TWM620834U - Circuit board and light-emitting apparatus - Google Patents

Abstract

A circuit board including a substrate, a circuit layer, a first solder resist layer and a second solder resist layer is provided. The circuit layer is disposed on the substrate. The circuit layer includes a first pad and a second pad. The first solder resist layer is disposed on the substrate and at least surrounds the first pad and the second pad. The second solder resist layer covers the first solder resist layer. A light-emitting apparatus is also provided.

Description

Circuit board and light emitting device

This new creation relates to an electronic product, and especially relates to a circuit board and a light-emitting device.

In the circuit board manufacturing process, the step of "solder mask opening" is usually to remove the corresponding solder mask material at the place to be soldered (usually the connection pad; but not limited) to expose the corresponding solder joint. The part that is not opened may still be covered with the substrate, other insulating materials, or conductive materials that are not to be exposed. For example, the solder mask can still cover part of the circuit (commonly known as: cover wire). The circuit covered by the solder resist layer can avoid contact with other conductive materials in the subsequent manufacturing process by the solder resist layer covering it.

Due to technological development and/or product requirements, the layout density of the circuit board may need to be higher and higher. In other words, the cover line may get closer and closer to the window opening. Therefore, how to improve the quality of the wire cover of the circuit board so that the solder mask layer can better cover or cover the circuit to be covered, so as to improve the yield rate and the reliability of the product, has become an urgent problem to be solved at present.

The present invention provides a circuit board and a light-emitting device, which can have better yield or quality.

The circuit board created by the new model includes a base material, a circuit layer, a first solder resist layer and a second solder resist layer. The circuit layer is located on the substrate. The circuit layer includes a first pad and a second pad. The first solder resist layer is located on the substrate and at least surrounds the first pad and the second pad. The second solder resist layer covers the first solder resist layer.

In an embodiment of the present invention, the first solder resist layer is in contact with the second solder resist layer.

In an embodiment of the present invention, there is an interface between the first solder resist layer and the second solder resist layer.

In an embodiment of the present invention, the circuit layer includes a first conductive layer and a second conductive layer. The second conductive layer covers the first conductive layer.

In an embodiment of the present invention, the light reflectivity of the second solder resist layer is greater than or equal to 80%.

In an embodiment of the present invention, the substrate has a bonding area and a pin area, the circuit layer further includes a plurality of pins, the first pad and the second pad are located in the bonding area, and the plurality of pins are located in the pin area , And the second solder resist layer is far away from the pin area.

In an embodiment of the present invention, the second solder resist layer is located in the junction area, and the second solder resist layer exposes part of the first solder resist layer.

In an embodiment of the present invention, the circuit board further includes reinforcing materials. The reinforcing material corresponds to the pin area configuration of the base material, and the Young's modulus of the reinforcing material is greater than the Young's modulus of the base material.

In an embodiment of the present invention, the circuit board further includes a reflective layer. The reflective layer covers the second solder resist layer.

The light-emitting device created by the present invention includes the aforementioned circuit board and light-emitting element. The light emitting element is arranged on the circuit layer of the circuit board and is electrically connected to the first pad and the second pad.

Based on the above, by covering the second solder resist layer of the first solder resist layer, the circuit board and/or the light-emitting device can have better yield or quality.

Refer to the drawings of this embodiment to more comprehensively explain the creation of the present invention. However, the new creation can also be embodied in a variety of different forms, and should not be limited to the embodiments described herein. The thickness of the layers and regions in the drawing will be exaggerated for clarity. The same or similar reference numbers indicate the same or similar elements, and the following paragraphs will not repeat them one by one. In addition, for clarity, some of the film layers or components may be omitted in the drawings.

The aforementioned and other technical content, features and effects of the creation of the new model will be clearly presented in the following detailed description of each embodiment with reference to the drawings. The directional terms mentioned in the following embodiments, for example: "up" or "down", etc., are only directions for referring to the attached drawings. Therefore, the direction terms used are used to illustrate, but not to limit the creation of the new model.

