Patent Application
20080223527
1. Field of the Invention
The present invention relates to a method for patterning a reel-to-reel strip in an automatic manufacturing process, and in particular to a patterning method which can prevent carbon residues and/or cut pieces from falling down.
2. The Prior Arts
A flexible printed circuit board is a substrate to mechanically support and electrically connect electronic components. A copper foil is laminated on one side or both sides of a resin substrate, and patterned by image transfer, thereby forming circuits. The circuits then electrically connect with chips or other electronic components. Chips or other electronic components then electrically connect with each other using the circuits.
In the process of the patterning, a hole, such as a blind via, a through via, or an alignment hole, is formed by mechanical drilling, laser drilling, photo via forming, plasma etching or chemical etching, etc.
The laser drilling uses CO2 mixed with other gas, such as N2, He, and CO, to emit pulsed infrared laser beam having a wavelength between 9,300 nm˜10,600 nm under increased power and maintained discharging time. However, during the laser drilling process, the resin substrate is prone to be carbonized due to the high temperature, so that carbon residues or debris will form on the surface of the flexible board or fall down through the holes.
A cleaning process removes the carbon residues and debris after repeated given periods. However, it is not feasible to remove the carbon residues and debris during the continuous automatic manufacturing process for the flexible board. Thus, Taiwan Patent Issue No. 407530, “Improved Cleaning Device for Flexible Board”, discloses a device to remove the carbon residues and debris. However, the improved cleaning device for flexible board is still unable to satisfactorily remove the carbon residues and debris completely.
In order to completely solve the problem of the carbon residues and debris, Taiwan Patent No. I249977, “Method for Manufacturing High-density Flexible Circuit Board”, uses regular etching or plasma etching to form holes. The manufacturing method does not generate high heat during the hole forming process, so that it does not generate the carbon residues and debris during the etching process. Thus, the method solves the problem of carbon residues and debris.
However, the plasma etching can only etch the resin substrate but not the copper foil. Therefore, it needs other etching processes such as chemical etching used together with the plasma etching to etch the copper foil. It is unlike the laser drilling process, which directly drills predetermined holes through the copper foil and the resin substrate, and thus make the manufacturing process more complicate.
A primary objective of the present invention is to provide a method for patterning a reel-to-reel strip in an automatic manufacturing process, which sticks carbon residues and/or cut pieces produced by laser drilling and prevents them from falling down onto and contaminating other reel-to-reel strips.
Based on the above objective, the method for patterning a reel-to-reel strip in an automatic manufacturing process in accordance with the present invention is attaching the reel-to-reel strip to a support plate having a low-tack adhesive, so that the carbon residues and the cut pieces are stuck on the support plate with the low-tack adhesive. Therefore, the carbon residues and cut pieces will not fall down to other reel-to-reel strips, and it does not need to clean the carbon residues and cut pieces.
The present invention will be apparent to those skilled in the art by reading the following detailed description of preferred embodiments thereof, with reference to the attached drawings, in which:
Referring to
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If the reel-to-reel strips 10 are the reinforcement plates or other plates, the method according to the present invention uses the laser beam to cut pieces from the reel-to-reel strip. It does not need to design and manufacture molds, so that the products can be delivered to the customers rapidly. The cost of cutting pieces using the method according to the present invention may be higher than using the molds, but it is capable of manufacturing samples rapidly and easily for the market testing. It prevents discarding or amending the molds in case the products are not accepted in the market.
Although the present invention has been described with reference to the preferred embodiments thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.
