Recently, Jiali Innovation launched the FPC soft board technology. You must have often used FPC soft boards or DuPont lines for flexible connections between boards in the process of work and study. I believe many people have used them, but they may not necessarily design them by themselves. Pass. So what is the difference between FPC soft board design and ordinary FR-4 design? Is it difficult to learn soft board design?
In fact, the design of FPC soft board is very simple, almost the same as that of ordinary FR-4 glass fiber board, with only two slight differences. There is a Jiali Chuang FPC design learning exchange group below. If you are interested, you can join the group for exchange and learning.
(Jiali Chuang FPC Design Learning Exchange Group)
1
To add reinforcement board
While the soft board is light, thin, and flexible, it also loses its rigidity. In order to increase the thickness and rigidity of the designated parts of the product to facilitate the customer's subsequent installation or assembly, we need to paste a piece on these positions. Rigid plates, that is, reinforced plates, generally have reinforcement methods such as PI, FR-4, and steel sheets.
PI reinforcement:
It is suitable for gold finger plug-in products, and can also replace FR-4, and it is applied to the reinforcement of the plug-in hole area;
FR-4 reinforcement:
It is suitable for relatively low-end products and is not recommended (cutting is easy to burn, too thin places are easy to break, and powder falls off);
Steel sheet reinforcement:
The price is relatively high, but the flatness is good, and it will not deform. It is suitable for products that require chip placement.
How is reinforcement designed?
The three elements of reinforcement: material, thickness, and layer area need to be clearly marked. It is recommended that the reinforcement area be designed on the bottom silk screen layer, and a screenshot should be taken to explain it. When placing an order, package and upload the picture together with the board making file. Examples are as follows:
1
Non-golden finger plate reinforcement mark
It is suitable for reinforcement in non-golden finger areas, and holes and slots can be drilled on the reinforcement;
2
Gold finger plate reinforcement mark
It is suitable for the reinforcement of the gold finger area, and the total thickness of the gold finger must be marked. Generally, the reinforcement height is more than 1mm longer than the gold finger PAD;
Note: When the reinforcement information is marked in GERBER, the marked information cannot be placed on the board to prevent the engineer from missing the reinforcement, or it can be printed on the board as text.
3
Jiali Chuang EDA Professional Edition supports reinforcement design
Click the placement menu in the top menu of the PCB page to find the FPC reinforcement board option.
2
FPC jigsaw design requirements
FPC panel does not support stamp and V-CUT process, only need to design the connecting bridge.
FPC panel requirements are as follows
Panel spacing
The distance between the board and the board is generally 2mm, and the distance with steel sheet reinforcement is recommended to be 3mm;
craft edge design
(1) The width of the process side is 5mm, and all four sides must be added;
(2) Copper cladding is required on the process side, and the copper skin is more than 0.5mm away from the light spot window opening and positioning hole;
(3) Add 4 positioning holes with a diameter of 2mm on the process side, one of which needs to be staggered by 5mm to facilitate error prevention;
(4) Add 4 SMT optical points, 1mm in diameter, 3.85mm from the center of the optical point to the edge of the board, and one of them needs to be staggered by 5mm, which is convenient for error prevention;
Connection bridge length
The length of the connecting bridge is 0.7-1.0mm, and the connecting bridge in the steel sheet reinforcement area should be 1mm as much as possible, and the bridge should be increased appropriately to prevent the expansion and contraction deformation of the FPC caused by the excessive weight of the steel sheet, which will affect the subsequent SMT;
Panel size
The maximum size of the panel is 250X500mm, and the minimum size is 70*70mm;
SMT bad board optical point
For boards that need to be placed, it is necessary to add bad board optical points next to each small board. When the small board FPC production is scrapped, the board factory will blacken the corresponding optical points. After the placement machine recognizes it, it will not be printed ,save costs;
Steel reinforcement jigsaw
The distance between the steel sheet reinforcement position plate and the plate should be more than 3mm: the steel sheet area needs to be grooved around the plate with a width of 0.8mm, which is convenient for laser forming.
Jigsaw suggestions
During mass production, the board must consider the utilization rate of the board, otherwise the price will be relatively high, and the width should be designed within 120mm as much as possible. In addition, the board size with a line width of less than 3mil should not be too large. If you don't know how to design panels, you can also choose Jiali Chuang's third-party panel services.
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There are two main differences between FPC design and FR-4 design. After learning this, you can also design a FPC soft board! Wait a minute, how could Jiali's new business be so simple?
Jiali Chuang FPC launched a strong proofing special board
150 yuan/style
When the price of FPC proofing in the same industry is generally still three to five hundred, Jiali Chuang FPC is strong, and the proofing price is only 150 yuan per model if the conditions are met. The price of batch and small batch board fees is also directly reduced to 300 yuan/m², which is cheap in short! If you want to know more about FPC design learning/FPC production, you can scan the QR code of the WeChat group below and join the Jiali Chuang FPC design learning exchange group to learn more.
(Jiali Chuang FPC Design Learning Exchange Group)