In this thesis, the characteristics of the stripline are studied in PCB (printed circuit board) designed with mSAP (modified Semi-Additive Process). The new mSAP technology can reduce stripline width and spacing compared to conventional subtractive processes. And it can design more circuits per unit...
In this thesis, the characteristics of the stripline are studied in PCB (printed circuit board) designed with mSAP (modified Semi-Additive Process). The new mSAP technology can reduce stripline width and spacing compared to conventional subtractive processes. And it can design more circuits per unit area and reduce PCB size. The mSAP technology used in IC substrate fabrication is an additive process and it is completely contrary to the conventional PCB fabrication process. So, manufactured stripline shape and characteristics have been changed significantly. The level and causes of characteristics change are studied and design guides are required. The striplines of both manufacturing processes are designed in different layers of the same PCB. The characteristics of the manufactured striplines are compared up to the 30 GHz band. To compare characteristics of pure striplines, two-tier calibration based on de-embedding technology has been studied and designed. The characteristic impedance, insertion loss and the crosstalk of adjacent striplines are measured. The causes of the measured characteristics change are analyzed by cross-section, theory of stripline and full-wave simulation. The shape of stripline manufactured in mSAP has been close to a rectangle unlike trapezoid of subtractive process, and the conductor roughness has been improved by 50%. The conductor roughness values are analyzed using the statistical definition in the PCB industry. The difference of conductor roughness is due to the different thickness of the seed copper layer between two fabrication processes. In the characteristic impedance, the subtractive process has a difference of 8.7 Ω between design target and experimental measurement, while the mSAP has just difference of 2.6 Ω. Despite the finer stripline width, the rectangular conductor shape and lower conductor roughness reduce the difference between the design target and the measurement. The insertion loss has improved 0.26 dB/cm at 30 GHz compared to conventional subtractive process. It is proved by simulation that lower insertion loss of mSAP is mainly due to improved conductor roughness At the minimum spacing of adjacent lines, crosstalk degradation is inevitable, but far-end crosstalk at high frequency over 2.5 GHz degrades just under 3.1 dB. It is not large in practical circuits design. However, in low frequency designs, the design of the guard traces or wider spacing between the striplines must be considered. And it has been analyzed by the experiment that the cause of crosstalk degradation is not only the narrower spacing between the adjacent striplines but the rectangular conductor shape and improved conductor roughness. In addition, a guard trace between adjacent striplines is studied. The far-end crosstalk has been compared while widening step by step the spacing between adjacent striplines without guard traces. The FEXT of striplines with a guard trace is similar to that of adjacent striplines with 150 μm spacing. Comparing the design area, it is more space-efficient to design the 150 μm spacing than a guard trace. In full wave simulation, ERD (effective roughness dielectric) design has been adapted to improve accuracy. It is especially useful to design of stripline because it can design different roughness of oxide and foil side. The accurate ERD information has been guided for conductor roughness of each process. And the manufacturing tolerance has been corrected and insertion losses of ideal design are compared. As a result, design of mSAP can maximize stripline density and reduces the PCB design area. At high frequencies design, it can design stricter characteristic impedance and reduce insertion loss. The mSAP will be an essential PCB manufacturing process.
In this thesis, the characteristics of the stripline are studied in PCB (printed circuit board) designed with mSAP (modified Semi-Additive Process). The new mSAP technology can reduce stripline width and spacing compared to conventional subtractive processes. And it can design more circuits per unit area and reduce PCB size. The mSAP technology used in IC substrate fabrication is an additive process and it is completely contrary to the conventional PCB fabrication process. So, manufactured stripline shape and characteristics have been changed significantly. The level and causes of characteristics change are studied and design guides are required. The striplines of both manufacturing processes are designed in different layers of the same PCB. The characteristics of the manufactured striplines are compared up to the 30 GHz band. To compare characteristics of pure striplines, two-tier calibration based on de-embedding technology has been studied and designed. The characteristic impedance, insertion loss and the crosstalk of adjacent striplines are measured. The causes of the measured characteristics change are analyzed by cross-section, theory of stripline and full-wave simulation. The shape of stripline manufactured in mSAP has been close to a rectangle unlike trapezoid of subtractive process, and the conductor roughness has been improved by 50%. The conductor roughness values are analyzed using the statistical definition in the PCB industry. The difference of conductor roughness is due to the different thickness of the seed copper layer between two fabrication processes. In the characteristic impedance, the subtractive process has a difference of 8.7 Ω between design target and experimental measurement, while the mSAP has just difference of 2.6 Ω. Despite the finer stripline width, the rectangular conductor shape and lower conductor roughness reduce the difference between the design target and the measurement. The insertion loss has improved 0.26 dB/cm at 30 GHz compared to conventional subtractive process. It is proved by simulation that lower insertion loss of mSAP is mainly due to improved conductor roughness At the minimum spacing of adjacent lines, crosstalk degradation is inevitable, but far-end crosstalk at high frequency over 2.5 GHz degrades just under 3.1 dB. It is not large in practical circuits design. However, in low frequency designs, the design of the guard traces or wider spacing between the striplines must be considered. And it has been analyzed by the experiment that the cause of crosstalk degradation is not only the narrower spacing between the adjacent striplines but the rectangular conductor shape and improved conductor roughness. In addition, a guard trace between adjacent striplines is studied. The far-end crosstalk has been compared while widening step by step the spacing between adjacent striplines without guard traces. The FEXT of striplines with a guard trace is similar to that of adjacent striplines with 150 μm spacing. Comparing the design area, it is more space-efficient to design the 150 μm spacing than a guard trace. In full wave simulation, ERD (effective roughness dielectric) design has been adapted to improve accuracy. It is especially useful to design of stripline because it can design different roughness of oxide and foil side. The accurate ERD information has been guided for conductor roughness of each process. And the manufacturing tolerance has been corrected and insertion losses of ideal design are compared. As a result, design of mSAP can maximize stripline density and reduces the PCB design area. At high frequencies design, it can design stricter characteristic impedance and reduce insertion loss. The mSAP will be an essential PCB manufacturing process.
주제어
#특성 임피던스 삽입손실 누화 가드 트레이스 mSAP SLP Subtractive process Characteristic impedance Insertion loss Crosstalk Guard trace
학위논문 정보
저자
김재훈
학위수여기관
Graduate School, Yonsei University
학위구분
국내석사
학과
Department of Electrical and Electronic Engineering
지도교수
Jong-Gwan Yook
발행연도
2019
총페이지
xi, 73장
키워드
특성 임피던스 삽입손실 누화 가드 트레이스 mSAP SLP Subtractive process Characteristic impedance Insertion loss Crosstalk Guard trace
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