TWI781786B - Co-axial via structure and manufacturing method of the same - Google Patents

Abstract

A co-axial structure includes a substrate, a first conductive structure, a second conductive structure, and an insulating layer. The substrate includes a first surface. The first conductive structure includes a first circuit disposed on the first surface and a first via penetrating the substrate. The second conductive structure includes a second circuit disposed on the first surface and a second via penetrating the substrate. The first via and the second via extend along a first direction. The first circuit and the second circuit extend along a second direction, and the second direction is perpendicular to the first direction. The insulating layer is located between the first via and the second via. The first conductive structure and the second conductive structure are electrically insulated. The first circuit and the second circuit are co-planar.

Description

Coaxial via structure and manufacturing method thereof

The present disclosure relates to a coaxial via structure, in particular to a coaxial via structure with coplanar signal lines and ground lines.

Most of the current coaxial via structures require a build-up process to place a dielectric layer between the ground line and the signal line of different layers, which requires a lot of cost. In addition, since the height of the inner line in the via hole is different from that of the outer line, there will be an impedance mismatch problem. The dielectric layer disposed between the ground wire and the signal wire will also produce shielding gaps, resulting in poor electromagnetic shielding effect.

In view of this, how to provide a coaxial via structure that can improve impedance matching and electromagnetic shielding effects is still one of the goals that the industry needs to study urgently.

One technical aspect of the present disclosure is a coaxial through-hole structure.

In an embodiment of the present disclosure, the coaxial via structure includes a substrate, a first conductive structure, a second conductive structure, and an insulating layer. The substrate has a first surface. The first conductive structure includes a first circuit on the first surface and a first through hole penetrating through the substrate. The second conductive structure includes a second line on the first surface of the substrate and a second through hole penetrating through the substrate. The first through hole and the second through hole extend in a first direction, the first circuit and the second circuit extend in a second direction, and the second direction is perpendicular to the first direction. The insulating layer is located between the first through hole and the second through hole, wherein the first conductive structure is electrically insulated from the second conductive structure, and the first circuit and the second circuit are coplanar.

In an embodiment of the present disclosure, the first through hole of the first conductive structure surrounds the second through hole of the second conductive structure and the insulating layer.

In an embodiment of the disclosure, the insulating layer, the first through hole and the second through hole are coaxial.

In an embodiment of the present disclosure, the insulating layer has a protruding portion located at an end of the insulating layer close to the first surface.

In an embodiment of the present disclosure, the protruding portion of the insulating layer protrudes along the second direction away from the second through hole.

In an embodiment of the present disclosure, the first through hole of the first conductive structure, the protruding portion of the insulating layer, and the second line of the second conductive structure overlap in the first direction.

In an embodiment of the present disclosure, the substrate further includes a second surface opposite to the first surface, and the coaxial via structure further includes a dielectric layer between the first surface and the second surface, and the insulating layer protrudes contact with the dielectric layer.

One technical aspect of the present disclosure is a method for manufacturing a coaxial through-hole structure.

In an embodiment of the present disclosure, the manufacturing method of the coaxial via structure includes forming a first through hole in the substrate; forming a first conductive material on the first surface of the substrate and in the first through hole; forming from the first surface a recessed groove, and make the groove communicate with the first through hole; form an insulating layer in the first through hole and in the groove; form a second conductive material on the first surface of the substrate and in the first through hole; and pattern Thinning the first conductive material and the second conductive material to form the first circuit and the second circuit on the first surface, so that the remaining first conductive material and the remaining second conductive material are electrically connected by the insulating layer in the groove sex insulation, and the first line and the second line are coplanar.

In an embodiment of the present disclosure, the coaxial via structure further includes a second surface opposite to the first surface, and forming the groove further includes drilling holes from the first surface along a first direction.

In an embodiment of the present disclosure, the coaxial via structure further includes a dielectric layer between the first surface and the second surface, and forming the groove further includes exposing the dielectric layer from the first conductive material.

In an embodiment of the present disclosure, forming the insulating layer in the first through hole and the groove further includes forming an insulating layer material in the first through hole and the groove, so that the insulating layer material contacts the dielectric layer; and forming the second through hole Holes are formed in the insulating layer material to form the insulating layer, wherein the insulating layer has a protrusion positioned in the groove.

