TWI528880B - Method for forming conductive through via at glass substrate - Google Patents

Description

Method for forming conductive vias on a glass substrate

The present invention relates to a method of forming a conductive via, and more particularly to a method of forming a conductive via in a glass substrate.

In addition to the powerful requirements of consumers, the requirements for electronic products are lighter, thinner, shorter, and smaller. Therefore, the integration of electronic products on the market is getting higher and higher, and the functions are getting stronger and stronger. In order to reduce the volume of the package structure of the wafer in the electronic product, the number of layers of the substrate on which the wafer is mounted is also changed from a single layer to a plurality of layers. In order to connect the lines between the multilayer substrates to each other in the thickness direction of the substrate, a plating through hole (PTH) technique may be employed in each of the substrates.

Plated through holes refer to the penetration of a plurality of through holes through a substrate on a substrate, and then electroplating is used to plate the conductive material into the through holes. After the plating step is completed, the conductive material in the through holes can be electrically connected to the lines of other layers.

Because of its low cost and mature technology, glass is a commonly used substrate material. In the prior art, when a through-hole technique is used for a glass substrate, a conductive material is directly plated in the via hole after the via hole is formed. However, the problem of poor adhesion between the conductive material and the glass substrate may result in poor yield of the formed conductive vias and poor reliability of signal transmission depending on the conductive vias.

The present invention provides a method of forming a conductive via in a glass substrate, and solves the problem of poor yield of the conductive via.

The present invention provides a method of forming a conductive via in a glass substrate, comprising the following steps. First, at least one first via hole is formed in a glass substrate. Then, an insulating material is filled in the aforementioned first through hole. Thereafter, an insulating material of the second via hole in the first via hole is formed. Wherein, the second through hole is formed such that the channel aperture of the middle portion is smaller than the aperture of the channel at both ends. Next, a conductive material is filled in the second through hole.

In an embodiment of the invention, the upper half and the lower half of the second through hole are respectively conical.

In an embodiment of the invention, the first through hole is formed using a laser.

In an embodiment of the invention, the insulating material is filled by pressing a film of insulating material to the glass substrate.

In an embodiment of the invention, when the second through hole is formed, the upper half of the second through hole is formed first, and then the lower half of the second through hole is formed.

In one embodiment of the invention, the second via is formed using a laser, wet etching, or dry etching.

In one embodiment of the invention, a method of filling a conductive material includes forming a plating seed layer on a hole wall of a second via hole, and plating a conductive material onto the plating seed layer using a plating seed layer.

In an embodiment of the present invention, the surface diameter range of the first through hole varies according to the thickness of the glass substrate. When the thickness of the glass substrate is from 180 micrometers to 300 micrometers, the surface diameter of the first through hole ranges from 35 Micron to 55 microns. When the thickness of the glass substrate 100 is between 30 micrometers and 180 micrometers, the surface diameter of the first via hole ranges from 15 micrometers to 35 micrometers. When the thickness of the glass substrate 100 is less than 30 μm, the surface diameter of the first through holes ranges from 5 μm to 15 μm.

In an embodiment of the invention, the thickness range of the insulating material varies depending on the thickness of the glass substrate. When the thickness of the glass substrate is between 30 micrometers and 180 micrometers, the thickness of the insulating material is between 15 micrometers and 35 micrometers. When the thickness of the glass substrate is less than 30 μm, the thickness of the insulating material is between 1 μm and 15 μm.

In an embodiment of the invention, the surface diameter range of the second through hole varies depending on the range of the diameter of the first through hole surface. When the surface diameter of the first through hole is between 15 μm and 35 μm, the surface diameter of the second through hole is between 10 μm and 30 μm. When the surface diameter of the first through hole is between 5 micrometers and 15 micrometers, the surface diameter of the second through hole is between 3 micrometers and 10 micrometers.

Based on the above, the present invention provides a method of forming a conductive via in a glass substrate, which utilizes good adhesion between the insulating material and the conductive material to improve the reliability of signal transmission depending on the conductive via.

