This application claims the priority benefit of Taiwan application serial no. 112102586, filed on Jan. 19, 2023. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
The disclosure relates to a substrate structure and a manufacturing method thereof, and more particularly to a circuit board structure and a manufacturing method thereof.
With the advancement and development of science and technology, the circuit board structure is developing towards miniaturization and high integration. Generally speaking, in the design of a fine pitch pad, the opening of the solder mask is usually used to define the pad, and then a corresponding solder ball is planted on the pad for joining with other components. However, with such a joining method, the solder ball is easy to break at the interface between the solder ball and the pad, resulting in the solder ball falling off and reducing reliability. In addition, the opening of the solder mask requires precise alignment, otherwise it is easy to expose the pad and cause abnormality, resulting in a drop in yield.
The disclosure provides a circuit board structure and a manufacturing method thereof, which may enhance the alignment tolerance of the process through the simplified process, thereby increasing the process yield. The circuit board structure may also have more wire routing space and the reliability of the conductive terminal may be enhanced.
The circuit board structure of the disclosure includes a line portion, a first insulating layer, and a conductive terminal. The first insulating layer is disposed on the line portion. The conductive terminal is disposed on the first insulating layer and embedded in the first insulating layer to be electrically connected with the line portion. The conductive terminal includes a first portion, a second portion, and a third portion. The first portion protrudes from a surface of the first insulating layer. The second portion is embedded in the first insulating layer and connected to the first portion. The third portion is disposed between the line portion and the second portion. A width of the second portion is greater than a width of the third portion.
In an embodiment of the disclosure, the third portion has a first width on a side close to the line portion, the third portion has a second width on a side away from the line portion, and the first width is greater than the second width.
In an embodiment of the disclosure, the above circuit board structure further includes a conductive connecting member disposed between the third portion and the line portion.
In an embodiment of the disclosure, a side of the conductive connecting member in contact with the third portion has a third width, a side of the conductive connecting member in contact with the line portion has a fourth width, and the fourth width is greater than the third width.
In an embodiment of the disclosure, the third width is substantially equal to the first width.
In an embodiment of the disclosure, an included angle between a side wall of the third portion and a top surface of the conductive connecting member is between 30 degrees and 85 degrees.
In an embodiment of the disclosure, the circuit board structure further includes a carrier, and the line portion is disposed on the carrier.
The manufacturing method of the circuit board structure of the disclosure includes the following process. A line structure is formed on a first carrier. The line structure has a first surface and a second surface opposite the first surface, and the first surface faces the first carrier. The line structure includes a first pad layer, a first insulating layer, a line portion, and a conductive connection portion. The first pad layer is close to the first surface of the line structure and disposed on the first carrier. The first insulating layer covers the first pad layer. The line portion is disposed on the first insulating layer. The conductive connection portion penetrates the first insulating layer, so that the line portion is electrically connected to the first pad layer; Afterwards, the first carrier is removed to expose the first surface of the line structure. The first pad layer is removed to form a first opening. A portion of the conductive connection portion is removed to form a second opening, and a conductive connecting member is formed by the conductive connection portion that has not been removed. The second opening and the first opening are connected to each other and expose the conductive connecting member, and a width of the first opening is greater than a width of the second opening. A conductive terminal is formed in the first opening and the second opening.
In an embodiment of the disclosure, the second opening has a first width on a side close to the conductive connecting member, the second opening has a second width on a side away from the conductive connecting member, and the first width is greater than the second width.
In an embodiment of the disclosure, a method of removing the first pad layer and removing the portion of the conductive connection portion includes wet etching.
In an embodiment of the disclosure, an etchant used in the wet etching includes sodium persulfate solution, sulfuric acid-hydrogen peroxide solution, nitric acid solution, copper chloride solution, or ammonium chloride solution.
In an embodiment of the disclosure, before removing the first carrier, a second carrier is disposed on the second surface of the line structure.
In an embodiment of the disclosure, a depth of the second opening is half of a height of the conductive connection portion before being partially removed.
