TWI384906B - Substrate having through hole structure - Google Patents

Description

Substrate having a via structure

The present invention relates to a substrate, and more particularly to a substrate having a through-hole structure.

In today's circuit board technology, circuit board traces are typically made of copper foil. Since the thermal conductivity of the copper foil is large, the heat conduction effect is quite good. Therefore, when the copper foil is directly irradiated with the laser beam, the copper foil will quickly disperse the heat energy generated by the laser beam, thereby causing the heat energy to be less likely to accumulate in the copper foil. The insulating layer below, it is not easy to improve the accuracy of the opening. Therefore, the direct laser Drilling (DLD) process of the surface of the copper foil with a laser beam is excessively efficient and low in cost compared to the conventional mechanical drilling process. Defects such as over etch and hole.

FIG. 1 is a schematic cross-sectional view showing a conventional substrate. Referring to FIG. 1, the substrate 100 is a prototype substrate for making a two-layer circuit, wherein the insulating layer 110 has an upper surface 112 and a corresponding lower surface 114. When the laser beam L is directly irradiated on the upper copper foil 120 and penetrates the upper copper foil 120, the lower insulating layer 110 is ablated to form an opening 110a. At this time, the laser beam L reflected by the lower copper foil 130 remains The hole walls of the insulating layer 110 are continued to be etched to increase the aperture of the opening, causing a portion of the upper copper foil 120 to overhang above the opening 110a. It is worth noting that the subsequent electroplating process is affected by the effect of excessive overhang, so that the conductive material (not shown) which should be completely filled in the opening 110a of the insulating layer 110, because the aperture of the upper copper foil 120 is smaller than the lower side The aperture of the insulating layer 110 is quickly deposited by the conductive material to be closed, so that defects such as poor holes are left in the opening 110a of the insulating layer 110 which cannot be completely deposited by the conductive material, thereby affecting the reliability of the plating process. In view of this, the above direct laser drilling process has defects such as over etch and hole, and the accuracy of the opening is not easy to be improved, which needs to be overcome by the research and development personnel.

The present invention provides a substrate having a via structure for overcoming defects such as over etching and cladding.

The invention provides a substrate with a through-hole structure for improving the accuracy of opening.

The invention provides a substrate having a via structure, the substrate comprising an insulating layer, a first conductor layer and a second conductor layer. The insulating layer has a first side and a second side opposite the first side. The first conductor layer is disposed on the first surface, and the first conductor layer has a first opening. The second conductor layer is disposed on the second surface, and the second conductor layer has a second opening, wherein the area of the first opening is larger than the area of the second opening, and the first opening and the second opening are aligned with each other with a reference line, when When the laser penetrates the insulating layer along the reference line, the insulating layer is formed with a through hole structure, and the aperture of the through hole structure is tapered from the first opening toward the second opening.

In an embodiment of the invention, the hole wall of the through hole structure is connected to the hole wall of the first opening to form a continuous wall and form a lead angle with the hole wall of the first opening.

In an embodiment of the invention, the hole wall of the through hole structure is connected to the hole wall of the second opening to form a continuous wall and form a lead angle with the hole wall of the second opening.

In an embodiment of the invention, the through hole structure has a funnel shape.

The invention provides a substrate having a via structure, the substrate comprising an insulating layer, a first conductor layer and a second conductor layer. The insulating layer has a first side and a second side opposite the first side. The first conductor layer is disposed on the first surface, and the first conductor layer has a first opening. The second conductor layer is disposed on the second surface, and the second conductor layer has a second opening, wherein the area of the first opening is smaller than the area of the second opening, and the first opening and the second opening are referenced The wires are aligned with each other. When a laser penetrates the insulating layer along the reference line, the insulating layer is formed with a through hole structure having a hole diameter equal to the size of the first opening and smaller than the size of the second opening. .

In an embodiment of the invention, the hole wall of the through hole structure is connected to the hole wall of the first opening to form a continuous vertical wall.

In an embodiment of the invention, the hole wall of the through hole structure is not connected to the hole wall of the second opening.

In an embodiment of the invention, the through hole structure has a cylindrical shape.

The invention provides a substrate having a via structure, the substrate comprising an insulating layer, a first conductor layer and a second conductor layer. The insulating layer has a first side and a second side opposite the first side. The first conductor layer is disposed on the first surface, and the first conductor layer has a first opening. a second conductor layer is disposed on the second surface, and the second conductor layer has a second opening, wherein the first opening and the second opening are aligned with each other with a reference line, when a laser penetrates the reference line In the case of the insulating layer, the insulating layer is formed with a via structure having a hole diameter smaller than a size of the first opening and a size of the second opening.

