1287415 九、發明說明： 【發明所屬之技術領域】 本發明係為一種減少訊號通過走線上寄生電感輻射電 磁波的裝置，係應用於電子裝置上印刷電路板之地線裝置。 【先前技術】 隨通訊與電腦技術的高速發展，使得高速印刷電路板 (printed circuit board，PCB)設計進入了 Gigabit 領域，新 的咼速元件應用使得如此向的速率在電路板上的長距離傳 輸成為可能，但在同時，印刷電路板設計中的訊號完整性問 題（si)、電源完整性以及電磁相容（dectr〇_magnetic compatibility，EMC)方面的問題也更加突出。印刷電路板幾 乎會出現在每-種電子設備#巾。設備巾的f子元件，依電 路佈局鑲在大小各異的印刷電路板上。除了固定各種小零件 外’印刷電雜社要魏是提供其上各項電子元件的相互 電流連接。然而，在高㈣路及高速數位電路中，印刷電路 板上的任-條走線就會形成寄生電感，如果有兩條走線則走 線上間就會縣寄生電城分及互敍分。所軸的電容電 感數值是鎌小的，因此在低_钱乎不成問題，但是在高 頻領域卻不能忽略寄生電容和寄生電感成分的影響。 1287415 請參照「第1圖」，係為一般習知的電路方塊圖，印刷 電路板10包含有··電源供應器20、負載阻抗30、傳輸線 40和寄生電感50。傳輸線40位於電源供應器20和負載阻 抗30之間，用以傳導由電源供應器20供應到負載阻抗3〇 的電壓或電流訊號。因為電源供應器20提供的是一個帶有 頻率的訊號，在低頻時，傳輸線4〇並沒有明顯寄生電感和 寄生電容效應，所以可以忽略其影響，但在考慮高頻的影響 下，則傳輸線40必須視為離散元件（distributed element)， 在此狀況下就要考慮高頻效應的影響。寄生電感中的信號頻 率越高，電感的阻抗就越大，因此，當輪出信號的上升和下 降沿諧波頻率落在電磁干擾(EMI)輻射頻帶範圍之内時(上 升時間為11ns或更快），寄生電感變會像天線般輻射出電磁 波’產生了電磁干擾(EMI)。 而且’寄生電感50為在高頻效應下，當印刷電路板1〇 專輸線40走線存在寄生電感，由下列公式知道存在有一 電壓的變化量： 心=L dl/dt，其中 電壓的變化量； L印刷電路板走線寄生電感阻抗值； 1287415 d卜流經印刷電路板走_電流變化； dt=電流變化的時間。 當電流若突然間要立即開始或停止流動 ，往往會使走線1287415 IX. Description of the Invention: [Technical Field] The present invention is a device for reducing electromagnetic waves radiated by a parasitic inductance of a signal through a trace, and is applied to a grounding device of a printed circuit board on an electronic device. [Prior Art] With the rapid development of communication and computer technology, high-speed printed circuit board (PCB) design has entered the Gigabit field, and new idle component applications have enabled such long-distance transmission of the rate on the board. This is possible, but at the same time, signal integrity issues (si), power integrity, and electromagnetic compatibility (EMC) issues in printed circuit board design are more prominent. Printed circuit boards appear almost exclusively in every kind of electronic device #巾. The sub-element of the equipment towel is mounted on a printed circuit board of various sizes depending on the circuit layout. In addition to fixing various small parts, the printing company is to provide mutual current connection of various electronic components. However, in high (four) and high-speed digital circuits, any traces on the printed circuit board will form parasitic inductance. If there are two traces, the county will be parasitic and divided. The value of the capacitance of the shaft is small, so it is not a problem at low cost, but the influence of parasitic capacitance and parasitic inductance cannot be ignored in the high frequency field. 1287415 Please refer to FIG. 1 for a conventional circuit block diagram. The printed circuit board 10 includes a power supply 20, a load impedance 30, a transmission line 40, and a parasitic inductance 50. A transmission line 40 is located between the power supply 20 and the load impedance 30 for conducting a voltage or current signal supplied by the power supply 20 to the load impedance 3〇. Since the power supply 20 provides a signal with a frequency, the transmission line 4 没有 has no significant parasitic inductance and parasitic capacitance effect at low frequencies, so its influence can be ignored, but under the influence of high frequency, the transmission line 40 Must be considered a discrete element, in which case the effects of high frequency effects should be considered. The higher the frequency of the signal in the parasitic inductance, the greater the impedance of the inductor. Therefore, when the rising and falling edges of the wheeled signal fall within the electromagnetic interference (EMI) radiation