Publishing Venue
Motorola
Related People
Authors:
Henry Wandt
•
Brian Cooper
Abstract
In an effort to remain competitive in a cost driven global market, electronic equipment manufacturers have become increasingly dependent on hard automa- tion and programmable robots for the placement of leaded as well as surface mounted components. The positional tolerances inherent in the assembly process forces the designer to specify a PCB through-plated hole size which is larger than desired from a solder joint strength standpoint. The invention described herein provides a method to allow for the positional tolerances of the assembly process and still provide a solder joint which is resistant to fracturing.
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MOTOROLA INC. Technical Developments Volume 13 July 1991
SELF-LOCATING AND REINFORCED SOLDER JOINT
by Henry Wandt and Brian Cooper
In an effort to remain competitive in a cost driven global market, electronic equipment manufacturers have become increasingly dependent on hard automa- tion and programmable robots for the placement of leaded as well as surface mounted components. The positional tolerances inherent in the assembly process forces the designer to specify a PCB through-plated hole size which is larger than desired from a solder joint strength standpoint. The invention described herein provides a method to allow for the positional tolerances of the assembly process and still provide a solder joint which is resistant to fracturing.
This invention consists of a deep drawn funnel shaped eyelet with solder paste preapplied to the inte- rior. The eyelet is placed into a plated through hole in the PCB by automatic methods and the lead of the component subsequently placed through the eyelet. The funnel shape permits a less accurate initial place- ment of the lead relative to the PCB hole. The assem- bly is then soldered as any other leaded component. The final assembly has the reinforcing structure of an optimally designed solder joint without the placement difficulties associated with a tightly dimensioned clearance hole. The figure below illustrates the opera- tion of this invention.
SELF LOCATING REINFORCED SOLDER JOINT
t ComDonent lead
112 0 Motorola, I...
