Q1. What is the recommended stencil thickness to apply the proper amount of solder for 0603 components? A1. The proper amount of solder is determined by: * Metal content of the solder paste. * Stencil thickness. * Aperture opening. * Other factors, such as stencil material, stencil opening fabrication methods, and the work place environment.
Initially, consider focusing on the relationship between the stencil thickness and the aperture opening. Search the fine SMTnet Archives for discussion on: * Aspect ratio * Area ration
Q2. How would this change the oven profile? A2. While your paste will probably be the primary driver to your oven profile, it possible for reflow profiles to affect the movement of components on pads. Consider measuring the temperature of the opposite pads of problem components. The temperatures should be very similar.
Q3. Are there any other ways to reduce the amount of solder applied? A3. See A1.
Q4. Am I looking in the right direction to solve this? A4. Good place to start. Other things to think about are: * While it is not necessary for the components to be centered on the pads, you are correct in trying to understand the causes behind this situation. * Pad design can cause components to float to one side of the pad or the other. Most component fabricators give good recommendations for pad layouts. [Additionally, the fine SMTnet Archives contain ample discussion in on the topic.]
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