TW201720247A - Circuit board structure and manufacturing method thereof - Google Patents

Abstract

A circuit board structure includes a substrate, a plurality of metaizeable and photo-imageable bases, a chemical plating seed layer and a second patterned circuit layer. The substrate includes a top surface, a bottom surface opposite to the top surface and a first patterned circuit layer. The metaizeable and photo-imageable bases are disposed on the top surface and the bottom surface respectively. Each metaizeable and photo-imageable base includes a plurality of vias exposing at least a part of the first patterned circuit layer, and the material of each metaizeable and photo-imageable base includes photo-sensitive material. The chemical plating seed layer is disposed on the metaizeable and photo-imageable bases and covers an inner wall of each via. The second patterned circuit layer is disposed on the first chemical plating seed layer and filled in the vias to be electrically connected to the first patterned circuit layer.

Description

Circuit board structure and manufacturing method thereof

The present invention relates to a circuit board structure and a method of fabricating the same, and more particularly to a circuit board structure having a metallizable photosensitive developing substrate and a method of fabricating the same.

In the current semiconductor packaging process, the circuit board has become one of the frequently used components due to the advantages of fine wiring, compact assembly, and good performance. The circuit board can be assembled with a plurality of electronic components such as a chip and a passive component. Through the circuit board, these electronic components can be electrically connected to each other, and signals can be transmitted between these electronic components.

Generally, the circuit board is mainly formed by alternately stacking a plurality of patterned circuit layers and a plurality of insulating layers, and electrically connecting the patterned circuit layers to each other by conductive vias. Conventional methods for forming conductive vias are generally to form a blind via through the insulating layer in a laser drilled manner and expose the blind vias to the underlying trace layer. Thereafter, a desmear process is performed to remove the slag generated by the laser drilling. Then, a conductive layer is formed in the blind via to electrically connect the underlying wiring layer.

It is worth noting that in the above laser drilling process, the glue that is not completely removed by the laser will remain on the hole wall of the blind hole, so it is necessary to carry out the desmear treatment with the alkaline liquid. The current blind hole manufacturing process is still quite complicated. Moreover, in the process of removing the slag, the copper layer under the blind hole is easily peeled off in the alkaline liquid, thereby affecting the yield of the process.

The invention provides a circuit board structure, which has high process efficiency and high process yield.

The invention provides a method for manufacturing a circuit board structure, which can effectively improve process efficiency and process yield.

The circuit board structure of the present invention comprises a substrate, a plurality of metallizable photosensitive development substrates, an electroless plating seed layer and a second patterned circuit layer. The substrate includes an upper surface, a lower surface opposite the upper surface, and a first patterned wiring layer. The metallizable photosensitive developing substrates are respectively disposed on the upper surface and the lower surface. Each of the metallizable photosensitive developing substrates includes a plurality of blind holes that respectively expose at least a portion of the first patterned wiring layer, and each of the materials of the metallizable photosensitive developing substrate includes a light sensitive material. The electroless plating seed layer is disposed on the metallizable photosensitive developing substrate and covers an inner wall of each blind hole. The second patterned circuit layers are respectively disposed on the first electroless plating seed layer and filled in the blind holes to be electrically connected to the first patterned circuit layer.

The manufacturing method of the wiring board structure of the present invention comprises the following steps. A substrate is provided, wherein the substrate includes an upper surface, a lower surface opposite the upper surface, and a first patterned wiring layer. A metallized photosensitive developing substrate is disposed on the upper surface and the lower surface, wherein each of the materials of the metallizable photosensitive developing substrate comprises a light sensitive material. An exposure and development process is performed on the metallizable photosensitive developing substrate to form a plurality of blind holes on each metallizable photosensitive developing substrate, and the blind holes expose a portion of the first patterned wiring layer. An electroless plating process is performed to form an electroless plating seed layer on the metallizable photosensitive developing substrate, and the electroless plating seed layer covers an inner wall of each blind hole. Forming a second patterned circuit layer, wherein the second patterned circuit layer is disposed on the electroless plating seed layer and filled in the blind hole to be electrically connected to the first patterned circuit layer.

