TWM488829U - High temperature resistance separable copper foil structure - Google Patents

Description

High heat resistant separable copper foil structure

The present invention relates to a copper foil structure with a carrier foil, in particular to a high heat-resistant separable copper foil structure which is suitable for the coreless build-up process and has adjustable tensile force and excellent acid and alkali resistance.

In recent years, multilayers of printed wiring boards have been widely used due to the increasing mounting density of printed wiring boards and miniaturization. Such a multilayer printed wiring board is often used in a portable electronic device for the purpose of weight reduction and miniaturization, and the thickness of the interlayer insulating layer needs to be further reduced to be more lightweight as a wiring board.

In order to meet the above requirements, a manufacturing method using a coreless layering method is employed. Further, the support substrate and the multilayer printed wiring board are peeled off by the copper foil of the carrier foil. Among them, the technology of the coreless layering method is as follows.

In the patent document 1 (JP-A-2002-292788), a composite in which the change in peel strength due to the heating temperature is small, the support copper foil which is laminated with the resin substrate is easily peeled off, and the peel strength is stable is provided. Copper foil, which discloses "a composite copper foil having a thermal diffusion protective layer between the support copper foil and the ultra-thin copper foil, the thermal diffusion protection layer for suppressing between the support copper foil and the ultra-thin copper foil Copper diffusion due to heat; and a release layer for mechanically separating the support copper foil from the ultra-thin copper foil.".

However, the composite copper foil of Patent Document 1 contains a support, a peeling layer, and heat. The diffusion protective layer and the ultra-thin copper foil layer, after the support is separated from the buildup layer, still have a heat resistant metal layer remaining on the surface of the buildup layer. If the heat resistant metal layer remains on the surface of the buildup layer, the step of removing the heat resistant metal layer must be performed when the copper foil layer is processed.

In addition, the conventional separable copper foil has only one bonding surface with a roughened copper tumor to be bonded to the substrate, and the other bonding surface is not bonded during the subsequent plating process of the printed circuit board (PCB) plating layer. Good and easy to separate.

In view of the fact that the copper foil structure with the carrier foil has the necessity of improvement, the present creator actively studies how to effectively improve the performance and efficiency of the coreless layering process with its years of experience in design and manufacturing in related fields. The creation of this creation was finally made under the careful consideration of the conditions of all parties.

One of the purposes of the present invention is to provide a high heat-resistant separable copper foil structure which can inhibit the interdiffusion between the carrier foil and the copper foil layer in a high-temperature or long-time thermocompression environment, and can also make the carrier foil and There is a suitable peel strength between the copper foil layers.

In order to achieve the above purposes and effects, the present invention adopts the following technical means: a high heat-resistant separable copper foil structure suitable for manufacturing a multilayer printed circuit board by a coreless build-up method, the high heat-resistant separable copper foil structure including A carrier foil, a release layer that protects the interdiffusion between the layers, and a copper foil layer. Wherein, the carrier foil has a first first bonding surface and a second bonding surface, and a second layer of finely roughened particles is formed on the second bonding surface; the peeling layer which can mutually protect the interdiffusion layer is formed on the carrier foil a bonding surface; the copper foil layer has a first copper foil surface and a second copper foil surface, the first copper foil surface of the copper foil layer is formed with another fine roughened particle layer, and the second The surface of the copper foil is in contact with the surface of the release layer in which the protective layer is interdiffused.

The present invention has at least the following beneficial effects: the high heat-resistant separable copper foil structure of the present invention does not require a heat-resistant metal layer (thermal diffusion layer) to prevent the carrier foil and the copper foil layer from being caused in a high temperature environment or by prolonged thermal compression bonding. Heat spread, so use this The process of manufacturing a multilayer printed circuit board by the Core-less Build-up method can eliminate the removal step of a refractory metal layer, thereby manufacturing a multilayer printed circuit board in a low cost manner.

Other objects and advantages of the present work can be further understood from the technical features disclosed in the present work. The above and other objects, features, and advantages of the present invention will become more apparent from the description of the appended claims

1‧‧‧High heat-resistant separable copper foil structure

10‧‧‧Carrier foil

10a‧‧‧first joint

10b‧‧‧second joint

20‧‧‧ peeling layer

30‧‧‧copper layer

30a‧‧‧First copper foil surface

30b‧‧‧Second copper foil surface

40‧‧‧Micronized coarse particle layer

50‧‧‧Support substrate

60‧‧‧ copper plating

70‧‧‧Addition wiring layer

1 is a schematic view showing the structure of a high heat-resistant separable copper foil according to a first embodiment of the present invention.

2 is a schematic view showing the structure of a high heat-resistant separable copper foil according to a second embodiment of the present invention.

Fig. 3 is a schematic view showing the structure of a high heat-resistant separable copper foil according to a third embodiment of the present invention.

4 is a schematic view showing the structure of a high heat-resistant separable copper foil according to a fourth embodiment of the present invention.

Fig. 5 is a schematic view (1) of a manufacturing process of a multilayer printed circuit board to which the present invention is applied.

Fig. 6 is a schematic view showing the manufacturing process of the multilayer printed circuit board to which the present invention is applied (2).

Fig. 7 is a schematic view (3) of a manufacturing process of a multilayer printed circuit board to which the present invention is applied.

The present disclosure relates to a high heat-resistant separable copper foil structure characterized in that the tensile force at a normal temperature is between 10 g/cm and 105 g/cm, and a heat-resistant metal layer (thermal diffusion layer) is not required. Preventing thermal diffusion between the carrier foil and the copper foil layer in a high temperature environment or by prolonged thermal compression bonding, so the process of manufacturing a multilayer printed circuit board by the Core-less Build-up method of the present invention is employed. The removal step of a refractory metal layer can be omitted, and the multilayer printed circuit board can be manufactured in a low cost manner.

