TWI703903B - Flexible circuit board - Google Patents

Abstract

A shaped through hole is formed on a solder resist layer of a flexible circuit board to reveal a surface of a flexible substrate. The shaped through hole is irradiated by a light to form an alignment light spot, and shapes of the alignment light spot and the shaped through hole are the same. An image detector can capture images according to the alignment light spot for follow-up process.

Description

Flexible circuit board

The invention relates to a flexible circuit board, in particular to a flexible circuit board with at least one geometric pattern perforation formed in a solder resist protective layer.

The conventional flexible circuit board includes a flexible substrate and a metal layer. The metal layer includes a plurality of circuits and a metal mark. The circuits and the metal mark are made of a metal plate, and the circuits and the metal mark are formed On an upper surface of the flexible substrate, when the flexible circuit board is rolled up, the metal mark will contact the lower surface of the flexible substrate, and the metal mark will be recessed in the flexible substrate due to the extrusion of the flexible substrate The upper surface of the metal material either causes the metal mark to detach from the soft base material, or causes the edge contour of the metal mark to deform.

When the metal mark is recessed in the soft substrate, or when the metal mark is separated from the soft base material, or when the edge contour of the metal mark is deformed due to extrusion, an image capturing device (not shown) The image of the metal mark cannot be captured for alignment. When alignment cannot be performed, it will be judged as scrap by the recognition system, that is, subsequent manufacturing processes cannot be performed.

The main purpose of the present invention is to form a solder resist protective layer on a flexible circuit board There is at least one geometric pattern perforation, and the geometric pattern perforation reveals a surface of the flexible substrate. When light irradiates the solder resist protection layer, the geometric pattern perforation can be used to form a pair of light spots, and the alignment The light spot can be captured by an image sensor.

A flexible circuit board of the present invention includes a flexible substrate, a circuit layer, and a solder resist protection layer. The flexible substrate has a first surface and a second surface. The circuit layer is disposed on the first surface. On the surface, the circuit layer includes a plurality of circuits, each of which has an inner lead section, an outer lead section, and a connecting section located between the inner lead section and the outer lead section. The solder resist protection layer consists of a Formed by a solder resist material, the solder resist protective layer has a first covering portion and a second covering portion, the first covering portion covers the conductive section of each of the lines, and the second covering portion covers the flexible substrate The first surface of the first surface, the second covering portion has at least one geometric perforation, the geometric perforation reveals the first surface of the flexible substrate, and the geometric perforation is used for a light irradiation to form a pair The alignment spot, the shape of the alignment spot is the same as the shape of the geometric figure perforation, and the alignment spot can be used by an image sensor to capture the image of the alignment spot.

The present invention covers the first surface of the flexible substrate by the second covering portion formed on the solder resist protection layer, and the geometric pattern of the second covering portion is used to perforate to expose the flexible substrate The first surface forms the alignment spot when the light irradiates the solder resist protection layer for an image sensor to capture the image of the alignment spot.

Since the second covering portion is formed of a solder resist material, when the flexible circuit board is rolled or the rolled flexible circuit board is released, the solder resist protective layer contacts the flexible substrate The second surface of the flexible substrate is prevented from falling off due to the extrusion or friction of the second surface of the flexible substrate, and the shape of the geometric perforation can be maintained, so that the light irradiates the solder resist protection When layering, the alignment spot can still be captured by the image sensor.

Please refer to Figures 1 to 10, a flexible circuit board 100 includes a flexible substrate 110, a circuit layer 120 and a solder resist protection layer 130, the flexible substrate 110 is selected from polyimide (Polyimide, PI), but not limited to this. Preferably, the flexible substrate 110 is formed of a light-transmitting material. The flexible substrate 110 has a first surface 111 and a second surface 112. The first surface 111 includes a circuit layer arrangement area 111a, a blank area 111b and a transmission hole arrangement area 111c. Please refer to Figures 1, 3 and 9. The blank area 111b is located in the transmission hole arrangement area 111c and the transmission hole arrangement Between the regions 111c, or, please refer to Figures 5 and 7. In different embodiments, the blank region 111b is located in the circuit layer arrangement region 111a, and the circuit layer 120 can be selected from a coating method (Casting), Lamination, sputtering (Sputtering) or electroplating (Plating) or other methods are arranged on the circuit layer arrangement area 111a of the first surface 111.

Please refer to Figures 1, 3, 5, 7 and 9, the circuit layer 120 includes a plurality of circuits 121. Each circuit 121 has an inner lead section 121a, an outer lead section 121c, and an inner lead section 121a. The connecting section 121b between the outer lead sections 121c, the inner lead section 121a is used to electrically connect at least one chip (not shown in the figure), and the outer lead section 121c is used to electrically connect to another electrical element (Figure Not shown, such as LCD panels, but not limited by this).