In an embodiment of the invention, the substrate further includes an insulating substrate, and the first patterned circuit layer is disposed on the insulating substrate.

In an embodiment of the invention, the substrate further includes a through hole penetrating the insulating substrate, and the first patterned circuit layer covers an inner wall of the through hole.

In an embodiment of the invention, the substrate further includes a filler filled in the through hole.

In an embodiment of the invention, the material of the metallizable photosensitive developing substrate comprises polyimide (PI).

In an embodiment of the invention, the material of each of the electroless plating seed layers includes nickel.

In an embodiment of the invention, the material of each of the second patterned circuit layers includes copper.

In an embodiment of the invention, the step of providing a substrate further comprises the step of providing an insulating substrate. A through hole is formed on the insulating substrate, wherein the through hole penetrates the insulating substrate. A first patterned wiring layer is formed on the insulating substrate, and the first patterned wiring layer covers an inner wall of the through hole.

In an embodiment of the invention, the method for fabricating the circuit board structure further includes the steps of: providing a filler material in the through hole to fill the through hole.

In an embodiment of the invention, the step of forming a blind via comprises: forming a patterned dry film layer on the plurality of removal regions of the metallizable photosensitive development substrate, wherein the positions of the removal regions are respectively blind hole. An exposure process is performed to expose a portion of the metallizable photosensitive development substrate that is not covered by each patterned dry film layer. A developing process is performed to remove the unexposed removal zone to form a blind spot. The patterned dry film layer is removed.

In an embodiment of the invention, the step of forming a blind via comprises: forming a patterned dry film layer on the metallizable photosensitive developing substrate, wherein the patterned dry film layer exposes a plurality of removal regions, and The positions of the removed areas correspond to blind holes, respectively. An exposure process is performed to expose the exposed removal area. A developing process is performed to remove the exposed removed areas to form a blind spot. The patterned dry film layer is removed.

In an embodiment of the invention, the step of forming the second patterned circuit layer comprises: forming a metal layer on the electroless plating seed layer. A patterned dry film layer is formed on the metal layer, and the patterned dry film layer covers at least a portion of the metal layer filled in the blind via. An etching process is performed to remove a portion of the metal layer not covered by the patterned dry film layer to form a second patterned circuit layer. The patterned dry film layer is removed.

In an embodiment of the invention, the step of forming the second patterned circuit layer comprises: forming a patterned dry film layer on the electroless plating seed layer, and the patterned dry film layer exposing at least the blind holes. An electroplating process is performed by patterning the dry film layer as a mask to form a second patterned circuit layer. The patterned dry film layer is removed to expose a portion of the underlying electroless seed layer. An etching process is performed to remove the exposed portion of the electroless plating seed layer.

Based on the above, the present invention utilizes a light-sensitive property of a metallizable photosensitive developing substrate to perform an exposure and development process to form a plurality of blind holes on the metallizable photosensitive developing substrate. Moreover, the present invention forms an electroless plating seed layer on the surface of the metallizable photosensitive developing substrate by an electroless plating process, so as to form a patterned wiring layer by using an electroless plating seed layer as a conductive path for electroplating, and patterning the circuit layer. Filled in the blind hole to electrically connect the patterned circuit between the stacked holes through the blind hole. Therefore, the invention effectively simplifies the manufacturing steps of the circuit board structure and improves the process efficiency. In addition, the present invention can also avoid the problem that the glue generated by the laser drilling in the conventional blind hole process remains in the blind hole, thereby improving the process yield of the circuit board structure.

The above described features and advantages of the invention will be apparent from the following description.

The above and other technical contents, features, and advantages of the present invention will be apparent from the following detailed description of the embodiments of the invention. The directional terms mentioned in the following embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only directions referring to the additional schema. Therefore, the directional terminology used is for the purpose of illustration and not limitation. Also, in the following embodiments, the same or similar elements will be given the same or similar reference numerals.

