A friend asked Xiaobian, in the process of producing FPC, whether we are single-chip production or mass production. Here Xiaobian will talk about it in detail through the actual experience of the factory.
In the production process of FPC, in order to save cost, improve production efficiency and shorten production cycle, imposition is always adopted instead of monolithic production. When making up FPC, we need to follow several principles.
1. On the premise that each process can be produced, make-up should be “crowded” as far as possible. The so-called “squeezing” means narrowing the distance between adjacent plates, thus reducing the size of the whole imposition, saving production materials and reducing production costs.
2. The spacing between single boards shall be at least greater than 2.5mm. First of all, this is to meet the demand of positioning holes. In the process of mass production, molding is generally done by stamping. In order to enhance the accuracy of stamping, positioning holes need to be placed between each piece in the layout, so as to avoid the offset of stamping, resulting in the rejection of FPC; In the process of sample production, laser cutting and molding are generally used. In order to avoid micro-deviation, and to prevent the occurrence of one partial deviation and the whole partial deviation, single pieces cannot be directly connected, so that they will not affect each other.
3. Etched characters should be added to the imposition, and the size and quantity of the imposition should be simply explained, so as to facilitate the check and verification in subsequent production.
4. Locating holes are added to the four corners of the whole imposition, and different locating holes are marked in one corner, which is convenient to keep the same direction in the production of subsequent processes, so as not to cause the sealing film to be pasted back and the characters to be printed back.
5. The imposition width is fixed to 250mm, and the length is within 250mm as much as possible. The bigger the layout size, the bigger the offset, the worse the production accuracy and the higher the defective rate of finished products.
Knowing the five principles of imposition, this paper briefly introduces three ways of imposition.
1. General imposition. Arranging imposition directly in the direction of a single chip is most suitable for FPC imposition with regular appearance, such as rectangle, square, circle, ellipse, etc.
2, oblique spelling. Tilt the single piece to a certain extent, and then array it, so as to maximize the use of the imposition space, such as curved strips, folds, etc.
3, reverse buckle spell. That is, a single PCS is combined with one positive and one negative to form a puzzle.
All make-up methods, on the premise of production, follow the principle of saving the most materials.