1220807 玖、發明說明： 【發明所屬之技術領域】 本發明是有關於一種電連接器，特別是指一種供一電 子元件接合而與一電路板傳遞訊號之電連接器。 5 【先前技術】 對現今電子設備内供替換或擴充功能使用之電子元 件來說，如電腦之記憶體模組、介面卡等等，為了與一設 計有電子電路之電路板達到電性連接的目的，皆會利用設 置於電路板上之電連接器作為與電子元件電性連接使用。 〇 如圖1，以桌上型電腦所使用之記憶體模組7等電子 元件為例，為了與電腦主機内之電路板8形成電性連接， 必須對應地在電路板8上設置供記憶體模組7插接之電連 接器9,電連接器9包括一絕緣殼體91及複數容置於絕緣 殼體91内之導電端子92,絕緣殼體91形成有一位於上方 5 之插接面911及一位於下方貼近電路板8之接合面912， 在插接面911上則設有一供記憶體模組7插接之插槽 913，而導電端子92具有一接觸端及一焊接端（圖未示）， 接觸端是位於插槽913當中用以與記憶體模組7對應的電 性接點71 (業界稱之為金手指）接觸，而焊接端則凸露出 〇 接合面912用以與電路板8之電子電路（圖未示）焊接， 使得呈矩形片狀的記憶體模組7得以直立於電路板8表面 的方向插入電連接器9的插槽913當中。 而記憶體模組7之記憶容量愈來愈大，由於電連接器 9内導電端子9 2通常具有一定規格數目的限制而使得寬度 4 1220807 無法增加的條件下，記憶體模組7之記憶體晶片顆粒增加 或是佈線的增加勢必導致其相對於電路板8表面的高度增 咼，所以在記憶體模組7插接至電連接器9後，電腦主機 必須預留此一谷置空間而造成整體高度（厚度）因此增 加。此點與一般電子產品講求輕薄短小之設計趨勢背道而 馳，尤其整體厚度的增加導致體積增大，將影響市場上消 費者的接受度。 10 如圖2，基於上述考量，便有將記憶體模組7以平行 於電路板8表面的方向而與電連接器9插接的設計，做法 上是使電連接器9之絕緣殼體91形成如圖侧視斷面為二 形之型態，使絕緣殼體91之插接面911與接合面912互成 垂直狀態，對應地，導電端子92亦彎折成L形而容置於 絕緣殼體91内，如此，記憶體模組7即能以平行於電路 15 板8表面的方向插入至電連接器9之插槽913内，藉著記 憶體模組7厚度遠較其高度為小的特點，可因此大幅降低 記憶體模組7在組裝之後相對於電路板8表面的高度，並 在產品厚度可容許的範圍内，採用如圖一大一小呈l形的 二電連接H 9、9,相互堆疊的方式，更能夠以水平的方式 20 同時供二記憶體模組7插接，可達到空間利用上更為密集 化的目的。 但是，現今數位電子元件運作時脈不斷提高下，所傳 送之訊號震蘯頻率均相當高，而高頻訊號的特色必須要有 良好的接地(G削nd)，故導電端子92中區分有訊號端子及 接地端子’配置方式可能―訊號端子對應-接地端子，亦 5 1220807 有可能複數訊號端子共同使用一接地端子。但當訊號端子 傳送高頻訊號時，每一訊號端子將如同天線一般發散出電 磁波’為了避免電磁波自電連接器9内向外發散而干擾其 他電子元件的運作，現行所有傳遞高頻訊號之電連接器9 對於防止電磁波干擾的做法不外乎兩方面，一方面是使導 電端子92長度盡量地縮短、且所有訊號端子更為緊密排 列，目的使訊號端子能夠更接近電路板8而使電磁波由電 路板8之接地迴路（reference ground)感應而導引接地，另 一方面則是利用連接電路板8接地迴路之金屬蓋體93,將 10 電連接器9之絕緣殼體91大面積地加以包覆，利用「圍 堵」的方式藉由金屬蓋體93感應接地而使電磁波不致自 絕緣殼體91内向外發散。 復參考圖2 ’如述電連接器9採L形相互堆疊的做法 雖然能夠達到有效利用空間的目的，但在電磁波干擾 15 ( EMI )的測試上卻無法通過。究其原因在於，位於下方 的電連接器9或許能夠利用金屬蓋體而將電磁波強度控 制在不發生干擾的範圍以下，主要還是在於其導電端子長 度短’且距離電路板8尚近，即導電端子所產生之電磁波 與所謂的reference ground距離近，故能夠由reference 20 ground感應而降低其發散的程度。但位於上方的電連接器 9因絕緣殼體91頂面距電路板8表面實際上可能有高達 1 · 5公为的距離’故在電磁波干擾的問題上將有不同的情 況發生，一為導電端子92長度增加，二為導電端子92距 離電路板8(reference ground)較遠，相形之下，各導電端子 6 1220807 92的天線效應明顯’使得電磁波發散的問題嚴重，而即使 利用至屬蓋體93包覆亦無法將電磁波強度降低至一定的 標準以下，若仍以強化金屬蓋體93的包覆性作為解決此 -問題唯-的手段作考量下，一來完全包覆有其困難，只 5 要至屬蓋體93 -有縫隙，電磁波即由此洩漏，二來製作 成本將大f田提同’但所得到的效果有限，造成所費不貨而 效果不心，並不符製作上的成本要求。種種原因均使得傳 統上利用金屬蓋體93包覆絕緣殼體91以圍堵電磁波發散 的做法並不能有效解決前述電磁波干擾的問題。 馨 10 【發明内容】 因此，本發明之目的，是在提供一種利用導引、而非 圍堵的方式達到抑制電磁波發散之電連接器， 於疋’本發明之具有電磁波引導作用之電連接器，是 设置於一電路板上以供一電子元件插接，電連接器包含一 15 絶緣鈸體及容置於絕緣殼體内之複數訊號端子及一接地 端子，各訊號端子具有一位於絕緣殼體内以供電子元件電 性接觸之插接端及一電性連接至電路板之接合端，使絕緣41 殼體内於該等訊號端子之接合端與插接端中間設有一供 訊號端子穿過並與接地端子電性連接之傳導片，使傳導片 20 作為訊號端子傳送訊號時所產生電磁波之最近接地導 體，以將電磁波即時導引接地而防止其發散。 本智明之功效在於利用傳導片改變reference gr〇und 的位置而可有效導引吸收電磁波以:避免其朝外發散。 【實施方式】 7 1220807 有關本發明之前述及其他技術内容、特點與功效，在 以下配合參考圖式之一較佳實施例的詳細說明中，將可清 楚的明白。 參閱圖3，本發明之電連接器1的一較佳實施例仍以 5 上述習知呈L形相互堆疊且位於上方的電連接器丨構造為 例。電連接器1包含一側視斷面概呈L形的絕緣殼體11， 及複數容置定位於絕緣殼體11内之導電端子。 絕緣殼體11具有一插接面111及一接合面丨丨2，接合 面112用以貼近一電路板2表面，而插接面i丨丨則與接合 10 面112垂直，並於插接面111上並形成供一電子元件插入 之一插槽113。 複數導電端子可區分為複數訊號端子12及複數接地 端子13，為便於說明，圖中僅繪出單一訊號端子丨2及單 一接地端子13，而訊號端子12具有一呈l形延伸之本體 15 121、一形成於本體121 —端並位於插槽113内之插接端 122及一形成於本體121之另一端並凸露出接合面112外 與電路板2焊接之接合端丨23，相同地，接地端子13亦具 有一 L形本體13卜一形成於本體131 一端並位於插槽113 内之插接端132及一形成於本體131之另一端並凸露出接 2〇 合面112外與電路板2焊接之接合端133，此外，接地端 子13並在本體131介於插接端132及接合端133中間形 成一干涉部134 ’本例中，干涉部134為一凸出於本體131 呈鱗片狀之突片。 與習知電連接器1構造之主要不同處在於，絕緣殼體 8 11内在訊號端子12及接地料13之接“ i22q_ 插接端123、133中間設置有-傳導片14，傳導片14可配 合絕緣殼體11之寬度（圖未示）而以金屬材料等導體製成 片狀且橫向地定位在絕緣殼體^，使傳導片Η概平行 間隔地位於電路板2上一定的距離，此―距離的多寡則視 Γ殼體U尺寸與㈣端子12之密集程度作適當的調 正。其中’傳導片14分別在對應訊號端子12之位置抓有 複數第-穿孔141，而在對應接地端子13的位置處設有又複 數弟二穿孔142,第一穿孔141可容納訊號端子12之本體 ⑵穿過但並不相互接觸，而第二穿孔142亦可容納接地 端子π之本體131通過，但可藉由干涉部134卡接於第 二穿孔142周圍之傳導片14材料上，使得傳導片μ可盥 接地端子U產生電性連接。而本例中接地端Μ雖然以 =部134卡接於第二穿& 142周圍之傳導片μ構成電 '於連接’但主要是在說明傳導片14是與接地端子13連接 而有接地的效果，實際上並非限定干涉部134之型態，故 其他可使傳導片14與接地端子13產生電性接觸之結構或 亦為可行，另外，說明令雖看似複數 -頁與傳導…性連接，然實際上傳導片14僅需與： 厂接地端子13形成電性接觸即可具有接地的效果。 