1A through 1H are schematic cross-sectional views showing a process of fabricating a circuit board structure in accordance with an embodiment of the present invention. The manufacturing method of the circuit board structure of this embodiment includes the following steps. First, a substrate 110 as shown in FIG. 1A is provided, wherein the substrate 110 includes an upper surface 112, a lower surface 114 opposite the upper surface 112, and a first patterned wiring layer 116. In detail, the method of forming the substrate 110 described above may, for example, first provide an insulating substrate 111. Next, a through hole 118 is formed on the insulating substrate 111, wherein the through hole 118 penetrates the insulating substrate 111. Then, a first patterned circuit layer 116 is formed on the insulating substrate 111, and the first patterned circuit layer 116 covers an inner wall of the through hole 118, and a filler 119 is disposed in the through hole 118 to fill the through hole. 118, a substrate 110 as shown in FIG. 1A can be formed. Of course, this embodiment is for illustrative purposes only, and the present invention does not limit the method of forming the substrate 110 and the form of the substrate 110.

Next, referring to FIG. 1B, a metallizable photosensitive developing substrate 120 is disposed on the upper surface 112 and the lower surface 114 of the substrate 110. The material of the metallizable photosensitive developing substrate 120 includes a light sensitive material and a polycrystalline material. Amine (PI). In this embodiment, the metallizable photosensitive developing substrate 120 can be a positive photoresist or a negative photoresist to facilitate subsequent exposure and development processes to the metallizable photosensitive developing substrate 120. If the metallizable photosensitive developing substrate 120 is a negative photoresist, the metallized photosensitive developing substrate 120 is cured after exposure and cannot be dissolved in the developing solution. Conversely, if the metallizable photosensitive developing substrate 120 is made into a positive light When the resist is formed, the metallized photosensitive developing substrate 120 is cracked after being exposed, and is extremely soluble in the developing solution. Also, the metallizable photosensitive developing substrate 120 can be, for example, a substrate subjected to a special activation and sensitization treatment to facilitate subsequent electroless plating processes thereon.

Next, referring to FIG. 1C and FIG. 1D, an exposure and development process is performed on the metallizable photosensitive developing substrate 120 to form a plurality of blind holes 122 as shown in FIG. 1D on each metallizable photosensitive developing substrate 120. And the blind via 122 exposes a portion of the first patterned wiring layer 116. In this embodiment, the blind via 122 can be a via for electrically connecting any two adjacent patterned circuit layers in the circuit board structure. It should be noted that in the embodiment shown in FIG. 1C, the metallizable photosensitive developing substrate 120 is a negative photoresist, that is, the metallizable photosensitive developing substrate 120 is cured after exposure. Dissolved in the developer. As such, the foregoing exposure and development process may include the following steps: First, a patterned dry film layer 150 is formed on the metallizable photosensitive developing substrate 120 as shown in FIG. 1C, wherein each patterned dry film layer 150 is covered. A plurality of removal regions of the photosensitive developing substrate 120 can be metalized. In the present embodiment, the positions of the removed areas correspond to the blind holes 122 as shown in FIG. 1D, respectively. Thereafter, an exposure process is performed to expose a portion of the metallizable photosensitive developing substrate 120 that is not covered by the patterned dry film layer 150. That is, the region of the metallizable photosensitive developing substrate 120 other than the removal region is subjected to ultraviolet light to cause a qualitative change, and the region of the metallizable photosensitive developing substrate 120 other than the removed region is solidified and becomes Not soluble in the developer. Thereafter, a developing process is further performed. Since the removed region is covered by the patterned dry film layer 150 and is not exposed to ultraviolet light, the removed region corresponding to the blind via 122 is dissolved in the developing solution of the developing process, and thus is movable. The removed regions, which are covered by the patterned dry film layer 150 and are not exposed, are formed to form a plurality of blind vias 122 as shown in FIG. 1D, after which the patterned dry film layer 160 is removed.

