This paper, which will be published in two parts in consecutive issues of Soldering & Surface Mount Technology, reproduces a chapter of the recently published book ‘Handbook of…
Abstract
This paper, which will be published in two parts in consecutive issues of Soldering & Surface Mount Technology, reproduces a chapter of the recently published book ‘Handbook of Printed Circuit Technology: New Processes, New Technologies’, edited by G. Herrmann and K. Egerer and published by Electrochemical Publications Ltd, Port Erin, Isle of Man.
This paper, which will be published in two parts in consecutive issues of Soldering & Surface Mount Technology, reproduces a chapter of the recently published book ‘Handbook of…
Abstract
This paper, which will be published in two parts in consecutive issues of Soldering & Surface Mount Technology, reproduces a chapter of the recently published book ‘Handbook of Printed Circuit Technology: New Processes, New Technologies’, edited by G. Herrmann and K. Egerer and published by Electrochemical Publications Ltd, Port Erin, Isle of Man.
The mechanical design of the automatic placement machine and the integrated application of different tools dictate the result of the placement process. The placement accuracy of…
Abstract
The mechanical design of the automatic placement machine and the integrated application of different tools dictate the result of the placement process. The placement accuracy of the system is a decisive factor for the quality and cost of the printed circuit board. Vision systems have become indispensable in today's SMD placement technology.
M & T Chemicals have announced the appointment of Mr David Smith as Director of PCB Systems and as a member of the company's Board of Management. Mr Smith, who was formerly Sales…
Abstract
M & T Chemicals have announced the appointment of Mr David Smith as Director of PCB Systems and as a member of the company's Board of Management. Mr Smith, who was formerly Sales and Marketing Director of Lea Ronal (UK) Ltd, has had more than seventeen years experience in the printed circuit industry.
Most footprints of surface mounted components have been calculated on the basis of the sizes and tolerances of their electrodes, taking into account the various inaccuracies of…
Abstract
Most footprints of surface mounted components have been calculated on the basis of the sizes and tolerances of their electrodes, taking into account the various inaccuracies of the mounting processes to be applied. The introduction of components with very small connecting areas or leads (e.g., fine pitch IC packages) does not only imply smaller solder land dimensions, but also a different approach for the calculation of the footprint. This approach tackles the question of the required insulation spacing and lead/land overlap, and the ‘optimum’ solder land dimensions and the available mounting (i.e., placing and fixing) freedom are then obtained. The reduction of mounting freedom with decreasing pitch distances is quantitatively demonstrated. The ratio width of lead/size of pitch proves to be an important parameter in this respect. Requirements for mounting quality are linked with certain criteria for inspection of soldered joints (for example, regarding shift and rotation and vice versa), and some of these criteria are discussed in more detail.