In an embodiment of the present disclosure, forming the second conductive material on the first surface of the substrate and in the first through hole further includes forming the second conductive material in the second through hole, and making the first through hole in the first through hole The conductive material surrounds the insulating layer and the second conductive material in the second through hole.

In an embodiment of the present disclosure, forming the second conductive material on the first surface of the substrate and the first through hole further includes making the insulating layer, the first conductive material in the first through hole and the first through hole in the second through hole The two conductive materials are coaxial.

In an embodiment of the present disclosure, patterning the first conductive material and the second conductive material to form the first line and the second line further includes making the first conductive material in the first through hole, the protruding portion of the insulating layer, and the second line The two lines overlap in the first direction.

In the above-mentioned embodiments, since the coaxial via structure of the present disclosure has the coplanar first line and the second line, and the first conductive structure and the second conductive structure can be electrically insulated through the insulating layer, the coaxial via structure of the present disclosure The shaft through-hole structure can have better electromagnetic noise shielding and impedance matching effects to improve high-frequency signal integrity. In addition, the disclosed coaxial via structure can reduce the number of dielectric layers to reduce the thickness of the coaxial via structure. Therefore, the coaxial via structure of the present disclosure also has the technical effect of reducing costs.

Several embodiments of the present invention will be disclosed in the following figures. For the sake of clarity, many practical details will be described together in the following description. It should be understood, however, that these practical details should not be used to limit the invention. That is, in some embodiments of the present invention, these practical details are unnecessary. In addition, for the sake of simplifying the drawings, some well-known structures and components will be shown in a simple and schematic manner in the drawings. Also, the thicknesses of layers and regions in the drawings may be exaggerated for clarity, and the same reference numerals denote the same elements in the description of the drawings.

FIG. 1 is a perspective view of a coaxial via structure 100 according to an embodiment of the present disclosure. Figure 2 is a cross-sectional view along line 2-2 in Figure 1 . Refer to Figure 1 and Figure 2 at the same time. The coaxial via structure 100 includes a substrate 110 , a first conductive structure 120 , a second conductive structure 130 and an insulating layer 140 .

The substrate 110 has a first surface 112 and a second surface 114 opposite to each other. The first conductive structure 120 includes a first circuit 122 and a first through hole 124 , and the second conductive structure 130 includes a second circuit 132 and a second through hole 134 . The first wiring 122 and the second wiring 132 are located on the first surface 112 . The first through hole 124 and the second through hole 134 pass through the substrate 110 . The first through hole 124 and the second through hole 134 extend in the first direction D1. The first line 122 and the second line 132 extend in a second direction D2 perpendicular to the first direction D1. The first trace 122 of the first conductive structure 120 is coplanar with the second trace 132 of the second conductive structure 130 . In other words, the first line 122 and the second line 132 are on the same level.

In this embodiment, the first direction D1 is a vertical direction in the figure, that is, the first direction D1 is a direction from the first surface 112 to the second surface 114 . The second direction D2 can be any horizontal direction perpendicular to the first direction D1, which will be described first. In this embodiment, the first line 122 and the third line 126 can be ground lines, and the second line 132 and the fourth line 136 can be signal lines, but the disclosure is not limited thereto.

As shown in FIG. 2 , the first conductive structure 120 further includes a third circuit 126 on the second surface 114 , and the second conductive structure 130 further includes a fourth circuit 136 on the second surface 114 . Two ends of the first through hole 124 are respectively connected to the first circuit 122 and the third circuit 126 . Two ends of the second through hole 134 are respectively connected to the second circuit 132 and the fourth circuit 136 . The third line 126 and the fourth line 136 extend in the second direction D2, and the third line 126 and the fourth line 136 are coplanar. In other words, the third line 126 and the fourth line 136 are on the same level.

The insulating layer 140 is located between the first through hole 124 and the second through hole 134 , and the insulating layer 140 extends in the first direction D1. The first through hole 124 surrounds the second through hole 134 and the insulating layer 140 , and the insulating layer 140 surrounds the second through hole 134 . As shown in FIG. 2 , the insulating layer 140 , the first through hole 124 and the second through hole 134 are coaxial with respect to the axis A. As shown in FIG.

