TWM493843U - Flexible copper layer substrate - Google Patents

Description

Soft copper-clad substrate

The present invention relates to a soft copper-clad layer substrate, in particular to a protective layer structure for forming a soft-layer substrate seed layer structure during the process of manufacturing a soft copper-clad layer substrate.

In the past few years, the mobileization of digital 3C electronic products has driven the trend of light, short, and fast, which has led to a high growth in the demand for flexible circuit boards. As global consumer electronics emphasizes thin and light designs in recent years, the demand for soft boards will only increase. It will not be reduced, and the application range will be expanded, including ultra-thin computers, smart phones and e-books, which will use a lot of soft boards, especially those that emphasize thin and light features.

Among them, 2L FCCL (two-layer non-adhesive soft copper foil substrate) is widely used in thin-line Fine Pitch soft boards, displays, COF soft boards, etc., so the growth of 2L FCCL is much higher than market expectations, and even the demand exceeds supply. The phenomenon.

The 2L FCCL can be subdivided into two types: Casting Type, Sputtering Type and Laminate Type, among which 2L FCCL type products are produced by sputtering method. First, the pre-treatment process of infrared radiation dehydration and plasma treatment is carried out. In the vacuum system, the infrared film heating system is used to remove the surface of the polymer film in the unfolded condition, and The surface of the polymer film is continuously bombarded with plasma, thereby increasing the bonding strength of the substrate and the subsequent layer.

In order to increase the bonding strength of the polymer film and the copper foil and improve the reliability of the product, it is necessary to additionally coat the surface of the polymer film with a very thin dielectric layer. This is the dielectric layer sputtering (Tie – Coat) process.

After the dielectric layer is sputtered, a copper seed plating (metal copper sputtering) process is performed, and the above process is to resputter a layer of metal copper as a seed layer for the purpose of conducting electroplating. The current impedance can be reduced during copper processing.

Finally, the electroplating (Electro Plating) process is described in which the copper foil is formed into a thickened layer by electrolytic plating.

The biggest advantage of the above-mentioned products manufactured by sputtering is that the thickness of the copper foil can be miniaturized according to customer requirements and has good dimensional stability.

However, the above process is rapidly oxidized or eroded by the environment after the seed layer is completed. If the next step of electroplating copper treatment or another oxidation treatment is not performed immediately, the surface of the seed layer usually forms an oxide layer or is exposed to the environment. Erosion, the above oxide layer will reduce product yield in subsequent processes. However, in addition to anti-oxidation treatment (wet chemical syrup anti-oxidation, vacuum nitrogen-filled packaging, vacuum storage room, etc.), in addition to increasing the cost, the treatment will increase the post-operation process, operating cost and handling, and storage volume increase. Big and so on.

In view of the lack of the conventional flexible substrate process, it is necessary to provide a roll process for producing a flexible substrate, which is low in cost and effectively avoids rapid oxidation or environmental erosion of the sputtered semi-finished layer in the process before electroplating. The first protective layer structure does not need to add a process of removing the first protective layer during the next step of the electroplating process, and the first protective layer structure does not cause a release phenomenon from the electroplated thickened layer.

The main purpose of this creation is to avoid rapid oxidation of the sputtered semi-finished layer when producing a soft copper-clad substrate, thereby increasing the oxidation resistance of the sputtered semi-finished layer, and maintaining the sputtered semi-finished product before proceeding to the next step of the process. The integrity of the layer further increases product yield.

The secondary purpose of this creation is to preserve the integrity of the semi-finished product by means of a low-cost method, thereby improving industrial utilization.

In order to achieve the above object, a soft copper-clad layer substrate according to a first embodiment of the present invention is provided with a polymer substrate made of a soft material, and a surface layer of the polymer substrate is provided on the surface of the polymer substrate, and the polymer substrate and the seed layer are provided. A dielectric layer is interposed in the middle. The surface of the seed layer is provided with a first protective layer made of an oxidation resistant material.

