JP2017157597A - Wiring board and manufacturing method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique of suppressing the separation of a metal oxide layer or a metal wiring layer from a glass substrate.SOLUTION: A wiring board includes a glass substrate, a metal oxide layer formed on the glass substrate, a metal wiring layer formed on the metal oxide layer, and a first resin layer covering the metal wiring layer. When the wiring board is viewed along a cross section, the metal oxide layer is formed to be narrower than the metal wiring layer, and a second resin layer formed between the glass substrate and the metal wiring layer in contact with a side surface of the metal oxide layer is provided. The resin included in the first resin layer is different from the resin included in the second resin layer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wiring board and a manufacturing method thereof.

  Conventionally, as a wiring substrate used for an IC package substrate, an interposer, or the like, a wiring substrate including a metal oxide layer and a metal wiring layer in this order on the substrate is known (for example, Patent Document 1). Patent Document 1 discloses a method in which after a metal oxide layer is patterned, a metal wiring layer is formed on the metal oxide layer by electroless copper plating.

JP 2003-213436 A

  However, in the metal wiring layer forming method described in Patent Document 1, the dimensional accuracy of the metal wiring layer is low. Therefore, in order to increase the dimensional accuracy of the metal wiring layer, it is preferable to perform patterning by wet etching after laminating the metal wiring layer on the metal oxide layer.

  When wet etching is performed after the metal wiring layer is stacked on the metal oxide layer, the metal oxide layer having an etching rate higher than that of the metal wiring layer is preferentially etched. As a result, there is a possibility that a gap is generated between the metal wiring layer and the substrate. Then, due to this gap, the adhesion area between the substrate and the metal oxide layer and the adhesion area between the metal oxide layer and the metal wiring layer are reduced, and the metal wiring layer and the metal oxide layer may be peeled off from the substrate. In particular, when liquid or gas enters the gap and receives heat in that state, the intruded liquid or gas expands, which may cause the metal wiring layer or metal oxide layer to peel off from the substrate.

  The present invention has been made to solve the above-described problems, and can be realized as the following forms.

(1) According to one aspect of the present invention, a wiring board is provided. The wiring board includes a glass substrate, a metal oxide layer formed on the glass substrate, a metal wiring layer formed on the metal oxide layer, and a first resin layer covering the metal wiring layer. When the wiring substrate is viewed in cross section, the metal oxide layer is narrower than the metal wiring layer and is formed between the glass substrate and the metal wiring layer. And a second resin layer in contact with the side surface of the metal oxide layer, wherein the resin contained in the first resin layer is different from the resin contained in the second resin layer It is characterized by. According to the wiring board of this form, by providing the second resin layer, it is possible to prevent the metal oxide layer and the metal wiring layer from being peeled from the glass substrate.

(2) In the wiring board of the above aspect, the metal oxide layer may be an oxide layer including at least one selected from the group consisting of zinc, titanium, tin, and chromium. According to this form of wiring substrate, the adhesion between the glass substrate and the metal oxide layer can be improved.

(3) In the wiring board of the above aspect, the metal wiring layer may include at least one selected from the group consisting of copper, nickel, and silver. According to the wiring board of this form, the conductivity can be improved.

(4) According to another aspect of the present invention, a method for manufacturing a wiring board is provided. The method for manufacturing a wiring board includes a glass substrate, a metal oxide layer formed on the glass substrate, and a metal wiring layer formed on the metal oxide layer, and when viewed in cross section, A preparation step of preparing a core substrate having a width narrower than that of the metal wiring layer, and between the glass substrate and the metal wiring layer, and on a side surface of the metal oxide layer; A first resin layer forming step of forming a second resin layer so as to come into contact; and a first resin layer forming step of forming a first resin layer covering the metal wiring layer. The resin contained in the resin layer is different from the resin contained in the second resin layer. According to the method for manufacturing a wiring board of this aspect, by providing the second resin layer, it is possible to prevent the metal oxide layer or the metal wiring layer from being peeled off from the glass substrate.

  In addition, this invention is not restricted to the form as a wiring board and the manufacturing method of a wiring board mentioned above, It is realizable in various forms. The present invention can be realized, for example, in the form of an electric device including a wiring board.

Explanatory drawing of the wiring board of this embodiment. Process drawing which shows the manufacturing method of a wiring board. The figure explaining a preparatory process. The figure explaining the 2nd resin layer formation process. Explanatory drawing which shows the state of the metal wiring layer after a roughening process. The figure explaining the preparatory process using a semi-additive method. The figure explaining the 2nd resin layer formation process of this modification.

