The Drilling Vibration Behavior of a Twisted Microdrill

2004 ◽  
Vol 126 (4) ◽  
pp. 719-726 ◽  
Author(s):  
Bo-Wun Huang
Keyword(s):  
Dynamic Characteristics ◽  
Printed Circuit Boards ◽  
Thrust Force ◽  
Time Dependent ◽  
Drilling Process ◽  
Improve Quality ◽  
Circuit Boards ◽  
Rotating Speed ◽  
Printed Circuit ◽  
Vibration Model

The dynamic characteristics of a microdrill in the drilling process were investigated in this study. The trend toward higher density printed circuit boards requires smaller holes, down to 0.3 mm in diameter, to be drilled through the board layers. To improve quality, produce a higher production rate, and avoid drill breakage, the dynamic characteristics of the microdrilling process must be studied. A stepped pretwisted beam is used to simulate the microdrill. A moving Winkler-Type elastic foundation is used to approximate the drilling process. A time-dependent vibration model for drilling is presented. The rotating speed, pretwisted angle, and thrust force effects of the microdrill are considered. The numerical analysis indicates that the natural frequency is reduced suddenly as the microdrill moves into a workpiece.

Dynamic characteristics of a drill in the drilling process

2003 ◽  
Vol 217 (2) ◽  
pp. 161-167 ◽  
Author(s):  
B W Huang
Keyword(s):  
Dynamic Characteristics ◽  
High Speed ◽  
Thrust Force ◽  
Time Dependent ◽  
Drilling Process ◽  
Improve Quality ◽  
Vibration Model ◽  
High Speed Drilling ◽  
Spinning Speed ◽  
Twisted Beam

The dynamic characteristics of high-speed drilling were investigated in this study. To improve quality and produce a higher production rate, the dynamic characteristics of the drilling process need to be studied. A pre-twisted beam is used to simulate the drill. The moving Winkler-type elastic foundation is used to approximate the drilling process. A time-dependent vibration model for drilling is presented. The spinning speed, pre-twisted angle and thrust force effects of the drill are considered. The numerical analysis indicates that the natural frequency is suddenly reduced as the drill moves into a workpiece.

Time-Dependent Rheological Behavior of Fluids For Electronics Packaging

2005 ◽  
Vol 127 (4) ◽  
pp. 370-374 ◽  
Author(s):  
X. B. Chen
Keyword(s):  
Rheological Behavior ◽  
Printed Circuit Boards ◽  
Flow Behavior ◽  
Electronics Packaging ◽  
Time Dependent ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Fluid Behavior ◽  
Surface Mounting

In electronics packaging, one of the key processes is dispensing fluid materials, such as adhesive, epoxy, encapsulant, onto substrates or printed circuit boards for the purpose of surface mounting or encapsulation. In order to precisely control the dispensing process, the understanding and characterization of the flow behavior of the fluid being dispensed is very important, as the behavior can have a significant influence on the dispensing process. However, this task has proven to be very challenging due to the fact that the fluids for electronics packaging usually exhibit the time-dependent rheological behavior, which has not been well defined in literature. In the paper a study on the characterization of the time-dependent rheological behavior of the fluids for electronics packaging is presented. In particular, a model is developed based on structural theory and then applied to the characterization of the decay and recovery of fluid behavior, which happen in the dispensing process due to the interruption of process. Experiments are carried out to verify the effectiveness of the model developed.