The insulating layer 140 has a first protruding portion 142 , and the first protruding portion 142 is located at an end of the insulating layer 140 close to the first surface 112 . The first protrusion 142 protrudes away from the second through hole 134 along the second direction D2. As shown in FIG. 2 , the substrate 110 further includes a dielectric layer 150 between the first surface 112 and the second surface 114 . In this embodiment, the substrate 110 further includes multilayer internal circuits 116 separated by the dielectric layer 150 , but the disclosure is not limited thereto. The first protrusion 142 of the insulating layer 140 contacts the dielectric layer 150 close to the first surface 112 . In other words, the first protruding portion 142 extends to the dielectric layer 150 through the first through hole 124 .

It should be understood that, in order to clearly show the structural relationship between the second line 132 and the first protruding portion 142, only the first through hole 124, the second line 132, and the insulating layer 140 are shown in FIG. One line 122.

As shown in FIG. 2 , the first through hole 124 of the first conductive structure 120 , the first protrusion 142 of the insulating layer 140 , and the second line 132 of the second conductive structure 130 overlap in the first direction D1 . The second line 132 of the second conductive structure 130 extends from the second through hole 134 and crosses the first protrusion 142 . In other words, the first through hole 124 and the second circuit 132 are electrically insulated by the first protrusion 142 , and the coplanar first circuit 122 and the second circuit 132 are separated from each other, so that the first conductive structure 120 and the second circuit 132 are separated from each other. The second conductive structure 130 is electrically insulated.

According to the above, since the first line 122 and the second line 132 of the coaxial via structure 100 are coplanar, and the first conductive structure 120 and the second conductive structure 130 are electrically insulated, the addition of an additional dielectric layer in the past can be omitted. A step of electrically isolating the first wiring on different layers from the second wiring. In this way, the first through hole 124 and the second through hole 134 in this application may have roughly the same height, so that the overall structure of the coaxial through hole structure 100 is more symmetrical, thereby improving the effect of impedance matching. In addition, since the present invention can omit the dielectric layer between the first circuit and the second circuit in different layers, the situation that the second through hole 134 protrudes out of the insulating layer is avoided. In this way, the coaxial through-hole structure in this case can avoid the problem of poor electromagnetic shielding effect caused by the gap in the shielding structure.

As shown in FIG. 2 , the insulating layer 140 also has a second protruding portion 144 , and the second protruding portion 144 is located at an end of the insulating layer 140 close to the second surface 114 . The second protrusion 144 protrudes away from the second through hole 134 along the second direction D2. The second protrusion 144 of the insulating layer 140 contacts the dielectric layer 150 near the second surface 114 . In other words, the second protrusion 144 extends to the dielectric layer 150 through the first through hole 124 .

As shown in FIG. 2 , the first through hole 124 of the first conductive structure 120 , the second protrusion 144 of the insulating layer 140 , and the fourth line 136 of the second conductive structure 130 overlap in the first direction D1 . The fourth line 136 of the second conductive structure 130 extends from the second through hole 134 and crosses the second protrusion 144 . In other words, the first through hole 124 and the fourth circuit 136 are electrically insulated by the second protrusion 144, and the third circuit 126 and the fourth circuit 136 are separated from each other, thereby making the first conductive structure 120 and the second conductive structure 120 electrically insulated. Structure 130 is electrically insulated. As mentioned above, the extending direction of the fourth line 136 can be any horizontal direction perpendicular to the first direction D1, FIG. 2 is only an example, and the present disclosure is not limited thereto.

It should be understood that the connection relationship, materials and functions of the components that have been described will not be repeated, and will be described first. In the following description, the manufacturing method of the coaxial via structure will be described.

FIG. 3A to FIG. 10A are top views of intermediate steps of a method for manufacturing a coaxial via structure according to an embodiment of the present disclosure. Figures 3B to 10B are cross-sectional views along line 3B-3B to line 10B-10B in Figures 3A to 10B, respectively. As shown in FIG. 3A and FIG. 3B , the manufacturing method of the coaxial via structure begins with forming the first through hole OP1 in the substrate 110 . The first through hole OP1 penetrates through the internal circuit 116 and the dielectric layer 150 of the substrate 110 . For example, the method of forming the first through hole OP1 may be laser drilling.