In an embodiment of the invention, the hole wall of the through hole structure is not connected to the hole wall of the first opening.

In an embodiment of the invention, the hole wall of the through hole structure is not connected to the hole wall of the second opening.

In an embodiment of the invention, the through hole structure has a cylindrical shape.

In an embodiment of the invention, the shape of the through hole structure is an hourglass shape having a slit portion, and an aperture of the through hole structure is gradually increased from the slit portion toward one end thereof.

In an embodiment of the invention, the end of the through hole structure has a lead angle.

In an embodiment of the invention, the substrate further includes a hole-filling material filled in at least the through-hole structure, the first opening and the second opening.

In an embodiment of the invention, the hole-filling material comprises a conductive material, and the hole-filling material is electrically connected between the first conductor layer and the second conductor layer.

Based on the above, the substrate of the present invention can overcome the defects of over etch and hole caused by the conventional direct laser drilling process, and the aperture accuracy is also close to conformal due to the aperture of the through hole structure. The aperture is increased, and it is not affected by the reflection of the laser beam, which causes the aperture to become large.

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

2A, 2B, and 2C are schematic cross-sectional views of a substrate having a via structure according to a third embodiment of the present invention.

In FIGS. 2A-2C , each of the substrates 200 a , 200 b , and 200 c has an insulating layer 210 , a first conductive layer 220 , and a second conductive layer 230 . The insulating layer 210 has a first surface 212 and a second surface 214 opposite to the first surface 212. The insulating layer 210 can be a high dielectric material or a low dielectric material, and the dielectric constant can be adjusted according to the impedance characteristics of the circuit. It is not limited here. The first conductor layer 220 is disposed on the first surface 212 of the insulating layer 210, for example, by full-addition or adhesion, and the material thereof includes copper or other highly conductive material, and the second conductive layer 230 is, for example, fully-added. Or attached to the second surface 214 of the insulating layer 210, the material of which comprises copper or other highly conductive material. The first/second conductor layer may be patterned after the electroplating process to form first/second patterned lines (not shown), and subsequent processes will not be described again.

In the present embodiment, in order to overcome the defects of the direct laser drilling process, the embodiment of FIGS. 2A to 2C first forms a first conductor layer 220 having a first opening OP1 and a second conductor layer 230 having a second opening OP2. Then, the laser drilling process is performed so that the laser beam does not need to be irradiated on the first conductor layer 220 and the second conductor layer 230, but is directly irradiated on the insulating layer 210. Thus, the via structures 210a, 210b, 210c formed by the laser beams in the respective insulating layers 210 have apertures close to conformal apertures, which are not affected by the reflection of the laser beam, resulting in a larger aperture.

The following description will be separately described for different embodiments. It should be noted that the various embodiments may be used separately, but different embodiments may be stacked in accordance with the level of the line to form a circuit board of four or more layers after the completion of the line fabrication, and thus the implementation is implemented. Although the specific drawings after combination are not illustrated, the present invention is not limited thereto.

Referring first to FIG. 2A, the first conductor layer 220 is formed with a first opening OP1, and the second conductor layer 230 is formed with a second opening OP2. The area of the first opening OP1 is larger than the area of the second opening OP2, and the first opening OP1 and the second opening OP2 are aligned with each other with a reference line S. When a laser penetrates the insulating layer 210 along the reference line S, the insulating layer 210 A via structure 210a is formed, and the aperture of the via structure 210a is tapered from the first opening OP1 toward the second opening OP2. In the present embodiment, the shape of the through hole structure 210a is, for example, a funnel shape (flat cone shape). Further, the hole wall of the through hole structure 210a is connected to the hole wall of the first opening OP1 to form a continuous wall, and forms a lead angle θ1 with the hole wall of the first opening OP1, as shown in FIG. 2A. Similarly, the hole wall of the through hole structure 210a is also connected to the hole wall of the second opening OP2 to form a continuous wall, and forms a lead angle θ2 with the hole wall of the second opening OP2, as shown in FIG. 2A. Also, since the hole wall of the first opening/second opening is connected to the hole wall of the through hole structure 210a, there is no excessive overhanging on the through hole structure 210a, thereby improving the opening accuracy of the through hole structure 210a.