Based on the above, the conductive terminal of the circuit board structure of the disclosure includes the first portion protruding from the insulating layer and the second portion and third portion embedded in the insulating layer, which may save the space of a portion of the pad and make the space more effective for wire routing design. In addition, through the design of a narrow top and wide bottom structure in the third portion, the conductive terminal is effectively fixed in the insulating layer, thereby reducing the possibility of the conductive terminal breaking and falling off and improving the reliability thereof. The manufacturing method of the circuit board structure of the disclosure uses the etching conductive portion to form the opening of the conductive terminal, which may improve the alignment tolerance in the process, simplify the process, and increase the process yield.
In the drawings, for clarity, the thickness of layers, films, plates, areas, and the like are magnified. Throughout the specification, the same reference numerals denote the same elements.
It should be understood that when an element such as a layer, a film, an area, or a substrate is indicated to be “on” another element or “connected to” another element, it may be directly on another element or connected to another element, or an element in the middle may exist. In contrast, when an element is indicated to be “directly on another element” or “directly connected to” another element, an element in the middle does not exist. As used herein. “to connect” may indicate to physically and/or electrically connect. Furthermore, “to electrically connect” or “to couple” may also be used when other elements exist between two elements.
It should be understood that, although the terms “first”, “second”, “third”, or the like may be used herein to describe various elements, components, regions, layers, and/or portions, these elements, components, regions, and/or portions should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Thus, “first element.” “component.” “region,” “layer.” or “portion” discussed below could be termed a second element, component, region, layer, or portion without departing from the teachings herein.
Terms such as “about”, “approximately”. “basically” or “substantially” appearing in the content of the application cover not only the explicitly stated values and numerical ranges, but also a range of permissible deviations that are understandable to those with ordinary knowledge in the technical field of the invention. The deviation range is determined by the error generated during the measurement, and the error is caused by, for example, the limitation of the measurement system or process conditions. Additionally. “about” may mean within one or more standard deviations of the aforementioned values, e.g., within ±20%, ±10%, or ±5%. Terms such as “about”. “approximately”. “basically” or “substantially” appearing in content of the application may refer to a more acceptable deviation range or standard deviation depending on optical properties, etching properties, mechanical properties, or other properties, and all of the above optical properties, etching properties, mechanical properties, and other properties may not be applied with one standard deviation.
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In detail, regarding the manufacturing method of the line structure ST, the first carrier 100 may be first provided, as shown in
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The first insulating layer 122 has a first inner side wall 122a, a second inner side wall 122b, and a connecting surface 122c connecting the first inner side wall 122a and the second inner side wall 122b. After removing the first pad layer 112 and a portion of the conductive connection portion CV1, the first inner side wall 122a, the second inner side wall 122b, and the connecting surface 122c are exposed. The first inner side wall 122a is connected to the first surface S1. The first inner side wall 122a, the connecting surface 122c, and the second inner side wall 122b may define an opening OP with a stepped side wall, and the opening OP may include the first opening OP1 and the second opening OP2 connected to each other. The first opening OP1 is defined by the first inner side wall 122a, and the second opening OP2 is defined by the second inner side wall 122b. A width w1 of the first opening OP1 is greater than a width w2 of the second opening OP2, so that the conductive connecting member CV1′ is exposed by the opening OP (namely, the first opening OP1 and the second opening OP2).
In some embodiments, a depth h1 of the second opening OP2 (i.e., the distance from the top surface of the conductive connecting member CV1′ to the connecting surface 122c) is half of a height h2 of the conductive connection portion CV1 before being partially removed, but the disclosure is not limited thereto. The depth h1 of the second opening OP2 may be adjusted by controlling the etching time according to actual requirements.
The second inner side wall 122b is an inclined side wall to define a second opening OP2 with a narrow top and a wide bottom. That is, the second opening OP2 has a first width w21 on a side close to the conductive connecting member CV1′, the second opening OP2 has a second width w22 on a side away from the conductive connecting member CV1′, and the first width w21 is greater than the second width w22.
Forming the opening OP on the first insulating layer 122 using the above method may simplify the process and increase the alignment tolerance, thereby increasing the process yield.