As shown in FIG. 4A and FIG. 4B, in the manufacturing method of the coaxial through hole structure, the first conductive material 120M is then formed on the first surface 112, on the second surface 114 and in the first through hole OP1 on the wall. The method of forming the first conductive material 120M is, for example, electroplating, and the first conductive material 120M is, for example, copper, but the present disclosure is not limited thereto, and those skilled in the art can select appropriate methods and materials according to actual conditions.

As shown in FIG. 5A and FIG. 5B , in the manufacturing method of the coaxial through-hole structure, the first groove TR1 is formed next. The first groove TR1 is recessed from the first surface 112 , and the first groove TR1 communicates with the first through hole OP1 . The method of forming the first groove TR1 includes drilling from the first surface 112 along the first direction D1, and exposing the dielectric layer 150 close to the first surface 112 from the first conductive material 120M.

Referring to FIG. 5B, this step also includes forming a second groove TR2. The second groove TR2 is recessed from the second surface 114 , and the second groove TR2 communicates with the first through hole OP1 . The method of forming the second groove TR2 includes drilling from the second surface 114 along the direction opposite to the first direction D1, and exposing the dielectric layer 150 close to the second surface 114 from the first conductive material 120M. For example, the method of forming the first groove TR1 and the second groove TR2 may be laser drilling.

In the top view of FIG. 5A, the distance between the first groove TR1 and the first through hole OP1 can be calculated according to the width of the second line 132 and the required distance between the first line 122 and the second line 132 . Similarly, in a bottom view (not shown), the distance between the second groove TR2 and the first through hole OP1 can be determined according to the width of the fourth line 136 and the required distance between the third line 126 and the fourth line 136 calculated.

As shown in FIG. 6A and FIG. 6B, in the manufacturing method of the coaxial via hole structure, the insulating layer material 140M is then filled into the first through hole OP1, the first groove TR1 and the second groove TR2, and The insulating layer material 140M is made to contact the dielectric layer 150 exposed from the first conductive material 120M. In this embodiment, the insulating layer material 140M can be, for example, hole-filling ink, but the disclosure is not limited thereto. After filling the insulating layer material 140M, the exposed parts of the insulating layer material 140M from the first surface 112 and the second surface 114 are ground so that the upper surface and the lower surface of the insulating layer 140 are respectively flush with the first conductive material 120M.

As shown in FIG. 7A and FIG. 7B , in the manufacturing method of the coaxial via structure, the second through hole OP2 is then formed in the insulating layer material 140M. In this embodiment, the second through hole OP2 and the first through hole OP1 are concentric circles. For example, the method of forming the second through hole OP2 is laser drilling, thereby removing a part of the insulating layer material 140M. After the second through hole OP2 is formed, the remaining insulating layer material 140M includes the part (ie, the insulating layer 140 ) located in the first through hole OP1 and the first protruding portion 142 and the second protruding portion 142 respectively located on both sides of the substrate 110 . protrusion 144 .

As shown in FIG. 8A and FIG. 8B , in the manufacturing method of the coaxial via structure, the second conductive material 130M is then formed on the first surface 112 , on the second surface 114 and in the second through hole OP2 . The method of forming the first conductive material 120M can be, for example, electroplating, and the first conductive material 120M is, for example, copper, but the present disclosure is not limited thereto, and those skilled in the art can select appropriate methods and materials according to actual conditions.

The second conductive material 130M is located in the second through hole OP2, and the first conductive material 120M in the first through hole OP1 (that is, the first through hole 124) surrounds the insulating layer 140 and the second conductive material in the second through hole OP2. The material 130M (that is, the second through hole 134 ) makes the insulating layer 140 , the first conductive material 120M in the first through hole OP1 , and the second conductive material 130M in the second through hole OP2 are coaxial with respect to the axis A.

As shown in FIG. 9A and FIG. 9B , in the manufacturing method of the coaxial via structure, a mask 160 is then formed on the first surface 112 and the second surface 114 . The photomask 160 includes patterns for forming the first lines 122 and the second lines 132 and patterns for forming the third lines 126 and the fourth lines 136 .