The surface of the first protective layer is provided with an electroplating thickening layer, and the thickness of the electroplating thickening layer is less than 8 um.

The material of the first protective layer is an easy-etching material, and does not cause a release phenomenon with the plating thickening layer. In a possible embodiment, the easy-etching material is a copper alloy, an aluminum metal, a zinc metal or an alloy of the above metals. It is composed of at least one of its oxides. And the first protective layer has a thickness of 3-100 nm.

In a second embodiment, the surface of the electroplated thickening layer forms another second protective layer.

In the third embodiment, the seed layer, the first protective layer and the electroplated thickening layer together remove a partial region, and the dielectric layer, the seed layer, the first protective layer and the electroplated thickening layer together form a patterned circuit.

The surface of the above patterned line forms another second protective layer.

The invention is characterized in that the process sputtering section is formed by adding a first protective layer structure to the layer of the polymer soft copper-clad layer substrate by sputtering, and in the production process, the first protective layer is protected from oxidation and protection. The layer of the polymer soft copper-clad layer substrate, thereby achieving the purpose of improving product yield, reducing cost, and increasing industrial applicability.

In order to further understand the structure, use and characteristics of this creation, we have a deeper and clearer understanding and understanding. The preferred embodiment is described below with reference to the following:

Referring to the first embodiment of the present invention, a flexible copper-clad laminate substrate 1 is provided with a polymer substrate 11 made of a soft material. A dielectric layer 12 is disposed above the surface of the polymer substrate 11, and the dielectric layer is disposed through the dielectric layer. The surface of the dielectric layer 12 is provided with a sub-layer 13 on the surface of the dielectric layer 12, a first protective layer 14 is disposed on the surface of the seed layer 13, and the surface of the first protective layer 14 is provided. There is an electroplated thickening layer 15.

The polymer substrate 11 described above has the characteristics of being light and flexible, and can be continuously produced by roll-to-roll.

In one embodiment, the dielectric layer 12 is formed by sputtering, and the dielectric layer 12 is selected from the group consisting of nickel (Ni), tin (Sn), zinc (Zn), silver (Ag), and copper (Cu). Aluminum (Al), titanium (Ti), chromium (Cr), molybdenum (Mo), tungsten (W), iron (Fe), vanadium (V), cobalt (Co), niobium (Nb), polymer materials At least one material or an oxide of the above materials.

In one embodiment, the seed layer 13 is formed by sputtering, and the seed layer 13 is made of copper metal.

The first protective layer 14 is made of a material which is resistant to oxidation, easy to etch, and has good bonding property with the plating thickening layer 15 and does not cause a release phenomenon. In a preferred embodiment, the first protective layer 14 is splashed. The plating method is formed, and the material of the first protective layer 14 is composed of at least one of a copper alloy, an aluminum metal, a zinc metal, or an alloy of the above metals or an oxide of the above metal.

In a possible embodiment, the plating thickening layer 15 is formed by electroplating, and the plating thickening layer 15 is made of copper metal.

2 shows a second embodiment of the present invention. The surface of the plating thickening layer 15 is further provided with another second protective layer 16 by electroplating, chemical plating or forming an organic copper layer using OSP antioxidant syrup.

3 is a third embodiment of the present invention. The seed layer 13, the first protective layer 14 and the plating thickening layer 15 are removed by a photoresist process, an exposure process, a development process, and an etching process to remove a local region. Layer 12, seed layer 13, first protective layer 14 and plating thickening layer 15 together form a patterned line.

The above upper photoresist process mainly forms a photoresist which reacts with ultraviolet rays on the surface of the substrate on which the circuit pattern is to be formed. In a possible embodiment, the photoresist is formed by a coating method, and the photoresist is mainly used for protecting the circuit. The pattern will not be etched away.

