PCB Boards Accommodate For Tensile Stresses
Printed circuit boards, or PCBs, are the lifeblood of modern technology. From the flashing LEDs of your cell phone to the complex processors of a laptop, they connect all the parts and components that make up an electronic device. In addition to connecting the devices, they also provide structural support for them. As the pace of technological advancement accelerated in recent decades, so did the size and sophistication of these boards.
PCBs went from being oversized and bulky, like the alarm clocks and video cassette recorders of the 1970s, to becoming small, sleek and powerful, like the personal computers and mobile MP3 players that are now commonplace. The change has meant that many more of these devices can be made in a single, compact package that’s much less likely to break from being dropped or subjected to other environmental stresses.
But as the size of these boards reduced, it became harder to modify them. In the past, simple rewiring could fix issues with these machines, but the changes required to do so now require specialized tools and expertise. The rapid development of pcb board since the end of World War II was a driving force behind this change. In the 1990s, PCBs were a key component in the explosion of smartphones, which quickly outclassed cordless antenna phones and are now used by virtually everyone. These newer devices were smaller, yet still powerful and durable enough to keep up with the demands of our hectic lifestyles.
How Do PCB Boards Accommodate For Tensile Stresses?
To accommodate these changes, the manufacturers of PCBs have had to adapt their manufacturing processes as well. A large part of this adaptation has been aimed at preventing the problems caused by warpage during the fabrication process. This problem can be the result of thermal expansion or other changes in the materials used to build the PCB. If the materials have different coefficients of expansion, this can cause the parts to separate from each other during the manufacturing process.
One way that this issue can be addressed is by ensuring that the outer layers of copper on both sides of the board are the same thickness. This ensures that the copper pouring areas are identical, which helps prevent warpage. Using the same supplier for prepregs and core sheets can also help to minimize this risk, as it helps to ensure that the materials have similar C of E values.
Another way to help avoid warpage is by ensuring that the PCBs are properly baked and dried, both before and after lamination. This will remove moisture and solidify the resin, which can prevent the board from shifting during the heating and cooling processes that occur during lamination. In addition, allowing the board to cool naturally on a marble or steel plate after hot air leveling can also reduce its chances of warping.
Another way that this problem can be avoided is by utilizing V-score panelization, which divides the PCB with V-shaped grooves. This is a more efficient method of panelization than traditional ganged cutting methods, and it’s also much less likely to create stress on the surface of the PCB that can lead to device failure.