Of course, in other embodiments, the metallizable photosensitive developing substrate 120 may also be a positive photoresist, that is, the metallizable photosensitive developing substrate 120 may be cracked after exposure to become extremely soluble in the developing solution. In this case, the formation of the blind vias 122 can be performed by forming the patterned dry film layer 160 on the metallizable photosensitive developing substrate 120 as shown in FIG. 2, wherein each patterned dry film layer 160 is as shown in FIG. The exposure can be metallized to remove a plurality of removal regions R1 of the photosensitive developing substrate 120. Thereafter, an exposure process such as ultraviolet rays is further performed to expose the removal region R1 of the metallizable photosensitive developing substrate 120. That is, the removal region R1 of the metallizable photosensitive developing substrate 120 is subjected to ultraviolet light to cause a qualitative change, so that the removal region R1 of the metallizable photosensitive developing substrate 120 is cracked and becomes extremely soluble in development. In the liquid. Thereafter, a further development process is performed, and since the removal region R1 is subjected to ultraviolet light to cause a qualitative change, the removal region R1 is dissolved in the developer in the development process, and thus the patterned dry film layer 160 is removed and exposed. The exposed region R1 is exposed to form a plurality of blind vias 122 as shown in FIG. 1D. The patterned dry film layer 160 can then be removed. The present invention does not limit the type of photoresist that can be metallized to the photosensitive developing substrate 120, and as long as it has light-sensitive properties, it can be directly patterned by an exposure and development process.

Next, referring to FIG. 1E, an electroless plating process is performed to form an electroless plating seed layer 130 on the metallizable photosensitive developing substrate 120, and the electroless plating seed layer 130 covers the inner walls of the blind holes 122. Specifically, the electroless plating seed layer 130 covers the surface of the metallizable photosensitive developing substrate 120 in a comprehensive manner and extends into each of the blind holes 122.

In the above, the electroless plating process deposits a plating layer on the surface of the metallizable photosensitive developing substrate 120 by a chemical redox reaction. In the present embodiment, the material of the electroless plating seed layer 130 includes nickel, that is, the electroless plating seed layer 130 of the present embodiment may be an electroless nickel plating layer. Specifically, electroless nickel plating is a method of reducing deposition of nickel ions in a solution onto a catalytically active surface with a reducing agent. For example, in this embodiment, for example, the photosensitive substrate can be subjected to special activation and sensitization treatment to form the metallizable photosensitive developing substrate 120 of the present embodiment. As such, the electroless plating process step may include immersing the metallizable photosensitive developing substrate 120 in a mixed solution such as nickel sulfate, sodium dihydrogen phosphate, sodium acetate, boric acid or the like to make it at a certain acidity and temperature. A change occurs in which nickel ions in the solution are reduced to atoms by sodium dihydrogen phosphate to be deposited on the surface of the metallizable photosensitive developing substrate 120 to form an electroless plating seed layer 130 as shown in FIG. 1E.

Next, a second patterned wiring layer 142 is formed as shown in FIG. 1H, wherein the second patterned wiring layer 142 is disposed on the electroless plating seed layer 130 and filled in the blind via 122 to be the first The patterned circuit layer 116 is electrically connected. In the present embodiment, the material of the second patterned wiring layer 142 includes copper. In the present embodiment, the second patterned wiring layer 142 can be formed, for example, by a substractive method. Specifically, the step of forming the second patterned circuit layer 142 may be performed by, for example, electroless plating the seed layer 130 as a conductive path to form a metal layer 140 as shown in FIG. 1F on the electroless plating seed layer 130. on. Next, a patterned dry film layer 170 as shown in FIG. 1G is formed on the metal layer 140, and the patterned dry film layer 170 covers at least a portion of the metal layer 140 filled in the blind via 122. Then, an etching process is performed to remove a portion of the metal layer 140 not covered by the patterned dry film layer 170 to form a second patterned wiring layer 142 as shown in FIG. 1H, and then the patterned dry film is removed. Layer 170, that is, the fabrication of the second patterned circuit layer 142 is completed. Thus, the method of fabricating the circuit board structure 100 is substantially completed.

Of course, in other embodiments of the present invention, the second patterned wiring layer 142 may also be formed by a semi-additive method. Specifically, the step of forming the second patterned wiring layer 142 may be formed, for example, after forming the electroless plating seed layer 130 of FIG. 1E, following the process illustrated in FIGS. 3A to 3C. First, a patterned dry film layer 180 as shown in FIG. 3A is formed on the electroless plating seed layer 130, and the patterned dry film layer 180 exposes at least the blind vias 122. Next, referring again to FIG. 3B, an electroplating process is performed by patterning the dry film layer 180 as a mask to form a second pattern wiring layer 142 at a portion exposed by the patterned dry film layer 180. Next, the patterned dry film layer 180 is removed as shown in FIG. 3C to expose a portion of the underlying electroless plating seed layer 130. An etching process is then performed to remove the exposed portion of the electroless plating seed layer 130 to form the wiring board structure 100 as shown in FIG. 1H.