band (rise time is 11 ns or more) Fast), the parasitic inductance will radiate electromagnetic waves like an antenna, which generates electromagnetic interference (EMI). Moreover, 'the parasitic inductance 50 is that under the high frequency effect, when there is parasitic inductance in the trace of the printed circuit board 1 〇 special transmission line 40, it is known by the following formula that there is a change in voltage: heart = L dl / dt, where the voltage changes Quantity; L printed circuit board trace parasitic inductance resistance value; 1287415 d pass through the printed circuit board to go _ current change; dt = current change time. When the current suddenly starts or stops flowing, it will often cause the line to be traced.
產生電級犬波。母-次轉態時，這_部分走線會產生極高的 麵的突波钱。因此，麵突波可_用絲式M^L 麵I絲。所以這些寄生電感不但會產生電磁干擾， 而且所產找電壓突波還會侵人整合式的控㈣路，使工作 不穩定。 因此’降低印刷電路板上導體的寄生電感值就很重要。 磁場的大小部份取決於導體的截面積。當導體能變寬、變厚 或變短時’磁場就會減弱，寄生電感就會降低。 為了減少由電流產生的電磁場影響，在印刷電路板上一 ω木取-些方式，應使電源和接地儘量接近佈線。此外，對 於佈線材質的面積’也應往變寬、變厚或類的方向去改 進。特別是在接地_配置上，若是接地、_電路佈局 lay_不⑷導致其上電磁干擾過大，則印刷 電路板而重新電路佈局（circuitlayout)，將會浪費成本與時 間。 ^ 因此’如何能提供一種應用於電子裝置上印刷電路板之 1287415 地線佈線方法，減少印刷電路板之訊號通過佈線上寄生電感 產生的電磁波作用，成為研究人員待解決問題之一。 【發明内容】 有鑑於先前技術存在之缺點與無法解決的問題，本發明 揭露-種減少電子產品電磁干擾之電路板，用於印刷電路板 之地線佈線裝置，姻金屬片跟金屬螺絲取代縣接地線走 線的部分，由於去除曲折，彎繞的接地線走線，所以電流訊號 可由較少的阻礙直接回到電源產生器的負極，也可以減少由 電路上寄生電感所輻射出的電磁波。 因此，為達上述目的，本發明所揭露之電路板，包括有 金屬片和複數個金屬螺絲。金屬片為取代縣傳輸線接地走 線’用以傳導電源供應器和負載阻抗之間的電流。複數個金 屬螺4 ’除了 U定電源供應器、和金屬片以及固定金屬片和印 刷電路板’更具有傳導電祕應器和貞載阻抗之間電流之功 月匕藉由孟屬片導體以及金屬螺絲導體較一般印刷電路板上 勺傳輸線I可生電感就會降低，所輻射的電磁干擾便降低。 有關本發明的特徵與實作，茲配合圖示作最佳實施例詳 細說明如下。 1287415 【實施方式】 請參照「第9> 圔J，係為去除原本接地線的佈局，利用 金屬片跟螺絲取代原本傳輸線接地走線佈局的電路方塊圖。 P刷電路板11上包含有··電源供應器2卜負載阻抗3卜 金屬片41、過孔71a、過孔71b、過孔71c和過孔71d。而金 上有孔洞51a、孔洞5ib、孔洞51c和孔洞5id在金 屬片41的四個聽外，更有—孔洞52位於金屬片41上。 電源供應器21 子元件所需的訊號源 為一個交流訊號的訊號源，提供一般電 訊號為一個帶有頻率的電壓或電流訊 上的佈線(trace) 號。電源供應器21正極透過印刷電路板^ 、串接方d載阻^L 31相連接，而電源供應器2丨負極則 不使用印刷電路的佈線方式，改採用透過一個螺絲幻固定 在金屬片41上，而螺絲62為一金屬材質。 負載阻抗3丨為電路上電子元件畴的負触抗，包括 有電容’電感或電I.物被航件，献如二極體、電晶 體之類的絲元件。-個或複數個貞載阻抗分佈在印刷電路 板11上’負載阻抗31 —端透過印刷電路板u上的饰線以串 接方式連接職祕魅21，㈣—端則細佩連接到印 刷電路板11上的過孔(via)，過孔於「第2圖」中有四個，為 1287415 過孔71a、過孔71b、過孔71c和過孔71d。如果存在更多的 電子元件，過孔數可依情況增加在印刷電路板η上。每一 過孔均對應到金屬片41上的一孔洞，以便利用一個金屬螺 絲將金屬片41和印刷電路板η鎖緊。因為電源供應器21 負極已透過螺絲62固定在金屬片41上，所以負載阻抗31 可以透過金屬片41與電源供應器21形成一導通的電路迴 路0 金屬片41於「第2圖」中，利用螺絲62將電源供應器 21固定在金屬片41上的孔洞52。金屬片41上還有孔洞 51a、孔洞Hb、孔洞51c和孔洞51d。金屬片41上的孔洞 數依照印刷電路板11上的過孔數可以增加於金屬片41的四 個邊緣，但金屬片41上的任一孔洞皆要和印刷電路板u上 的過孔位置相同且大小相同，以便孔洞51a、孔洞训、孔 洞51c和孔洞51d可以分別用螺絲61a、螺絲6化、螺絲6ic、 螺絲61d鎖緊在過孔71a、過孔71b、過孔仏和過孔加 甲。如此可以將金屬41緊密固定在印刷電路板^上。金 屬片Μ的材質為鐵片，金屬片41上除了電源供應器21外， 沒有任何的電子元件。再者，金屬片41上除了孔洞51a、 孔洞51b、孔洞51C和孔洞51(1在金屬片41的四個角落外， 11 1287415 其金屬面為沒有任何孔洞阻擋的光滑平面。使用金屬片41 代替原本的接地的傳輸線，使原本由傳輸線傳回的電流訊號 改由金屬片41傳回，由於去除原本曲折彎繞的傳輸線地線 走線’所以電流dl號可由較少的阻礙直接回到電源產生器的 負極。因此將減少電流訊號在傳遞中的損耗(1〇ss)，且金屬 片41導體與一般的傳輸線比較起來較寬和較厚，所以，金 屬片41上的寄生電感也會降低。如此也可以減少電磁干擾 (EMI) 〇 在過孔71a、過孔71b、過孔71c和過孔71 d的選擇上， 在南速、高密度的印刷電路板設計時，印刷電路板的過孔越 小越好，因為一個過孔主要由兩個部分組成，一是中間的鑽 孔（drillhole)，二是鑽孔周圍的焊盤區（未標示），這兩 部分的尺寸大小決定了過孔的大小。很顯然，在高速、高密 度的PCB設計時’過孔越小越好，這樣板上可以留有更多 的佈線空間，此外，過孔越小，其自身的寄生電容也越小， 更適合用於高速電路。而在印刷電路板11上，過孔7ia、 過孔71b、過孔71c和過孔71d需與金屬板41上孔洞51a、 孔洞51b、孔洞51c和孔洞51d透過螺絲61a、螺絲61b、 螺絲61c、螺絲61d固定，所以在金屬片41上的孔洞也符 12 1287415 合印刷電路板11的過孔大小。 螺絲61a、螺絲61b、螺絲61c、螺絲6M和螺絲62皆 為金屬材質，如鐵，銅’合金之類傳導能力佳金屬螺絲，螺 絲的功用除了固定電源供應器Ή到金屬片W上以及固定金 屬片41到印刷電路板n上之功能外，更是連接負載阻抗 31和電源供應器21之間的線路，使由負載阻抗31回來的 電流訊號可以通過金朗、_金屬片41，在通過金屬片Μ 的表面後，經由另—金屬獅和電源供應H 21形成-電流 迴路。 在此結射’.是金屬_或金屬片接駿寬且較厚 之導體與—般傳輪線比較起來，所以當金屬>{ 41取代一般 用印刷電路方式形成的傳輸線地線時，其上的寄生電感財 降低’由於寄生電感降低，所輻射的電磁干擾便降低。並且 因為金屬Μ為—寬平面之導體，電流不需依照以往走線， 而可以由最&路逕仃走’可以確定最少阻礙酬電源產生器 的負極，減少電流訊號在傳遞時的祕。 °° a雖然本翻簡述之實施例揭露如上，然其並非用以限 林么明’任何抑相像技藝者，在不脫離本發明之精神和 範圍内’當可作些許之更動與潤飾，因此本發明之專利保護 1287415 範圍須視本說明書所附之申請專利範圍所界定者為準。 【圖式簡單說明】 第1圖係為習知之電路方塊圖；以及 第2圖係為本發明之電路方塊圖。 【主要元件符號說明】 10 印刷電路板 11印刷電路板 20電源供應器 21電源供應器 30負載阻抗 31負載阻抗 40傳輸線 41金屬片 50寄生電感 51a孔洞 51b孔洞 51c孔洞 51d孔洞 52 孔洞 14 1287415 61a螺絲 61b螺絲 61c螺絲 61d螺絲 62 螺絲 71a過孔 71b過孔 71c過孔 71d過孔Produce a power level dog wave. In the case of the mother-second transition, this _ part of the trace will produce a very high surface surge. Therefore, the surface glitch can be used as a wire M^L surface I wire. Therefore, these parasitic inductances will not only cause electromagnetic interference, but also the induced voltage surge will invade the integrated control (four) way, making the work unstable. Therefore, it is important to reduce the parasitic inductance of the conductors on the printed circuit board. The size of the magnetic field depends in part on the cross-sectional area of the conductor. When the conductor can be widened, thickened or shortened, the magnetic field will be weakened and the parasitic inductance will be reduced. In order to reduce the influence of the electromagnetic field generated by the current, the ω wood should be taken on the printed circuit board in such a way that the power supply and the ground should be as close as possible to the wiring. In addition, the area of the wiring material should be improved in the direction of widening, thickening, or class. Especially in the grounding_configuration, if the grounding, _ circuit layout lay_ not (4) causes excessive electromagnetic interference, printing circuit boards and circuit layout, will waste cost and time. ^ Therefore, how to provide a 1287415 ground wiring method for printed circuit boards on electronic devices and reduce the electromagnetic wave generated by the printed circuit board signals through parasitic inductance on the wiring has become one of the problems to be solved by researchers. SUMMARY OF THE INVENTION In view of the shortcomings of the prior art and the problems that cannot be solved, the present invention discloses a circuit board for reducing electromagnetic interference of electronic products, a ground wiring device for a printed circuit board, and a metal plate and a metal screw to replace the county. The part of the grounding wire is removed by the twisted and bent grounding wire. Therefore, the current signal can be directly returned to the negative pole of the power generator by less obstruction, and the electromagnetic wave radiated by the parasitic inductance on the circuit can also be reduced. Therefore, in order to achieve the above object, the circuit board disclosed in the present invention comprises a metal piece and a plurality of metal screws. The metal piece replaces the county transmission line grounding wire' to conduct current between the power supply and the load impedance. A plurality of metal screws 4' in addition to the U-set power supply, and the metal sheet and the fixed metal piece and the printed circuit board' have more electrical current between the conductive secret and the load-carrying impedance. The metal screw conductor is lower in inductance than the scoop transmission line I on the conventional printed circuit board, and the radiated electromagnetic interference is reduced. The features and implementations of the present invention are described in detail with reference to the preferred embodiments. 