應用時，藉由傳導片利用接地端子13形成接地的 用’等於提供了較電路板2更為接近訊號端子12之 reference ground 的位罢.. t 位置，所以訊號端子12在傳遞高頻訊 5 虎而產生電磁波時，傳導片Η將成為電磁波最近的接地 1220807 導體，可將電磁波在最短時間内導引接地而避免其天線效 應，自然能夠有效降低電磁波向外發散的機率 際測试結果顯示，無傳導片！ 4構造的電連接 強度可高達11 dB，而具有傳導片14的電連接 5 ，而根據實 器1電磁波 器1之電磁 波強度則可大幅下降至6dB，效果比傳統上利用金屬材料 包覆絕緣殼體11外表面而以圍堵電磁波發散的方式更為 顯著，同時在結構及製作上亦較為簡單。 10 15 再者，絕緣殼體11之背面亦可進一步結合大面積的導 電蓋體15,並可使導電蓋體15與傳導片14電性連接，藉 由導電蓋體15對電磁波的屏蔽作用，可更強化整體電連 接器1對電磁波發散之防護效果。 歸納上述，本發明之電連接器，藉由設置於絕緣殼體 内之傳V片，可長：升reference ground的位置，並藉由「引 導」電磁波的方式取代傳統上「圍堵」電磁波的做法，達 到明顯改善電連接器對於電磁波發散的問題，故確實能達 到本發明之目的。又以上雖以斷面呈L形的電連接器來作 說明，並不因此限定本發明實施之電連接器型態，其他一 般之電連接器亦可採用相同之設計。1220807 发明 Description of the invention: [Technical field to which the invention belongs] The present invention relates to an electrical connector, and more particularly to an electrical connector for joining an electronic component and transmitting a signal to a circuit board. 5 [Previous technology] For current electronic components in electronic equipment for replacement or expansion functions, such as computer memory modules, interface cards, etc., in order to achieve electrical connection with a circuit board designed with electronic circuits The purpose is to use the electrical connector provided on the circuit board for electrical connection with electronic components. 〇As shown in FIG. 1, taking the electronic components such as the memory module 7 used in the desktop computer as an example, in order to form an electrical connection with the circuit board 8 in the host computer, a memory for the circuit board 8 must be provided correspondingly. The electrical connector 9 to which the module 7 is plugged. The electrical connector 9 includes an insulating casing 91 and a plurality of conductive terminals 92 accommodated in the insulating casing 91. The insulating casing 91 forms a plugging surface 911 located above 5 And a joint surface 912 located close to the circuit board 8 below, a socket 913 for inserting the memory module 7 is provided on the plugging surface 911, and the conductive terminal 92 has a contact end and a soldering end (not shown in the figure) (Shown), the contact end is located in the slot 913 to be in contact with the electrical contact 71 corresponding to the memory module 7 (referred to as a golden finger in the industry), and the soldering end is exposed. The joint surface 912 is used to contact the circuit. The electronic circuit (not shown) of the board 8 is soldered, so that the rectangular memory module 7 can be inserted into the slot 913 of the electrical connector 9 in a direction standing on the surface of the circuit board 8. The memory capacity of the memory module 7 is getting larger and larger. Since the conductive terminals 9 2 in the electrical connector 9 usually have a certain number of specifications and the width 4 1220807 cannot be increased, the memory of the memory module 7 The increase of chip particles or the increase of wiring will inevitably lead to an increase in the height of the chip relative to the surface of the circuit board 8. Therefore, after the memory module 7 is connected to the electrical connector 9, the computer host must reserve this valley space and cause The overall height (thickness) is therefore increased. This point runs counter to the general trend of light, thin and short electronic products. In particular, the increase in overall thickness leads to an increase in volume, which will affect consumer acceptance in the market. 