In terms of structure, the circuit board structure 100 can include a substrate 110, a plurality of metallizable photosensitive developing substrates 120, an electroless plating seed layer 130, and a second patterned wiring layer 142 as shown in FIG. 1H. The substrate 110 includes an insulating substrate 111, an upper surface 112, a lower surface 114 opposite the upper surface 112, and a first patterned wiring layer 116 disposed on the insulating substrate 111, as shown in FIG. 1A. In detail, the substrate 110 may include a through hole 118 and a filler 119 penetrating the insulating substrate 111 , and the first patterned wiring layer 116 covers the inner wall of the through hole 118 . The filler 119 can be filled in the through hole 118. The metallizable photosensitive developing substrates 120 are respectively disposed on the upper surface 112 and the lower surface 114 of the substrate 110. Each metallizable photosensitive developing substrate 120 includes a plurality of blind holes 122 that respectively expose at least a portion of the first patterned wiring layer 116, and the material of the metallizable photosensitive developing substrate 120 includes a light sensitive material to facilitate transmission exposure. The metallizable photosensitive developing substrate 120 is directly patterned by a developing process. The electroless plating seed layer 130 is disposed on the metallizable photosensitive developing substrate 120 and covers the inner walls of the blind holes 122. The second patterned circuit layer 142 is respectively disposed on the first electroless plating seed layer 130 and filled in the blind via 122 to be electrically connected to the first patterned wiring layer 116.

In summary, the present invention utilizes a light-sensitive property of a metallizable photosensitive developing substrate to perform an exposure and development process to form a plurality of blind holes on the metallizable photosensitive developing substrate. Moreover, the present invention forms an electroless plating seed layer on the surface of the metallizable photosensitive developing substrate by an electroless plating process, so as to form a patterned wiring layer by using an electroless plating seed layer as a conductive path for electroplating, and patterning the circuit layer. Filled in the blind hole to electrically connect the patterned circuit between the stacked holes through the blind hole. Therefore, the invention effectively simplifies the manufacturing steps of the circuit board structure and improves the process efficiency. In addition, the present invention can also avoid the problem that the glue generated by the laser drilling in the conventional blind hole process remains in the blind hole, thereby improving the process yield of the circuit board structure.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

100‧‧‧Circuit board structure
110‧‧‧Substrate
111‧‧‧Insulating substrate
112‧‧‧ upper surface
114‧‧‧ lower surface
116‧‧‧First patterned circuit layer
118‧‧‧through hole
119‧‧‧Filling materials
120‧‧‧Metalizable photosensitive developing substrate
122‧‧‧Blind hole
130‧‧‧Electroplating seed layer
140‧‧‧metal layer
142‧‧‧Second patterned circuit layer
150, 160, 170, 180‧‧‧ patterned dry film
R1‧‧‧Remove area

1A through 1H are schematic cross-sectional views showing a process of fabricating a circuit board structure in accordance with an embodiment of the present invention. 2 is a partial cross-sectional view showing a method of fabricating a circuit board structure in accordance with another embodiment of the present invention. 3A-3C are partial cross-sectional schematic views showing a method of fabricating a circuit board structure in accordance with another embodiment of the present invention.

100‧‧‧Circuit board structure

110‧‧‧Substrate

116‧‧‧First patterned circuit layer

118‧‧‧through hole

119‧‧‧Filling materials

120‧‧‧Metalizable photosensitive developing substrate

122‧‧‧Blind hole

130‧‧‧Electroplating seed layer

142‧‧‧Second patterned circuit layer

Claims (14)