1A to 1D are schematic partial cross-sectional views of a method for manufacturing a circuit board according to an embodiment of the present invention. Fig. 2 is a schematic partial top view of a circuit board according to an embodiment of the invention. FIG. 1D may be a schematic partial cross-sectional view corresponding to a section in FIG. 2.

FIG. 3 is a schematic partial cross-sectional view of a circuit board according to a possible embodiment of the present invention. FIG. 3 may be the same or similar to the enlarged view of the area R1 in FIG. 1D.

Please refer to FIG. 1A, a substrate structure 110 is provided. The substrate structure 110 may include a substrate 120 and a patterned first conductive layer 141. The first conductive layer 141 may be located on the substrate 120.

In an embodiment, the substrate 120 may include a rigid substrate, but the invention is not limited to this. Rigid substrates can include glass, epoxy-containing glass fiber layers (such as common FR4 substrates), bismaleimide triazine (BT) boards, similar to the aforementioned boards (such as BT-like boards) (BT-like board), FR5 board, etc.) or other suitable boards.

In an embodiment, the substrate 120 may include a flexible substrate, but the invention is not limited to this. The material of the flexible substrate includes, for example, polyimide (PI) and polyethylene terephthalate (PET), but the invention is not limited thereto. For example, the flexible substrate may include a PI board, an MPI (Modify PI) board, an LCP (liquid crystal substrate) board, or other suitable plates.

In an embodiment, the substrate 120 may include a flexible and rigid bonding plate.

In an embodiment, the color of the substrate 120 may be white, but the invention is not limited to this. For example, the substrate 120 may include a white LCP board, a white BT board, or a white BT-like board, but the invention is not limited thereto.

It should be noted that in FIG. 1A or other similar drawings, the substrate 120 is only schematically shown. In other words, the substrate 120 may be a block with a single structure, a block coated with at least one film layer, a stack of multiple materials or film layers, or other suitable similar materials.

In this embodiment, based on the consideration of conductivity, the material of the first conductive layer 141 may include metal. For example, the material of the first conductive layer 141 may include copper. The first conductive layer 141 can be formed by a build-up method or a subtraction method, which is not limited in the creation of the present invention.

In an embodiment, the first conductive layer 141 may be formed by plating and photolithography, but the invention is not limited to this.

In an embodiment, the substrate structure 110 may be formed of a copper foil substrate. For example, the copper foil on the copper foil substrate can be patterned by a suitable method.

1A to 1B, a first solder resist layer (a type of insulating layer) 151 is formed on the substrate structure 110. The first solder resist layer 151 at least surrounds a part of the first conductive layer 141. For example, the first solder resist layer 151 may have an opening, and the opening exposes a part of the first conductive layer 141.

In this embodiment, the first solder resist layer 151 and a part of the sidewall 141a of the first conductive layer 141 may have a distance 141d, but the invention is not limited to this.

In one embodiment, a solder resist material (such as: liquid photoimageable solder mask (LPSM); but not limited to) may be coated on the substrate structure 110. Then, part of the solder resist material can be removed by etching or other suitable patterning methods to expose at least a part of the first conductive layer 141. The solder resist material on the substrate structure 110 can be cured by an appropriate step (such as light curing and/or thermal curing) to form the corresponding first solder resist layer 151.

1B to 1C, a second solder resist layer (a type of insulating layer) 152 is formed on the substrate structure 110. The second solder resist layer 152 may cover the first solder resist layer 151.

In an embodiment, the first solder resist layer 151 may be formed of thermal curable ink or thermal curable ink, and the second solder resist layer 152 may be formed of developing ink (developing ink). ) Formed.

In an embodiment, a reflective layer (such as the reflective layer 260 described later, but not limited) may be formed on the second solder resist layer 152.

In an embodiment, the first solder resist layer 151 may be formed of a developing ink, and the second solder resist layer 152 may be made of highly reflective (eg: reflectivity at about 470nm> 70%; at about 550nm Reflectivity>70%; and/or reflectivity>70% in the range of about 470nm~550nm) is formed by the characteristic material, film or sheet. For example, a patterned film or sheet having the aforementioned characteristics can be attached to the substrate structure 110, and the corresponding second solder resist layer 152 can be formed.

