Shenzhen Jinzhou Precision Technology Corporation

Shenzhen, China

Shenzhen Jinzhou Precision Technology Corporation

Shenzhen, China
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Zheng L.J.,Guangdong University of Technology | Wang C.Y.,Guangdong University of Technology | Song Y.X.,Guangdong University of Technology | Yang L.P.,Guangdong University of Technology | And 3 more authors.
Advanced Materials Research | Year: 2011

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.


Zheng L.,Guangdong University of Technology | Wang C.,Guangdong University of Technology | Yang L.,Guangdong University of Technology | Song Y.,Guangdong University of Technology | Fu L.,Shenzhen Jinzhou Precision Technology Corporation
International Journal of Machine Tools and Manufacture | Year: 2012

In order to meet the requirements of electronic product miniaturisation, the use of thinner and smaller printed circuit boards (PCBs) will be required. To achieve this, many more micro-holes must be drilled in a smaller area than before. PCBs are anisotropic multi-material sheets consisting of a dielectric layer (resin/glass fibre cloth) and a high purity metal conductor (copper foil). It is difficult to achieve high machining precision, surface quality, drilling efficiency and long drill life when drilling PCB micro-holes. In this study, micro-drills with a diameter of 0.1 mm were used to drill the PCBs at rotational speeds of up to 300 krpm. The drilling process was digitally photographed. The chip morphology and the hole wall were observed. The quality of the hole wall, such as hole wall roughness and nail head and exit burr formation were observed and measured. The influence of drilling condition on the drilling process and hole quality were studied. It was found that the morphology of the chips and the hole wall surface depended on the material properties of the printed circuit board. Chips were formed normally as conical helical chips from the aluminium entry board, conical helical chips from the copper foil and discontinuous chips from the glass fibre and softened resin. The hole wall through the copper foil seemed much smoother than that of resin/glass fibre cloth layer. However, nail heads and burrs were formed at the copper foil layers, which decreased the hole quality. Chip morphology and hole quality were affected by feed rate, spindle speed and tool wear. The basic removal mechanism of the PCB micro-holes was analysed, and this study provided a firm foundation for further work in this area. © 2011 Elsevier Ltd. Allrightsreserved.


Zheng L.J.,Guangdong University of Technology | Wang C.Y.,Guangdong University of Technology | Fu L.Y.,Shenzhen Jinzhou Precision Technology Corporation | Yang L.P.,Guangdong University of Technology | And 2 more authors.
Journal of Materials Processing Technology | Year: 2012

In this paper, micro-drills with diameters of 0.1-0.3 mm were used to drill printed circuit boards (PCBs) with a highest spindle speed of 300 krpm. To study the wear mechanisms of PCB micro-drills, micro-drill morphology was observed, and the flank wear of the micro-drills was measured. The factors affecting flank wear were studied. In addition, hole wall roughness, nail head formation, and the accuracy of hole location were measured and analysed to determine how micro-drill wear influenced hole quality. It was found that abrasion was the main mechanism controlling the deterioration of cemented tungsten carbide micro-drills. The aggressive rubbing by glass fibre broken chips and reinforcing fillers, and the diffusion of cobalt caused abrasive wear of the flank, the chisel edge, the rake face, and the minor flank of the micro-drills. Resin that was softened by cutting heat would adhere to the micro-drills, which decreased chip removal and the accuracy of hole location. Micro-drill wear was inclined to cause nail heads and decrease the accuracy of hole location. © 2012 Elsevier B.V.


Song F.,Hans Tech | Fu L.,Shenzhen Jinzhou Precision Technology Corporation | Zhang F.,Hans Tech
Circuit World | Year: 2011

Purpose - The purpose of this paper is to present and describe a solution of aluminum substrate drilling. Design/methodology/approach - The development of LED and printed circuit board with metal substrate are reviewed first. Then the challenges of drilling metal substrate, particularly the aluminum substrate, are described. To find the solution, coated micro drill bit with optimized helix angle is developed. The performance of developed micro drill bit is examined via drilling force investigation. Finally, the drilling tests are conducted to verify the solution of aluminum substrate drilling. Findings - Coated drill bit is a very good choice to solve the problems of drilling burr and chip clogging in aluminum substrate drilling. The reason is that the drilling force can be obviously reduced by using a coated drill bit. The drill bit with medium helix angle is beneficial to prevent chip clogging. A satisfactory solution of aluminum substrate drilling can be achieved by applying coated drill bit with medium helix angle together with appropriate entry board. Originality/value - The paper presents a satisfactory solution of aluminum substrate drilling. By employing the presented solution, the problems of drilling burr and chip clogging can be avoided in aluminum substrate drilling. © 2011 Emerald Group Publishing Limited. All rights reserved.


Shi H.,Shenzhen University | Song F.,Hans Tech | Fu L.,Shenzhen Jinzhou Precision Technology Corporation
Circuit World | Year: 2011

Purpose - 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. Design/methodology/approach - 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. Findings - 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. Originality/value - 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. © Emerald Group Publishing Limited.


