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Article
Publication date: 1 January 1990

J.H. Lau, S.J. Erasmus and D.W. Rice

A review of state‐of‐the‐art technology pertinent to tape automated bonding (for fine pitch, high I/O, high performance, high yield, high volume and high reliability) is…

217

Abstract

A review of state‐of‐the‐art technology pertinent to tape automated bonding (for fine pitch, high I/O, high performance, high yield, high volume and high reliability) is presented. Emphasis is placed on a new understanding of the key elements (for example, tapes, bumps, inner lead bonding, testing and burn‐in on tape‐with‐chip, encapsulation, outer lead bonding, thermal management, reliability and rework) of this rapidly moving technology.

Details

Circuit World, vol. 16 no. 2
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 1 January 1992

J. Lau, G. Dody, W. Chen, M. McShane, D. Rice, S. Erasmus and W. Adamjee

The reliability of 0·5 mm pitch, 208‐pin FQFP solder joints has been studied by experimental temperature cycling and 3‐D nonlinear finite element analysis. Temperature cycling…

Abstract

The reliability of 0·5 mm pitch, 208‐pin FQFP solder joints has been studied by experimental temperature cycling and 3‐D nonlinear finite element analysis. Temperature cycling results have been presented as a Weibull distribution. Thermal fatigue life of the solder joints has been estimated based on the calculated plastic strain and isothermal fatigue data on solders. A correlation between the experimental and analytical results has also been made.

Details

Circuit World, vol. 18 no. 2
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 1 March 1991

J. Lau, S. Leung, R. Subrahmanyan, D. Rice, S. Erasmus and C.Y. Li

In this study, the reliability of solder joints and plated‐through hole copper pads/barrels of pin grid array assemblies under rework condition has been determined by fatigue…

Abstract

In this study, the reliability of solder joints and plated‐through hole copper pads/barrels of pin grid array assemblies under rework condition has been determined by fatigue experiments. The cross‐sections of the re‐worked PGA assemblies (before and after fatigue tests) are also provided for a better understanding of the failure mechanisms of the composite structure. Furthermore, the load‐drop curves of the PGA interconnects for up to three reworks are provided for a better estimate of their fatigue life.

Details

Circuit World, vol. 17 no. 4
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 1 April 1993

J. Lau, S. Golwalkar, P. Boysan, R. Surratt, R. Forhringer and S. Erasmus

The reliability of 0.5 mm pitch, 32‐pin thin small outline package (TSOP) solder joints has been studied by experimental temperature cycling and a cost‐effective 3‐D non‐linear…

Abstract

The reliability of 0.5 mm pitch, 32‐pin thin small outline package (TSOP) solder joints has been studied by experimental temperature cycling and a cost‐effective 3‐D non‐linear finite element analysis. Temperature cycling results have been presented as a Weibull distribution, and an acceleration factor has been established for predicting the failure rate at operating conditions. Thermal fatigue life of the corner solder joints has been estimated based on the calculated plastic strain, Coffin‐Manson law and isothermal fatigue data on solders. A correlation between the experimental and analytical results has also been made. Furthermore, failure analysis of the solder joints has been performed using scanning electron microscopy (SEM) and an optical method. Finally, a quantitative comparison between the Type‐I and Type‐II TSOP solder joints has been presented.

Details

Circuit World, vol. 20 no. 1
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 1 April 1992

J. Lau, R. Govila, C. Larner, Y.‐H. Pao, S. Erasmus, S. Dolot, M. Jalilian and M. Lancaster

Solvent‐clean and no‐clean mass reflow processes of 0.4 mm pitch, 28 mm body size, 256‐pin fine pitch quad flat packs (QFPs) are presented. Emphasis is placed on fine pitch…

Abstract

Solvent‐clean and no‐clean mass reflow processes of 0.4 mm pitch, 28 mm body size, 256‐pin fine pitch quad flat packs (QFPs) are presented. Emphasis is placed on fine pitch parameters such as printed circuit board (PCB) design, solder paste selection, stencil design, printing technology, component placement, mass reflow, cleaning and inspection. Furthermore, cross‐sections of component/PCB assemblies from both processes have been thoroughly studied using scanning electron microscopy (SEM).