A. Embodiment:
A1. Wiring board configuration:
FIG. 1 is an explanatory diagram of the wiring board 10 of the present embodiment. The wiring board 10 of this embodiment is used as an IC package board or an interposer, for example. As shown in FIG. 1, the wiring substrate 10 includes a glass substrate 100, a metal oxide layer 110, a metal wiring layer 120, a first resin layer 130, and a second resin layer 140. FIG. 1 shows a part of the wiring board 10.

  In the present embodiment, the glass substrate 100 is formed of non-alkali glass having a 300 mm square and a thickness of 0.3 mm.

  The metal oxide layer 110 is a layer formed of a metal oxide and is formed on the glass substrate 100. The metal oxide layer 110 is preferably made of a material having high adhesion to the glass substrate 100. For example, at least selected from the group consisting of zinc (Zn), titanium (Ti), tin (Sn), and chromium (Cr). An oxide layer including one is preferable. In the present embodiment, the metal oxide layer 110 is formed of zinc oxide (ZnO). In the present embodiment, the thickness of the metal oxide layer 110 is about 20 nm.

  The metal wiring layer 120 is a layer formed of metal and is used for wiring. The metal wiring layer 120 is formed on the metal oxide layer 110. The metal wiring layer 120 includes a seed layer 122 and a plating layer 125 in order from the layer in contact with the metal oxide layer 110. The metal wiring layer 120 is preferably formed of a highly conductive metal, and preferably includes at least one selected from the group consisting of copper (Cu), nickel (Ni), and silver (Ag), for example. . In the present embodiment, the metal wiring layer 120 is formed of copper (Cu).

  The metal oxide layer 110 is narrower than the metal wiring layer 120 when the wiring substrate 10 is viewed in cross-section by etching in a preparation step (step P100) described later. As a result, a gap is generated between the glass substrate 100 and the metal wiring layer 120. In the present embodiment, the thickness of the metal oxide layer 110 is about 100 nm, and this gap is also considered to be 100 nm. Note that “when the wiring substrate 10 is viewed in cross section” indicates a case where the wiring substrate 10 is viewed on a cross section perpendicular to the direction in which the metal wiring layer 120 extends on the substrate 100. The “width” indicates a dimension in a direction perpendicular to the direction in which the metal oxide layer 110 is stacked on the metal wiring layer 120 when viewed in cross section.

  The first resin layer 130 is a layer formed of a resin and has insulating properties. The first resin layer 130 covers the metal wiring layer 120. In this embodiment, the 1st resin layer 130 is formed with the epoxy resin, and the filler which consists of inorganic materials, such as a silica, in order to provide desired intensity | strength and heat resistance is contained.

  The second resin layer 140 is formed between the glass substrate 100 and the metal wiring layer 120 and is in contact with the side surface of the metal oxide layer 110. Here, that the second resin layer 140 is in contact with the side surface of the metal oxide layer 110 indicates that at least a part of the second resin layer 140 is in contact with the side surface of the metal oxide layer 110. The second resin layer 140 is made of resin. The resin contained in the second resin layer 140 is different from the resin contained in the first resin layer 130. In the present embodiment, the second resin layer 140 is formed of a polyimide resin, and includes a filler made of an inorganic material such as silica from the viewpoint of facilitating entering the gap between the glass substrate 100 and the metal wiring layer 120. It is preferable not to use a liquid type resin.

A2. Manufacturing method of wiring substrate 10:
FIG. 2 is a process diagram showing a method for manufacturing the wiring board 10. First, the manufacturer of the wiring substrate 10 prepares a core substrate 10 </ b> A including the metal oxide layer 110 and the metal wiring layer 120 on the glass substrate 100 in the process P <b> 100. Process P100 is also called a preparation process.

  In the present embodiment, in the preparation process, the manufacturer forms the metal oxide layer 110 and the metal wiring layer 120 on the glass substrate 100. Examples of a method for forming the metal oxide layer 110 and the metal wiring layer 120 include a subtractive method and a semi-additive method. In the present embodiment, a subtractive method is used as a method for forming the metal oxide layer 110 and the metal wiring layer 120.

  FIG. 3 is a diagram illustrating the preparation process (process P100). Specifically, first, the manufacturer forms a zinc oxide (Zn) layer 110A to be the metal oxide layer 110 on the glass substrate 100, and then, on the layer 110A by electroless copper plating. A layer 122A to be the seed layer 122 is formed (see FIG. 3A). Examples of the method for forming the layer 110A include a dipping method, a spin coating method, a sputtering method, and a screen printing method. In this embodiment, a dipping method is used as a method for forming the layer 110A.

  Next, the manufacturer forms a layer 125A to be the plating layer 125 on the layer 122A by electrolytic copper plating (see FIG. 3B), and forms a pattern 160 of dry film resist on the layer 125A. (See FIG. 3C). Thereafter, the manufacturer removes unnecessary layers 110A, 122A, and 125A that are not covered with the pattern 160 by wet etching, and includes the glass substrate 100, the metal oxide layer 110, and the metal wiring layer 120. A core substrate 10A is obtained (see FIG. 3D).