Next, referring to FIG. 2B, the first conductor layer 220 is formed with a first opening OP1, and the second conductor layer 230 is formed with a second opening OP2. The area of the first opening OP1 is smaller than the area of the second opening OP2, and the first opening OP1 and the second opening OP2 are aligned with each other with a reference line S. When a laser penetrates the insulating layer 210 along the reference line S, the insulating layer 210 A via structure 210b is formed, and the aperture of the via structure 210b is equal to the size of the first opening OP1 and smaller than the size of the second opening OP2. In the present embodiment, the shape of the via structure 210b is, for example, a columnar shape. Further, the hole wall of the through hole structure 210b is connected to the hole wall of the first opening OP1 to form a continuous vertical wall, so that there is no lead angle as shown in FIG. 2A. In addition, the hole wall of the through hole structure 210b is not connected to the hole wall of the second opening OP2 to form a discontinuous wall, which is advantageous for the opening margin of the second conductor layer 230 to become large. Also, since the hole wall of the first opening OP1 is connected to the hole wall of the through hole structure 210b, it does not overhang the through hole structure 210b, thereby improving the opening accuracy of the through hole structure 210b. In addition, the aperture structure 210b has a small aperture (corresponding to the size of the laser beam, such as 80 to 100 microns) suitable for subsequent electroplating and hole filling processes.

Next, referring to FIG. 2C, the first conductor layer 220 is formed with a first opening OP1, and the second conductor layer 230 is formed with a second opening OP2. The area of the first opening OP1 and the area of the second opening OP2 may be equal or unequal, and the first opening OP1 and the second opening OP2 are aligned with each other with a reference line S, when a laser penetrates the insulating layer 210 along the reference line S. The insulating layer 210 forms a via structure 210c, and the aperture of the via structure 210c is smaller than the size of the first opening OP1 and the size of the second opening OP1, that is, the via structure 210c is suspended from the first opening OP1 and the second Between the openings OP2. In the present embodiment, the shape of the through hole structure 210c is, for example, a cylindrical shape (as shown in FIG. 2B) or an hourglass shape having a slit portion 210d. When the shape of the through hole structure 210c is formed by the laser ablation to form the slit portion 210d, the aperture of the through hole structure 210c is gradually increased from the slit portion 210d toward one end thereof. Typically, the end of the via structure 210c will be formed with a lead angle θ3.

As described above, the hole wall of the through hole structure 210c is not connected to the hole wall of the first opening OP1, so that the continuous wall shown in Figs. 2A and 2B is not formed. In addition, the hole wall of the through hole structure 210c and the hole wall of the second opening OP2 are not connected to each other to form a discontinuous wall, which is advantageous for the opening margin of the second conductor layer 230 to become large. Also, since the size of the first opening OP1 is larger than the aperture of the through hole structure 210c, there is no excessive overhanging on the through hole structure, thereby improving the opening accuracy of the through hole structure 210c. In addition, the aperture structure 210c has a small aperture (approximately equivalent to the size of the laser beam, such as 80 to 100 microns) suitable for subsequent electroplating and hole filling processes.

Please refer to FIG. 3A to FIG. 3C for a cross-sectional view of the substrate of FIG. 2A to FIG. 2C respectively. The hole-filling material 240 is, for example, a conductive material, which is covered, for example, by electroplating on the first conductor layer 220, the second conductor layer 230, and filled in the through-hole structure, the first opening OP1 and the second opening OP2, and can be overcome. Defects such as holes or voids. The hole-filling material 240 is electrically connected between the first conductor layer 220 and the second conductor layer 230 to transmit an electrical signal. In addition, in another embodiment, the hole-filling material may also be an insulating material, and thus the material of the hole-filling material is not limited.

In summary, the substrate of the present invention can prevent the laser beam reflected by the lower copper foil from continuing to etch the hole wall of the insulating layer to enlarge the aperture of the opening, causing a portion of the upper copper foil to overhang the opening. In addition, the substrate of the present invention can be overcome by the conventional upper copper foil having a smaller aperture than the aperture of the lower insulating layer and being quickly closed by the conductive material, so that the hole of the insulating layer which cannot be completely deposited by the conductive material remains poor. And other defects.

