Characterization of drill bit breakage in PCB drilling process based on high-speed video analysis

Circuit World ◽  
2017 ◽  
Vol 43 (3) ◽  
pp. 89-96 ◽  
Author(s):  
Hongyan Shi ◽  
Xiaoke Lin ◽  
Yun Wang
Keyword(s):  
Video Analysis ◽  
High Speed ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Drilling Process ◽  
Drill Bit ◽  
Content Type ◽  
High Speed Video ◽  
Micro Drill

Purpose The purposes of this paper are to study the characterization of drill bit breakage in printed circuit board (PCB) drilling process based on high-speed video analysis and to provide an important reference for micro drill bit breakage prediction. Design/methodology/approach Based on PCB drilling experiment, the high-speed camera was used to observe the micro drill breakage process and the chip removal process. The variation of chip in the drilling process was studied and one of the key reasons for the drill bit breakage was analysed. Finally, the swing angles’ feature during the breakage process of the micro drill was analysed and researched with the image processing tools of MATLAB. Findings The micro drill was prone to breakage mainly because of the blocked chips. The breakage process of the micro drill can be divided into the stage of stable chips evacuation, the stage of blocked chips and the stage of drill bit breakage. The radians of swing angles were basically in the range of ±0.01 when the drilling possess is normal. But when the radians of swing angles considerably exceeded the range of ±0.01, the micro drill bit may be fractured. Originality/value This paper presented the method to study the characterization of drill bit breakage in the PCB drilling process by using high-speed video analysis technology. Meanwhile, an effective suggestion about monitoring the radians of swing angles to predict the breakage of micro drill bit was also provided.

Experimental study on micro-drills wear during high speed of drilling IC substrate

Circuit World ◽  
2014 ◽  
Vol 40 (2) ◽  
pp. 61-70 ◽  
Author(s):  
Linfang Wang ◽  
Lijuan Zheng ◽  
Cheng yong Wang ◽  
Shan Li ◽  
Yuexian Song ◽  
...  
Keyword(s):  
High Speed ◽  
Base Material ◽  
Circuit Board ◽  
Drilling Process ◽  
Wall Roughness ◽  
Location Accuracy ◽  
Content Type ◽  
Drill Diameter ◽  
Micro Holes ◽  
Micro Drill

Purpose – Compared with the traditional printed circuit board (PCB) drilling process, the technology of drilling IC substrate is facing more problems, such as much smaller hole diameter, more intensive hole space, thinner sheet and more complicated materials are drilled in process. Moreover, the base material of IC substrate is different from traditional PCB, more kinds of fillers added in IC substrate which make the drill worn seriously during drilling process. Micro-drills wear and micro holes quality are the most important questions when drilling IC substrate so far. Wear morphology of micro-drill, holes wall roughness and hole location accuracy are researched in this paper. The influence factors of micro-drills wear and micro holes quality are also studied in this drilling process. The paper aims to discuss these issues. Design/methodology/approach – Two drills with same structure and different diameter are used to drill different stacks of IC substrate and drill different holes in this paper. There are four experiments made and the drilling parameters including spindle speed (n), feed rate (vf) and retraction speed (vr) are recommended by drill manufacturing company. Wear morphologies of drill are observed, holes wall roughness (Rmax) and holes location accuracy (Cpk) are measured in this paper. Analyzing the main factors influence on drill wear, holes wall roughness and holes location accuracy through these experiments. Findings – The micro-drills of IC substrate wear more severely compared with other material of PCB through the experimental results in this paper. Drill diameter has influence on micro-drill wear when drilling IC substrate, the smaller of drill is, the more severely of micro-drill wears. Drill diameter affect the holes wall roughness too, the holes wall roughness of larger holes is better than smaller one in a certain range. The drilled holes number also has influence on micro-drills wear, holes wall roughness and holes location accuracy. The more drilled holes, the seriously of micro-drills wear, and the worn drill would destroy the hole quality. Therefore, the more drilled holes lead the bad holes wall roughness and holes location accuracy in this paper. In addition, stacks of IC substrate affect much on the holes location accuracy, the more stacks, the worse holes location accuracy. Originality/value – Chinese Mainland is obviously lagging behind in technology and manufacturer of IC substrate which is incompatible with the nation circumstances. There is few research of drilling IC substrate in China and research data are lacking so far. It is most necessary to improve the technology level of drilling IC substrate in China. In order to reduce the wear of micro-drills and improve the quality of micro-holes, many experimental tests about drilling IC substrate are researched in this paper.