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

1A to 1F are flowcharts showing a method of forming a conductive via hole in a glass substrate according to an embodiment of the invention. Please refer to Figure 1A first, first, provide a glass Glass substrate 100. Next, as shown in FIG. 1B, at least one first through hole 100a is formed in the glass substrate 100, and the present embodiment takes a plurality of first through holes 100a as an example. The manner in which the first through holes 100a are formed may be laser drilling. The first through hole 100a made by laser drilling has high precision, but the present invention does not limit the method of forming the first through hole 100a, and the designer can use a mechanical drilling process or the like depending on the actual application requirements. A method of forming a via hole.

The surface diameter range of the first through hole 100a varies depending on the thickness of the glass substrate 100. When the thickness of the glass substrate 100 is 180 to 300 um, the surface diameter of the first through hole 100a ranges from 35 to 55 um. When the thickness of the glass substrate 100 is 30 to 180 um, the surface diameter of the first through hole 100a ranges from 15 to 35 um. When the thickness of the glass substrate 100 is less than 30 um, the surface diameter of the first through hole 100a ranges from 5 to 15 um.

Referring to FIG. 1C, an insulating material 120 is filled in the first through hole 100a. The method of filling the insulating material 120 into the first through hole 100a may be performed by pressing, for example, an insulating material film made of the insulating material 120 is directly pressed to the glass substrate 100 to fill the insulating material 120. Inside the first through hole 100a. The range of the thickness 120a of the insulating material 120 varies depending on the thickness of the glass substrate 100. The thickness of the glass substrate 100 is 30 to 180 um, and the thickness 120a of the insulating material 120 is in the range of 15 to 30 um. The thickness of the glass substrate is less than 30 um, and the thickness 120a of the insulating material 120 is in the range of 1 to 15 um.

Thereafter, the insulating material 120 of the second via hole 121 in the first via hole 100a is formed. The second through hole 121 is formed, for example, in two parts. Referring first to FIG. 1D, the insulating material 120 is first formed in the first through hole 100a. The upper half 121a of the second through hole 121 is formed. Next, as shown in FIG. 1E, the lower half 121b of the second through hole 121 is formed. Of course, the step of forming the upper half 121a of the second through hole 121 and the step of forming the lower half 121b of the second through hole 121 may also be performed simultaneously. The upper half 121a and the lower half 121b communicate with each other to constitute the second through hole 121. The second through hole 121 is formed such that the channel aperture 1211 of the middle portion is smaller than the channel aperture 1222 at both ends. For example, the upper half 121a and the lower half 121b of the second through hole 121 have a conical shape, respectively.

The surface diameter of the second through hole 121 varies according to the range of the surface diameter of the first through hole 100a. The surface diameter of the first through hole 100a ranges from 15 to 35 um, and the surface diameter of the second through hole 121 The range is between 10~30 um. The first through hole 100a has a surface diameter ranging from 5 to 15 um, and the second through hole 121 has a surface diameter ranging from 3 to 10 um. The axis of the upper and lower conical passages of the second through hole 121 has an offset tolerance of about 3 um. The method of forming the second through holes 121 may be laser drilling, or may be performed by wet etching, dry etching, or the like.

Referring to FIG. 1F, a conductive material 160 is filled in the second via hole 121. In this step, a plating seed layer 140 is formed on the wall of the second through hole 121, and the material of the plating seed layer 140 is, for example, copper, nickel, zinc or other conductive material. After forming the electroplated seed layer 140, the electroplated seed layer 140 is used to electroplate the conductive material 160 onto the electroplated seed layer 140. In the present embodiment, the conductive material 160 fills the second through hole 121, but the present invention is not limited thereto. Conductive material 160 can be copper or other similar material that is electrically conductive, such as silver, nickel, tin, or aluminum.

In this embodiment, an insulating material 120 is formed in the first via hole 100a of the glass substrate 100, a second via hole 121 is formed in the insulating material 120, and the conductive material 160 is formed on the insulating material 120. Two through holes 121. Since the conductive material 160 and the insulating material 120 have good adhesion, and the insulating material 120 and the glass substrate 100 also have good adhesion, the adhesion of the conductive material 160 to the glass substrate 100 can be improved, and Improve the reliability of signal transmission relying on conductive vias.

