DSpace community: 機械工程學系碩士在職專班

印刷電路板自動光學檢測設備設計與驗證;Design and Validation of Automated Optical Inspection System for Printed Circuit Boards

title: 印刷電路板自動光學檢測設備設計與驗證;Design and Validation of Automated Optical Inspection System for Printed Circuit Boards abstract: 本研究針對印刷電路板(PCB)製程之尺寸量測與瑕疵檢查需求，提出一套自製自動光學檢測(AOI)設備之設計與驗證流程。系統架構涵蓋花崗岩平台、焊接機架、X、Y、Z 運動模組、高倍率光學量測模組與背光模組，並以有限元素分析評估主體結構在靜態負載、慣性力與模態特性下之變形與固有頻率，以作為幾何精度與結構優化之依據。在設備組裝後，依據 ISO 230-1 與 ISO 230-2 標準，分別以花崗岩尺規、接觸式數位感測器與雷射干涉儀進行直線度與平行度等幾何精度驗證。其後利用雷射干涉儀建立軸向定位補償模型，並以玻璃光罩上的棋盤格進行座標映射，用以修正平台於全域量測範圍內之體積誤差。最終再以玻璃光罩進行定位精度與重複精度量測驗證，補償後量測結果顯示，定位精度與重複精度皆符合設計目標。另於瑕疵檢查測試中，系統亦能穩定辨識 PCB 上之特徵與缺陷，檢出能力符合預期。綜合上述結果，本研究所提出之 AOI 系統硬體設計已達成 PCB 精密量測與瑕疵檢查所需之性能，確認整體設計流程、結構分析方法與補償策略的可行性。 ;This study proposes a design and verification process of a self-developed Automated Optical Inspection (AOI) system to meet the requirements of dimensional measurement and defect detection in Printed Circuit Board (PCB) manufacturing. The system architecture comprises a granite platform, welded machine frame, X–Y–Z motion modules, a high-magnification optical measurement module, and a backlight module. Finite element analysis was employed to evaluate the structural deformation and natural frequencies of the main body under static loading, inertial forces, and modal conditions, providing a basis for geometric accuracy assessment and structural optimization. After system assembly, geometric accuracy verification was performed in accordance with ISO 230-1 and ISO 230-2, using granite rulers, a contact-type digital gauge, and a laser interferometer to assess straightness, parallelism, and other geometric errors. A positioning compensation model for each axis was subsequently established using the laser interferometer, while a chessboard pattern on a glass photomask was used to conduct coordinate mapping and correct volumetric errors across the measurement area. Finally, positioning accuracy and repeatability were validated using the same glass photomask. The compensated results demonstrated that both accuracy and repeatability met the design targets. In defect-inspection tests, the system reliably identified PCB features and defects, achieving the expected detection capability. Overall, the proposed AOI system successfully fulfills the performance requirements for precision PCB measurement and defect inspection, confirming the feasibility of the design workflow, structural analysis approach, and compensation strategies.

軸向超音波振動輔助於放電加工SKD11微孔之研究;A Study on Axial Ultrasonic Vibration-Assisted Electrical Discharge Machining of Micro Holes in SKD11