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

100. . . Substrate

110. . . Insulation

110a. . . Opening

112. . . Upper surface

114. . . lower surface

120. . . Upper copper foil

130. . . Lower copper foil

L. . . Laser beam

200a, 200b, 200c. . . Substrate

210‧‧‧Insulation

210a, 210b, 210c‧‧‧through hole structure

212‧‧‧ first side

214‧‧‧ second side

220‧‧‧First conductor layer

230‧‧‧Second conductor layer

240‧‧‧ hole filling materials

OP1‧‧‧ first opening

OP2‧‧‧ second opening

S‧‧‧ baseline

Θ1, θ2, θ3‧‧‧ lead angle

1 is a schematic cross-sectional view of a conventional substrate.

2A, 2B, and 2C are schematic cross-sectional views of a substrate having a via structure according to a third embodiment of the present invention.

3A-3C are schematic cross-sectional views showing the process of completing the electroplating and filling process of the substrate of FIGS. 2A to 2C, respectively.

200a. . . Substrate

210. . . Insulation

210a. . . Through hole structure

212. . . First side

214. . . Second side

220. . . First conductor layer

230. . . Second conductor layer

OP1. . . First opening

OP2. . . Second opening

S. . . Baseline

Θ1, θ2. . . Leading angle

Claims (15)

A substrate having a via structure, the substrate comprising: an insulating layer having a first surface and a second surface opposite to the first surface; a first conductor layer disposed on the first surface, and the a conductor layer having a first opening; and a second conductor layer disposed on the second surface, the second conductor layer having a second opening, wherein the first opening has an area larger than an area of the second opening, and the The first opening and the second opening are aligned with each other with a reference line. When a laser penetrates the insulating layer along the reference line, the insulating layer is formed with a through hole structure, and the aperture of the through hole structure is formed by the first opening. Shrinking toward the second opening, and the hole wall of the through hole structure is connected to the hole wall of the first opening to form a continuous wall, and forms a lead angle with the hole wall of the first opening, and the through hole structure The wall of the hole is connected to the wall of the hole of the second opening to form a continuous wall and form a lead angle with the wall of the hole of the second opening. The substrate of claim 1, further comprising a hole-filling material filled in at least the through-hole structure, the first opening and the second opening. The substrate of claim 2, wherein the hole-filling material comprises a conductive material, and the hole-filling material is electrically connected between the first conductor layer and the second conductor layer. The substrate of claim 1, wherein the through hole structure has a funnel shape. A substrate having a via structure, the substrate comprising: an insulating layer having a first surface and a second surface opposite to the first surface; a first conductor layer disposed on the first surface, and the a conductor layer having a first opening; a second conductor layer is disposed on the second surface, and the second conductor layer has a second opening, wherein an area of the first opening is smaller than an area of the second opening, and the first opening and the second opening are a reference line is aligned with each other. When a laser penetrates the insulating layer along the reference line, the insulating layer is formed with a through hole structure having an aperture equal to the size of the first opening and smaller than the second opening. The hole wall of the through hole structure is connected to the hole wall of the first opening to form a continuous vertical wall, and the hole wall of the through hole structure is not connected to the hole wall of the second opening. The substrate of claim 5, further comprising a hole-filling material filled in at least the through-hole structure, the first opening and the second opening. The substrate of claim 6, wherein the hole-filling material comprises a conductive material, and the hole-filling material is electrically connected between the first conductor layer and the second conductor layer. The substrate of claim 5, wherein the through hole structure has a cylindrical shape. A substrate having a via structure, the substrate comprising: an insulating layer having a first surface and a second surface opposite to the first surface; a first conductor layer disposed on the first surface, and the a conductor layer has a first opening; a second conductor layer is disposed on the second surface, and the second conductor layer has a second opening, wherein the first opening and the second opening are aligned with each other with a reference line When a laser penetrates the insulating layer along the reference line, the insulating layer is formed with a through hole structure having a hole smaller than a size of the first opening and a size of the second opening; and a hole filling material, Covering the first conductor layer and the second conductor layer and filling the via structure, the first opening and the second opening. The substrate of claim 9, wherein the hole-filling material comprises a conductive material, and the hole-filling material is electrically connected between the first conductor layer and the second conductor layer. The substrate of claim 9, wherein the hole wall of the through hole structure is not connected to the hole wall of the first opening. The substrate of claim 9, wherein the hole wall of the through hole structure is not connected to the hole wall of the second opening. The substrate of claim 9, wherein the through hole structure has a cylindrical shape. The substrate of claim 9, wherein the through hole structure has an hourglass shape having a slit portion, and an aperture of the through hole structure is gradually increased from the slit portion toward one end thereof. The substrate of claim 14, wherein the end of the via structure has a lead angle.