Preparation and performances of coated and aluminous entry boards with water-soluble resins for PCB drilling

Circuit World ◽  
2016 ◽  
Vol 42 (4) ◽  
pp. 153-161 ◽  
Author(s):  
Hu Zhou ◽  
Bin Yu ◽  
Ning Li ◽  
Jie Zhou ◽  
Xiaoyang Luo ◽  
...  
Keyword(s):  
Production Efficiency ◽  
Heat Dissipation ◽  
Water Solubility ◽  
Water Soluble ◽  
Circuit Board ◽  
Drilling Process ◽  
Drill Bit ◽  
Scanning Calorimetry ◽  
Location Accuracy ◽  
Content Type

Purpose This paper aims to provide a new drilling entry board for printed circuit board (PCB) process, superior in heat dissipation, lubrication, water solubility and hole location accuracy, achieving an excellent drilling process. Design/methodology/approach Using a mixture of polyethylene glycol (PEG) and water-soluble adhesives as hydrosoluble, endothermic and lubricant resins and aluminum foils as baseplates, a series of coated and aluminous entry boards (CABs) for PCB drilling was successfully prepared. The surface appearance of the entry boards was observed clearly by scanning electron microscopy (SEM). The endothermic and lubricant effects of the resins applied on the CABs was characterized by differential scanning calorimetry (DSC) and their water solubility was tested in the normal-temperature water (25°C). Moreover, the CABs’ good drilling properties were tested when they were used for PCB drilling. Findings The SEM analysis showed that the surfaces of the resin layers coated on the CABs whose coating thicknesses were less than 80 μm were smoother and flatter, which could improve hole location accuracy and reduce drill breakage ratio. By virtue of DSC, the endothermic and lubricant effects of the CABs were proven. The fusion of PEG in the resin layers could absorb the heat produced by drilling, restrain the temperature of the drill bit and hole rising and lubricate the drill bit efficiently when a hole was being drilled, which could achieve high-quality holes with good production efficiency. The water-soluble test showed that the prepared CABs had excellent water solubility at normal temperature, enabling the resin left on the hole walls and in the flute of the drill bit to be washed away easily and thereby improving the drilling efficiency and quality. The drilling tests showed that the increase in the thickness of the CABs’ coating could improve the hole location accuracy and alleviate the bit wear. In addition, the suitable coating thickness could ensure the firm adhering of the resin coating the aluminum foil, effectively avoid drill intertwist and prevent the resin debris from blocking the drilled holes on the surface of the entry board, which could hinder chip removal, resulting in poor hole wall quality and drill breakage. Originality/value This paper has a remarkably high industrial practicality in the PCB manufacture process.

Influence of Pulsed-DC Power Frequency on Mechanical Properties and High Speed Drilling Application of a-C:H:Zr-x Coatings

2011 ◽  
Vol 328-330 ◽  
pp. 861-867
Author(s):  
Wen Hsien Kao ◽  
Yan Liang Su ◽  
Sun Hui Yao ◽  
S.H. Liu
Keyword(s):  
High Speed ◽  
Printed Circuit Board ◽  
Deposition Process ◽  
Circuit Board ◽  
Hole Drilling ◽  
Closed Field ◽  
Machining Performance ◽  
Dc Power ◽  
Pulsed Dc ◽  
Micro Drill

The a-C:H:Zr-x coatings are deposited on micro-drills using a closed field unbalanced magnetron (CFUBM) sputtering system with pulsed-DC power frequencies in the range 30 kHz to 110 kHz (the x in the term a-C:H:Zr-x is the frequency varied in the deposition process). The hardness of the various coatings is systematically explored. Additionally, the machining performance of the coated micro-drills is investigated by conducting high-speed through-hole drilling tests utilizing Printed Circuit Board (PCB) specimens. The experimental results reveal that the a-C:H:Zr-70 coating has the highest hardness (42 GPa), while the a-C:H:Zr-110 coating has the lowest hardness (26 GPa). In addition, it is shown that the a-C:H:Zr-70 coating increases the life of the micro-drill by a factor of three compared to that of an uncoated micro-drill.