Further, the second through hole 121 is formed such that the channel aperture 1211 of the middle portion is smaller than the channel aperture 1222 at both ends. Therefore, when the conductive material 160 is formed on the hole wall of the second through hole 121 by electroplating, the middle portion of the second through hole 121 may be first before the both ends of the second through hole 121 are blocked by the conductive material 160. Filling the conductive material 160 has the advantage of reducing void generation. The glass substrate 100 of the present embodiment and its conductive via structure may constitute an interposer. The interposer can be placed between the printed circuit board and the wafer to provide a high density of signal input or output between the printed circuit board and the wafer.

In summary, the present invention provides a method for forming a conductive via hole in a glass substrate, which has good adhesion between the insulating material and the conductive material and between the insulating material and the glass substrate, and the conductive material is attached to the glass substrate. a second through hole of the insulating material in the through hole, and thereby improving the reliability of signal transmission by the conductive via. In addition, the channel aperture of the middle portion of the second through hole is smaller than the aperture of the channel at both ends, and the occurrence of voids when the conductive material is plated in the second through hole can be avoided.

Although the invention has been disclosed above by way of example, it is not intended to be limiting The scope of the present invention is defined by the scope of the appended claims, and the scope of the invention is defined by the scope of the appended claims. Prevail.

100‧‧‧ glass substrate

100a‧‧‧first through hole

120‧‧‧Insulation materials

120a‧‧‧thickness

121‧‧‧Second through hole

1211, 1222‧‧‧ channel aperture

The first half of 121a‧‧

The second half of 121b‧‧

140‧‧‧Electroplating seed layer

160‧‧‧Electrical materials

1A to 1F are flowcharts showing a method of forming a conductive via hole in a glass substrate according to an embodiment of the invention.

100‧‧‧ glass substrate

100a‧‧‧first through hole

120‧‧‧Insulation materials

121‧‧‧Second through hole

The first half of 121a‧‧

The second half of 121b‧‧

140‧‧‧Electroplating seed layer

160‧‧‧Electrical materials

Claims (9)

A method for forming a conductive via in a glass substrate, comprising: forming at least one first via in a glass substrate, wherein a surface diameter of the first via is when the thickness of the glass substrate is between 180 micrometers and 300 micrometers Between 35 micrometers and 55 micrometers, when the thickness of the glass substrate is between 30 micrometers and 180 micrometers, the surface diameter of the first via hole is between 15 micrometers and 35 micrometers, and when the thickness of the glass substrate is less than 30 micrometers The first through hole has a surface diameter of 5 μm to 15 μm; the at least one first through hole is filled with an insulating material; and the insulating material in the at least one first through hole forms a second pass a hole, wherein the second through hole is formed such that a channel aperture of the middle portion is smaller than a channel aperture at both ends; and a conductive material is filled in the second through hole. The method for forming a conductive via hole in a glass substrate according to the first aspect of the invention, wherein the upper half and the lower half of the second through hole are respectively conical. A method of forming a conductive via hole in a glass substrate as described in claim 1, wherein the at least one first via hole is formed using a laser. A method of forming a conductive via hole in a glass substrate as described in claim 1, wherein the insulating material is filled in by pressing a film of an insulating material to the glass substrate. The method of forming a conductive via hole in a glass substrate according to claim 1, wherein the forming the second via hole firstly forms the second via hole The upper half of the second half of the second through hole is then formed. A method of forming a conductive via hole in a glass substrate as described in claim 1 or 5, wherein the second via hole is formed by using a laser, performing wet etching, or performing dry etching. The method for forming a conductive via hole in a glass substrate according to claim 1, wherein the method of filling the conductive material comprises: forming a plating seed layer on a hole wall of the second through hole; and using the plating The seed layer electroplates the electrically conductive material onto the electroplated seed layer. The method of forming a conductive via hole in a glass substrate according to claim 1, wherein the thickness of the insulating material is between 15 micrometers and 30 micrometers when the thickness of the glass substrate is between 30 micrometers and 180 micrometers. And when the thickness of the glass substrate is less than 30 microns, the thickness of the insulating material is between 1 micrometer and 15 micrometers. The method of forming a conductive via hole in a glass substrate according to claim 1, wherein when the surface diameter of the first via hole is between 15 μm and 35 μm, the surface diameter of the second via hole is between 10 micrometers to 30 micrometers, and when the surface diameter of the first via hole is between 5 micrometers and 15 micrometers, the surface diameter of the second via hole is between 3 micrometers and 10 micrometers.