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The purpose of this paper is to present a system for accurately measuring drilling force in the printed circuit board micro drilling process and to characterize the drilling force to provide a better understanding of the micro drilling process.

The drilling force measurement system was established first. Then the drilling force in printed circuit board micro drilling process was characterized experimentally. In particular, the drilling forces in drilling halogen‐free and lead‐free assembly compatible printed circuit boards and the drilling force characteristics in ultra small hole drilling were investigated.

A drilling force measurement system, with the key component of a KISTLER 9256C2 dynamometer, can accurately measure the drilling forces in the printed circuit board micro drilling process. The micro drilling process can be characterized by drilling force. Meanwhile, drilling force is very sensitive to drill breakage and drilling force can be utilized to detect drill breakage in the micro drilling process.

The paper presents a system for accurately measuring the drilling force. Drilling force provides fundamental information for the optimal design of micro drill bits. Drilling force can also characterize the micro drilling process, especially the ultra small hole micro drilling process.

The purpose of this paper is to study and obtain the influence of resin and filler properties of printed circuit board (PCB) on the drilling force during micro drilling.

Experiments were carried out to study the influence of PCB on micro-hole drilling force under high spindle speed. A drilling force measurement system was applied, and then, the influence of resin and filler properties of PCBs on the force was analyzed. The proportion of resin and filler in the PCB was defined as four levels, and the influence of PCBs based on the drilling force measurement was summarized.

The drilling force decreased with the decrease in the feed rate, and lower filler (16-30 per cent) and average resin (31-50 per cent) would have a positive impact on the drilling force. At the same time, the size of uniform and fine fillers would help to reduce the drilling force.

The drilling force measurement system was applied, and the influence of PCBs on force was analyzed, which could provide a reference value on the optimization of the drilling force during micro drilling.

The purpose of this paper is to present a clear picture of the challenges of micro drill bit and the developments of novel micro‐drill bits for flexible circuit boards, environmental‐friendly printed circuit boards (PCBs), high aspect ratio drill bit and ultra‐small micro drill bit, as well as the developments of geometry design of micro drill bit.

The paper details the developments trend and challenges of micro drill and PCBs first. Then the current research status of novel micro drill bits for flexible circuit boards, environmental‐friendly PCBs, high aspect ratio drill bit, ultra‐small micro drill bit are described. Finally, the developments of geometry design and drilling process are reviewed.

To achieve excellent performance for drilling flexible PCB, a large helical angle, large flute/land ratio and small web thickness that guarantee the sharp evacuation capability, are adopted in drill bit design. A small helix angle and an appropriate primary face angle are employed for drill bit to process environmental‐friendly printed circuit boards. It is beneficial to implement big helix angle, small primary face angles and small point angles in the design of ultra‐small micro drill bit. An optimum web thickness and step feed should be taken into consideration in high aspect ratio drill bits design.

The paper reviews different solutions of micro drill bits for the state‐of‐the‐art PCB and the developments of geometry design of drill bit for printed circuit boards.

The purpose of this paper is to present a robotic arm that can offer better stiffness than traditional industrial robots for improving the quality of holes in robotic drilling process.

The paper introduces a five-degree of freedom (DOF) robot, which consists of a waist, a big arm, a small arm and a wrist. The robotic wrist is composed of two DOFs of pitching and tilting. A parallelogram frame is used for robotic arms, and the arm is driven by a linear electric cylinder in the diagonal direction. Double screw nuts with preload are used in the ball screw to remove the reverse backlash. In addition, dual-motor drive is applied for each DOF in the waist and the wrist to apply anti-backlash control method for eliminating gear backlash.

The proposed robotic arm has the potential for improving robot stiffness because of its truss structure. The robot can offer better stiffness than industrial robots, which is beneficial to improve the quality of robotic drilling holes.

This paper includes the design of a five-DOF robot for robotic drilling tasks, and the stiffness modeling of the robot is presented and verified by the experiment. The robotic system can be used instead of traditional industrial robots for improving the hole quality to a certain extent.

In an integrated circuit (IC) substrate, more fillers, including talcum powder and aluminium hydroxide, are added, which leads to much higher rigidity and hardness compared with a traditional printed circuit board. However, the micro drilling of IC substrates is harder. This paper aims to test the drilling process of IC substrates to improve the drilling process and the micro hole quality.

Substrate drilling by a micro drill with 0.11-mm diameter was used under several drilling conditions. The influence of drilling conditions on the drilling process was observed. Drilling forces, drill wear and micro hole quality were also studied.