10 As shown in FIG. 2, based on the above considerations, there is a design for inserting the memory module 7 into the electrical connector 9 in a direction parallel to the surface of the circuit board 8. In practice, the insulating housing 91 of the electrical connector 9 is used. Formed as shown in the side view, the cross-section is dimorphic, so that the insertion surface 911 and the joining surface 912 of the insulating housing 91 are perpendicular to each other. Correspondingly, the conductive terminal 92 is also bent into an L shape to be accommodated in the insulation. In the case 91, the memory module 7 can be inserted into the slot 913 of the electrical connector 9 in a direction parallel to the surface of the circuit 15 board 8. The thickness of the memory module 7 is much smaller than its height. Therefore, the height of the memory module 7 relative to the surface of the circuit board 8 after assembly can be greatly reduced, and within the allowable range of the product thickness, two electrical connections H 9 with a large and a small L shape as shown in the figure are used. , 9, stacked on top of each other, can also be used to connect two memory modules 7 in a horizontal manner 20, which can achieve the purpose of more space utilization. However, with the continuous improvement of the operating clock of current digital electronic components, the frequency of the transmitted signals is quite high, and the characteristics of high-frequency signals must have a good ground (G-cut). Therefore, signals are distinguished in the conductive terminal 92 Terminals and ground terminals' configuration is possible-corresponding to signal terminals-ground terminals, and 5 1220807 It is possible to use a common ground terminal for multiple signal terminals. But when the signal terminals transmit high-frequency signals, each signal terminal will emit electromagnetic waves like an antenna. In order to prevent electromagnetic waves from radiating from the inside of the electrical connector 9 and interfere with the operation of other electronic components, all current electrical connections that transmit high-frequency signals The method of the device 9 for preventing electromagnetic wave interference is nothing more than two aspects. On the one hand, the length of the conductive terminal 92 is shortened as much as possible, and all signal terminals are arranged more closely. The purpose is to make the signal terminals closer to the circuit board 8 and allow electromagnetic waves to pass from the circuit. The reference ground of the board 8 senses and guides the ground. On the other hand, a metal cover 93 connected to the ground circuit of the circuit board 8 is used to cover the insulation housing 91 of the electrical connector 9 over a large area. In order to prevent electromagnetic waves from radiating from the inside of the insulating casing 91 through the "containment" method, the metal cover 93 is inductively grounded. Repeating reference to FIG. 2 ′ As described above, the electrical connectors 9 are stacked in an L shape. Although they can achieve the purpose of effectively using space, they cannot pass the electromagnetic interference 15 (EMI) test. The reason is that the electrical connector 9 located below may be able to use a metal cover to control the intensity of electromagnetic waves below the range where no interference occurs, mainly because its conductive terminals are short in length and close to the circuit board 8, that is, conductive. The electromagnetic wave generated by the terminal is close to the so-called reference ground, so it can be induced by the reference 20 ground to reduce its degree of divergence. However, the electrical connector 9 located above may actually have a distance of up to 1.5 cm from the surface of the circuit board 8 due to the top surface of the insulating housing 91. Therefore, there will be