Evaluation of Backstitch Tool Path Strategy for Stability and Productivity in Micro-Drilling

2012 ◽  
Author(s):  
Jong-Seol Moon ◽  
Hae-Sung Yoon ◽  
Gyu-Bong Lee ◽  
Sung-Hoon Ahn
Keyword(s):  
Manufacturing Process ◽  
Printed Circuit Boards ◽  
Tool Path ◽  
Thrust Force ◽  
Circuit Boards ◽  
Micro Manufacturing ◽  
Printed Circuit ◽  
Duration Time ◽  
Micro Drilling ◽  
Conventional Methods

Micro-drilling with spacing intervals in the hundred micrometer range is an essential process, however suitable methods are lacking despite efforts to develop useful strategies for precision micro-drilling. For efficiency, printed circuit boards are stacked in several layers and drilled through simultaneously but the process results in misalignment of holes as observed between consecutive layers from top to bottom. The work herein proposes a new tool path strategy in comparison with conventional methods. Hole positioning, drilling thrust force, and duration time were measured and evaluated. This strategy can be utilized in micro-manufacturing process for improving machining stability and productivity.

A Review on Drilling Printed Circuit Boards

2011 ◽  
Vol 188 ◽  
pp. 441-449 ◽  
Author(s):  
L.J. Zheng ◽  
Cheng Yong Wang ◽  
Yue Xian Song ◽  
L.P. Yang ◽  
Y.P. Qu ◽  
...  
Keyword(s):  
Printed Circuit Boards ◽  
Cutting Temperature ◽  
Structure Design ◽  
Machining Process ◽  
Drilling Process ◽  
Circuit Boards ◽  
Tool Materials ◽  
Printed Circuit ◽  
Small Defect ◽  
Critical Issues

Drilling is a particularly complicated machining process, and it becomes much more complicated when the workpiece is printed circuit boards (PCBs). PCB is composite materials with anisotropy. Even a small defect in PCB may cause great losses. Both the drilling process and PCB structure design have been researched by many scholars. But the investigations into the drilling processes of PCB are not systematic. The present review article address the report about tool materials and geometrics, cutting force, cutting temperature, radial run-out and damages occurring in drilling processes. And as a conclusion, some of these critical issues are proposed to meet the challenges in analysis and optimization for PCB drilling.

Estimation of Micro-Hole Shape in Laser Direct Drilling of High Heat Radiation Typed Printed Circuit Boards (Process Monitoring with a High Speed Camera)

2014 ◽  
Vol 625 ◽  
pp. 172-177
Author(s):  
Suguru Onchi ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
Keiji Ogawa
Keyword(s):  
High Speed ◽  
Printed Circuit Boards ◽  
Drill Hole ◽  
High Heat ◽  
Heat Radiation ◽  
Drilling Process ◽  
High Speed Camera ◽  
Circuit Boards ◽  
Processing Efficiency ◽  
Printed Circuit

Recently, the development of electronic devices, such as smartphones, has meant that printed circuit boards (PCBs) have become complex multi-layer ones to provide both multiple functions and be compact. Blind via holes (BVHs) connecting the layers of the multi-layer board are processed by using a CO2 laser. The many benefits of direct processing by CO2 laser include a lower disconnect of the hole position as a result of the base drilling process in the inner layer circuit pattern. Also, efficiently dissipating heat from components improves the quality of the product as digital home appliances are increasingly compact, lightweight, and thinner. Using PCBs raises the radiation performance by the addition of alumina filler at the insulated layer. However, adding alumina filler means that laser processing is difficult, processing efficiency is reduced, and debris on the surface around the drilled hole increases. We consider what causes the changes in the processing hole by changes in the alumina filler content on the basis of data on drilling phenomena gathered with a high-speed camera. We found that the insulating layer material didn’t effect the diameter of the drill hole per laser spot diameter. The cross-section processing is done in a cone initially, and the truncated cone is then processed. And, we found that the hole depth and processing overhang was reduced, and the amount of scattering increased with the amount of alumina content filler.

Energy Analysis of Micro-drilling Process Used to Manufacture Printed Circuit Boards

2012 ◽  
pp. 305-309 ◽  
Author(s):  
Hae-Sung Yoon ◽  
Binayak Bhandari ◽  
Jong-Seol Moon ◽  
Chung-Soo Kim ◽  
Gyu-Bong Lee ◽  
...  
Keyword(s):  
Printed Circuit Boards ◽  
Energy Analysis ◽  
Drilling Process ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Micro Drilling
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