TW202231137A - 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 through hole structure and manufacturing method thereof

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

Most of the current coaxial via structures require a dielectric layer between the ground lines and signal lines of different layers through a lamination build-up process, which requires a lot of cost. In addition, since the heights of the inner and outer layers in the vias are different, impedance mismatch problems arise. The dielectric layer disposed between the ground wire and the signal wire also creates a shielding gap, resulting in poor electromagnetic shielding effect.

In view of this, how to provide a coaxial through-hole 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 via 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 the substrate. The second conductive structure includes a second circuit on the first surface of the substrate and a second through hole penetrating the substrate. The first through hole and the second through hole extend in the first direction, the first line and the second line extend in the 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 and the second conductive structure are electrically insulated, and the first line and the second line 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 present 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 away from the second through hole along the second direction.

In an embodiment of the present disclosure, the first through hole of the first conductive structure, the protrusion 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 located between the first surface and the second surface, and the insulating layer protrudes The part contacts the dielectric layer.

One technical aspect of the present disclosure is a method for manufacturing a coaxial via structure.

In an embodiment of the present disclosure, a method for manufacturing a coaxial via structure includes 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 a first through hole from the first surface a recessed groove, 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 on the first surface of the substrate and in the first through hole; and a pattern The first conductive material and the second conductive material are melted to form the first line and the second line on the first surface, so that the remaining first conductive material and the remaining second conductive material are electrically connected through the insulating layer in the groove. 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 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 a second through hole Holes are formed in the insulating layer material to form the insulating layer, wherein the insulating layer has protrusions located in the grooves.

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 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 in the first through hole further includes making the insulating layer, the first conductive material in the first through hole and the first conductive material 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 circuit and the second circuit further includes making the first conductive material in the first through hole, the protrusion of the insulating layer, and the first circuit. The two lines overlap in the first direction.

In the above-mentioned embodiment, 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 common The shaft through hole structure can have better electromagnetic noise shielding and impedance matching effect, so as to improve the integrity of high frequency signals. In addition, the coaxial via structure of the present disclosure 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 can also have the technical effect of reducing cost.

Several embodiments of the present invention will be disclosed in the drawings below, and 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 invention, these practical details are unnecessary. In addition, for the purpose of simplifying the drawings, some well-known structures and elements 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 like reference numerals refer to like 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. FIG. 2 is a cross-sectional view along line 2-2 in FIG. 1. FIG. Refer to Figures 1 and 2 simultaneously. 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 line 122 and a first through hole 124 , and the second conductive structure 130 includes a second line 132 and a second through hole 134 . The first traces 122 and the second traces 132 are located on the first surface 112 . The first through hole 124 and the second through hole 134 penetrate 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 the second direction D2 perpendicular to the first direction D1. The first line 122 of the first conductive structure 120 is coplanar with the second line 132 of the second conductive structure 130 . In other words, the first line 122 and the second line 132 are located on the same level.

In this embodiment, the first direction D1 is the vertical direction in the figure, that is, the first direction D1 is the 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 together first. In this embodiment, the first line 122 and the third line 126 may be ground lines, and the second line 132 and the fourth line 136 may be signal lines, but the disclosure is not limited thereto.

As shown in FIG. 2 , the first conductive structure 120 further includes a third line 126 located on the second surface 114 , and the second conductive structure 130 further includes a fourth line 136 located on the second surface 114 . Two ends of the first through hole 124 are respectively connected to the first line 122 and the third line 126 . Two ends of the second through hole 134 are respectively connected to the second line 132 and the fourth line 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 located 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 protrusion 142 , and the first protrusion 142 is located at the 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 the present embodiment, the substrate 110 further includes the multi-layer internal circuits 116 separated by the dielectric layer 150, but the present disclosure is not limited thereto. The first protrusions 142 of the insulating layer 140 contact the dielectric layer 150 near the first surface 112 . In other words, the first protrusion 142 extends through the first through hole 124 to the dielectric layer 150 .

It should be understood that, in order to clearly show the structural relationship between the second line 132 and the first protrusion 142, only the first through hole 124, the second line 132, and the insulating layer 140 are shown in FIG. A 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 line 132 are electrically insulated by the first protrusion 142 , and the coplanar first line 122 and the second line 132 are separated from each other, so that the first conductive structure 120 and the second line 132 are separated from each other. The second conductive structure 130 is electrically insulated.

