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In the last decade through‐hole mounting to printed wiring boards has matured and people now have the tools to diagnose and correct any solderability problems which might arise. Such is not the case with surface mount soldering technology. In surface mount the connections are smaller and are often hidden from view. Therefore when a solderability problem does occur it may never be known until the assembly fails. The solution to the situation is to understand the nature of the problems and provide assurance that they will not occur during assembly soldering. This paper is structured in two parts. The first details the types of solderability problems unique to surface mounting. Examples of these problems will be shown and discussed with reference to solder joint life. The second part of the paper discusses the solderability testing of surface mount devices and printed wiring boards intended for surface mounting. This discussion will concentrate on the new quantitative solderability test methods being developed in this company's laboratory for leadless devices and printed wiring boards. As part of this development, new solderability criteria have been defined which reflect the unique problems associated with surface mounting.
Surface Mounting is shown to be the fourth generation of electronic interconnection technology. It has several facets and is seen differently from various viewpoints in the assembly industry. A review of published papers shows that the subject grew during the 1970s with no single inventor and as a result of numerous developments which are now combining into a coherent technology with important compatibility with other recent innovations.
A brief review is presented of the aims and activities of the trade and professional associations that offer a participation in the advancement of surface mount technology…
A brief review is presented of the aims and activities of the trade and professional associations that offer a participation in the advancement of surface mount technology. Membership fees and contact addresses are also given.
The International Electronic Components Show in Paris in November, 1983, provided the occasion for a very successful meeting of ISHM‐France which attracted 170 attendees…
The International Electronic Components Show in Paris in November, 1983, provided the occasion for a very successful meeting of ISHM‐France which attracted 170 attendees. The following presentations were given:
As guest editor, I was asked to view Surface Mount Technology (SMT) in the U.S. through the eyes of a member of the Surface Mount Council. As such, my observations are…
As guest editor, I was asked to view Surface Mount Technology (SMT) in the U.S. through the eyes of a member of the Surface Mount Council. As such, my observations are interwoven with the work of the Surface Mount Council.
Testing has become one of the dominant costs in the process of bringing a product from initial conception to the market place. Because of this, it is now imperative that…
Testing has become one of the dominant costs in the process of bringing a product from initial conception to the market place. Because of this, it is now imperative that the impact of any technology change on the test process is considered at an early stage. In this light, the increasing trend towards the use of surface‐mounting techniques in the fabrication of electronic systems is examined, with particular emphasis on the consequences on product testing during design validation, manufacture and repair. The aim is to highlight areas in which new attitudes and replacements for traditional solutions will be needed if surface‐mounting techniques are to be as cost‐effective as possible.
First, a short history of surface mount technology is given, followed by a section describing the current status of surface mount components and the impact of these on…
First, a short history of surface mount technology is given, followed by a section describing the current status of surface mount components and the impact of these on printed wiring boards. Then, two essential steps of SMT, component mounting and soldering, as practised in Japan, are discussed. The advantage of additive technology for SMT is briefly reviewed.
Alpha Metals Ltd (UK) have announced the appointment of David Crimp to the position of General Manager. Having served the company for four years as Sales Manager, Mr Crimp now assumes complete responsibility for Alpha's entire UK operation. Prior to his appointment with Alpha Metals, he was employed by AMAX in both the UK and France.
Low relative humidity (RH) effect surface mount devices in numerous ways. The smaller size (0201) capacitor and resistor start wasting when RH is low. Due to low RH…
Low relative humidity (RH) effect surface mount devices in numerous ways. The smaller size (0201) capacitor and resistor start wasting when RH is low. Due to low RH, electrostatic charges built-up on the surface of surface mount devices (SMDs) and component’s reel. The positive charged SMDs stick with the negatively charged reel tape and are wasted. This paper comprehensively explores the environmental effects on 0201 size surface mount devices during mounting process. Different type and size of surface mount devices are tested in low and desired RH to validate the effectiveness of the proposed approach. This paper will also highlight high electrostatic discharge (ESD) due to low RH which can be detrimental for small size surface mount devices. The experimental and graphical illustrations will stipulate the results of success rate for mounting components. The effect on ESD, subsequently varying temperature and humidity will also be analyzed.
In this paper, 0201 SDMs will be considered for analysis. The surface mount technology (SMT) plant temperature and humidity has been varied to examine the properties of small size SMDs. Total 5 hours production data are collected from Laptop motherboard production environment. This approach is applicable to all SMT environment.
The authors reduced the wastage of 0201 chip size resistor and capacitor. Total 11 components are selected of this size, and there success rate is observed during mounting. These components are first observed in harsh environment where the temperature is first set to 20ºC and RH is set to 25 per cent. The success rate of these components is very low due to component’s wastage. When the plant temperature is set to 25ºC and RH is set to 45 per cent, the success rate of mounting increased up to 100 per cent. A single component placement success rate with respect to RH is observed for one month. The results are shown in Table IV. It can be seen that the success rate is near 100 per cent when RH and temperature is maintained in production environment. To eliminate the ESD build-up in material and equipment in manufacturing environment humidification is a very effective way. When the RH is kept to 45 per cent, the moisture content of the air is a natural conductor and earths any ESD in environment.
Experimental data have been obtained from Laptop motherboard manufacturing process to validate the effectiveness of proposed approach.