different situations on the issue of electromagnetic interference. One is conductive. The length of the terminal 92 is increased. The second is that the conductive terminal 92 is far away from the circuit board 8 (reference ground). In contrast, the antenna effect of each conductive terminal 6 1220807 92 is obvious. This makes the problem of electromagnetic wave divergence serious, even if it is used as a cover. The 93 coating can not reduce the electromagnetic wave intensity below a certain standard. If the coating of the metal cover 93 is still strengthened as a solution to this problem, considering the problem, the complete coating has its difficulties. 5 To the cover 93-there is a gap, and the electromagnetic waves leak out. Second, the production cost will be the same as the big field, but the effect obtained is limited, resulting in the cost is not good and the effect is not intentional, which is not consistent with the production. Cost requirements. For various reasons, the traditional use of a metal cover 93 to cover the insulating case 91 to block electromagnetic wave divergence cannot effectively solve the aforementioned electromagnetic wave interference problem. Xin 10 [Summary of the Invention] Therefore, the object of the present invention is to provide an electrical connector that can suppress electromagnetic wave divergence by using a guiding method instead of a containment method. The electrical connector of the present invention has an electromagnetic wave guiding effect. It is arranged on a circuit board for plugging in an electronic component. The electrical connector includes a 15-insulating body and a plurality of signal terminals and a ground terminal housed in an insulating housing. Each signal terminal has an insulating shell. A plug end electrically contacting the power supply element in the body and a joint end electrically connected to the circuit board, so that an insulation 41 housing is provided between the joint end and the plug end of the signal terminal for the signal terminal to pass through. The conductive sheet passing through and electrically connected to the ground terminal makes the conductive sheet 20 as the nearest ground conductor of the electromagnetic wave generated when the signal terminal transmits the signal, so as to guide the electromagnetic wave to ground in real time and prevent it from diverging. The function of this wisdom is to change the position of the reference grund by using a conductive sheet to effectively guide and absorb electromagnetic waves: to prevent it from diverging outward. [Embodiment] 7 1220807 The foregoing and other technical contents, features, and effects of the present invention will be clearly understood in the following detailed description of a preferred embodiment with reference to the accompanying drawings. Referring to FIG. 3, a preferred embodiment of the electrical connector 1 of the present invention still takes the above-mentioned conventional electrical connector in an L-shape stacked on top of each other as an example. The electrical connector 1 includes an insulating shell 11 having an L-shaped cross section when viewed from one side, and a plurality of conductive terminals housed in the insulating shell 11. The insulating housing 11 has a mating surface 111 and a mating surface 丨 丨 2. The mating surface 112 is used to be close to the surface of a circuit board 2, and the mating surface i 丨 丨 is perpendicular to the mating surface 112 and is on the mating surface. A slot 113 is formed on 111 to insert an electronic component. The plurality of conductive terminals can be divided into a plurality of