title: 軸向超音波振動輔助於放電加工SKD11微孔之研究;A Study on Axial Ultrasonic Vibration-Assisted Electrical Discharge Machining of Micro Holes in SKD11 abstract: 本研究針對熱處理後高硬度SKD11模具鋼進行放電加工，熱處理後之SKD11模具鋼具備高硬度、高強度與優異耐磨性，然而在傳統切削或研磨加工製程中，經常遭遇刀具損耗嚴重與加工效率低下的問題。放電加工(EDM)製程因不受材料硬度影響，廣泛應用於難加工材料領域。本研究進一步導入軸向超音波振動工具電極進行SKD11微孔加工之研究，採用加工參數包括超音波功率段數、脈衝休止時間、高壓電流與低壓電流，並針對加工參數對品質特性之影響進行分析，品質特性包括加工時間、微孔深度、微孔孔徑、電極損耗量與微孔側壁之表面粗糙度，並輔以掃描式電子顯微鏡(SEM)與雷射共軛焦暨白光干涉顯微鏡(LSCM)觀察微孔表面形貌。實驗結果顯示，透過軸向超音波振動輔助，能有效促進介電液循環與放電渣排除，降低加工時集中放電現象，從而增進加工效率與改善工件加工後之微孔內表面粗糙度。此外，加工參數中之高壓電流與低壓電流對加工時間、微孔孔深有顯著影響，而脈衝休止時間則對微孔內表面粗糙度亦具顯著影響。當採用本研究較佳實驗參數組合為超音波功率等級8、高壓電流2.4 A、脈衝休止時間 13 μs及低壓電流1 A時，可獲得2.14 μmRa之加工後表面粗糙度，相較於無超音波振動輔助加工時之表面粗糙度2.53 μmRa下降了15.42%，加工時間由2170秒降低至1532秒，加工效率提升了29.36%，能夠有效兼顧表面品質與加工效率。 ;This study conducted electrical discharge machining on high-hardness SKD11 mold steel. Heat-treated SKD11 mold steel is characterized by high rigidity, high strength and excellent resistance to abrasion. However, in traditional machining or grinding process, there often exist problems of serious abrasion of cutting tools and low machining efficiency. electrical discharge machining process is widely used in fields where it is difficult to machine materials because this process is not affected by rigidity of materials. This research further introduces tool electrode with axial ultrasonic vibration to study machining of SKD11 micro holes. Machining parameters adopted contain ultrasonic power level, high voltage current, pulse off time, and low voltage current. The influence of machining parameters on quality characteristic is analyzed. Quality characteristic include machining time, micro hole depth, micro hole diameter, electrode wear quantity and micro hole surface roughness. Scanning electron microscope and laser scanning confocal microscopy are adopted to observe surface appearance of micro holes. Results of experiments show that Axial Ultrasonic Vibration can effectively promote circulation of dielectric fluid and removal of discharge slag and reduce phenomenon of centralized electricity discharge during machining so as to enhance machining efficiency and micro hole surface roughness in machined workpieces. In addition, among machining parameters, high voltage current and low voltage current have outstanding effect on machining time and depth of micro holes, while pulse off time also has obvious influence on micro hole surface roughness of micro holes. Optimal experiment parameter composition of this research is ultrasonic power level 8 ,high voltage current 2.4 A, pulse off time 13 μs and low voltage current 1 A . When this composition is adopted, surface roughness after machining can reach 2.14 μmRa. Comparing with micro hole surface roughness 2.53 μmRa obtained in machining without assistance of ultrasonic vibration, micro hole surface roughness is reduced by 15.42%, machining time is decreased from 2170 seconds to 1532 seconds and machining efficiency is improved by 29.36%. This method can effectively ensure both surface quality and machining efficiency.

幾何細長與薄壁之不銹鋼分歧管精密鑄造開發---縮孔缺陷模擬驗證與鑄件變形量測分析;Investment Casting Process Development of Geometrically Slender and thin-Walled Stainless Steel Manifolds--- Simulation Verification of Shrinkage Porosity Defects and Measurement Analysis of Casting Distortion

title: 幾何細長與薄壁之不銹鋼分歧管精密鑄造開發---縮孔缺陷模擬驗證與鑄件變形量測分析;Investment Casting Process Development of Geometrically Slender and thin-Walled Stainless Steel Manifolds--- Simulation Verification of Shrinkage Porosity Defects and Measurement Analysis of Casting Distortion abstract: 本研究成功利用精密鑄造工藝做出AI伺服器液冷散熱系統的重要零件之一分歧管，該產品具高度細長比與薄壁幾何(長440*寬65*高35 mm，厚度2.5-4 mm )。原加工方式是將整塊板料加工需超過10小時，經精密鑄造做出鑄件再加工特徵只需1小時，節省90 %的加工時間，大幅提升加工效率。初期利用3D列印快速試樣得知方案可行性，試樣六種組樹方案後選出最佳方案為case 4。分歧管鑄件的主要變形Z軸方向及Y軸方向，經3D掃描比對結果顯示，case 4的Z軸方向的平均最大變形量為0.97 mm，優於case 5的3.21 mm，變形差異2.24 mm，Y軸方向平均最大變形量為0.3 mm。case 4方案的Z軸方向變形量較小，整形後的鑄件高度差優於case 5可控制在0.85 mm內，可以符合機械加工需求，並得知未來量產整型後的高度尺寸管制上限(UCL)為17.7 mm，管制下限(LCL)為16.9mm，以及控制線(CL)為17.24 mm。鑄件縮孔缺陷進行兩次改善，第一次改善縮孔比例從70 %降至45 %，第二次改善調整澆口位置及尺寸，並經加工後確認縮孔比例為0 %。觀察鑄件變形趨勢及整型後結果，以及鑄造的得料率、脫蠟殼裂狀況及縮孔改善情形，最佳方案為case 4並建議成為未來量產方案。;This study successfully applies precision investment casting to fabricate a manifold, one of the key components in an AI server liquid-cooling thermal management system. The product features a high aspect ratio and thin-walled geometry (length 440 mm, width 65 mm, height 35 mm, wall thickness 2.5–4 mm). Compared with the original process of machining the part from a solid plate, which required more than 10 h, the new route of producing a near-net-shape casting followed by local feature machining reduces machining time to 1 h, achieving a time saving of approximately 90% and significantly improving manufacturing efficiency. In the early stage, rapid prototyping by 3D printing was used to verify process feasibility, and six different tree assembly (gating) layouts were tested. Among these, case 4 was identified as the optimal scheme. 3D scanning and CAD model comparison show that the main distortion of the manifold casting occurs in the Z and Y directions. For case 4, the average maximum deformation in the Z direction is 0.97 mm, which is superior to 3.21 mm in case 5, corresponding to a difference of 2.24 mm; the average maximum deformation in the Y direction is 0.3 mm. Owing to the smaller Z-direction distortion in case 4, the height variation of the casting after straightening can be controlled within 0.85 mm, satisfying the subsequent machining requirements. Furthermore, for future mass production after straightening, the statistical process control limits of the height dimension are determined as an upper control limit (UCL) of 17.7 mm, a lower control limit (LCL) of 16.9 mm, and a center line (CL) of 17.24 mm. Shrinkage porosity in the castings was improved in two stages. The first optimization reduced the shrinkage porosity ratio from 70% to 45%. In the second optimization, by adjusting the gate positions and dimensions and confirming the internal quality after machining, the shrinkage porosity ratio was further reduced to 0%. Considering the casting distortion behavior, straightening results, casting yield, shell cracking during dewaxing, and shrinkage porosity improvement, case 4 is identified as the best scheme and is recommended as the layout for future mass production.