In an embodiment, the color of the first solder resist layer 151 may be white, and the color of the second solder resist layer 152 may be silver or metallic luster with or similar high reflection characteristics.

In a possible embodiment, the material and/or formation method of the second solder resist layer 152 may be the same or similar to the material and/or formation method of the first solder resist layer 151, but the invention is not limited to this.

In this embodiment, the second solder resist layer 152 may cover the surface of the first solder resist layer 151 away from the first conductive layer 141. For example, on a cross-section (such as the cross-section shown in FIG. 1C; but not limited to), the first solder resist layer 151 may have a first side surface 151a and a second side surface 151b opposite to each other, wherein the second side surface 151b is relatively larger The first side surface 151a is far away from the first conductive layer 141 closest to it (ie, the first solder resist layer 151 described above), and the second solder resist layer 152 may cover the second side surface of the first solder resist layer 151 151b.

In one embodiment, during the patterning process of the first solder resist layer 151, there may be some slight or unexpected undercut phenomenon; and/or, after the curing step is used to form the corresponding second In the case of a solder resist layer 151, a part of the first solder resist layer 151 (such as the edge portion of the first solder resist layer 151) may be A slight or unexpected peeling occurs between the substrates 120. Therefore, in the process of forming the second solder resist layer 152, the second solder resist layer 152 can be filled in the aforementioned undercut and/or peeling place correspondingly. For example, when the solder resist material used to form the second solder resist layer 152 is coated on the substrate structure 110, part of the solder resist material may be filled in the aforementioned undercut and/or peeling place. In this way, the production yield and/or quality of the formed circuit board 100 (marked in FIG. 1D or FIG. 2) can be improved.

In this embodiment, the first solder resist layer 151 and the second solder resist layer 152 may be in contact. Moreover, the first solder resist layer 151 and the second solder resist layer 152 are made of different materials and/or are formed by different steps. In this way, there may be a corresponding interface 159 between the first solder resist layer 151 and the second solder resist layer 152 that are in contact. In an embodiment, the first solder resist layer 151 and the second solder resist layer 152 may be regarded as different solder resist layers.

1C to 1D, the second conductive layer 142 is formed on the first conductive layer 141. For example, the second conductive layer 142 can be formed on a portion of the first conductive layer 141 exposed by the first solder resist layer 151 and the second solder resist layer 152 by plating or other suitable methods. At least part of the first conductive layer 141 and at least part of the second conductive layer 142 may constitute the circuit layer 130. In other words, the circuit layer 130 may include a corresponding first conductive layer 141 and a corresponding second conductive layer 142.

In an embodiment, the oxidation resistance of the second conductive layer 142 may be better than the oxidation resistance of the first conductive layer 141. In an embodiment, the second conductive layer 142 may include a nickel-gold layer or a nickel-palladium-gold layer. For example, the second conductive layer 142 may include an electroless nickel immersion gold (ENIG) layer or an electroless nickel electroless palladium immersion gold (ENEPIG) layer.

As shown in FIG. 3, in one embodiment, even (but still may not be) in the process of forming the first solder resist layer 151, there may be slight or unexpected undercuts and/or peelings, but Because the second solder resist layer 152 covering the first solder resist layer 151 can be filled in the aforementioned undercut and/or peeling place. Therefore, it is possible to reduce the possibility that the second conductive layer 142 formed later will fill the aforementioned undercuts and/or peelings. In this way, it is possible to reduce the possibility of unexpected electrical changes (such as possible short circuits or unstable electrical signals; but not limited) due to the filling of the aforementioned undercut and/or peeling of the second conductive layer 142 . For example, during the formation of the second conductive layer 142, the possibility of the corresponding conductive material contacting the conductive elements embedded in the first solder resist layer 151 from the aforementioned undercut and/or peeling point can be reduced. In this way, the manufacturing yield and/or quality of the formed circuit board 100 can be improved. In addition, as shown in FIG. 3, in the above case, part of the second solder resist layer 152 may be located between the first solder resist layer 151 and the substrate 120.