signal terminals 12 and a plurality of ground terminals 13. For the convenience of explanation, only a single signal terminal 2 and a single ground terminal 13 are drawn in the figure, and the signal terminal 12 has an l-shaped extension body 15 121 A plug end 122 formed on the end of the body 121 and located in the socket 113 and a joint end formed on the other end of the body 121 and protruding from the joint surface 112 and soldered to the circuit board 2 丨 23, the same ground The terminal 13 also has an L-shaped body 13 and a plug end 132 formed on one end of the body 131 and located in the slot 113 and a second end formed on the other end of the body 131 and protruding out of the joint 20 and the circuit board 2 Welded joint end 133. In addition, the ground terminal 13 forms an interference portion 134 in the body 131 between the plug end 132 and the joint end 133. In this example, the interference portion 134 is a scale protruding from the body 131. Protruding piece. The main difference from the structure of the conventional electrical connector 1 lies in the fact that the insulating housing 8 11 has a signal terminal 12 and a grounding material 13 inside. The “i22q_” plug-in terminals 123 and 133 are provided with a conductive plate 14 in between. The conductive plate 14 can cooperate with The width of the insulating case 11 (not shown) is made of a conductive material such as a metal material and positioned laterally on the insulating case ^, so that the conductive sheet is located at a certain distance on the circuit board 2 in parallel and at a certain distance. The length of the distance is appropriately adjusted depending on the U size of the Γ case and the denseness of the ㈣ terminal 12. Among them, the 'conducting sheet 14 has a plurality of -perforations 141 at the positions corresponding to the signal terminals 12, and the corresponding ground terminal 13 There are multiple perforations 142 at the position. The first perforation 141 can accommodate the body of the signal terminal 12 through but does not touch each other, and the second perforation 142 can also accommodate the body 131 of the ground terminal π, but can The interference portion 134 is snapped onto the material of the conductive sheet 14 around the second through hole 142, so that the conductive sheet μ can be electrically connected to the ground terminal U. In this example, although the ground terminal M is snapped to the first portion 134 Second wear & 142 surrounding conductive sheet μ The structure is electrically connected, but it mainly explains that the conductive sheet 14 is connected to the ground terminal 13 and has the effect of grounding. Actually, the type of the interference portion 134 is not limited. Therefore, other conductive sheets 14 and the ground terminal 13 can generate electricity. The structure of sexual contact may also be feasible. In addition, although the description makes it seem that plural-pages are conductively connected, in fact, the conductive sheet 14 only needs to make electrical contact with the factory ground terminal 13 to have the effect of grounding. In application, the use of the grounding terminal 13 to form a ground through the conductive sheet is equivalent to providing a bit closer to the reference ground of the signal terminal 12 than the circuit board 2. The t position, so the signal terminal 12 is transmitting high-frequency signals 5 When an electromagnetic wave is generated by a tiger, the conductive sheet 成为 will become the nearest grounding 1220807 conductor of the electromagnetic wave, which can guide the electromagnetic wave to the ground in the