本文選題：PCB + 信號(hào)完整性��； 參考：《電子科技大學(xué)》2015年碩士論文

【摘要】：隨著電子技術(shù)的飛躍發(fā)展,高速系統(tǒng)的時(shí)鐘頻率不斷提高,上升時(shí)間不斷變短,印制電路板中傳輸線的性能對(duì)電子系統(tǒng)的影響越來(lái)越嚴(yán)重,印制電路板中傳輸線的信號(hào)完整性問(wèn)題變得越來(lái)越重要。在低速電路中主要起電氣連接作用的互連線在高速電路中表現(xiàn)為傳輸線,并可能導(dǎo)致在信號(hào)在正確的電氣連接情況下發(fā)生錯(cuò)誤。在這樣的情況下,通過(guò)使用仿真工具來(lái)研究信號(hào)完整性問(wèn)題是一種非常行之有效的方法,利用精確可靠的三維電磁場(chǎng)仿真,可以模擬高速電路板上的三維結(jié)構(gòu)電磁場(chǎng)效應(yīng)。HFSS軟件作為高頻結(jié)構(gòu)仿真求解器,提供了許多最先進(jìn)的求解器技術(shù),它們基于有限元、積分方程或高級(jí)混合算法,可解決非常廣泛的信號(hào)完整性問(wèn)題。傳輸線主要由銅箔和介質(zhì)材料構(gòu)成,對(duì)于銅箔,分別采用不同表面粗糙度的銅箔制作傳輸線,測(cè)出不同粗糙度傳輸線的損耗差異,與仿真的光滑傳輸線對(duì)比,得到粗糙度對(duì)信號(hào)傳輸?shù)挠绊?對(duì)于介質(zhì)材料,首先使用不同損耗因子的介質(zhì)制作傳輸線獲取其對(duì)損耗的影響,然后針對(duì)介質(zhì)中的增強(qiáng)材料玻纖布,研究它在與傳輸線不同幾何關(guān)系下對(duì)信號(hào)產(chǎn)生的影響;而介質(zhì)材料本身的介電系數(shù)和損耗因子會(huì)隨頻率的改變而發(fā)生改變,通過(guò)測(cè)量不同頻率的介電系數(shù)和損耗因子獲取它們的變化趨勢(shì)。在PCB中布線時(shí),有兩種不連續(xù)結(jié)構(gòu)不可避免,也不能被替代,那就是拐角和過(guò)孔。在高速設(shè)計(jì)中,過(guò)大的拐角會(huì)產(chǎn)生容性突變,必須對(duì)拐角外側(cè)做切角處理,減小反射,通過(guò)HFSS對(duì)不同處理方法做定量研究,確定最佳處理方式。過(guò)孔作為PCB中最常見(jiàn)的不連續(xù)結(jié)構(gòu),使用HFSS通過(guò)單因子變量法研究孔的焊盤(pán)、反焊盤(pán)、殘樁和接地孔對(duì)阻抗的影響。最后,從PCB工藝管控入手,研究PCB制造時(shí)不可避免的缺陷對(duì)信號(hào)產(chǎn)生的影響。傳輸線的線寬和介質(zhì)高度是一個(gè)管控要點(diǎn),尤其是當(dāng)線寬和介質(zhì)厚度較小時(shí),它們更容易引起傳輸線特性阻抗的改變。層間偏移在一定程度上影響信號(hào),打靶時(shí)測(cè)出層偏量,鉆孔時(shí)給一定的補(bǔ)償。阻焊層厚度很小時(shí),對(duì)阻抗產(chǎn)生很大影響,在設(shè)計(jì)時(shí)必須考慮清楚,如有需要需適當(dāng)減小線寬。
[Abstract]:With the rapid development of electronic technology, the clock frequency and rising time of high speed system are increasing, and the performance of transmission line in printed circuit board has more and more serious influence on electronic system. The signal integrity of transmission lines in printed circuit boards (PCB) is becoming more and more important. The main function of electrical connection in low speed circuits is the transmission line, which may lead to the error of the signal in the correct electrical connection. In this case, using simulation tools to study signal integrity problems is a very effective method, using accurate and reliable three-dimensional electromagnetic field simulation, HFSS software can be used as a high-frequency structure simulation solver, which provides many advanced solver techniques, which are based on finite element, integral equation or advanced hybrid algorithm. Can solve a very wide range of signal integrity problems. The transmission line is mainly composed of copper foil and dielectric material. For copper foil, copper foil with different surface roughness is used to make transmission line, and the loss difference of transmission line with different roughness is measured. The effect of roughness on signal transmission is obtained. For dielectric materials, transmission lines with different loss factors are first used to obtain their effects on loss. The influence of the dielectric coefficient and the loss factor of the dielectric material on the signal under the different geometric relation with the transmission line is studied, and the dielectric coefficient and the loss factor of the dielectric material change with the change of the frequency. The variation trend of dielectric coefficient and loss factor are obtained by measuring the dielectric coefficient and loss factor of different frequencies. In PCB wiring, two discontinuous structures are inevitable and cannot be replaced, that is, corners and holes. In the design of high speed, too large corner will produce capacitive abrupt change, it is necessary to cut the corner outside to reduce the reflection, and make quantitative research on different processing methods through HFSS to determine the best treatment method. As the most common discontinuous structure in PCB, HFSS is used to study the influence of solder pad, reverse pad, residual pile and grounding hole on the impedance by single factor variable method. Finally, starting with PCB process control, the paper studies the influence of the inevitable defects in PCB manufacturing on the signal. The line width and medium height of transmission line are a key point of control, especially when the line width and medium thickness are small, they are more likely to cause the change of transmission line characteristic impedance. The interlayer offset affects the signal to some extent, the offset of the layer is measured when shooting, and the compensation is given when drilling. The thickness of the resistance welding layer is very small, which has a great influence on the impedance, so it must be considered clearly in the design, and the line width should be reduced appropriately if necessary.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：TN41

【參考文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

1 宋雪臣;PCB工藝對(duì)射頻傳輸性能影響的研究[D];山東大學(xué);2008年

，

本文編號(hào)：1991972