Please refer to Figures 1 to 10, the solder resist protection layer 130 is formed of a solder resist material, the solder resist protection layer 130 has a first covering portion 131 and a second covering portion 132, the first covering portion 131 covers The connecting section 121b of each line 121 exposes the inner lead section 121a and the outer lead section 121c, the second covering portion 132 is disposed in the blank area 111b, and the second covering portion 132 covers the flexible For the first surface 111 of the flexible substrate 110, please refer to Figures 1, 3, 5, 7 and 9. The second covering portion 132 has at least one geometric pattern perforation 133, and the geometric pattern perforation 133 reveals the flexible substrate Preferably, on the first surface 111 of the 110, the solder resist protection layer 130 exposes the transmission hole group arrangement area 111c, and the rigidity of the solder resist protection layer 130 is not greater than the rigidity of the flexible substrate 110.

Please refer to Figures 1 and 2, which is a first embodiment in which the solder resist protection layer 130 covers the flexible substrate 110 and the circuit layer 120. In this embodiment, the solder resist protection layer 130 The second covering portion 132 is not connected to the first covering portion 131, and the blank area 111b is adjacent to the transmission hole arrangement area 111c, and the edge 133a of the geometric pattern perforation 133 is a closed edge.

Please refer to Figures 3 and 4, which is a second embodiment in which the solder resist protection layer 130 covers the flexible substrate 110 and the circuit layer 120. The difference between the second embodiment and the first embodiment lies in the The second covering portion 132 is connected to the first covering portion 131.

Please refer to Figures 5 and 6, which is a third embodiment in which the solder resist protection layer 130 covers the flexible substrate 110 and the circuit layer 120. The difference between the third embodiment and the first embodiment is that the geometry The edge 133a of the graphic perforation 133 is an open edge, the geometric perforation 133 has at least one notch 133b, and the gap 133b connects the geometric perforation 133 and the blank area 111b, or the solder mask 130 further has at least one The groove 134 exposes the first surface 111 of the flexible substrate 110, and the groove 134 communicates with the notch 133b, and the geometric perforation 133 communicates with the blank area 111b through the groove 134.

Please refer to Figures 7 and 8, which is a fourth embodiment in which the solder resist protection layer 130 covers the flexible substrate 110 and the circuit layer 120. The difference between the fourth embodiment and the first embodiment lies in the The blank area 111b is located in the circuit layer setting area 111a.

Please refer to Figures 9 and 10, which is a fifth embodiment in which the solder resist protection layer 130 covers the flexible substrate 110 and the circuit layer 120. The difference between the fifth embodiment and the fourth embodiment lies in the The second covering portion 132 is connected to the first covering portion 131.

Please refer to Figures 1, 3, 5, 7 and 9, the geometric pattern perforation 133 is used for a light to illuminate to form an alignment spot X, the shape of the alignment spot X is the same as the shape of the geometric pattern perforation 133 , And the alignment spot X can be used by an image sensor (not shown in the figure) to capture the image of the alignment spot X, the area of the alignment spot X is not less than 0.03mm, preferably, the alignment spot The area of X is between 0.03 mm and 0.06 mm, so that the image sensor can capture the image of the alignment spot X.

Please refer to Figures 2, 4, 6, 8 and 10, the first covering portion 131 covering the conductive section 121b of each of the lines 121 has a first exposed surface 131a and a first covering surface 131b, covering the flexible The second covering portion 132 of the first surface 111 of the flexible substrate 110 has a second exposed surface 132a and a second covering surface 132b. The first covering surface 131b contacts the circuit 121, and the second covering surface 132b contacts the flexible The first surface 111 of the substrate 110 has a first thickness D1 between the first surface 111 and the first exposed surface 131a, and has a second thickness D2 between the first surface 111 and the second exposed surface 132a , The first thickness D1 is not less than the second thickness D2, preferably, the second thickness D2 is equal to the first thickness D1, more preferably, the second thickness D2 is less than the first thickness D1, the second exposed The area of the surface 132a is not less than 0.06 mm. Preferably, the area of the second exposed surface 132a is between 0.06 mm and 0.1 mm, so that the image sensor can capture the image of the alignment spot X.

Please refer to FIGS. 1-10. In an image capturing embodiment, when the light and the image sensor are disposed on the first surface 111 of the flexible substrate 110, the alignment spot X is The light irradiates the solder resist protection layer 130, and the light passes through the geometric pattern perforation 133 and then is projected onto the first surface 111. The alignment spot X is located in the blank area 111b. Please refer to Figures 1, 3 and 5 , The alignment spot X is located between the circuit layer arrangement area 111a and the transmission hole group arrangement area 111c.