As can be seen from 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 need to add an additional dielectric layer in the past can be omitted. so as to electrically insulate the first line and the second line in different layers. In this way, the first through hole 124 and the second through hole 134 in the present case may have approximately the same height, so that the overall structure of the coaxial through hole structure 100 is relatively symmetrical, thereby improving the effect of impedance matching. In addition, since the dielectric layer between the first line and the second line of different layers can be omitted in this case, the situation in which the second through hole 134 protrudes out of the insulating layer is avoided. In this way, the coaxial through-hole structure of the present application can avoid the problem of poor electromagnetic shielding effect caused by the gap of the shielding structure.

As shown in FIG. 2 , the insulating layer 140 further has a second protrusion 144 , and the second protrusion 144 is located at the 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 protrusions 144 of the insulating layer 140 contact the dielectric layer 150 near the second surface 114 . In other words, the second protrusions 144 extend through the first through holes 124 to the dielectric layer 150 .

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 via 124 and the fourth line 136 are electrically insulated by the second protrusion 144, and the third line 126 and the fourth line 136 are separated from each other, thereby making the first conductive structure 120 and the second conductive Structure 130 is electrically insulating. As mentioned above, the extending direction of the fourth line 136 can be any horizontal direction perpendicular to the first direction D1 , and FIG. 2 is only an example, and the present disclosure is not limited thereto.

It should be understood that the connection relationships, materials and functions of the components already described will not be repeated, but will be described first. In the following description, the manufacturing method of the coaxial via structure will be explained.

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

As shown in FIGS. 4A and 4B , in the method of manufacturing the coaxial via structure, the first conductive material 120M is then formed on the first surface 112 , the second surface 114 and inside 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, and those skilled in the art can select appropriate methods and materials as appropriate.

As shown in FIGS. 5A and 5B , in the method of manufacturing the coaxial via structure, the first groove TR1 is subsequently formed. The first groove TR1 is recessed from the first surface 112, and the first groove TR1 communicates with the first through hole OP1. The manner 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 further 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 manner of forming the second groove TR2 includes drilling from the second surface 114 in the opposite direction of the first direction D1 and exposing the dielectric layer 150 near 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 FIGS. 6A and 6B , in the method for manufacturing the coaxial via 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 brought into contact with the dielectric layer 150 exposed from the first conductive material 120M. In this embodiment, the insulating layer material 140M may be, for example, a hole-filling ink, but the present disclosure is not limited thereto. After the insulating layer material 140M is filled, the exposed portions of the insulating layer material 140M from the first surface 112 and the second surface 114 are ground so that the upper and lower surfaces of the insulating layer 140 are flush with the first conductive material 120M, respectively.

As shown in FIGS. 7A and 7B , in the method of manufacturing 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 portion located in the first through hole OP1 (ie the insulating layer 140 ) and the first protrusions 142 and the second protrusions 142 located on both sides of the substrate 110 respectively. Protrusions 144 .

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

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 (ie, the first through hole 124 ) surrounds the insulating layer 140 and the second conductive material in the second through hole OP2 The material 130M (ie 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 coaxial with respect to the axis A.

As shown in FIGS. 9A and 9B , in the manufacturing method of the coaxial via structure, a photomask 160 is then formed on the first surface 112 and the second surface 114 . The mask 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 the 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 line 122 and the second line 132 separated from each other can be formed, and the first line 122 and the second line 132 are coplanar. The first through hole 124 and the second circuit 132 are electrically insulated by the first protrusion 142 in the first groove TR1. The first line 122 may include any line pattern, as long as the first line 122 and the second line 132 are electrically insulated.

Likewise, after the above-mentioned steps, the third line 126 and the fourth line 136 separated from each other can be formed, and the third line 126 and the fourth line 136 are coplanar. The first through hole 124 and the fourth circuit 136 are electrically insulated 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 and the fourth circuit 136 are electrically insulated.

Refer to 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 adjusted correspondingly 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, thereby reducing the risk of disconnection of the second line 132 . There is an interval I between the second line 132 and the adjacent first line 122 . Under the requirement of a specific impedance, 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 , thereby improving the impedance matching effect.

