pcb design

Each day the electronic gadgets complexity increases with the miniaturization requirements, boards are becoming much denser. Multilayer PCB technology can satisfy today’s miniaturization board requirement. Multilayer PCBs has more than two layers of PCBs, arrangement of layer should be done with great care because inefficient layer arrangement will lead to the noisy board with unexpected performances. This article addresses the layer stack-up basics and the general layer stack-up considerations. 2 . Layer stack-up basics  Layer stack-up specifies the proper arrangement of circuit board layers for multilayer boards before starting board layout design.  Stack-up mainly defines which layers should be solid power and ground planes, the substrate (dielectric constant), and the spacing between layers.  While planning a layer stack-up, also compute the desired trace dimension and minimum trace spacing. SIDE VIEW    Multilayer boards ...

When you give a PCB for fabrication, you need to specify details on PCB materials, impedance controls, finish, copper thickness and so on. Most of the details are so common that they are always assumed. However still it is better to know them. Below is a screenshot of quotation submitted by a fabricator for a PCB design  Let us understand each term one by one and things related to them 1) 4 layer specifies NUMBER OF LAYERS - This means the number of conducting layers. The layers may be either routing layer or plane layer. The commonly used no. of layers are 1, 2, 4, 6, 8 and other even numbered layers. Odd number layer boards may be formed but they are not standard boards and doesn’t offer any savings. The PCB materials used for 3 or 4 layers would almost be same. Routing layers contains tracks while plane layer are generally used to connect power or ground. Plane layers have plane of copper from which connections are drawn up or down wherever needed. I...

Designing a proper stack-up is critical to achieve the lowest cost and highest reliability PCB design. This is getting increasingly more difficult as high speed digital design is getting more complex. A stack-up refers to the arrangement of the copper and insulating layers that make up a Printed Circuit Board (PCB). The stack-up must consider several job functions to ensure success. A collaborative effort between the layout, signal integrity, hardware engineer and manufacturing (fabrication/assembly) vendor is key to ensuring that all parameters are met and incorporated into the stack-up . It is critical that the stack-up is generated and agreed upon by all parties early in the design phase. This ensures that each discipline knows what the final layout will entail and prevents any issues during the critical layout phase of a design. It is strongly recommended to follow the associated Platform Design Guide (PDG) whenever possible. A collaborative effort between the layout, signal int...