  Thus, the preparation process (process P100) is completed. In the present embodiment, the core substrate 10A is manufactured, but a core substrate 10A manufactured in advance may be used. As shown in FIG. 3D, the core substrate 10 </ b> A is narrower in the metal oxide layer 110 than in the metal wiring layer 120 when viewed in cross section. This is because the metal oxide layer 110 is etched more preferentially than the metal wiring layer 120 because the metal oxide layer 110 has a higher etching rate than the metal wiring layer 120 due to the wet etching described above. A point is mentioned.

  After the preparation process (process P100) (see FIG. 2), the manufacturer contacts the side surface of the metal oxide layer 110 between the glass substrate 100 and the metal wiring layer 120 in the process P110. A second resin layer 140 is formed. Step P110 is also referred to as a second resin layer forming step.

  FIG. 4 is a diagram for explaining the second resin layer forming step (step P110). First, the manufacturer coats the metal oxide layer 110 and the metal wiring layer 120 with a positive photosensitive insulating material 140A (see FIG. 4A). Next, the manufacturer exposes the photosensitive insulating material 140A from above with an exposure apparatus (see FIG. 4B). At this time, the photosensitive insulating material 140A formed between the glass substrate 100 and the metal wiring layer 120 is not exposed because the metal wiring layer 120 is above. Thereafter, the manufacturer removes unnecessary photosensitive insulating material 140 </ b> A except between the glass substrate 100 and the metal wiring layer 120 by performing development. After removing the unnecessary photosensitive insulating material 140A, heat treatment is performed to cure the photosensitive insulating material 140A to form the second resin layer 140 (see FIG. 4C).

  After the second resin layer forming step (step P110) (see FIG. 2), the manufacturer performs a roughening process on the surface of the metal wiring layer 120 in step P120. As a roughening method, wet etching is used.

  FIG. 5 is an explanatory diagram showing the state of the metal wiring layer 120 after the roughening treatment. As shown in FIG. 5, the surface of the metal wiring layer 120 becomes rough, and the adhesion between the metal wiring layer 120 and the first resin layer 130 formed in the next step can be improved.

  After the roughening process of the surface of the metal wiring layer 120 (process P120) (see FIG. 2), the manufacturer forms the first resin layer 130 covering the metal wiring layer 120 in process P130. Step P130 is also referred to as a first resin layer forming step. Through these steps, the wiring board 10 is completed.

  The wiring substrate 10 of the present embodiment includes a second resin layer 140 that is formed between the glass substrate 100 and the metal wiring layer 120 and is in contact with the side surface of the metal oxide layer 110. For this reason, according to the wiring board 10 of this embodiment, the clearance gap between the glass substrate 100 and the metal wiring layer 120 can be filled. As a result, gas or liquid can be prevented from entering the gap. In addition, since the second resin layer 140 is in close contact with the metal wiring layer 120, it is possible to prevent the metal wiring layer 120 and the metal oxide layer 110 from being peeled from the glass substrate 100.

  In the wiring board 10 of the present embodiment, the resin contained in the first resin layer 130 is different from the resin contained in the second resin layer 140. When the resin included in the first resin layer 130 includes a filler having a size of several μm, such a resin is not used for the second resin layer 140, so that the filler is connected to the glass substrate 100 and the metal wiring. By closing the entrance of the gap with the layer 120, it is possible to prevent the resin from entering the gap. Further, by using a resin different from the resin contained in the second resin layer 140 for the first resin layer 130, it is possible to select a resin that matches the physical properties required for the resin layer covering the metal wiring layer, It is also possible to use a filler.

  In the method for manufacturing the wiring substrate 10 of the present embodiment, the second resin layer forming step (step P110) is performed before the roughening treatment (step P120). By doing in this way, it can suppress that the clearance gap between the glass substrate 100 and the metal wiring layer 120 expands by a roughening process. For this reason, it can suppress that the metal wiring layer 120 and the metal oxide layer 110 peel from the glass substrate 100 resulting from this clearance gap.

  The metal oxide layer 110 of the wiring board 10 of this embodiment is an oxide layer including at least one selected from the group consisting of zinc (Zn), titanium (Ti), tin (Sn), and chromium (Cr). . For this reason, the adhesiveness of the glass substrate 100 and the metal oxide layer 110 can be improved. In addition, the metal wiring layer 120 of the wiring board 10 includes at least one selected from the group consisting of copper (Cu), nickel (Ni), and silver (Ag). For this reason, the conductivity of the wiring board 10 can be improved. In addition, the wiring board 10 includes a second resin layer 140. Therefore, as a result of combining the metal oxide layer 110 and the metal wiring layer 120 listed above, even if a gap between the glass substrate 100 and the metal wiring layer 120 caused by wet etching is likely to occur, the metal wiring It is possible to effectively prevent the layer 120 and the metal oxide layer 110 from being peeled off from the glass substrate 100.

