This paper presents the requirements for infra‐red soldering machines for reflow soldering of printed boards with components for surface mounting. Guidelines for…
This paper presents the requirements for infra‐red soldering machines for reflow soldering of printed boards with components for surface mounting. Guidelines for controlling and adjusting the infra‐red reflow soldering process, as well as a computer model to help the user of infra‐red reflow systems to adjust an infra‐red oven, are provided. In specifying the various process conditions, the authors have considered that a careful adjustment of the process parameters will improve the soldering quality.
Highlights the lack of detailed published information on the use of infra‐red heating in food processing in the UK. Provides a number of answers based on conclusions from a recent seminar. These are a reluctance of users to reveal information to their competitors of where it is used, perceived technical problems (some infra‐red heaters contain glass) and fears on energy costs which restrict its wider use and lack of knowledge of the technology by food processing plant manufacturers. Discusses the attributes of infra‐red heating and gives some examples of its use (not all in the UK) for food processing.
The use of infra red radiant heat equipment has extended in recent years to most industries, including the lubricating oil industry. Not only is this equipment valuable…
The use of infra red radiant heat equipment has extended in recent years to most industries, including the lubricating oil industry. Not only is this equipment valuable for the stoving and drying of new and reconditioned oil barrels, but a still more modern adaption is to assist the emptying of grease kegs and oil barrels. Our readers in the oil industry will quickly appreciate the importance and value of infra red units, but users of lubricants, who may not be already conversant with these methods will probably observe its possibilities within their own industries.
Infra‐red ovens and furnaces have been in use in the microelectronics industry for a long time, but recent design advancements and process developments have provided the…
Infra‐red ovens and furnaces have been in use in the microelectronics industry for a long time, but recent design advancements and process developments have provided the precise furnace control dictated by surface mount technology. This paper addresses the process implemented by state‐of‐the‐art infra‐red equipment and the impact which that technology has on the surface mount industry. The temperature cycles that current infra‐red equipment utilises to reflow surface mount devices differ from the competing technologies in several distinct areas. Infra‐red equipment provides controlled preheat rates in the critical initial heating stages, followed by temperature equilibration and final reflow. The radiative and other processes involved in the preheat of product are discussed, with particular attention paid to the removal of volatile organics from the solder paste and the stress induced on all elements of the assembly. The control of temperature uniformity is discussed, and the effects of geometry, thermal complexity, and absorptivity are examined with reference to heat transfer theory. The ability of infra‐red equipment to provide close control of the ambient atmosphere during reflow cycles is outlined. Control of the atmosphere can benefit process control, reliability, and cosmetics. Inert atmospheres, such as pure nitrogen, can provide faster processing, more rapid and easier cleaning of fluxes, better solderability of secondary joints, and better cosmetics for the assembly. The inclusion of small amounts of hydrogen in the ambient can induce changes in the contact angle of the flux to polymers and ceramics, providing benefits for other process considerations, such as component shifting, solder balling and flux removal.
Contrary to popular stories put about during World War II, man's ability to see better in the black‐out was not helped by eating carrots. But it was at this time that scientists in both Britain and Germany fought a one‐upmanship battle to produce equipment capable of spotting the enemy in darkness.
PHOTOGRAPHIC details of various aircraft and missiles recently released in conjunction with the Soviet air show at Tushino Airport on July 9, 1961, has provided a basis…
PHOTOGRAPHIC details of various aircraft and missiles recently released in conjunction with the Soviet air show at Tushino Airport on July 9, 1961, has provided a basis for the start of an evaluation of Soviet air‐to‐air rocket weapons. These pictorial data, coupled with Russian textbooks, as well as evidence of Soviet interest in the guided‐missile work of the Western Powers, indicated by the material that has been translated from English into Russian,1 has led to this brief evaluation of their work in this field.
To investigate the effects of the infra‐red power level on sintering behaviour in the high speed sintering (HSS) process.
Single‐layer parts were produced using the HSS process, in order to determine the effect of the infra‐red power level on the maximum achievable layer thickness, and the degree of sintering. The parts were examined using both optical microscopy and contact methods.
It was initially expected that an increase in the infra‐red lamp powder might allow an increase in the depth of sintering that could be achieved, as a result of increased thermal transfer through the powder. However, results in fact indicated that there is a maximum layer thickness that can be achieved, as a result of part shrinkage in the z direction. Optical microscopy images have shown that a greater degree of sintering occurs at higher power levels, which would be expected to correspond to an improvement in the mechanical properties of the parts produced. These images also indicate that the radiation absorbing material forms in small “islands” on the powder bed surface. As sintering progresses, these islands begin to merge; this occurs to a greater extent at higher infra‐red lamp powers.
These results are based only on single layer parts. Further work will examine the sintering characteristics of multiple layer parts.
Results have shown that, whilst it is not possible to increase the achievable layer thickness of the parts produced by modifying the infra‐red lamp power, the degree of sintering can be improved greatly by increasing the power.
HSS is an entirely new process which is currently still under development; the results presented here will directly impact the direction of further development and research into this process.
This article describes the move towards integrated coating systems, where the coating and method of drying or curing are selected to ensure efficient coating processes…
This article describes the move towards integrated coating systems, where the coating and method of drying or curing are selected to ensure efficient coating processes, while ensuring there is no reduction in the function of the coating itself. It briefly explores various methods of radiation curing and explains how these techniques can be used to meet production requirements and constraints and develop optimum coating solutions. There is also a brief case study, which describes the installation of an infra‐red system for pre‐heating steel drums in order to speed up a lacquering operation.
Slough based Spectral Technology Ltd is the world's largest manufacturer of accelerated drying equipment, and along with its lamp manufacturing subsidiary Primarc Ltd has been involved in the development of UV and drying technology since the 1970's. The Group manufactures products employed for the drying and curing of inks and other surface coatings in the widest range of applications: from printing to wood finishing and printed circuit boards.