art] Electromagnetic Interference (EMI) is one of the major problems in the electronics industry. As the frequency of integrated circuits increases, the internal transmission wires, power supplies, or printed circuit boards have higher The electronic components of the working frequency will emit electromagnetic waves to the outside, and other components will be disturbed, which will affect the normal working operation. Therefore, practitioners attach great importance to the design of reducing electromagnetic interference. The printed circuit board is the basis for the normal operation of the entire electronic system. The work of preventing electromagnetic interference at the beginning of the printed circuit board layout is the primary task of constructing a high-reliability electronic system. When designing a printed circuit board, in addition to designing a ground plane to reduce electromagnetic interference, it is common to place a grounded copper pig as much as possible in the available space on the outer layer of the printed circuit board to increase the ground contact area, thereby reducing the impedance of some ground loops. Reduce electromagnetic interference, or provide a metal shield in areas where printed circuit boards are prone to electromagnetic radiation to reduce electromagnetic interference. However, due to the intricate wiring of printed circuit boards or other reasons, the available space is very limited. It is difficult to lock a large area of ground copper foil or some areas where electromagnetic radiation is generated on a printed circuit board. The metal shield is provided, so that the electromagnetic radiation in this area is not effectively suppressed, thereby causing electromagnetic interference. Therefore, it is necessary to improve the conventional shielding device for reducing electromagnetic interference to eliminate the above-mentioned deficiency. SUMMARY OF THE INVENTION In view of the above, it is necessary to provide a shielding device for reducing electromagnetic interference for reducing electromagnetic interference on a printed circuit board. A shielding device for reducing electromagnetic interference, which is used for reducing electromagnetic interference on a printed circuit board, the shielding device for reducing electromagnetic interference comprises a plurality of exposed conductive ground portions disposed on the printed circuit board, an insulating sheet and a guide 5 1291853 Each of the first and second grounding portions of the printed circuit board has an equal conductive ground portion to open a plurality of through holes, and the conductive conductive guide is fixed on the printed circuit board and each of the insulating sheets is fixed on the printed circuit board. Fix it, bare out of the insulation sheet 'the conductive sheet touches. ,. Hai,, '邑, 彖 且 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该 该The portion and the conductive sheet 妯 'in addition to increasing the ground contact area of the printed circuit board to reduce the connection = == outside ' also form a good shield on the area to effectively reduce the electromagnetic interference of the printed circuit board. [Embodiment] Referring to the first to third figures, the preferred embodiment of the present invention for reducing electromagnetic interference is used to reduce electromagnetic interference on a printed circuit board (such as an electric circuit board). The area 110 is an area where the printed circuit board 100 is easy to produce if light light. The area 110 is difficult to use a grounded copper foil with a large area or a metal screen cover due to the complicated or two reasons of the wiring (not shown). Ways to reduce electromagnetic interference. The shielding device for reducing electromagnetic interference comprises a plurality of exposed conductive ground portions 11 disposed at a suitable position in the region, and an insulating sheet 200 and a sheet 300'. In the embodiment, the conductive ground portions m are copper foils. The insulating sheet 200 is an insulating patch or an insulating sticker, and the conductive sheet 3 is an electric patch or a conductive sticker. Each of the conductive ground portions 1U is electrically connected to a grounding point (not shown) in the printed circuit board 1 ,. The number and size of the conductive ground portions 1U can be determined according to the available space of the region 110. The more the number and the larger the size of the conductive grounding portions U1, the better the effect of preventing electromagnetic interference. ^ The size of the insulating sheet 200 can satisfy the area 110, and the insulating sheet + 200 should be electrically conductive. The grounding portion ι includes a plurality of through holes 210. In the present embodiment, the insulating sheet 2〇〇 and the region n〇 are larger in size I291853, and the size of the through hole 210 is corresponding to the conductive conductive sheet 300. The surface of the conductive sheet 3 is formed to cover the through holes 210. In the present embodiment, the conductive sheet 300 and the insulating sheet 200 have the same size. And the fifth figure 'the insulating sheet _ is fixed on the area H0 of the y-plate U) and the conductive ground portions iu are all exposed through the insulating sheet except for the conductive grounds. Exposed to the outside of the insulating sheet, the region 11G is covered by the insulating sheet 200 = conductive sheet The conductive surface of 300 is attached to the insulating sheet 2, and the conductive grounding layer 111 outside the 5-inch insulating sheet 200 is in good contact with the conductive surface. Because of the conductive ground portion U1 Between the non-grounding circuits in the i-domain and the non-grounding circuit in the i-domain, the conductive surface of the conductive strip 3 is connected to the ground plane of the printed circuit board 100. The sample of the printed circuit board 100 increases the grounding impedance of some grounding circuits in the region 110 and the electromagnetic impedance caused by the high ground impedance. At the same time, due to the conductive sheet 300, the conductive surface, Area 11. Above 'This creates a good shielding protection for this area 11G, which prevents the area 110 from being lightly affected by other circuits in the printed circuit board. Electromagnetic interference of 00. μΪ上=, the invention complies with the requirements of the invention patent, and the person who is familiar with the skill of the present invention according to the law, in the spirit of the invention, should be covered in the following Within the scope of the patent application. Less 12 91853 [Simplified description of the drawings] The first figure is a schematic diagram of a conductive grounding portion of a preferred embodiment of the shielding device for reducing electromagnetic interference according to the present invention, which is disposed on a printed circuit board. The second figure is a shielding device for reducing electromagnetic interference according to the present invention. The third embodiment is a preferred embodiment of the shielding device for reducing electromagnetic interference according to the present invention. The conductive sheet of the method is not intended. The fourth embodiment is a preferred embodiment of the shielding device for reducing electromagnetic interference according to the present invention. The schematic diagram of the insulating sheet fixed on the printed circuit board. The fifth figure is a schematic view of the conductive sheet of the preferred embodiment of the electromagnetic interference reducing shielding device of the present invention fixed on the insulating sheet. [Main component symbol description]
印刷電路板 100 區域 110 導電接地部 111 絕緣片 200 通孔 \ 210 導電片 300Printed Circuit Board 100 Area 110 Conductive Grounding 111 Insulation Sheet 200 Through Hole \ 210 Conductive Sheet 300