An FPC structure for checking ink exposure offset

Abstract

The utility model discloses a kind of FPC structures for testing ink exposure deviation, including FPC female plate, at least two opposite corners of FPC female plate are respectively provided with etching pad, the outer surface of etching pad is covered with the printing ink layer that can be photoetching developed, ink window is provided in printing ink layer, the inner edge of ink window and the outer edge of etching pad are set with spacing each other, so it can effectively and quickly identify whether the resistance welding ink is too large when exposure alignment deviation.

Description

Technical Field

[0001] This utility model relates to the field of FPC production technology, and in particular to an FPC structure for inspecting ink exposure misalignment. Background Technology

[0002] FPC, short for Flexible Printed Circuit Board, is a printed circuit made of a flexible insulating substrate. Generally, copper foil is first placed on a polyimide substrate, and then patterned copper lines are etched on it using a photolithography process. Solder resist ink is then applied to the outer surface of the copper lines to protect them. However, due to misalignment of the solder resist ink during exposure, the solder resist ink may cover part of the copper lines, resulting in poor electrical properties. Utility Model Content

[0003] To address the aforementioned problems, this invention provides an FPC structure for detecting ink exposure misalignment, which can effectively and quickly identify whether the printing ink (such as solder resist ink) has excessive deviation during exposure alignment.

[0004] To achieve the above objectives, the technical solution provided by this utility model is as follows: This utility model provides an FPC structure for inspecting ink exposure misalignment, including an FPC motherboard, wherein etched pads are respectively provided at at least two opposite corners of the FPC motherboard, the outer surface of the etched pads is covered with a photolithographically developable printing ink layer, and ink windows are provided in the printing ink layer, wherein the inner edge of the ink windows and the outer edge of the etched pads are spaced apart from each other.

[0005] Furthermore, both the etched pads and the ink openings are square.

[0006] Furthermore, the area of ​​the ink window is larger than the area of ​​the etched pad.

[0007] Furthermore, the standard distance between the four outer edges of the etched pad and the inner edge of the corresponding ink opening is 0.05 mm.

[0008] Furthermore, the printed ink layer is a photosensitive solder resist ink layer.

[0009] The technical solution provided by this utility model has the following beneficial effects: By setting the inner edge of the ink window and the outer edge of the etched pad at a distance from each other, the inspector can visually identify whether the etched pad is covered by the printing ink, thereby effectively and quickly identifying whether the printing ink deviates too much during exposure alignment. Attached Figure Description

[0010] Figure 1 The diagram shown is a schematic diagram of one corner of the FPC motherboard when it is in normal alignment and has zero deviation in the embodiment. Figure 2 The diagram shown is a schematic of one corner of the FPC motherboard when it is in a misalignment situation in the embodiment. Detailed Implementation

[0011] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention and are mainly used to illustrate the embodiments, and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention. The components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0012] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0013] Reference Figure 1 and Figure 2 This embodiment provides an FPC structure for inspecting ink exposure misalignment, including an FPC motherboard. Two etched pads 1 are respectively disposed at each of the four corners of the FPC motherboard. The outer surface of the etched pads 1 is covered with a photolithographically developable printing ink layer 2. Specifically, the printing ink layer 2 is made of photosensitive solder resist ink. Two ink openings 21, corresponding to the etched pads 1, are respectively disposed within the printing ink layer 2 in the areas where the four corners of the FPC motherboard are located. One etched pad 1 corresponds to one ink opening 21, and the inner edge of the ink opening 21 and the outer edge of the etched pad 1 are spaced apart from each other. Of course, in other embodiments, etched pads 1 can also be disposed at two opposite corners or three of the corners of the FPC motherboard.

[0014] In this embodiment, as Figure 1 As shown, both the etched pad 1 and the ink opening 21 are square, and the area of ​​the ink opening 21 is larger than the area of ​​the etched pad 1. That is, the standard distance L between the four outer edges of the etched pad 1 and the corresponding inner edge of the ink opening 21 is 0.05 mm. Of course, in other embodiments, the etched pad 1 and the ink opening 21 can also be circular or regular polygonal.

[0015] After exposure and development, the printed ink layer 2, composed of solder resist ink, forms ink windows 21. Then, visual inspection is performed based on the positional relationship between the ink windows 21 and the corresponding etched pads 1 to determine whether the ink exposure misalignment is abnormal. The specific inspection method is as follows: like Figure 2As shown, if the solder resist ink covers part of the copper (i.e., the part of the etched pad 1), and the part of the etched pad 1 extends beyond the inner edge of the ink window 21, then it is determined that the solder resist ink is too misaligned during exposure, i.e., it exceeds the standard tolerance range required for production.

[0016] like Figure 1 As shown, if the entire etched pad 1 is fully exposed within the ink window 21 and the etched pad 1 is not covered by the solder resist ink, it is determined that the solder resist ink is properly misaligned during exposure, which meets the production requirements and ensures that its electrical test is normal.

[0017] Therefore, by setting the inner edge of the ink window 21 and the outer edge of the etched pad 1 at a distance from each other, the inspector can visually identify whether the etched pad 1 is covered by the solder resist ink, thereby effectively and quickly identifying whether the solder resist ink deviates too much during exposure alignment.

[0018] Although the present invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims, and all such changes shall be within the scope of protection of the present invention.

Claims

1. An FPC structure for detecting ink exposure misalignment, comprising an FPC motherboard, characterized in that: At least two diagonal corners of the FPC motherboard are provided with etched pads. The outer surface of the etched pads is covered with a photolithographically developable printing ink layer. The printing ink layer has ink windows, and the inner edge of the ink windows and the outer edge of the etched pads are spaced apart from each other.

2. The FPC structure for detecting ink exposure misalignment according to claim 1, characterized in that: Both the etched pads and the ink openings are square.

3. The FPC structure for detecting ink exposure misalignment according to claim 2, characterized in that: The area of ​​the ink window is larger than the area of ​​the etched pad.

4. The FPC structure for detecting ink exposure misalignment according to claim 3, characterized in that: The standard distance between the four outer edges of the etched pad and the inner edge of the corresponding ink opening is 0.05 mm.

5. The FPC structure for detecting ink exposure misalignment according to any one of claims 1-4, characterized in that: The printed ink layer is a photosensitive solder resist ink layer.

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