depending on the target insertion loss you are aiming fo and the frequesncy to are going to be operating at will determine the type of material you are choosing.
As the frequency gets higher the choice of materials reduces until you reach RF frequencies with a limited choice of materials
Once I know the answers to this we can then start to discuss which materials would best suit the application
different fabricators use the same glass styles but apply different % of resin so they may use the same glass but have a 60% version and a 70% version which will press out at different thicknesses
I usually supply designers the galass and resin content but there is more to it, you need to know what the fabricators press out value is for each material and you need to calculate the resin loss due to the copper weight and copper density on the layer as well as the type of tooling on the boarders of the fabrication panel. when you know all this you can do an accurate thickness calculation for each glass style and resin content
I am co-chair of the IPC 9121 committee “Process and Fabrication Defects”
There are various reasons for this, usually its a process related defect like moisture, insufficient baking , oxide etc
A full FMEA would need to be completed at the fabricator to see where the likely defect occured, it could be material, expired, unbaked etc
If i see a picture of the delamination I can usally point engineers in the right direction as where to start looking. I just completed an investigation last month into a delam issue and it was to to an extended hold time after oxide that was the root cause.
I would need to know more about the application, is it an antenna, filter, multilayer, phased array, heat requirements, what is the operating frequency etc
When I know the answers to these questions I would have a better idea as to the types of materials
The leverage is the fact that they are flexible and can be manufactured to be hard wearing. Depending on what and where the application is going can help determine which flexible material are suitable. you need to consider intended life of the product, cost, environments etc
different fabricators use the same glass styles but apply different % of resin so they may use the same glass but have a 60% version and a 70% version which will press out at different thicknesses
I usually supply designers the glass and resin content but there is more to it, you need to know what the fabricators press out value is for each material and you need to calculate the resin loss due to the copper weight and copper density on the layer as well as the type of tooling on the boarders of the fabrication panel. when you know all this you can do an accurate thickness calculation for each glass style and resin content
So you would choose materials to meet you thickness requirements and SI requirements ie what you target impedance requirements are including line and space. The fabricator can provide you a stack-up to meet those SI requirements by selecting the materials based on your Cu weights and overall thickness