In the exposure and development process, the exposed portion is formed by aligning and flattening the circuit pattern on the polymer substrate 11 on which the photoresist has been formed, and then vacuuming, pressing the plate and ultraviolet irradiation through the exposure machine. carry out. A photoresist that is irradiated with ultraviolet rays will cause a polymerization reaction, and a photoresist pattern that is blocked by a photomask and cannot be transmitted by ultraviolet rays will not cause a polymerization reaction.

In the developing portion in the above exposure and development process, the photoresist portion which does not cause the polymerization reaction is removed by the developer, so that the line to be retained remains and appears, and the circuit formed by the process step has a straight and flat line. Characteristics.

The etching process is performed by etching with an etching solution, and the dielectric layer 12, the seed layer 13, the first protective layer 14 and the plating thickening layer 15 having no photoresist barrier on the surface of the polymer substrate 11 are simultaneously The portions of the dielectric layer 12, the seed layer 13, and the first protective layer 14 and the plating thickening layer 15 are removed to form a patterned circuit.

Finally, another second protective layer 16 is formed on the surface of the patterned line by electroplating, electroless plating or using one of the OSP antioxidants.

This creation can be applied to 2L-FCCL, touch metal mesh film, flexible printed circuit board (L/S 20um or less), COF, TAB, IC-Substrate, electromagnetic wave shielding film and so on.

In summary, the present invention is characterized in that a first protective layer structure is added to the layer body in the sputtering process section of the flexible substrate process, and the oxidation resistance of the layer body in the semi-finished product is increased through the first protective layer structure, that is, The integrity of the surface of the semi-finished product can be protected before proceeding to the next process, thereby improving product yield and avoiding damage to the semi-finished layer due to oxidation or environmental erosion.

The above embodiments are used for convenience only to illustrate that the present invention is not limited. In the spirit of the creative spirit, all kinds of simple deformations and modifications made by those skilled in the industry in accordance with the scope of the patent application and the creative description of the creation should still be It is included in the scope of the following patent application.

1‧‧‧Soft copper-clad substrate
11‧‧‧ Polymer substrate
12‧‧‧ dielectric layer
13‧‧‧ seed layer
14‧‧‧First protective layer
15‧‧‧Electroplating thickening layer
16‧‧‧Second protective layer

1 is a schematic structural view of a first embodiment of the present invention; FIG. 2 is a schematic structural view of a second embodiment of the present invention; FIG. 3 is a schematic structural view of a third embodiment of the present invention.

1‧‧‧Soft copper-clad substrate

11‧‧‧ Polymer substrate

12‧‧‧ dielectric layer

13‧‧‧ seed layer

14‧‧‧First protective layer

15‧‧‧Electroplating thickening layer

Claims (9)

A soft copper-clad layer substrate is provided with a polymer substrate composed of a soft material, and a surface layer is disposed on the surface of the polymer substrate, and a dielectric layer is interposed between the polymer substrate and the seed layer, and the surface of the seed layer is A first protective layer of an oxidation resistant material is provided. The soft copper-clad layer substrate of claim 1, wherein the surface of the first protective layer is provided with an electroplating thickening layer. The soft copper-clad layer substrate according to claim 1, wherein the material of the first protective layer is an easily etchable material, and does not cause a release phenomenon from the plating thickening layer. The soft copper-clad layer substrate according to claim 3, wherein the etchable material is at least one of a copper alloy, an aluminum metal, a zinc metal, or an alloy of the above metal or an oxide thereof. The soft copper-clad layer substrate according to claim 1, wherein the first protective layer has a thickness of from 3 to 100 nm. The soft copper-clad layer substrate of claim 2, wherein the plating thickening layer has a thickness of less than 8 um. The soft copper-clad layer substrate of claim 2, wherein the surface of the plating thickening layer forms another second protective layer. The soft copper-clad layer substrate according to claim 2, wherein the dielectric layer, the seed layer, the first protective layer and the plating thickening layer jointly remove a local region, and the dielectric layer, the seed layer and the first protective layer are The electroplated thickening layer forms a patterned line. The soft copper-clad layer substrate of claim 8, wherein the surface of the patterned line forms another second protective layer.