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In some embodiments, a maximum width w3 of the first portion 130a is greater than a width w4 of the second portion 130b, and the width w4 of the second portion 130b is greater than a width w5 of the third portion 130c. Since the third portion 130c has an inclined side wall, the width w5 of the third portion 130c changes with its height. The third portion 130c has a first width w51 on a side close to the first conductive layer 114, the third portion 130c has a second width w52 on a side away from the first conductive layer 114, and the first width w51 is greater than the second width w52. It is seen that the third portion 130c is a structure with a narrow top and a wide bottom. Since the third portion 130c is a structure with a narrow top and a wide bottom, the conductive terminal 130 is effectively fixed on the first insulating layer 122, thereby reducing the possibility of the conductive terminal 130 falling off.
In some embodiments, the maximum width w3 of the first portion 130a may be between 50 μm and 220 μm. The width w4 of the second portion 130b is between 50 μm and 200 μm. The first width w51 of the third portion 130c may be between 12.5 μm and 57.5 μm, and the second width w52 of the third portion 130c may be between 10 μm and 55 μm. However, the sizes of the first portion 130a, the second portion 130b, and the third portion 130c are not limited thereto. The first portion 130a, the second portion 130b, and the third portion 130c may be adjusted according to actual requirements, as long as the width w4 of the second portion 130b is greater than the width w5 of the third portion 130c and the first width w51 of the third portion 130c is greater than the second width w52 of the third portion 130c.
In some embodiments, a side of the conductive connecting member CV1′ in contact with the third portion 130c has a third width w61, a side of the conductive connecting member CV1′ in contact with the line portion L1 has a fourth width w62, and the fourth width w62 is greater than the third width w61. In some embodiments, the third width w61 of the conductive connecting member CV1′ is basically the same as the first width w51 of the third portion 130c. In some embodiments, the fourth width w62 of the conductive connecting member CV1′ may be between 15 μm and 60 μm, but the disclosure is not limited thereto.
The third portion 130c and the conductive connecting member CV1′ are located in the via V1 of the first insulating layer 122 (marked in
After the above process, a circuit board structure 10 is basically completed.
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In some embodiments, the third portion 130c has a first width w51 on a side close to the line portion L1, the third portion 130c has a second width w52 on a side away from the line portion L1, and the first width w51 is greater than the second width w52. In this way, the conductive terminal 130 is effectively fixed in the first insulating layer 122, thereby reducing the possibility of breaking and falling off of the conductive terminal 130 and improving the reliability of the circuit board structure 10.
In some embodiments, the circuit board structure 10 further includes a conductive connecting member CV1′ embedded in the first insulating layer 122 and disposed between the third portion 130c and the line portion L1. A side of the conductive connecting member CV1′ in contact with the third portion 130c has a third width w61, and a side of the conductive connecting member CV1′ in contact with the line portion L1 has a fourth width w62, and the fourth width w62 is greater than the third width w61. In some embodiments, the third width w61 of the conductive connecting member CV1′ is basically the same as the first width w51 of the third portion 130c. The fourth width w62 of the conductive connecting member CV1′ is larger than the second width w52 of the third portion 130c.
In some embodiments, the conductive connecting member CV1′ overlaps the third portion 130c on a normal direction of the carrier 200.
In some embodiments, an included angle θ between a side wall of the third portion 130c and a top surface of the conductive connecting member CV1′ is between 30 degrees and 85 degrees, so that the conductive terminal 130 is effectively fixed in the first insulating layer 122, thereby reducing the possibility of breaking and falling off of the conductive terminal 130.
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To sum up, the conductive terminal of the circuit board structure of the disclosure includes the first portion protruding from the insulating layer and the second portion and third portion embedded in the insulating layer, which may save the space of a portion of the pad and make the space more effective for wire routing design. In addition, through the design of a narrow top and wide bottom structure of the third portion, the conductive terminal is effectively fixed in the insulating layer, thereby reducing the possibility of breaking and falling off of the conductive terminal and improving the reliability thereof. The manufacturing method of the circuit board structure of the disclosure uses an etching conductive portion to form the opening of the conductive terminal, which may improve the alignment tolerance in the process, simplify the process, and increase the process yield.
Number | Date | Country | Kind |
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112102586 | Jan 2023 | TW | national |