BeBoPr++ Production
2014-02-16 Initial version.
After the experience with production of the BeBoPr boards in the US, a local assembly company was searched for and found in Eindhoven. BeBoPr++ production was started there on Valentine's day 2014 as documented on this page.
The BeBoPr++ board was redesigned for a less complicated assembly process. Contrary to the original BeBoPr board that had most SMD components on the bottom side of the PCB, the BeBoPr++ has all components mounted on the top side of the board. This way the BeBoPr++ can be soldered in two passes with standard reflow and wave soldering processes.
During the first pass, all SMT components are placed and soldered to the board when it passes through the reflow oven. For the second pass all leaded components are placed on the board. The boards then travels through a second (wave soldering) oven where a wave of molten tin solders the components to the bottom side of the board.
The SMD production line: Stencil printer (left side, not on the picture), solder paste quality inspection, three pick and place machines and the reflow oven (entrance can be seen on the far right).
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Bare boards (PCBs). The black finish of the BeBoPr++ caused some problems with a sensor on the automatic feeder, so the first boards were fed manually into the stencil printer.
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A peek inside the stencil printer. This machine applies solder paste to the PCB at the locations where SMD components are placed. A metal stencil with apertures is placed on top of the PCB and the solder paste is spread over the stencil. After lifting the stencil from the PCB, the solder paste in the holes is left on the board. The amount determined by the stencil aperture size and stencil thickness.
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As the solder paste quality is a major factor in production yield, each board has its applied paste inspected. Each of the 540 pads should have the proper amount of paste applied, or the board is being rejected.
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The first pick and place machine handles the smaller components with high repeat count. Mostly decoupling capacitors, (pull-up) resistors and beads.
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The second pick and place machine does many of the remaining small components. All machines use visual inspection for component validation and orientation check. The third machine can also detect missing or bent leads for leaded parts.
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[Missing picture(s) of the third pick and place machine]
The third machine places the more complex shaped and/or larger components.
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After pick-and-placement, the boards have all components placed and are queued for a last inspection before entering the reflow oven.
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The rear side of the reflow oven. Here the completed boards arrive.
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One more board ready for THT assembly.
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And a nice batch of (SMD) completed BeBoPr++ boards.
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All Through Hole Type (THT) components (the connectors, switches, fuse and other leaded parts) are placed manually on the board. The boards are then placed into carriers that are transported through the wave soldering oven.
While being transported through the machine the board is gradually being heated and in the final section, a wave of molten solder hits the bottom of the board and attaches all components to the board.
The wave soldering oven. Boards enter at the left side.
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The right side (exit) of the oven.
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Tunnel vision: the empty oven.
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A carrier with two BeBoPrs has just passed the solder wave. See the wave soldering process on this youtube video.
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The carrier with two boards, still too hot to touch.
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The rear side of the carrier shows the neatly soldered bottom side of the boards. The yellow kapton tape keeps the solder from entering 'forbidden' areas and is removed afterwards.