As shown in FIG. 10A and FIG. 10B , in the manufacturing method of the coaxial via structure, the first conductive material 120M and the second conductive material 130M are then patterned by a photomask 160 . The second conductive material 130M and the first conductive material 120M exposed from the photomask 160 are successively removed until the insulating layer 140 and the dielectric layer 150 are exposed from the photomask 160 .

Also refer to Figures 10A, 10B, 11A and 11B. In the manufacturing method of the coaxial via structure, the photomask 160 is finally removed, and the insulating protection layer 170 is formed. The insulating protection layer 170 has openings for connecting conductive elements, such as metal bumps, bumps or solder balls (not shown).

As shown in FIG. 11B , after the above steps, the first lines 122 and the second lines 132 separated from each other can be formed, and the first lines 122 and the second lines 132 are coplanar. The first through hole 124 is electrically insulated from the second circuit 132 by the first protrusion 142 in the first groove TR1. The first circuit 122 may include any circuit pattern, as long as the first circuit 122 is electrically insulated from the second circuit 132 .

Likewise, after the above steps, the third lines 126 and the fourth lines 136 separated from each other can be formed, and the third lines 126 and the fourth lines 136 are coplanar. The first through hole 124 is electrically insulated from the fourth circuit 136 by the second protrusion 144 in the second groove TR2. The third circuit 126 may include any circuit pattern (not shown), as long as the third circuit 126 is electrically insulated from the fourth circuit 136 .

See Figure 11A. In this example, the second line 132 has a width W1, and the connection between the insulating layer 140 and the first protrusion 142 has a width W2. The width W2 can be correspondingly adjusted by changing the distance between the first groove TR1 and the first through hole OP1, and the width W2 can also depend on the diameter of the first groove TR1. Therefore, according to the required width W1, an appropriate distance between the first groove TR1 and the first through hole OP1 can be calculated in the step of forming the first groove TR1. In this way, the width W2 can be ensured to be wide enough to reduce the risk of disconnection of the second circuit 132 . There is an interval I between the second line 132 and the adjacent first line 122 . Under the limitation of specific impedance requirements, the distance I can be determined according to the width W1 and thickness of the second line 132 and the parameters of the dielectric layer 150 , so as to improve the impedance matching effect.

In summary, since the coaxial via structure of the present disclosure has coplanar ground lines and signal lines (the first line and the second line), and the first conductive structure and the second conductive structure can be electrically insulated through the insulating layer , so the coaxial via structure of the present disclosure can have better electromagnetic noise shielding and impedance matching effects, so as to improve the integrity of high-frequency signals. In addition, the disclosed coaxial via structure can reduce the number of dielectric layers to reduce the thickness of the coaxial via structure. Therefore, the coaxial via structure of the present disclosure also has the technical effect of reducing costs.

Although the present invention has been disclosed above in terms of implementation, it is not intended to limit the present invention. Anyone skilled in this art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection of the present invention The scope shall be defined by the appended patent application scope.

100: coaxial through-hole structure 110: Substrate 112: first surface 114: second surface 116: Internal wiring 120: the first conductive structure 120M: The first conductive material 122: The first line 124: the first through hole 126: The third line 130: second conductive structure 130M: Second conductive material 132: second line 134: Second through hole 136: The fourth line 140: insulating layer 140M: insulating layer material 142: The first protrusion 144: second protrusion 150: dielectric layer 160: mask 170: insulating protective layer D1: the first direction D2: Second direction OP1: the first through hole OP2: Second through hole TR1: first groove TR2: second groove A: axis 3B-3B, 4B-4B, 5B-5B, 6B-6B, 7B-7B, 8B-8B, 9B-9B, 10B-10B, 11B-11B: line segment W1, W2: width I: Spacing

FIG. 1 is a perspective view of a coaxial via structure according to an embodiment of the present disclosure. Figure 2 is a cross-sectional view along line 2-2 in Figure 1 . FIG. 3A to FIG. 11A are top views of intermediate steps of a method for manufacturing a coaxial via structure according to an embodiment of the present disclosure. Figures 3B to 11B are cross-sectional views along line 3B-3B to line 11B-11B in Figures 3A to 11A, respectively.