To sum up, 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 Therefore, 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 coaxial via structure of the present disclosure 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 can also have the technical effect of reducing cost.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone skilled in the 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 determined by the scope of the appended patent application.

100: Coaxial through hole structure 110: Substrate 112: First Surface 114: Second Surface 116: Internal circuit 120: the first conductive structure 120M: first conductive material 122: The first line 124: first through hole 126: Third line 130: Second Conductive Structure 130M: Second Conductive Material 132: Second line 134: second through hole 136: Fourth line 140: Insulation layer 140M: Insulation layer material 142: First protrusion 144: Second protrusion 150: Dielectric layer 160: Photomask 170: Insulation protective layer D1: 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. FIG. 2 is a cross-sectional view along line 2-2 in FIG. 1. FIG. FIGS. 3A to 11A are top views of intermediate steps of a method for fabricating a coaxial via structure according to an embodiment of the present disclosure. FIGS. 3B to 11B are cross-sectional views along line segment 3B-3B to line segment 11B-11B in FIGS. 3A to 11A, respectively.

110: Substrate

112: First Surface

114: Second Surface

116: Internal circuit

120: the first conductive structure

122: The first line

124: first through hole

126: Third line

130: Second Conductive Structure

132: Second line

134: second through hole

136: Fourth line

140: Insulation layer

142: First protrusion

144: Second protrusion

150: Dielectric layer

A: Axis

D1: first direction

D2: Second direction

Claims (14)

A coaxial through-hole structure comprising: a substrate having a first surface; a first conductive structure including a first circuit on the first surface and a first through hole penetrating the substrate; a second conductive structure including a second circuit on the first surface of the substrate and a second through hole penetrating the substrate, the first through hole and the second through hole extending in a first direction, The first 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 conductive structure and the second conductive structure are electrically insulated, and the first line and the second line are coplanar. The coaxial via structure of 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 through hole structure of claim 1, wherein the insulating layer, the first through hole and the second through hole are coaxial. The coaxial via structure of 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 of claim 4, wherein the protruding portion of the insulating layer protrudes away from the second via hole along the second direction. The coaxial via structure of claim 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 up. The coaxial via structure of claim 4, wherein the substrate further comprises a second surface opposite to the first surface, and the coaxial via structure further comprises a surface located between the first surface and the second surface a dielectric layer therebetween, and the protrusion of the insulating layer contacts the dielectric layer. A manufacturing method of 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 a groove recessed from the first surface, and making the groove communicate with the first through hole; forming an insulating layer in the first through hole and the groove; forming a second conductive material on the first surface of the substrate and in the first through hole; and patterning the first conductive material and the second conductive material to form a first line and a second line on the first surface, so that the remaining first conductive material and the remaining second conductive material It is electrically insulated by the insulating layer in the groove, and the first line and the second line are coplanar. The method for manufacturing a coaxial via structure according to claim 8, wherein the coaxial via structure further comprises a second surface opposite to the first surface, and forming the groove further comprises: Drill holes are drilled from the first surface along a first direction. The method for manufacturing a coaxial via structure according to claim 8, wherein the coaxial via structure further comprises a dielectric layer between the first surface and the second surface, and forming the groove further Include: The dielectric layer is exposed from the first conductive material. The method for manufacturing a coaxial via structure according to claim 10, wherein forming the insulating layer in the first through hole and the groove further comprises: forming an insulating layer material in the first through hole and the groove, so that the insulating layer material contacts the dielectric layer; and A second through hole is formed in the insulating layer material to form the insulating layer, wherein the insulating layer has a protrusion located in the groove. The method for manufacturing a 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: The second conductive material is formed in the second through hole so that the first conductive material in the first through hole surrounds the insulating layer and the second conductive material in the second through hole. The method for manufacturing a 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: The insulating layer, the first conductive material in the first through hole and the second conductive material in the second through hole are made coaxial. The method for manufacturing a coaxial via structure according to claim 8, wherein patterning the first conductive material and the second conductive material to form the first circuit and the second circuit, further comprising: The first conductive material in the first through hole, the protruding portion of the insulating layer, and the second circuit are made to overlap in the first direction.

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