TWI420637B - Package substrate - Google Patents

Description

Package substrate

The invention relates to a package substrate, in particular to a package substrate capable of improving product reliability.

With the rapid development of the electronics industry, electronic products are gradually moving towards multi-functional and high-performance trends. In order to meet the requirements of high integration and miniaturization of semiconductor packages for more active and passive components and lines, the package substrate has gradually evolved from a two-layer circuit board to a multilayer circuit board (multi- Layer board), which uses an interlayer connection to expand the layout area available on the package substrate in a limited space, and can be used in conjunction with a high line density integrated circuit. The thickness of the package substrate is reduced, and the package is light and thin, and the electrical function is improved.

In order to meet the development direction of thin, versatile, high-speed and high-frequency packaging substrates, the package substrate has developed toward thin lines and small apertures. Currently, in the build-up process of the package substrate, in order to avoid the thermal cycle, the dielectric layer and the copper line in the package substrate are peeled off, often by Czochralski (CZ) or blackening process. Forming a rough surface on the surface of the inner copper channel of the package substrate, that is, forming a uniform oxide layer on the surface of the copper line, and the oxide layer is used to improve the copper bonding strength of the inner copper line to make the dielectric After lamination is combined with the copper line, the roughness of the surface of the copper line is increased, and the bonding strength between the dielectric layer and the copper line can be enhanced.

Please refer to FIGS. 1A and 1C for a method of forming an oxide layer on the surface of the inner copper channel of a conventional package substrate to improve the roughness.

As shown in FIG. 1A, first, a substrate body 10 having a circuit layer 11 on its surface is provided, and the circuit layer 11 has a plurality of conductive traces 110 and a plurality of electrical contact pads 111, and the material layer of the circuit layer 11 is formed. copper.

As shown in FIG. 1B, a CZ or blackening process is then performed to form a rough surface 12 on all exposed surfaces of the wiring layer 11.

As shown in FIG. 1C, a dielectric layer 13 is formed on the substrate body 10 and the rough surface 12, and a plurality of openings 130 are formed in the dielectric layer 13 to expose the electrical contact pads 111 to the respective layers. The opening 130 is formed; wherein the material forming the dielectric layer 13 is an epoxy resin.

However, in the conventional method of manufacturing a package substrate, when the line width and the line pitch of the circuit layer 11 are reduced, the roughened circuit layer 11 is susceptible to the roughness of the rough surface 12, thereby causing the impedance of the circuit layer 11. The change, or the conductive trace 110 causes defects such as cracking and floating, which causes the package substrate to fail to meet the requirement of fine pitch; in addition, the cost of performing the CZ or blackening process is too high, thereby reducing economic efficiency.

Therefore, how to avoid the above-mentioned various problems caused by the CZ or the blackening process in the conventional technology has become a problem to be solved at present.

In view of the above-mentioned various deficiencies of the prior art, it is an object of the present invention to provide a package substrate which can enhance the bonding force between a line and a dielectric layer and meet the fine pitch requirements of the line.

Another object of the present invention is to provide a seal that can reduce manufacturing costs. Mount the substrate.

To achieve the above and other objects, the present invention discloses a package substrate comprising: a substrate body; a circuit layer disposed on the substrate body; an oxidation resistant layer formed on the exposed surface of the circuit layer, and the oxidation resistance The layer contains nitrogen; and a dielectric layer is disposed on the substrate body and the oxidation resistant layer, such that nitrogen of the oxidation resistant layer forms a bond with atoms in the dielectric layer to enhance the dielectric layer and the anti-corrosion layer The bonding force between the oxide layers.

In the above package substrate, the material forming the wiring layer is copper, and the circuit layer has a plurality of conductive traces and a plurality of electrical contact pads.

In the above package substrate, preferably, the oxidation resistant layer is formed of a nitrogen-containing Aliphatic single ring hydrogen compound such as Benzotriazole.

In the above package substrate, the dielectric layer is formed of a polymer material, and preferably formed of an epoxy resin.

As can be seen from the above, the package substrate of the present invention forms the anti-oxidation layer on the circuit layer to enhance the bonding force between the circuit layer and the dielectric layer by bonding between the oxidation resistant layer and the dielectric layer. There is no need to use a CZ or blackening process to form a rough surface on the exposed surface of the circuit layer. Therefore, the present invention can reduce the roughness of the surface of the circuit layer and reduce the resistance and impedance change of the circuit layer to facilitate It is made at a fine pitch to achieve the purpose of enhancing the bonding force between the wiring and the dielectric layer and satisfying the requirement of fine pitch; further, the oxidation resistant layer is easy to form, and the manufacturing cost can be reduced.

The embodiments of the present invention are described below by way of specific embodiments. Other advantages and effects of the present invention will be readily apparent to those skilled in the art from this disclosure.

Please refer to FIGS. 2A-2C , which are a method for fabricating a package substrate according to the present invention.

As shown in FIG. 2A, a substrate body 20 having a circuit layer 21 on its surface is provided, and the circuit layer 21 has a plurality of conductive traces 210 and a plurality of electrical contact pads 211. The material of the circuit layer 21 is copper.