After the above-mentioned manufacturing process, the manufacturing of the circuit board 100 of this embodiment can be substantially completed.

1D and FIG. 2, the circuit board 100 includes a substrate 120, a circuit layer 130, a first solder resist layer 151, and a second solder resist layer 152. The circuit layer 130 is located on the substrate 120. The circuit layer 130 includes a first pad 131 and a second pad 132. The first solder resist layer 151 is located on the substrate 120. The first solder resist layer 151 at least surrounds the first pad 131 and the second pad 132. The second solder resist layer 152 covers the first solder resist layer 151.

In this embodiment, the first pad 131 and the second pad 132 can be electrically separated from each other.

In this embodiment, the layout design of the circuit layer 130 can be adjusted according to requirements, and is not limited in the creation of the present invention. That is to say, in the circuit layer 130, the unconnected parts in the drawing may be electrically connected by other unillustrated parts and/or other conductive elements.

In this embodiment, the substrate 120 may have a bonding area 121 and a pin area 124. The first pad 131 and the second pad 132 may be located in the bonding area 121.

In this embodiment, the circuit layer 130 may further include a plurality of pins 134 and connecting wires 133. The pin 134 may be located in the pin area 124, and the connection line 133 may extend from the bonding area 121 to the pin area 124. In one embodiment, the pins 134 can be electrically connected to corresponding pads (eg, the first pad 131 or the second pad 132) through the corresponding connecting wire 133.

In an embodiment, the area corresponding to the connecting line 133 in the circuit board 100 may be suitable for bending. For example, because the upper side of the connecting wire 133 is covered by only a solder resist layer (such as the first solder resist layer 151), the area corresponding to the connecting wire 133 can be made larger (such as compared to the bonding area 121). ) Suitable for being bent. For another example, the first solder resist layer 151 can be formed by an ink suitable for flexible boards (such as PI ink or Photoimageable Coverlay). Therefore, compared to Often used for the solder resist layer formed by the ink of the rigid board, the circuit board 100 can have wider applicability, better yield or quality. In terms of application, polyimide ink (PI ink) or The photoimageable coverlay can have a low rebound force, but the new creation does not limit the use of other materials. For example, you can also use the traditional coverlay (Coverlay; CVL) (such as: PI cover Film) or liquid photo imageable (liquid photo imageable; LPI) ink.

In one embodiment, the circuit board 100 can be electrically connected to other electronic components (such as Chip On Film (COF), but not limited) through its pins 134.

In the embodiment shown in FIG. 1D, the circuit board 100 is a single-sided circuit (for example, a circuit layer 130 is provided on one surface of the substrate 120), but the invention is not limited to this. In other embodiments or other similar embodiments not shown, the circuit board 100 may be a double-sided circuit. For example, the substrate 120 may be located between the circuit layer 130 and other circuit layers. In addition, part of the wiring in the aforementioned other circuit layers may be configured corresponding to the first pad 131, the second pad 132, the connecting line 133 or the pin 134, but the creation of the present invention is not limited to this.

In this embodiment, the second solder resist layer 152 may be far away from the pin area 124, but the invention is not limited to this.

In this embodiment, the second solder resist layer 152 is located in the junction area 121, and the second solder resist layer 152 exposes a part of the first solder resist layer 151.

Fig. 4 is a schematic partial cross-sectional view of a circuit board according to a possible embodiment of the invention. The circuit board 200 of this embodiment is similar to the circuit board 100 of the foregoing embodiment, and similar components thereof are denoted by the same reference numerals, and have similar functions, structures, materials, and/or formation methods, and the description is omitted.

1D/FIG. 2 and FIG. 4, the circuit board 200 includes a substrate 120, a first circuit layer 130, a first solder resist layer 151, a second solder resist layer 152, a third solder resist layer 253, and a second circuit layer 230 and conductive vias 235. The substrate 120 may be located between the first circuit layer 130 and the second circuit layer 230. The conductive via 235 may penetrate the substrate 120. The corresponding circuit in the first circuit layer 130 and the corresponding circuit in the second circuit layer 230 may be electrically connected by the conductive via 235.