車用碳化矽功率模組銅燒結固晶製程對熱阻及接合強度影響;Effect of Copper Sintering Die Attach Process on Thermal Resistance and Bonding Strength of Automotive Silicon Carbide Power Modules

title: 車用碳化矽功率模組銅燒結固晶製程對熱阻及接合強度影響;Effect of Copper Sintering Die Attach Process on Thermal Resistance and Bonding Strength of Automotive Silicon Carbide Power Modules abstract: 高導熱固晶的材料與製程設計，是影響車用碳化矽功率模組熱管理及可靠性的關鍵。燒結固晶在溫度餘裕、熱膨脹係數及功率密度均較錫焊料更適合碳化矽功率模組。而平價電動車的市場趨勢，驅使著銅燒結加速製程開發及良率的提升。本研究基於前人的銅燒結三角補償理論，將既有車用牽引逆變器功率模組的銀燒結材料變更為銅燒結，並考量產能優化將燒結時間控制在180秒。因此本研究在氮化矽陶瓷基板上對碳化矽晶片進行銅燒結固晶，根據文獻以進行參數設定實驗，進而分析溫度及壓力對燒結層空洞率、熱阻(Thermal Resistance, Rth)、推力測試等性能的影響，藉此建立通用且標準化的熱管理基礎。實驗結果顯示 X-ray 或超音波掃描難以識別燒結銅燒結邊界，無法量化 void rate。溫度 260°時，15 或 20 MPa 都取得相近的Rth與推力。而維持壓力15MPa，溫度由260°C 提高到275°C 時，Rth由0.4925(°C/W) 降低到0.2860(°C/W)，推力從4.1 ± 2.73 MPa 提升為25.94 ± 4.84 MPa。銀燒結在180秒燒結時間下測得Rth 0.2485 (℃/W)，推力41.24 ± 4.28 MPa。銅燒結具備製程可行性且不須陶瓷基板鍍銀，銅膏價格是銀膏的1/3，取代銀燒結能夠使模組的材料成本降低。;High thermal conductivity die attach materials and process design are key factors affecting thermal management and reliability of automotive silicon carbide power modules. Sintered die attach offers superior temperature margin, thermal expansion coefficient, and power density compared to solder for silicon carbide power modules. The market trend toward affordable electric vehicles is driving accelerated development of copper sintering processes and yield improvement. Based on previous copper sintering triangular compensation theory, this study replaced the existing silver sintering material in automotive traction inverter power modules with copper sintering, while controlling the sintering time to 180 seconds for production capacity optimization. Therefore, this research conducted copper sintering die attach of silicon carbide chips on silicon nitride ceramic substrates. Parameter setting experiments were performed based on literature review, followed by analysis of the effects of temperature and pressure on sintering layer void rate, thermal resistance (Rth), and shear strength, thereby establishing a universal and standardized thermal management foundation. Experimental results showed that X-ray or ultrasonic canning had difficulty identifying the copper sintering area boundary, making void rate quantification impossible. At 260°C, both 15 MPa and 20 MPa achieved similar thermal resistance and shear strength. When maintaining 15 MPa pressure and increasing temperature from 260°C to 275°C, Rth decreased from 0.4925 (°C/W) to 0.2860 (°C/W), and shear strength improved from 4.1 ± 2.73 MPa to 25.94 ± 4.84 MPa. Silver sintering measured Rth of 0.2485 (°C/W) and shear strength of 41.24 ± 4.28 MPa under 180 second sintering time. Copper sintering demonstrates process feasibility without requiring silver plating on ceramic substrates. The copper paste price is one-third that of silver paste, enabling material cost reduction for modules when replacing silver sintering.