As shown in FIG. 2B, a nitrogen-containing oxidation resistant layer 22 is formed on all exposed surfaces of the wiring layer 21, for example, the oxidation resistant layer 22 is a nitrogen-containing aliphatic monocyclic hydrogen compound (Aliphatic single ring hydrogen compound). The formed, such as Benzotriazole. The chemical structural formula of the benzotriazole is as follows:

As shown in FIG. 2C, a dielectric layer 23 is formed on the substrate body 20 and the oxidation resistant layer 22, and a plurality of openings 230 are formed in the dielectric layer 23, so that the respective electrical contact pads 211 are exposed to each other. The opening 230 is in the middle. The dielectric layer 23 is formed of a polymer material. For example, the polymer material may be, for example, an epoxy resin.

As shown in FIG. 2C', the nitrogen 22a in the oxidation resistant layer 22 forms a bond K with the atom 23a in the dielectric layer 23 to enhance the dielectric layer 23 and the oxidation resistance by the bonding K. The bonding force between the layers 22 can increase the The bonding strength between the dielectric layer 23 and the wiring layer 21 prevents the dielectric layer 23 and the wiring layer 21 from being peeled off during the thermal cycle process.

Before the dielectric layer 23 is pressed onto the circuit layer 21, the circuit layer 21 is first treated with an antioxidant to cause a bond K between the circuit layer 21 and the dielectric layer 23, thereby improving The bonding force avoids the peeling of the circuit layer 21 and the dielectric layer 23 to increase the reliability of the product; furthermore, the present invention not only reduces the roughness of the surface of the circuit layer 21, but also effectively reduces the roughness of the circuit layer 21 compared with the prior art. The resistance and impedance of the conductive traces 210 vary, and are affected by the roughness, which is advantageous for the fine pitch requirement of the circuit layer 21. The material of the oxidation resistant layer 22 is easy to manufacture, so the cost can be greatly reduced. Economic benefits.

The present invention provides a package substrate, comprising: a substrate body 20, a circuit layer 21 disposed on the substrate body 20, an oxidation resistant layer 22 attached to the exposed surface of the circuit layer 21, and a substrate body 20 disposed on the substrate body 20. And a dielectric layer 23 on the oxidation resistant layer 22; wherein the oxidation resistant layer 22 contains nitrogen and forms a bond K with atoms in the dielectric layer 23 to enhance the dielectric layer 23 and the oxidation resistant layer 22 The bond between the two.

The circuit layer 21 has a plurality of conductive traces 210 and a plurality of electrical contact pads 211, and the material forming the circuit layer 21 is copper.

The anti-oxidation layer 22 is formed by an aliphatic single ring hydrogen compound containing nitrogen 22a, such as Benzotriazole.

The dielectric layer 23 is formed of a polymer material, and is preferably formed of an epoxy resin.

In summary, the package substrate of the present invention forms the anti-oxidation layer on the circuit layer to enhance the bonding force between the circuit layer and the dielectric layer by bonding between the oxidation resistant layer and the dielectric layer. Therefore, it is not necessary to form a rough surface on the exposed surface of the circuit layer by a CZ or blackening process, so that the present invention can reduce the roughness of the surface of the circuit layer and reduce the resistance and impedance change of the circuit layer, and It is advantageous for fine pitch fabrication, and achieves the purpose of enhancing the bonding force between the wiring and the dielectric layer and meeting the requirement of fine pitch; further, the oxidation resistant layer is easy to form, and the manufacturing cost can be reduced.

The above embodiments are intended to illustrate the principles of the invention and its effects, and are not intended to limit the invention. Any of the above-described embodiments may be modified by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention should be as set forth in the appended claims.

10,20‧‧‧Substrate body

11, 21‧‧‧ circuit layer

110,210‧‧‧ conductive traces

111,211‧‧‧Electrical contact pads

12‧‧‧Rough surface

13,23‧‧‧ dielectric layer

130,230‧‧‧ openings

22‧‧‧Antioxidant layer

22a‧‧‧Nitrate

23a‧‧‧Atomic

K‧‧‧ Bond

1A to 1C are schematic views showing a method of manufacturing a conventional package substrate; and Figs. 2A to 2C are schematic views showing a method of manufacturing the package substrate of the present invention; wherein the 2C' is a partially enlarged schematic view.

20‧‧‧Substrate body

21‧‧‧Line layer

210‧‧‧ conductive traces

211‧‧‧Electrical contact pads

22‧‧‧Antioxidant layer

23‧‧‧Dielectric layer

230‧‧‧ openings

Claims (5)

A package substrate includes: a substrate body; a circuit layer disposed on the substrate body; an oxidation resistant layer formed on an exposed surface of the circuit layer, wherein the oxidation resistant layer is an aliphatic monocyclic ring containing nitrogen Formed by an aliphatic single ring hydrogen compound, and the nitrogen-containing aliphatic monocyclic hydride is Benzotriazole; and a dielectric layer is disposed on the substrate body and the oxidation resistant layer The nitrogen of the oxidation resistant layer is bonded to atoms in the dielectric layer to enhance the bonding force between the dielectric layer and the oxidation resistant layer. The package substrate of claim 1, wherein the circuit layer has a plurality of conductive traces and a plurality of electrical contact pads. The package substrate of claim 1, wherein the material forming the wiring layer is copper. The package substrate of claim 1, wherein the dielectric layer is formed of a polymer material. The package substrate of claim 4, wherein the dielectric layer is formed of an epoxy resin.