In this embodiment, the wiring design of the second circuit layer 230 can be adjusted according to requirements, and is not limited in the creation of the present invention. That is to say, in the second circuit layer 230, the unconnected parts in the drawing may be electrically connected by other unillustrated parts and/or other conductive elements.

In this embodiment, the circuit board 200 may further include a reflective layer 260. The reflective layer 260 may cover the second solder resist layer 152. The reflectivity of the reflective layer 260 is substantially greater than or equal to 85%. Preferably, the reflectivity of the reflective layer 260 may be greater than or equal to approximately 90%.

In an embodiment, the color of the reflective layer 260 may be silver or metallic luster with or similar high reflection characteristics.

In an embodiment, the reflective layer 260 may be formed on the second solder resist layer 152 by, for example, sputtering, evaporation, electroless plating, electroplating, chemical displacement reaction, silver mirror reaction, or other suitable methods. For example, the reflective layer 260 may include aluminum, silver, gold, copper, beryllium, chromium, molybdenum, platinum, nickel, iron, or any combination thereof, or other metal layers with high reflectivity. In one embodiment, the reflectivity of silver at a wavelength of 800nm can be as high as about 99.2%, and the reflectivity at a wavelength of 500nm can also reach about 97.9%. Therefore, silver can be the best at wavelengths of visible light and near-infrared light. The material of the aforementioned reflective layer. In addition, aluminum also has good reflectivity at wavelengths such as near-ultraviolet light, visible light, and near-infrared light (the reflectance of aluminum at a wavelength of 800nm is about 86.7%, and the reflectivity at a wavelength of 500nm can be as high as about 91.8%) , But due to its softer and easier to oxidize characteristics, when used as the material of the aforementioned reflective layer, a protective layer must be plated on its surface, and it can also be plated with a metal or non-metal coating to improve its performance at a specific wavelength. Reflectivity. The reflectance of gold and copper between 650nm~800nm is also very good (the reflectance of gold at the wavelength of 800nm and 650nm is about 98.0% and 95.5, respectively, and the reflectivity of copper at the wavelength of 800nm and 650nm is about 98.1% and 98.1%, respectively. 96.6), but the reflectance at a wavelength of 500nm is poor, so gold and copper can also be used as the material of the aforementioned reflective layer under the conditions of wavelengths of 800nm and 650nm. Of course, the aforementioned materials or methods are only used for illustration, and are not used to limit the material of the reflective layer 260.

In this embodiment, the circuit board 200 may further include a third solder resist layer (a type of insulating layer) 253. The third solder resist layer 253 may cover the second circuit layer 230.

In an embodiment, the material or formation method of the third solder resist layer 253 may be the same or similar to that of the first solder resist layer 151, but the present invention is not limited to this.

In this embodiment, the circuit board 200 may further include a reinforcing material 270. The reinforcing material 270 may be configured corresponding to the pin area 124 of the base material 120. In an embodiment, the Young's modulus of the reinforcing material 270 may be greater than the Young's modulus of the base material 120. In this way, when the pins 134 of the circuit board 200 (or the pin area 124 of the substrate 120) are connected to other components, the damage or damage of the circuit board 200 can be reduced.

Fig. 5 is a schematic partial cross-sectional view of a light-emitting device according to an embodiment of the present invention.

An example of a part of the manufacturing method of the light-emitting device 500 is as follows.

Please refer to Figure 5 to provide a circuit board. In this embodiment, the provided circuit board may be the same as the aforementioned circuit board 100. Therefore, in the subsequent description and/or corresponding drawings, the circuit board 100 and its corresponding symbols are used for description. In an embodiment, the provided circuit board may be a circuit board similar to the aforementioned circuit board 100 (eg, circuit board 200, but not limited to).