The deformation circle around holes, hole location accuracy, bugle hole and burrs were the major defects of micro holes that were observed during the drilling of the substrate. Reducing the drilling force and drill wear was the effective way to improve hole quality.

The technology and manufacturing of IC substrates has been little investigated. Research data on drilling IC substrates is lacking. The micro hole quality directly affects the reliability of IC substrates. Thus, improving the drilling technology of IC substrates is very important.

The purpose of this paper is to present a novel force sensing jig for robot-assisted drilling used to drill holes for the fastening of floating nut plates in aircraft assembly.

The paper describes the drill jig, which consists of a parallel gripper, peg-in-hole pins and a back-plate with a recess where a Polydimethylsiloxane cone is placed on top of a force sensor. As the jig approaches the part, the force sensor registers the applied force until it reaches steady state, which indicates full contact between the jig and the part. The peg-in-hole pins then lock into a pre-existing hole, which provides a mechanical reference, and the support plate provides back support during drilling.

Positional accuracy and the repeatability of the system were successfully placed within the specification for accuracy and repeatability (0.1 mm tolerance and 0.2 mm tolerance, respectively).

The drill jig can be integrated into existing robot drilling solutions and modified for specific applications. The integration of the force sensor provides data for engineers to monitor and analyze forces during drilling. The design of the force sensing drill jig is particularly suited to industrial prototype robot drilling end-effectors for small and medium manufacturers.

The key novelties of this drilling jig are in the compact assembly, modular design and inclusion of force sensing and back support features.

The purpose of this paper is to provide a method and system to achieve automated measurement of micro drill bit wear.

A method and system of automated measurement of micro drill bit wear on the basis of machine vision are presented. Experiments are conducted to verify the developed method and system.

The worn area of the primary face is an appropriate index to reflect the wear condition of a micro drill bit. A machine vision based technique is an applicable tool for capturing and characterising images of worn micro drill bit. The developed system can accurately measure and characterise the wear performance of micro drill bits with different materials and different parameter designs.

The paper highlights the method and the system for achieving automated measurement of micro drill bit wear. The developed method and system can provide fast and precise evaluation of micro drill bit wear.

Each of the four objectives can be applied within the military training environment. Military training often requires that soldiers achieve specific levels of performance or proficiency in each phase of training. For example, training courses impose entrance and graduation criteria, and awards are given for excellence in military performance. Frequently, training devices, training media, and training evaluators or observers also directly support the need to diagnose performance strengths and weaknesses. Training measures may be used as indices of performance, and to indicate the need for additional or remedial training.

The purpose of this paper is to present a method and a system for measuring drill bit temperature on‐line in the micro drilling process and to characterize drilling processes via drill bit temperature.

The drill bit temperature measurement system was first established by the utilization of an infrared camera. Then the drill bit temperature in a drilling cycle was characterized. The temperatures of an ultra‐small micro drill bit and a coated drill bit were measured and compared.

The temperature of an ultra‐small drill bit can be measured on‐line via the proposed temperature measurement system. The drilling process can be characterized by the drill bit temperature. The drill bit temperature decreased when a coated drill bit was used.

The paper highlights key points for measuring the drill bit temperature on‐line by an infrared camera and characterizes PCB drilling processes by measuring the drill bit temperature.

An investigation of drilling temperature is essential in understanding the drilling mechanism of the material, thus improving the process efficiency. The aim of this study is to experimentally investigate influences of drilling conditions such as the drilling depth, feed rate and spindle speed on the twist drill bit temperature and thrust force in the dry drilling of AISI 1040 steel material using statistical techniques.

Drill bit temperatures were measured by inserting standard thermocouples through the oil hole of TiN/TiAlN‐coated carbide drills. The settings of drilling parameters were determined by using Taguchi experimental design method. An orthogonal array, the signal‐to‐noise (S/N) ratio, and the analysis of variance (ANOVA) were employed to analyze the effect of drilling parameters. The objective was to establish a model using multiple regression analysis between spindle speed, drilling depth and feed rate with the drill bit temperature and thrust force in an AISI 1040 steel material.

Statistical results show that drill bit temperature was significantly influenced (at 95 percent confidence level) by drilling depth and spindle speed values. The spindle speed has smaller influence (7.66 percent) on the thrust force value. The feed rate has no significant influence on the drill bit temperature.

In this paper, a new experimental approach was developed to measure drill bit temperature in dry drilling process.