High speed video monitor by two-color method of laser via hole processing of printed circuit board

2018 ◽  
Vol 2018.12 (0) ◽  
pp. C10
Author(s):  
Ryuta YAMAGUCHI ◽  
Koji KANKI ◽  
Toshiki HIROGAKI ◽  
Eiichi AOYAMA ◽  
Keiji OGAWA
Keyword(s):  
High Speed ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Video Monitor ◽  
Printed Circuit ◽  
High Speed Video ◽  
Via Hole

Temperature simulation and its application in on-line temperature measurement of a micro drill bit

Circuit World ◽  
2015 ◽  
Vol 41 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Hongyan Shi ◽  
Hui Li ◽  
Shengzhi Chen
Keyword(s):  
Temperature Measurement ◽  
Temperature Drop ◽  
Infrared Camera ◽  
Simulation Software ◽  
Drilling Process ◽  
Drill Bit ◽  
Content Type ◽  
Micro Drilling ◽  
On Line ◽  
Micro Drill

Purpose – The purpose of this paper is to obtain the micro drill bit temperature field distribution in micro-drilling process and the temperature drop in retracting process with simulation software. Meanwhile, the key factors that affect the micro drill bit temperature will be obtained as well. The results can also be used to improve the accuracy in on-line drilling temperature measurement. Design/methodology/approach – The purpose of this paper is to obtain the micro drill bit temperature field distribution in micro-drilling process and the temperature drop in retracting process with simulation software. Meanwhile, the key factors that affect the micro drill bit temperature will be obtained as well. The results can also be used to improve the accuracy in on-line drilling temperature measurement. Findings – Micro drill bit high-temperature area mainly concentrates in the cutting edge and chisel edge. With the increase of spindle speed and feed speed, the micro drill bit highest temperature increased. The micro drill bit temperature drop rate reaches 20° in the micro-drilling retraction process with certain parameters. The micro drill bit highest temperature detected by an infrared camera is lower by 22° than that in real drilling. The simulation results can be used to guide the actual industrial production. Originality/value – The simulation results can be applied to revise the temperature measurement by an infrared camera in the drilling process. Drilling experiments show that the simulation method is correct and has certain practical significance. The current temperature measurement method can satisfy most of the requirements of temperature measurements.

The entry drilling process of flexible printed circuit board and its influence on hole quality

Circuit World ◽  
2015 ◽  
Vol 41 (4) ◽  
pp. 147-153 ◽  
Author(s):  
Lijuan Zheng ◽  
Chengyong Wang ◽  
Xin Zhang ◽  
Yuexian Song ◽  
Lunqiang Zhang ◽  
...  
Keyword(s):  
Printed Circuit Board ◽  
Circuit Board ◽  
Drilling Process ◽  
Hole Quality ◽  
Location Accuracy ◽  
Content Type ◽  
Printed Circuit ◽  
Flexible Printed Circuit ◽  
Micro Drilling ◽  
Micro Hole

Purpose – The purpose of this study is to present the entry drilling process of flexible printed circuit board (FPCs) and its influence on hole quality, especially hole location accuracy. Compared with the traditional PCB drilling process, the technology of drilling FPCs is facing more problems, such as hole location accuracy, smear on the hole wall surface, burned hole wall surface, etc. Moreover, the materials of FPCs are quite different from the rigid printed circuit boards (RPCs). FPCs no longer contain glass fiber cloths to reinforce resin, resulting in flexibility. Micro-hole quality is the most important issue in FPC drilling. Suggestions were given to obtain higher hole qualities and higher FPC reliability. Design/methodology/approach – The entry drilling process of FPC with different kind of entry boards was observed by a high-speed camera. The hole qualities of FPC micro-drilling, especially hole location accuracy and hole entrance quality, were measured. The relationship between entry boards and hole quality was analyzed. Findings – Significant sliding occurred when drilling FPC with using no-entry board or pure aluminum plate entry board. On the contrary, no significant sliding occurred when using LC-110 or resin-coated aluminum foil (MVC) entry boards. The type, thickness and use-pattern of entry boards influenced hole location accuracy of FPCs seriously. In addition, entry board also influenced the micro-hole entrance quality and micro-hole diameter. The entrance quality of drilling FPC with LC-110 entry board was the best. The diameter variation of drilling FPC with MVC entry board was the smallest. The hole location accuracy decreased as the thickness of entry board increased. Thus, the best use-pattern of entry board was putting a LC-110 under MVC entry board, resulting in best entrance quality and hole location accuracy. Originality/value – The technology and manufacturing of FPCs in China are obviously behind. Research of FPCs micro-drilling and research data are lacking so far. Thus, it is most necessary to improve the technology level of FPCs micro-drilling in China. Researches on hole quality, especially hole location accuracy of FPCs drilling, were performed in this paper. Suggestions were given to obtain higher hole quality of FPCs.

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