Analysis of Solderless Press-Fit Interconnections During the Assembly Process

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Hironori Tohmyoh ◽  
Kiichiro Yamanobe ◽  
Masumi Saka ◽  
Jiro Utsunomiya ◽  
Takeshi Nakamura ◽  
...  
Keyword(s):  
Printed Circuit Boards ◽  
Small Scale ◽  
Assembly Process ◽  
Circuit Boards ◽  
Element Analysis ◽  
Plastic Properties ◽  
Printed Circuit ◽  
Elastic Plastic ◽  
Press Fit ◽  
The Press

This paper deals with typical mechanical problems that are encountered in a solderless press-fit assembly process. First, the elastic-plastic properties of two types of press-fit pins and the friction coefficients of the pins in thin plated through holes are determined both experimentally and by three-dimensional finite element analysis. The elastic-plastic properties of the press-fit pins are determined by small-scale testing under three-point bending. The coefficients of friction of the pins in the through holes are successfully determined from the load-displacement relationships of the pins during press-fit assembly processes. The validity of the parameters that are determined is clarified by inserting the press-fit pins into holes of different diameters. By comparing the damaged areas of the printed circuit boards after assembly and the numerically obtained stress distributions, the failure stress of the boards is determined. Finally, both the retention force of the pins and the degree of damage to the printed circuit boards after assembly are predicted by numerical analysis.

Reliability Analysis of Solderless Press-Fit Interconnections

2007 ◽  
Author(s):  
Hironori Tohmyoh ◽  
Kiichiro Yamanobe ◽  
Masumi Saka ◽  
Jiro Utsunomiya ◽  
Takeshi Nakamura ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Printed Circuit Boards ◽  
Circuit Board ◽  
Small Scale ◽  
Plastic Properties ◽  
Printed Circuit ◽  
Elastic Plastic ◽  
Press Fit ◽  
The Press ◽  
Plated Through Hole

This paper treats typical mechanical problems met in a solderless press-fit assembly. First, the elastic-plastic properties of a pin and the friction coefficient of the pin in thin plated through hole (TH) are determined by the experiments and the three-dimensional finite element (FE) analysis. The elastic-plastic properties of the press-fit pin are determined by the small scale three-point bending. The friction coefficient of the pin in the TH is successfully determined from the load-displacement relationship of the pin during press-fit assembly. The validity of the determined parameters is to be clarified by conducting the press-fit assemblies into the holes with different diameters. By comparing the damaged area of the printed circuit boards after assembly and the stress distributions obtained numerically, the failure stress of the board is determined. Finally, both the retention force of the pin and the damage of the printed circuit board after assembly become possible to be predicted by the numerical analysis.

Forced Response and Random Vibration Analysis of Printed Circuit Boards

2000 ◽  
Author(s):  
James F. Tarter
Keyword(s):  
Random Vibration ◽  
Printed Circuit Boards ◽  
Random Excitation ◽  
Forced Response ◽  
Circuit Boards ◽  
Element Analysis ◽  
Design Data ◽  
Improve Design ◽  
Printed Circuit ◽  
Contour Plots

Abstract Finite element analysis has been used in conjunction with developed algorithms to analyze forced response and random vibration response of printed circuit boards. Analytical predictions have been compared to random vibration test data for model correlation and validation of the analysis methods. The described methods provide design data for predicting deflections and G levels as a function of frequency or predicting RMS levels for random excitation. These data are utilized for initiating design changes and guiding component placement. Deflection versus frequency contributions for random excitation are analyzed to identify critical design frequencies. Forced response contour plots include effects of modal coupling, modal participation factors, and system damping. These data provide a better description of the expected operating deflection shapes man a simple mode shape. All of these methods are used to improve design integrity and ensure specification compliance prior to hardware fabrication. The analyses utilize aggregate board properties, and do not currently provide data for individual components which are installed on the board.