shortest time to avoid its antenna effect. Naturally, it can effectively reduce the probability of the electromagnetic wave emitting outward. No conductive sheet! The strength of the electrical connection of the 4 structure can be as high as 11 dB, while the electrical connection of the conductive sheet 14 has 5, and according to the electromagnetic wave strength of the real device 1 electromagnetic wave device 1 It can be greatly reduced to 6dB, the effect is more significant than the traditional method of covering the outer surface of the insulating casing 11 with a metallic material to block the electromagnetic wave from spreading, and it is also simpler in structure and manufacturing. 10 15 Furthermore, insulation The rear surface of the housing 11 can further be combined with a large-area conductive cover 15 and can electrically connect the conductive cover 15 and the conductive sheet 14. By using the conductive cover 15 to shield electromagnetic waves, the overall electrical connection can be further strengthened. The protective effect of device 1 on electromagnetic wave divergence. To sum up, the electrical connector of the present invention can be extended to the position of reference ground by using a V-transmitting piece arranged in an insulating case, and "guide" the electromagnetic wave. Instead of the traditional method of "enclosing" electromagnetic waves, the problem of electromagnetic wave divergence of the electrical connector is obviously improved, so the object of the present invention can be achieved. Furthermore, although the above description is made with an electrical connector having an L-shaped cross section, it does not limit the type of the electrical connector implemented in the present invention. Other general electrical connectors can also adopt the same design.
20 惟以上所述者，僅為本發明之較佳實施例而已，當不 能以此限定本發明實施之範圍，即大凡依本發明申請專利 範圍及說明書内容所作之簡單的等效變化與修飾，皆應仍 屬本發明專利涵蓋之範圍内。【圖式簡單說明】 圖1是一立體圖’說明一習知記憶體模組以直立的方 10 1220807 式插接於一電連接器之型態； 圖2是一側面剖視示意圖，說明習知以水平方式結合 記憶體模組之電連接器型態；及 圖3是本發明之一較佳實施例的側面剖視示意圖。 1220807 【囷式之主要元件代表符號說明】 1 電連接 11 絕緣殼體 111 插接面 112 接合面 113 插槽 12 訊號端子 121 本體 122 插接端 123 接合端 13 接地端子 131 本體 132 插接端 133 接合端 134 干涉部 14 傳導片 第一穿孔 第二穿孔 導電蓋體 電路板 記憶體模組 電性接點 電路板 電連接器 絕緣殼體 插接面 接合面 插槽 導電端子 金屬蓋體 電連接器 1220 However, the above are only the preferred embodiments of the present invention. When the scope of implementation of the present invention cannot be limited in this way, that is, the simple equivalent changes and modifications made according to the scope of the patent application and the contents of the description of the present invention, All should still fall within the scope of the invention patent. [Brief description of the figure] FIG. 1 is a perspective view illustrating a conventional memory module plugged into an electrical connector in an upright 10 1220807 type; FIG. 2 is a schematic side sectional view illustrating the conventional method. The electrical connector type of the memory module is combined in a horizontal manner; and FIG. 3 is a schematic side sectional view of a preferred embodiment of the present invention. 1220807 [Description of the main symbols of the main components] 1 Electrical connection 11 Insulating housing 111 Mating surface 112 Mating surface 113 Slot 12 Signal terminal 121 Body 122 Mating terminal 123 Mating terminal 13 Ground terminal 131 Body 132 Mating terminal 133 Bonding end 134 Interference part 14 Conductive sheet First perforation Second perforated conductive cover Circuit board memory module Electrical contact circuit board electrical connector Insulation housing Mating surface Slot conductive terminal Metal cover electrical connector 12