Please continue to refer to FIG. 5, the light emitting element 580 is disposed on the circuit layer 130 of the circuit board 100 to be electrically connected to the first pad 131 and the second pad 132 of the circuit layer 130. For example, the light-emitting element 580 can be electrically connected to the corresponding first pad 131 and the second pad 132 through the corresponding conductive connector 585. The conductive connection 585 may include solder balls, but the invention is not limited to this.

In an embodiment, the light reflectivity of the second solder resist layer 152 may be greater than or equal to 80%. In this way, the performance of the light emitting device 500 can be improved. In an embodiment, the appearance of the second solder resist layer 152 may be white, silver-white, or a similar color with metallic luster.

In an embodiment, the light-emitting element 580 may include a light-emitting diode. The aforementioned light-emitting diodes may include red light-emitting diodes, green light-emitting diodes, blue light-emitting diodes, or white light-emitting diodes, but the invention is not limited to this.

In an embodiment, the light-emitting device 500 may be a backlight module, but the invention is not limited to this.

In an embodiment, the light-emitting device 500 may be a display panel or a part of a display panel, but the invention is not limited to this.

In summary, by covering the second solder resist layer of the first solder resist layer, the circuit board and/or the light-emitting device created by the present invention can have better yield or quality.

100: circuit board 110: substrate structure 120: Substrate 121: Junction Zone 124: Pin area 130: circuit layer 131: first pad 132: second pad 133: connection line 134: Pin 230: circuit layer 235: Conductive vias 141: first conductive layer 141a: side wall 141d: spacing 142: second conductive layer 151: The first solder mask 151a, 151b: side 152: The second solder mask 253: The third solder mask 159: Interface 260: reflective layer 270: Reinforcement Material 500: Light-emitting device 580: Light-emitting element 585: Conductive connector R1: area

1A to 1D are schematic partial cross-sectional views of a method for manufacturing a circuit board according to an embodiment of the present invention. Fig. 2 is a schematic partial top view of a circuit board according to an embodiment of the invention. Fig. 3 is a schematic partial cross-sectional view of a circuit board according to a possible embodiment of the invention. Fig. 4 is a schematic partial cross-sectional view of a circuit board according to a possible embodiment of the invention. Fig. 5 is a schematic partial cross-sectional view of a light-emitting device according to an embodiment of the present invention.

100: circuit board

120: Substrate

121: Junction Zone

124: Pin area

130: circuit layer

131: first pad

132: second pad

133: connection line

134: Pin

141: first conductive layer

142: second conductive layer

151: The first solder mask

152: The second solder mask

R1: area

Claims (10)

A circuit board, including: Substrate A circuit layer located on the substrate, and the circuit layer includes a first pad and a second pad; A first solder resist layer located on the substrate and at least surrounding the first pad and the second pad; and The second solder resist layer covers the first solder resist layer. The circuit board according to claim 1, wherein the first solder resist layer is in contact with the second solder resist layer. The circuit board according to claim 2, wherein there is an interface between the first solder resist layer and the second solder resist layer. The circuit board according to claim 1, wherein the circuit layer includes: The first conductive layer; and The second conductive layer covers the first conductive layer. The circuit board according to claim 1, wherein the light reflectivity of the second solder resist layer is greater than or equal to 80%. The circuit board according to claim 1, wherein: The substrate has a bonding area and a pin area; The circuit layer further includes a plurality of pins, wherein the first pad and the second pad are located in the bonding area, and the plurality of pins are located in the pin area; and The second solder resist layer is far away from the pin area. The circuit board according to claim 6, wherein the second solder resist layer is located in the bonding area, and the second solder resist layer exposes a part of the first solder resist layer. The circuit board as described in claim 6, further including: The reinforcing material is configured corresponding to the pin area of the base material, and the Young's modulus of the reinforcing material is greater than the Young's modulus of the base material. The circuit board as described in claim 1, further including: The reflective layer covers the second solder resist layer. A light emitting device includes: Such as the circuit board of claim 1; and The light-emitting element is disposed on the circuit layer of the circuit board and is electrically connected to the first pad and the second pad.

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