110: Substrate 112: first surface 114: second surface 116: Internal wiring 120: the first conductive structure 122: The first line 124: the first through hole 126: The third line 130: second conductive structure 132: second line 134: Second through hole 136: The fourth line 140: insulating layer 142: The first protrusion 144: second protrusion 150: dielectric layer A: axis D1: the first direction D2: Second direction

Claims (14)

A coaxial via structure, comprising: a substrate having a first surface; a first conductive structure comprising a first circuit on the first surface and a first through hole penetrating the substrate; a first Two conductive structures, including a second circuit on the first surface of the substrate and a second through hole penetrating through the substrate, the first through hole and the second through hole extend in a first direction, the first through hole extends in a first direction, and the first through hole extends in a first direction. A line and the second line extend in a second direction, and the second direction is perpendicular to the first direction; and an insulating layer is located between the first through hole and the second through hole, wherein the first through hole A conductive structure is electrically insulated from the second conductive structure, and the first circuit and the second circuit are coplanar. The coaxial via structure as claimed in claim 1, wherein the first via of the first conductive structure surrounds the second via of the second conductive structure and the insulating layer. The coaxial via structure as claimed in claim 1, wherein the insulating layer, the first via hole and the second via hole are coaxial. The coaxial via structure as claimed in claim 1, wherein the insulating layer has a protruding portion located at an end of the insulating layer close to the first surface. The coaxial via structure as claimed in claim 4, wherein the protruding portion of the insulating layer protrudes along the second direction away from the second via hole. The coaxial via structure as claimed in item 4, wherein the first via hole of the first conductive structure, the protrusion of the insulating layer, and the second line of the second conductive structure are on the first side Overlap upwards. The coaxial via structure according to claim 4, wherein the substrate further comprises a second surface opposite to the first surface, and the coaxial via structure further comprises a position between the first surface and the second surface a dielectric layer in between, and the protruding portion of the insulating layer contacts the dielectric layer. A method for manufacturing a coaxial through hole structure, comprising: forming a first through hole in a substrate; forming a first conductive material on a first surface of the substrate and in the first through hole; forming from the first through hole A groove is recessed on the surface, and the groove is communicated with the first through hole; an insulating layer is formed in the first through hole and the groove; a second conductive material is formed in the first through hole of the substrate on the surface and in the first through hole; and patterning the first conductive material and the second conductive material to form a first circuit and a second circuit on the first surface, so that the remaining first The conductive material and the remaining second conductive material pass through the insulation in the groove The insulating layer is electrically insulated, and the first circuit and the second circuit are coplanar. The manufacturing method of the coaxial via structure as claimed in item 8, wherein the coaxial via structure further includes a second surface opposite to the first surface, and forming the groove further includes: from the first surface Holes are drilled along a first direction. The manufacturing method of the coaxial via structure as claimed in item 9, wherein the coaxial via structure further comprises a dielectric layer between the first surface and the second surface, and forming the groove also comprising: exposing the dielectric layer from the first conductive material. The manufacturing method of the coaxial via structure according to claim 10, wherein forming the insulating layer in the first through hole and the groove further includes: forming an insulating layer material in the first through hole and the groove making the insulating layer material contact the dielectric layer; and forming a second through hole in the insulating layer material to form the insulating layer, wherein the insulating layer has a protruding portion located in the groove. The manufacturing method of the coaxial via structure according to claim 11, wherein forming the second conductive material on the first surface of the substrate and in the first through hole further comprises: forming the second conductive material on the first through hole in the second through hole, and make the first conductive material in the first through hole surround the insulating layer and the second through hole in the second conductive material. The manufacturing method of the coaxial via structure according to claim 12, wherein forming the second conductive material on the first surface of the substrate and in the first through hole further comprises: making the insulating layer, the first The first conductive material in the through hole is coaxial with the second conductive material in the second through hole. The manufacturing method of the coaxial via structure according to claim 9, wherein patterning the first conductive material and the second conductive material to form the first circuit and the second circuit further includes: making the first through The first conductive material in the hole, the protrusion of the insulating layer, and the second circuit overlap in the first direction.

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