Method for manufacturing flexible printed circuit boards

1. A method for manufacturing flexible printed circuit boards, the method comprising:

providing a tape substrate having an electrically insulating layer and an electrically conducting layer;

forming a plurality of flexible printed circuit boards in the tape substrate;

attaching a continuous back film on a surface of the tape substrate; and

cutting the tape substrate to separate the plurality of flexible printed circuit boards, each of the separated flexible printed circuit boards being attached on a same surface of the continuous back film.

2. The method as claimed in claim 1 , wherein the continuous back film is pressed on the surface of the electrically insulating layer.

3. The method as claimed in claim 1 , wherein the continuous back film is pressed on a surface of the tape substrate on which the plurality of flexible printed circuit boards is formed.

4. The method as claimed in claim 1 , wherein a thickness of the electrically conducting layer is in the range from 5 micrometers to 50 micrometers.

5. The method as claimed in claim 1 , wherein the continuous back film is made of polyimide, polyethylene terephalate, liquid crystal polymer or Teflon.

6. The method as claimed in claim 1 , wherein a thickness of the continuous back film is 75 micrometers.

7. The method as claimed in claim 1 , wherein the continuous back film is attached on the electrically insulating layer of the tape substrate.

8. The method as claimed in claim 1 , wherein the continuous back film is attached on the electrically conducting layer with the plurality of flexible printed circuit boards formed thereat.

9. The method as claimed in claim 8 , wherein the tape substrate further comprises another electrically conducting layer cooperating with the electrically conducting layer to sandwich the electrically insulating layer therebetween, and the method further comprises forming another plurality of flexible printed circuit boards at the another electrically conducting layer.

10. The method as claimed in claim 9 , further comprising:

attaching another continuous back film on the another electrically conducting layer before forming the plurality of flexible printed circuit boards at the electrically conducting layer; and

removing the another continuous back film before forming the another plurality of flexible printed circuit boards at the another electrically conducting layer.

11. A method fix manufacturing flexible printed circuit boards, said method comprising the following steps:

providing a substrate comprising an electrically insulating layer and an electrically conducting layer;

transferring the substrate between a pair of reels and attaching a continuous back film on the substrate when the substrate is transferred;

transferring the substrate with the continuous back film attached thereon using a roll-to-roll system and forming a plurality of flexible printed circuit boards in the tape substrate when the substrate is transferred; and

cutting the substrate to separate the flexible printed circuit boards, each of separated flexible printed circuit boards being attached on a same surface of the continuous back film.

12. The method as claimed in claim 11 , wherein the substrate is cut via a die.

13. The method as claimed in claim 11 , wherein leavings formed in the cutting process are adhered to the back film.

14. The method as claimed in claim 13 , further comprising a step of removing the leavings from the back film.

15. The method as claimed in claim 11 , wherein the back film is pressed to the substrate via another pair of rolls which presses the back film to the substrate when the back film and the substrate pass through a clearance formed therebetween.

16. The method as claimed in claim 15 , wherein the back film and the substrate are wrapped around two different reels before they are pressed together and wrapped around one reel after they are pressed together.

17. A method for manufacturing flexible printed circuit boards, said method comprising the following steps:

providing a substrate comprising an electrically insulating layer and an electrically conducting layer;

transferring the substrate between a pair of reels and forming a plurality of flexible printed circuit boards in the substrate when the substrate is transferred;

transferring the substrate having the plurality of flexible printed circuit boards using a roll-to-roll system and attaching a continuous back film on the electrically insulating layer of the substrate when the substrate is transferred; and cutting the substrate to separate the flexible printed circuit boards, each of separated flexible printed circuit boards being attached on a same surface of the continuous back film.

18. The method as claimed in claim 1 , wherein the tape substrate is provided via a reel.

19. The method as claimed in claim 1 , wherein the tape substrate is transferred between a pair of reels during formation of the plurality of flexible printed circuit boards in the tape substrate.

20. The method as claimed in claim 1 , wherein the tape substrate with the continuous back film formed thereon is transferred using a roll-to-roll system.