1287415 [Embodiment] Please refer to "9th> 圔J, in order to remove the layout of the original grounding wire, replace the layout of the original transmission line grounding wiring with metal plate and screw. P brush circuit board 11 contains ·· The power supply 2 has a load impedance 3, a metal piece 41, a via 71a, a via 71b, a via 71c, and a via 71d. The gold has a hole 51a, a hole 5ib, a hole 51c, and a hole 5id in the metal piece 41. In addition, the hole 52 is located on the metal piece 41. The signal source required for the sub-component of the power supply 21 is an AC signal source, and the general electrical signal is a voltage or current signal with a frequency. Wiring (trace) No. The positive pole of the power supply 21 is connected through the printed circuit board ^, the serial connection d load resistance ^ L 31, and the negative power supply 2 丨 negative does not use the printed circuit wiring, instead use a screw The magic is fixed on the metal piece 41, and the screw 62 is made of a metal material. The load impedance is 3丨, which is the negative reactance of the electronic component domain on the circuit, including the capacitor 'inductance or electric I. , such as a transistor Wire element - one or a plurality of load impedance distributions on the printed circuit board 11 'load impedance 31 — end through the decorative line on the printed circuit board u to connect the secrets 21 in series, (4) - the end is finely connected To the vias on the printed circuit board 11, there are four vias in the "second drawing", which are 1287415 vias 71a, vias 71b, vias 71c and vias 71d. If there are more electronic components, the number of vias can be increased on the printed circuit board η as appropriate. Each of the via holes corresponds to a hole in the metal piece 41 to lock the metal piece 41 and the printed circuit board n with a metal screw. Since the negative pole of the power supply 21 is fixed to the metal piece 41 via the screw 62, the load impedance 31 can form a conductive circuit 0 through the metal piece 41 and the power supply 21. The metal piece 41 is used in the "Fig. 2". A screw 62 secures the power supply 21 to the hole 52 in the metal piece 41. The metal piece 41 also has a hole 51a, a hole Hb, a hole 51c and a hole 51d. The number of holes in the metal piece 41 can be increased to the four edges of the metal piece 41 in accordance with the number of via holes on the printed circuit board 11, but any hole in the metal piece 41 must be the same as the position of the via hole on the printed circuit board u. The same size, so that the hole 51a, the hole training, the hole 51c and the hole 51d can be locked with the screw 61a, the screw 6, the screw 6ic, the screw 61d in the through hole 71a, the through hole 71b, the through hole and the through hole . In this way, the metal 41 can be tightly fixed on the printed circuit board. The metal piece is made of iron, and the metal piece 41 has no electronic components other than the power supply 21. Furthermore, the metal piece 41 has a hole 51a, a hole 51b, a hole 51C and a hole 51 (1 in the four corners of the metal piece 41, 11 1287415, the metal surface of which is a smooth plane without any hole blocking. The metal piece 41 is used instead. The original grounded transmission line causes the current signal originally transmitted back from the transmission line to be returned from the metal piece 41. Since the original winding wire is removed from the transmission line, the current dl number can be directly returned to the power source by less obstruction. The negative pole of the device will therefore reduce the loss (1 〇 ss) of the current signal in the transmission, and the conductor of the metal piece 41 is wider and thicker than the general transmission line, so the parasitic inductance on the metal piece 41 is also lowered. This also reduces electromagnetic interference (EMI) 〇 in the selection of vias 71a, vias 71b, vias 71c and vias 71d, in the design of south-speed, high-density printed circuit boards, printed circuit board vias The smaller the better, because a via is mainly composed of two parts, one is the drill hole in the middle, and the other is the pad area around the hole (not shown). The size of these two parts determines The size is obvious. In high-speed, high-density PCB design, the smaller the via, the better, so that more wiring space can be left on the board. In addition, the smaller the via, the smaller the parasitic capacitance. It is more suitable for use in a high-speed circuit. On the printed circuit board 11, the via hole 7ia, the via hole 71b, the via hole 71c, and the via hole 71d are required to pass through the hole 51a, the hole 51b, the hole 51c, and the hole 51d of the metal plate 41 through the screw. 61a, the screw 61b, the screw 61c, and the screw 61d are fixed, so the hole in the metal piece 41 also corresponds to the size of the through hole of the printed circuit board 11. The screw 61a, the screw 61b, the screw 61c, the screw 6M, and the screw 62 are all Metal material, such as iron, copper 'alloy, and other metal screws with good conductivity. The function of the screw is not only the function of fixing the power supply to the metal piece W but also the function of fixing the metal piece 41 to the printed circuit board n. The line between the impedance 31 and the power supply 21 causes the current signal returned by the load impedance 31 to pass through the gilt, _ metal piece 41, after passing through the surface of the metal piece ,, via the other metal lion and the power supply H 21 form- Flow loop. Here the junction '. is metal _ or metal sheet to connect the wide and thick conductor compared with the general transmission line, so when the metal > { 41 replace the transmission line ground formed by the general printed circuit At the time, the parasitic inductance on the device is reduced. 'Because the parasitic inductance is reduced, the radiated electromagnetic interference is reduced. And because the metal crucible is a wide-plane conductor, the current does not need to follow the previous trace, but can be the most & path. Going 'can determine the minimum negative resistance of the power generator's negative pole, reducing the secret of the current signal during transmission. ° ° a Although the embodiment of the brief description is as above, it is not used to limit Lin Mingming's any suppression technique The scope of the patent protection 1287415 of the present invention is defined by the scope of the patent application attached to the specification, without departing from the spirit and scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram of a conventional circuit; and Fig. 2 is a block diagram of the circuit of the present invention. [Main component symbol description] 10 Printed circuit board 11 Printed circuit board 20 Power supply 21 Power supply 30 Load impedance 31 Load impedance 40 Transmission line 41 Metal sheet 50 Parasitic inductance 51a Hole 51b Hole 51c Hole 51d Hole 52 Hole 14 1287415 61a Screw 61b screw 61c screw 61d screw 62 screw 71a through hole 71b through hole 71c through hole 71d through hole