FPC print tray & SMT tray

Because FPC is characterized by thin, soft, small and so on, so there are a few different things when designing compared to rigid boards:

1. Since the FPC is generally thin, in addition to the customer's request to PTH, generally do not do.

2. If the FPC has a stiffener, it is necessary to dig the groove on both the front side and the back side to ensure the flatness of the FPC during printing; If the stiffener under the components on the printing surface, the depth accuracy requirement for the groove avoidance is relatively high; If the thickness of the stiffener under the printing surface component is 0.2 mm, then the depth of the groove is required to be 0.15 - 0.2mm; if the stiffener is not directly under the printing surface component, the depth of the escaping groove may exceed the thickness of the stiffener. For example, if the thickness of the stiffener is 0.2 mm, the depth of the escape groove can be between 0.2 mm and 0.5 mm.

3. If the FPC is positioned in the shape, the size of the milling sunk area is 0.02 to 0.04mm larger than the FPC; in order to improve the production efficiency, a layer of silica paper can be affixed in the sunken plate area, so that the FPC will be relatively flat. If you want to stick silicone paper, then the depth of the sinking area should be added to the thickness of the silicone paper.

4. If the FPC is positioned by pin, then it is necessary to add a positioning base and press the pin to position the FPC on the base. The basic operation flow is: first put the tray on the base, the pin on the base will be higher than the surface of the tray, then put the FPC on the tray, you can use the pin on the base to locate the FPC, then fix the FPC on the tray with adhesive tape, remove the tray from the base, and put it on the track of the printing press to print it.

5. When designing the base, it is necessary to make 3 needles to facilitate the accurate placement of the tray into the base, and to take two handles to facilitate the removal of the tray.

To sum up: The conventional practice of FPC SMT trays in design is basically like this, and it is necessary to sum up experience in practice.