Fu L.,Shenzhen Jinzhou Precision Technology Corporation | Guo Q.,Shenzhen Jinzhou Precision Technology Corporation
Circuit World | Year: 2012

Purpose - 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. Design/methodology/ approach - 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. Findings - 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. Originality/value - 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. Copyright © 2012 Emerald Group Publishing Limited. All rights reserved.


Fu L.,Shenzhen Jinzhou Precision Technology Corporation | Guo Q.,Shenzhen Jinzhou Precision Technology Corporation
Circuit World | Year: 2010

Purpose - The paper aims to present key points regarding the development of an ultra-small micro drill bit for packaging substrate hole processing. Design/methodology/approach - Key points for the development of ultra-small drill bits are presented. These are based on a study of the influential mechanisms of micro drill bit material properties, key parameters and coating techniques on the behaviours of micro drill bit. Experiments were conducted to verify the drilling capability of the developed ultra-small micro drill bits. Findings - The material properties of micro drill bits are of great importance in ensuring the performance. Helix angle, primary face angle and point angle are three key parameters that significantly influence drill bit behaviour. Computer-aided engineering analysis, temperature monitoring and video monitoring techniques in high-speed drilling are useful tools for achieving the optimal design of ultra-small drill bits. Using coating technology on ultrasmall drill bits can improve their hit limits by nearly four times. Originality/value - The paper highlights key points to consider when developing ultra-small micro drill bits. The presented points can provide an overall understanding of the challenges and solutions during ultra-small micro drill bit design. Additionally, this paper presents a solution for packaging substrate ultra-small hole processing by mechanical drilling. © Emerald Group Publishing Limited.


Fu L.,Shenzhen Jinzhou Precision Technology Corporation | Li X.,Shenzhen Jinzhou Precision Technology Corporation | Guo Q.,Shenzhen Jinzhou Precision Technology Corporation
Circuit World | Year: 2010

Purpose: The purpose of this paper is to present key points relating to the development of micro drill bits with high aspect ratios and to provide a solution for high aspect ratio hole drilling. Design/methodology/approach: Based on the analysis of challenges in high aspect ratio hole drilling, key points for the development of micro drills bit with high aspect ratio are discussed. A design example of a micro drill bit with 0.3 mm diameter and a 7.2 mm flute length is presented. Experiments are conducted to verify the performance of the developed micro drill bit. Findings: Helix angle, web thickness and flute land ratio are three key parameters that significantly influence the behaviour of micro drill bits with high aspect ratios. Large helix angle, web thickness and flute land ratio are beneficial in terms of improving the performance of high aspect ratio micro drill bits. Step drilling is essential to prevent drill breakage and to ensure smooth debris evacuation. Meanwhile, proper steps and drilling parameters are of great importance to complete high aspect ratio hole drilling. Originality/value: The paper highlights key points relating to the development of micro drill bits with high aspect ratios that can provide a © Emerald Group Publishing Limited.


Patent
SHENZHEN JINZHOU PRECISION TECHNOLOGY Corporation | Date: 2014-07-17

The present invention relates to the field of manufacture of miniature drills and discloses a miniature drill, which includes a drill body, a drill tip formed at one end of the drill body, and a plurality of spiral chip slots spiraling on a surface of the drill body; the chip slots include a long chip slot, a short chip slot, and a communicating chip slot, the long chip slot and the short chip slot are arranged at intervals and have the same helix angles, and the long chip slot is communicated with the short chip slot by the communicating slot. In the miniature drill provided by the present invention, the long chip slot and the short chip slot that have the same helix angle and do not intersect are communicated with each other by the communicating slot, which effectively avoids swing of the drill tip caused by deviation of the centroid from the rotation axis and affecting the position accuracy of the drilled holes; moreover, the communicating slot broadens the widths of the chip slots, increases the chip space, and thereby improves the heat dissipating property; furthermore, the communicating slot reduces the width of the body clearance and reduces heat generated by friction between the body clearance and walls of the drilled holes, which enhances the ability of resisting breaks caused by the thermal deformation of the miniature drill.


Patent
SHENZHEN JINZHOU PRECISION TECHNOLOGY Corporation | Date: 2014-07-17

A micro-drill includes a first rake face, a first rear face, a second rake face, a second rear face, a first spiral groove extending from a drill point to a tail of the drill, a second spiral groove symmetrically arranged about the first spiral groove, and a biasing groove arranged in front of the drill point. Where the first rake face, the first rear face, the second rake face, and the second rear face are arranged on the drill point. The first spiral groove and the first rake face intersect to form a first cutting edge, and the second spiral groove and the second rake face intersect to form a second cutting edge. The biasing groove and the second rake face intersect to make a length of the second cutting edge be less than a length of the first cutting edge, and the biasing groove and the second spiral groove intersect each other.

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