Stress Analysis of Printed Circuit Boards With Highly Populated Solder Joints and Components: A Micromechanics Approach

1996 ◽  
Vol 118 (2) ◽  
pp. 87-93
Author(s):  
K. X. Hu ◽  
Y. Huang ◽  
C. P. Yeh ◽  
K. W. Wyatt
Keyword(s):  
Stress Analysis ◽  
Printed Circuit Boards ◽  
Solder Joints ◽  
Effective Properties ◽  
Mechanical Analysis ◽  
Computational Effort ◽  
Circuit Boards ◽  
Element Analysis ◽  
Printed Circuit ◽  
Board Level

The single most difficult aspect for thermo-mechanical analysis at the board level lies in to an accurate accounting for interactions among boards and small features such as solder joints and secondary components. It is the large number of small features populated in a close neighborhood that proliferates the computational intensity. This paper presents an approach to stress analysis for boards with highly populated small features (solder joints, for example). To this end, a generalized self-consistent method, utilizing an energy balance framework and a three-phase composite model, is developed to obtain the effective properties at board level. The stress distribution inside joints and components are obtained through a back substitution. The solutions presented are mostly in the closed-form and require a minimum computational effort. The results obtained by present approach are compared with those by finite element analysis. The numerical calculations show that the proposed micromechanics approach can provide reasonably accurate solutions for highly populated printed circuit boards.

Research on Preparing Recycling Boards by Using Non-Metallic Materials of Obsolete Printed Circuit Boards

2013 ◽  
Vol 743 ◽  
pp. 199-202
Author(s):  
Yan Chao Zhang ◽  
Bo Liu ◽  
Wei Jing Gao ◽  
Jia Hui Zhu ◽  
Wu Biao Duan ◽  
...  
Keyword(s):  
Working Conditions ◽  
Noble Metals ◽  
Printed Circuit Boards ◽  
Hydraulic Pressure ◽  
Metallic Materials ◽  
Circuit Boards ◽  
Optimum Conditions ◽  
Printed Circuit ◽  
Pressing Time ◽  
The Press

The printed circuit boards (PCBs) are the basis of all electrical and electronic equipment (EEE) and thus are one of the most important branches of WEEE stream. Present researches mainly concentrate on the processes of reusing noble metals and copper, and a great deal of nonmetals in PCBs are disposed by combustion or filling, which may cause secondary pollution and resource-wasting. So in this paper, we study how nonmetals are used to produce recycling boards through adding different adhesives, and obtain the best formulation and working conditions. The best formulation is that the binder is Polypropylene (less than 20%), additive are methenamine (little) and stearic acid (little). Effects of working conditions on the molding results are investigated. The results show that the optimum conditions for hydraulic pressure machine are the temperatures of 160 °C, warming and pressing time of 10 minutes and the press of 30MPa.

scholarly journals Deformation and Anchoring of AA 2024-T3 rivets within thin printed circuit boards

2021 ◽  
Author(s):  
Maria Clara Farah Antunes Vilas Boas ◽  
Camila Fernanda Rodrigues ◽  
Lucian-Attila Blaga ◽  
Jorge Fernandez dos Santos ◽  
Benjamin Klusemann
Keyword(s):  
Printed Circuit Boards ◽  
Frictional Heating ◽  
Composite Plates ◽  
Single Step ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Press Fit ◽  
Aa 2024 ◽  
Mechanical Fastening ◽  
Processing Steps

This work evaluates the viability of applying Friction Riveting as an alternative for the assembly of components on printed circuit boards (PCBs). The popular press-fit technology for assembling components on PCBs consists of a pin inserted tightly into a relatively smaller hole, resulting in good electrical and mechanical properties. However, some limitations are highlighted, such as numerous processing steps and the need for predrilled holes. Friction Riveting is based on mechanical fastening and friction welding principles, where polymeric components are joined with metallic rivets through frictional heating and pressure. The main benefits of using Friction Riveting in PCBs compared with fit-press are (i) a reduced number of processing steps and (ii) shorter joining cycles, because there is no pre-drilling involved with fasteners anchored within the PCB in a single step. The joints were manufactured using 5 mm diameter AA-2024-T3 rivets and 1.5 mm thick glass-fiber-reinforced epoxy laminates (FR4-PCB). It is shown for the first time that it is possible to deform metallic rivets within thin composite plates at a reduced diameterto-thickness ratio. The feasibility study followed a one-factor-a-time approach for parameter screening and optical microscopy assessed joint formation of the deformed rivets inside the laminates through volumetric ratio (VR). The joints present significant deformation (VR=0.5) at the tip of the rivet inserted into overlapped PCBs plates, with thicknesses below 3.0 mm, which is considered the lowest achieved so far with Friction Riveting.

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