A circuit board structure comprising: a substrate comprising an upper surface, a lower surface opposite the upper surface, and a first patterned circuit layer; a plurality of metallizable photosensitive developing substrates respectively disposed on the upper surface and the lower surface The surface of each of the metallizable photosensitive developing substrates comprises a plurality of blind holes respectively exposing at least a portion of the first patterned wiring layer, and each of the materials of the metallizable photosensitive developing substrate comprises a light sensitive material An electroless plating seed layer disposed on the metallizable photosensitive developing substrate and covering an inner wall of each of the blind holes; and a second patterned circuit layer respectively disposed on the first electroless plating seed layer And filling in the blind holes to electrically connect with the first patterned circuit layer. The circuit board structure of claim 1, wherein the substrate further comprises an insulating substrate, and the first patterned circuit layer is disposed on the insulating substrate. The circuit board structure of claim 2, wherein the substrate further comprises a through hole penetrating the insulating substrate, the first patterned circuit layer covering an inner wall of the through hole. The circuit board structure of claim 3, wherein the substrate further comprises a filler material filled in the through hole. The circuit board structure of claim 1, wherein the material of the metallizable photosensitive developing substrate comprises polyimide (PI). The circuit board structure of claim 1, wherein the material of each of the electroless plating seed layers comprises nickel. The circuit board structure of claim 1, wherein the material of each of the second patterned circuit layers comprises copper. A method for fabricating a circuit board structure, comprising: providing a substrate, wherein the substrate comprises an upper surface, a lower surface opposite to the upper surface, and a first patterned circuit layer; each of which is provided with a metallizable photosensitive developing substrate The upper surface and the lower surface, wherein the material of each of the metallizable photosensitive developing substrates comprises a light sensitive material; and the metallizable photosensitive developing substrate is subjected to an exposure and development process for each of the metallizable photosensitive developing groups Forming a plurality of blind holes on the material, the blind holes exposing a portion of the first patterned circuit layer; performing an electroless plating process to form an electroless plating seed layer on the metallizable photosensitive developing substrates, and An electroless plating seed layer covers an inner wall of each of the blind holes; and a second patterned circuit layer is formed, wherein the second patterned circuit layer is disposed on the electroless plating seed layer and filled in the blind holes to Electrically connected to the first patterned circuit layer. The method for fabricating a circuit board structure according to claim 8, wherein the step of providing the substrate further comprises: providing an insulating substrate; forming a through hole on the insulating substrate, wherein the through hole penetrates the insulating base And forming the first patterned circuit layer on the insulating substrate, and the first patterned circuit layer covers an inner wall of the through hole. The method for fabricating a circuit board structure according to claim 8, further comprising: providing a filler material in the through hole to fill the through hole. The method for fabricating a circuit board structure according to claim 8, wherein the forming the blind holes comprises: forming a patterned dry film layer on the plurality of removal regions of the metallizable photosensitive developing substrates Wherein the positions of the removed regions respectively correspond to the blind holes; performing an exposure process to expose a portion of the metallizable photosensitive developing substrate not covered by each of the patterned dry film layers; a process to remove the unexposed portions of the removal to form the blind spots; and removing the patterned dry film layer. The method for fabricating a circuit board structure according to claim 8, wherein the forming the blind holes comprises: forming a patterned dry film layer on the metallizable photosensitive developing substrates, wherein the patterning The dry film layer exposes a plurality of removal regions, and the positions of the removal regions respectively correspond to the blind holes; performing an exposure process to expose the exposed regions to be exposed; performing a development process to Removing the removed regions that are exposed to form the blind spots; and removing the patterned dry film layer. The method for fabricating a circuit board structure according to claim 8, wherein the forming the second patterned circuit layer comprises: forming a metal layer on the electroless plating seed layer; forming a patterned dry film layer And the patterned dry film layer covers at least a portion of the metal layer filled in the blind holes; performing an etching process to remove a portion of the metal layer not covered by the patterned dry film layer And forming the second patterned circuit layer; and removing the patterned dry film layer. The method for fabricating a circuit board structure according to claim 8, wherein the forming the second patterned circuit layer comprises: forming a patterned dry film layer on the electroless plating seed layer, and the patterning is dry The film layer exposes at least the blind holes; performing an electroplating process by using the patterned dry film layer as a mask to form the second pattern circuit layer; and removing the patterned dry film layer to expose the underlying portion of the electroless plating a seed layer; and performing an etching process to remove the exposed portion of the electroless seed layer.