Please refer to FIGS. 1-10. In another image capturing embodiment, when the light is disposed above the first surface 111 of the flexible substrate 110, and the image sensor is disposed on the flexible substrate When the second surface 112 of 110 is below the second surface 112, the alignment spot X is irradiated with the solder resist protection layer 130 by the light, and after the light passes through the geometric pattern perforation 133 and penetrates the flexible substrate 110, it is projected on the The second surface 112 of the flexible substrate 110 is formed. In this image capturing embodiment, the circuit layer arrangement area 111a is projected onto the second surface 112 to form a first area 112a, and the blank area 111b is projected onto the The second surface 112 forms a second area 112b, the transmission hole group arrangement area 111c is projected onto the second surface 112 to form a third area 112c, and the alignment spot X is located in the second area 112b, please refer to Figures 1 to 6 , The alignment spot X is located between the first area 112a and the third area 112c.

Please refer to FIGS. 1-10. In another image capturing embodiment, when the image sensor is disposed on the first surface 111 of the flexible substrate 110, and the light is disposed on the flexible substrate When the second surface 112 of 110 is below the second surface 112, the alignment spot X is illuminated by the light on the second surface 112 of the flexible substrate 110, and after the light passes through the flexible substrate 110, it passes through the second The covering portion 132 is masked and formed by the geometric pattern perforation 133.

In the present invention, the second covering portion 132 formed on the solder resist protection layer 130 covers the first surface 111 of the flexible substrate, and the geometric pattern perforation 133 of the second covering portion 132 reveals the After the first surface 111 of the flexible substrate 110 is irradiated with the light, the alignment spot X is formed for the image sensor to capture the image of the alignment spot X. In addition, since the second covering portion 132 is It is formed of solder resist material, and the first thickness D1 of the first covering portion 131 is not less than the second thickness D2 of the second covering portion 132, so when the flexible circuit board 100 is rolled or released When the flexible circuit board 100 is rolled up, the solder resist protection layer 130 is used to contact the second surface 112 of the flexible substrate 110, which can prevent the second covering portion 132 from being damaged by the flexible substrate 110. The second surface 112 is squeezed or rubbed and falls off. Even if the second surface 112 of the flexible substrate 110 rubs the second covering portion 132 to deform the edge profile of the second covering portion 132, the geometrical figure can still be made The perforation 133 maintains its shape, so that the alignment spot X formed by forming the geometric pattern perforation 133 can be used for the image sensor to capture images.

The scope of protection of the present invention shall be subject to the scope of the attached patent application. Anyone who is familiar with the art and makes any changes and modifications without departing from the spirit and scope of the present invention shall fall within the scope of protection of the present invention. .

100: Flexible circuit board

110: Flexible substrate

111: first surface

111a: Line layer setting area

111b: blank area

111c: Transmission hole group setting area

112: second surface

112a: District 1

112b: District 2

112c: District 3

120: circuit layer

121: Line

121a: inner lead segment

121b: lead section

121c: Outer lead segment

130: Solder mask protective layer

131: The first covering part

131a: First Appearance

131b: first coverage

132: The second covering part

132a: Second Appearance

132b: second coverage

133: geometric perforation

133a: Edge

133b: gap

134: Groove

D1: first thickness

D2: second thickness

X: counterpoint spot

Figure 1: A top view of the first embodiment of the flexible circuit board of the present invention.

Figure 2: A cross-sectional view of the first embodiment of the flexible circuit board of the present invention.

Figure 3: The top view of the second embodiment of the flexible circuit board of the present invention.

Figure 4: A cross-sectional view of the second embodiment of the flexible circuit board of the present invention.

Figure 5: A top view of the third embodiment of the flexible circuit board of the present invention.

Figure 6: A cross-sectional view of the third embodiment of the flexible circuit board of the present invention.

Figure 7: A top view of the fourth embodiment of the flexible circuit board of the present invention.

Figure 8: A cross-sectional view of the fourth embodiment of the flexible circuit board of the present invention.

Figure 9: A top view of the fifth embodiment of the flexible circuit board of the present invention.

Figure 10: A cross-sectional view of the fifth embodiment of the flexible circuit board of the present invention.

100: Flexible circuit board

110: Flexible substrate

111: first surface

111a: Line layer setting area

111b: blank area

111c: Transmission hole group setting area

121a: inner lead segment

121b: lead section

121c: Outer lead segment

130: Solder mask protective layer

131: The first covering part

132: The second covering part

133: geometric perforation

133a: Edge

X: counterpoint spot

Claims (23)