B. Variations:
B1. Modification 1:
In the above-described embodiment, a subtractive method is used as a method for forming the metal oxide layer 110 and the metal wiring layer 120. However, it is not limited to this. As a method for forming the metal oxide layer 110 and the metal wiring layer 120, a semi-additive method may be used. Note that the subtractive method is preferable because the wiring substrate 10 having good adhesion between the metal oxide layer 110 and the metal wiring layer 120 can be formed as compared with the semi-additive method.

  FIG. 6 is a diagram illustrating a preparation process using the semi-additive method. First, the manufacturer forms a layer 110A of zinc oxide (Zn) to be the metal oxide layer 110 on the glass substrate 100 as in the above-described embodiment, and then performs electroless copper plating to form the layer 110A. A layer 122A to be a seed layer 122 is formed thereon (see FIG. 6A).

  Next, the manufacturer forms a pattern 160A made of a dry film resist on the layer 122A (see FIG. 6B). Then, after forming a plating layer 125 on the layer 122A by electrolytic copper plating, the pattern 160A is removed (see FIG. 6C). Thereafter, the manufacturer obtains the core substrate 10A including the glass substrate 100, the metal oxide layer 110, and the metal wiring layer 120 by wet etching (see FIG. 6D).

B2. Modification 2:
In the above-described embodiment, the second resin layer forming step (step P110) uses a photosensitive insulating material. However, the present invention is not limited to this. As the second resin layer forming step (step P110), for example, the following method may be employed.

  FIG. 7 is a diagram for explaining a second resin layer forming step of the present modification. First, the manufacturer coats the metal oxide layer 110 and the metal wiring layer 120 with the resin 140B (see FIG. 7A). In this modification, a polyimide resin is used as the resin 140B. Next, the manufacturer cures the resin 140B by heat treatment (see FIG. 7B). Thereafter, the manufacturer forms the second resin layer 140 by removing unnecessary resin by dry etching (see FIG. 7C).

B3. Modification 3:
In the above-described embodiment, the wiring board 10 includes the metal oxide layer 110 and the metal wiring layer 120 one by one. However, the present invention is not limited to this. For example, the wiring substrate 10 may include a plurality of metal oxide layers 110 and metal wiring layers 120 on the glass substrate 100.

  The present invention is not limited to the above-described embodiments and modifications, and can be realized with various configurations without departing from the spirit thereof. For example, the technical features in the embodiments and the modifications corresponding to the technical features in each form described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the effects, replacement or combination can be performed as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

DESCRIPTION OF SYMBOLS 10 ... Wiring board 10A ... Core board 100 ... Glass board 110 ... Metal oxide layer 110A ... Layer 120 ... Metal wiring layer 122 ... Seed layer 122A ... Layer 125 ... Plating layer 125A ... Layer 130 ... First resin layer 140 ... First Two resin layers 140A ... photosensitive insulating material 140B ... resin 160A ... pattern 160 ... pattern

Claims (4)

A glass substrate;
A metal oxide layer formed on the glass substrate;
A metal wiring layer formed on the metal oxide layer;
A wiring board comprising a first resin layer covering the metal wiring layer,
When the wiring board is viewed in cross section, the metal oxide layer is narrower than the metal wiring layer,
A second resin layer formed between the glass substrate and the metal wiring layer and in contact with a side surface of the metal oxide layer,
The wiring board according to claim 1, wherein the resin contained in the first resin layer is different from the resin contained in the second resin layer. The wiring board according to claim 1,
The wiring board according to claim 1, wherein the metal oxide layer is an oxide layer including at least one selected from the group consisting of zinc, titanium, tin, and chromium. The wiring board according to claim 1 or 2,
The wiring board according to claim 1, wherein the metal wiring layer includes at least one selected from the group consisting of copper, nickel, and silver. A method for manufacturing a wiring board, comprising:
A glass substrate, a metal oxide layer formed on the glass substrate, and a metal wiring layer formed on the metal oxide layer. Preparing a core substrate having a narrower width than the metal wiring layer; and
A second resin layer forming step of forming a second resin layer between the glass substrate and the metal wiring layer and in contact with a side surface of the metal oxide layer;
A first resin layer forming step of forming a first resin layer covering the metal wiring layer,
The method for manufacturing a wiring board, wherein the resin contained in the first resin layer is different from the resin contained in the second resin layer.

Images