Details

Circuit World, vol. 19 no. 1
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 1 July 1983

Inder Singh, P. Sabita and V.A. Altekar

Silver has been known to mankind from time immemorial. It was one of the prized possessions of kings and nobles. From earliest times, it has been known for its intimate…

Abstract

Silver has been known to mankind from time immemorial. It was one of the prized possessions of kings and nobles. From earliest times, it has been known for its intimate association with (i) monetary system, (ii) use as a silverware for household purposes and (iii) beauty and elegance when shaped into ornaments. Now, an increased understanding of the properties of silver results in its application in the rapidly developing technologies, namely communications, electronics, space explorations, etc.

Details

Anti-Corrosion Methods and Materials, vol. 30 no. 7
Type: Research Article
ISSN: 0003-5599

Article
Publication date: 1 January 1991

R.H. Rautioaho, L.P. Karjalainen and M.K. Lahdenperä

The deterioration of surface mounted solder and adhesive joints on different substrate materials under thermal cycling was investigated metallographically. Ceramic chip resistors…

Abstract

The deterioration of surface mounted solder and adhesive joints on different substrate materials under thermal cycling was investigated metallographically. Ceramic chip resistors and leadless chip carriers were soft‐soldered or glued onto alumina, FR‐4, aluminium or steel boards and the various cracking modes were observed. Fatigue cracking in the solder under the component (mode A) took place in the case of resistors on an Al substrate and carriers on all boards except alumina. Cracking on the outward surface near the upper and lower corners (mode B) occurred on all boards, but most notably on alumina. Adhesive joints seemed to offer the highest fatigue strength, but their electrical properties suffered continuously in the course of cycling even though cracking was not observed at all in many cases.

Details

Microelectronics International, vol. 8 no. 1
Type: Research Article
ISSN: 1356-5362

Article
Publication date: 1 March 1990

E.E. de Kluizenaar

In Part 1, background information on mechanical properties and metallurgy of solder alloys and soldered joints has been presented. In Part 2, mechanisms of damage and degradation…

Abstract

In Part 1, background information on mechanical properties and metallurgy of solder alloys and soldered joints has been presented. In Part 2, mechanisms of damage and degradation of components and soldered joints during soldering, transport and field life have been discussed, the most important mechanism being low cycle fatigue of the solder metal. In this third part, the determination of the fatigue life expectancy of soldered joints is discussed. Accelerated testing of fatigue is needed, as the possibilities of calculations are strongly limited. A temperature cycle test under specified conditions is proposed as a standard. A model is worked out for the determination of the acceleration factor of this test. A compilation of a number of solder fatigue test results, generated in the author's company, is presented.

Details

Soldering & Surface Mount Technology, vol. 2 no. 3
Type: Research Article
ISSN: 0954-0911

Article
Publication date: 1 February 1991

J.H. Lau

The basic equations (infinitesimal strain‐displacement relations, constitutive equation, conservation of mass, conservation of momentum, conservation of energy, rate of change of…

Abstract

The basic equations (infinitesimal strain‐displacement relations, constitutive equation, conservation of mass, conservation of momentum, conservation of energy, rate of change of entropy, heat conduction equation, and definition of specific heat) and the governing equations (coupled, coupled‐quasi‐static, uncoupled‐quasi‐static, isotropic‐uncoupled‐quasi‐static and isotropic‐uncoupled‐steady) of thermoelasticity for a linear elastic package are briefly mentioned in the present study. The assumptions and limitations of these equations are also highlighted. Furthermore, two electronic packaging examples with closed form solutions using these equations are provided.

Details

Microelectronics International, vol. 8 no. 2
Type: Research Article
ISSN: 1356-5362

Article
Publication date: 1 January 1994

J.H. Huang, J.Y. Pei, Y.Y. Qian and Y.H. Jiang

In this paper, a formula for life prediction of SMT solder joints under thermal cycling has been established on a damage model. The major failure mechanisms such as fatigue, creep…

Abstract

In this paper, a formula for life prediction of SMT solder joints under thermal cycling has been established on a damage model. The major failure mechanisms such as fatigue, creep and atmospheric oxidation have been considered in the formula. The experimental verification shows that the life formula established in this paper coincides with the experimental results.

Details

Soldering & Surface Mount Technology, vol. 6 no. 1
Type: Research Article
ISSN: 0954-0911

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