Microelectronics | 80386DX SBMC - OSHPark vs. JLCPCB

Synopsis

Lately I received an 80386DX SBMC PCB from a retrocomputing enthusiast. This PCB was made in China at JLCPCB. I still have a couple of bare PCBs produced at OSHPark so I decided to do a quick comparison between them.

If you are interested in the main project that spanned this PCB design, refer to the 32-bit 80386DX ISA Single Board Microcomputer article.

Unfortunately OSHPark does not offer a 1.2 mm PCB thickness option. I previously made some 30-pin SIMM PCBs but they ended up being in standard 1.6 mm thickness so they don't correctly fit the SIMM sockets. I am planning to redo them at JLCPCB but first I need to be sure they can offer a good quality service. This is where this comparison comes in handy.

Essay

The first impression that I had when I received the parcel and uncovered the PCB was that of a quality product. The PCB is a bit stiffer than the OSHPark counterpart which appears to be a bit more flexible. However without scientific data on the PCB material, this is just a supposition and I might be wrong.

By far, the best thing is that JLCPCB does clear outline router cuts on the PCBs they produce. As I'm writing this article, OSHPark doesn't have the means to industrially remove the fixture tabs. So this operation is left to the one that assembles the PCB. I don't like to manually file out the dents on the PCB edges. It is messy and if I am not careful then I can easily optically damage the PCB.

The most visible difference is when I look at the silkscreen. The OSHPark PCB has a very clean and crisp silkscreen. Even the smallest symbols are easily readable. By contrast, JLCPCB appears to use a lower quality inkjet method for laying out the silkscreen. The symbols appear choppy.

Conclusions

Hope you found this essay useful.