PCB Tech - Minimum solder mask sliver

Solder mask is not just about protecting your PCB; It helps to improve the accuracy and reliability of PCB assembly. Usually, the solder mask sliver has openings that expose copper pads for soldering components onto the PCB. The minimum gap or strip should be maintained between these openings to ensure the functionality and reliability of the PCB. Usually, a minimum electrode width is set to prevent issues such as solder mask sliver and core routing.

The minimum solder mask sliver width depends on the manufacturing tolerance and PCB manufacturing capability. The numerical range ranges from a few milliliters (several thousand in an inch) to tens of micrometers.

In order to ensure the normal operation of the PCB, designers need to follow the recommended electrode width, which is the minimum electrode design rule. This rule specifies the minimum width of solder mask sliver to avoid manufacturing issues.

The influence of minimum solder mask sliver error on PCB design

1) The minimum solder mask sliver error will have a significant impact on PCB design. For example, there is a problem called solder bridging. If the solder mask between two adjacent pads is too small, there is a risk that the solder may flow through the solder mask, forming a weld bridge at the top of the solder mask. This may cause short circuits, wiring or component burnout, or general circuit failures.

2) In some cases, such as through holes or surface mount components with exposed heat pads, solder can be applied along the copper core between the solder mask openings if the silver width is too small. This may lead to solder joint failure and electrical connection damage.

To alleviate the problems caused by errors in minimum solder mask sliver, design rule checks and other strategies can be considered.

1) Prototyping and testing: Consider prototyping and testing your design before mass production. In this way, the performance and reliability of PCBs can be verified in practical scenarios. Ensure that the area with very small solder mask sliver does not cause any problems during testing.

2) Component placement: Carefully check the placement of components on the PCB layout diagram. Identify areas where the welding rod does not meet the width criteria and move components or change the routing to solve the problem.

3) Design Rule Check: Most PCB design software tools have Design Rule Check (DRC), which can detect the smallest violations of welding rods. Run DRC on PCB design to identify areas where welding rods do not comply with manufacturing rules. Modify the solder mask opening or adjust the design layout to address these issues.

Solder mask sliver is one of the most important processes in the manufacturing and assembly of electronic components. The purpose of solder mask is to avoid overheating and combustion of electrical connections between components embedded in holes and circuit boards. When using metal components or circuit boards in the manufacturing process, especially when these circuits and packaging components are embedded in small holes, soldering resistance is essential.