A flexible circuit board, comprising: a flexible substrate having a first surface and a second surface; a circuit layer disposed on the first surface, the circuit layer including a plurality of circuits, each circuit having a Inner lead section, an outer lead section and a connecting section located between the inner lead section and the outer lead section; and a solder resist protective layer formed of a solder resist material, the solder resist protective layer having a first A covering portion and a second covering portion, the first covering portion covers the conductive section of each of the lines, the second covering portion covers the first surface of the flexible substrate, and the second covering portion has at least one Geometric perforation, the geometric perforation reveals the first surface of the flexible substrate, the geometric perforation is used for a light to irradiate to form an alignment spot, the shape of the alignment spot is the same as the geometric perforation Has the same shape, and the alignment spot can be used by an image sensor to capture the image of the alignment spot. The flexible circuit board described in item 1 of the scope of patent application, wherein the first covering portion covering the conductive section of each circuit has a first exposed surface and a first covering surface, covering the flexible substrate The second covering portion of the first surface has a second exposed surface and a second covering surface, the first covering surface is in contact with the circuit, the second covering surface is in contact with the first surface of the flexible substrate, and the first surface There is a first thickness between the first exposed surface and the second thickness between the first surface and the second exposed surface. The first thickness is not less than the second thickness. The flexible circuit board described in item 2 of the scope of patent application, wherein the second thickness is smaller than the first thickness. The flexible circuit board described in item 2 of the scope of patent application, wherein the second thickness is equal to the first thickness. For the flexible circuit board described in item 1 of the scope of patent application, the alignment spot is made of The light irradiates the solder resist protection layer, and the light passes through the geometric pattern perforation and is then projected onto the first surface. As for the flexible circuit board described in item 1 of the scope of patent application, after the alignment spot is irradiated by the light on the solder resist protective layer, and the light passes through the geometric pattern and penetrates the flexible substrate, Formed by projecting on a second surface of the flexible substrate. As for the flexible circuit board described in claim 1, wherein the alignment spot is illuminated by the light on a second surface of the flexible substrate, and the light passes through the flexible substrate after passing through the flexible substrate. The second covering part masks and is formed by perforating the geometric pattern. The flexible circuit board according to any one of items 1 to 7 in the scope of patent application, wherein the second covering part is not connected with the first covering part. The flexible circuit board according to any one of items 1 to 7 in the scope of the patent application, wherein the second covering portion is connected to the first covering portion. The flexible circuit board described in item 5 of the scope of patent application, wherein the first surface includes a circuit layer setting area and a blank area, the circuit layer is provided with the circuit layer setting area, and the second covering portion is provided on the In the blank area, the alignment spot is located in the blank area. For the flexible circuit board described in claim 10, the first surface further includes a transmission hole arrangement area, and the alignment spot is located between the circuit layer arrangement area and the transmission hole group arrangement area. The flexible circuit board described in item 1 of the scope of patent application, wherein the first surface includes a circuit layer setting area and a blank area, the circuit layer is provided with the circuit layer setting area, and the second covering portion is provided on the In the blank area, the alignment spot is located in the blank area, an edge of the geometric figure perforation is an open edge, the geometric figure perforation has at least one gap, and the gap connects the geometric figure perforation and the blank area. The flexible circuit board according to claim 12, wherein the solder resist protection layer further has at least one groove, the groove reveals the first surface of the flexible substrate, and the groove communicates The gap and the geometric pattern perforation are connected to the blank area through the groove. The flexible circuit board described in item 1 of the scope of patent application, wherein the first surface includes a circuit layer setting area and a blank area, the circuit layer is provided with the circuit layer setting area, and the second covering portion is provided on the In the blank area, the alignment spot is located in the blank area, and the blank area is located in the circuit layer setting area. For the flexible circuit board described in item 6 of the scope of patent application, wherein the first surface includes a circuit layer arrangement area and a blank area, the second covering portion is arranged in the blank area, and the circuit layer arrangement area is projected onto The second surface forms a first area, the blank area is projected onto the second surface to form a second area, and the alignment spot is located in the second area. For the flexible circuit board described in item 15 of the scope of patent application, the first surface further includes a transmission hole arrangement area, the transmission hole arrangement area is projected onto the second surface to form a third area, and the alignment spot is located Between the first zone and the third zone. The flexible circuit board as described in item 1 of the scope of patent application, wherein the flexible substrate is formed of a light-transmitting material. As for the flexible circuit board described in item 1 of the scope of patent application, the area of the alignment spot is not less than 0.03mm. For the flexible circuit board described in item 18 of the scope of patent application, the area of the alignment spot is between 0.03mm and 0.06mm. The flexible circuit board described in item 18 of the scope of patent application, wherein the second covering portion has a second exposed surface, and the area of the second exposed surface is not less than 0.06 mm. The flexible circuit board described in item 20 of the scope of patent application, wherein the second exposed surface The area is between 0.06mm to 0.1mm. In the flexible circuit board described in item 1 of the scope of patent application, the rigidity of the solder resist protection layer is not greater than the rigidity of the flexible substrate. In the flexible circuit board described in item 1 of the scope of patent application, an edge of the geometric pattern perforation is a closed edge.

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