More importantly, compared with the copper foil structure of the conventional carrier foil, in the high heat-resistant separable copper foil structure of the present invention, a roughened copper tumor is formed on at least one side of the carrier foil and the copper foil layer, wherein The roughened copper on one side can increase the bonding force with the surface of the substrate, and the roughened copper on the other side can be added to the subsequent PCB plating. With the combination of the surface, the process of manufacturing a multilayer printed circuit board by the core-less Build-up method of the present invention can produce a high-quality multilayer printed circuit board.

The structural features and application embodiments of the present invention will be described in the following by means of a plurality of specific embodiments and the accompanying drawings, so that those skilled in the art can easily understand the features and functions of the present invention through the disclosure of the present invention. And in the spirit of this creation, various modifications and changes are made to implement or apply the creation based on different viewpoints.

[First Embodiment]

Please refer to FIG. 1 , which is a schematic diagram of a high heat-resistant separable copper foil structure according to a first embodiment of the present invention. As shown, the high heat-resistant separable copper foil structure 1 of the present embodiment comprises a carrier foil 10, a release layer 20 which protects the interdiffusion between layers, and a copper foil layer 30.

The carrier foil 10 may be a copper foil, a copper alloy foil, a titanium foil, a stainless steel foil, or the like. The present invention is not limited thereto, and has a thickness of approximately between 12 μm and 70 μm and has a first joint surface 10a and a relative to the first A second joint surface 10b of the joint surface 10a. In actual practice, in consideration of economy and recyclability, the carrier foil 10 may be an electrolytic copper foil or a rolled copper foil having excellent surface flatness and a thickness of between 18 μm and 35 μm. On the other hand, the first joint surface 10a and the second joint surface 10b of the carrier foil 10 may be a smooth surface (S surface) and a rough surface (M surface), respectively, or both the first joint surface 10a and the second joint surface 10b. Both can be smooth surfaces (S surface).

The peeling layer 20 is formed on the first joint surface 10a of the carrier foil 10, and is mainly made of an alloy containing molybdenum, nickel, chromium, and potassium or a metal oxide of the above alloy. That is, the peeling layer 20 for suppressing the mutual diffusion between the carrier foil 10 and the copper foil layer 30 is a quaternary alloy layer containing molybdenum, nickel, chromium and potassium or containing molybdenum, nickel, chromium and potassium. Alloy metal oxide layer.

It should be noted that the present invention can have a suitable peel strength between the carrier foil 10 and the copper foil layer 30 due to the use of the release layer 20, whereby the two are hot pressed at a high temperature or for a long time. Environment can still maintain a good combination Force, but not because of the strong binding force can not be separated.

Further, in order to form the above-mentioned specific effect of the peeling layer 20, the special plating bath used in the present invention comprises at least: nickel sulfate hexahydrate having a concentration of 50 to 100 g/L, and molybdic acid having a concentration of 10 to 30 g/L. Sodium dihydrate and K ₄ P ₂ O _{7 with a} concentration of 50-150 g/L. Furthermore, the present invention can further form a protective layer (not shown) on the surface of the peeling layer 20 by a copper pyrophosphate plating bath having a pH of 6 to 10, wherein the copper pyrophosphate plating bath contains at least a concentration of 10 ~60g/L of Cu ₂ P ₂ O ₇ . 3H ₂ O and K ₄ P ₂ O _{7 having a} concentration of 100 to 400 g/L, whereby the release layer 20 is protected from being washed away by the subsequent copper sulfate plating bath.

The copper foil layer 30 is formed on the release layer 20 (or a protective layer) having a thickness substantially between 1 μm and 6 μm and having a first copper foil surface 30a and a second copper foil relative to the first copper foil surface 30a. The surface 30b, wherein the second copper foil surface 30b is in contact with the surface of the peeling layer 20. On the other hand, the first copper foil surface 30a and the second copper foil surface 30b may be a rough surface (M surface) and a smooth surface (S surface), respectively, or both the first copper foil surface 30a and the second copper foil surface 30b. Both can be smooth surfaces (S surface).

In actual implementation, the copper foil layer 30 can be formed by using a copper sulfate plating bath having a pH of 1 to 12, and the sulfuric acid concentration in the copper sulfate plating bath is 90 to 125 g/L and the copper concentration is 50 to 100 g/L. The thickness of the formed copper foil layer 30 is approximately between 3 μm and 5 μm, and may even be controlled to be 3 μm or less.

[Second embodiment]

Please refer to FIG. 2, which is a schematic diagram of a high heat-resistant separable copper foil structure according to a second embodiment of the present invention. As shown in the figure, the high heat-resistant separable copper foil structure 1 of the present embodiment differs from the first embodiment in that a fine roughened particle layer 40 is further formed on the second joint surface 10b of the carrier foil 10.

Specifically, the finely roughened particle layer 40 is an alloy finely roughened particle layer in which the composition settings can be adjusted according to the process requirements. Further, in the present embodiment, the finely roughened particle layer 40 may be further subjected to a rustproof treatment and/or a coupling agent (decane coupling agent) treatment. That is to say, this embodiment is used to increase the fineness of the interlayer bonding force. The particle layer 40 may be an alloy finely roughened particle layer which is subjected to rustproof treatment or an alloy finely roughened particle layer which is subjected to rustproof treatment and coupling agent treatment.

Accordingly, when the high heat-resistant separable copper foil structure 1 of the present embodiment is used for manufacturing a multilayer printed circuit board by the coreless build-up method, the carrier foil 10 and a support substrate composed of a highly insulating material can be added (Fig. The combination between the two is not shown.

[Third embodiment]

Please refer to FIG. 3, which is a schematic diagram of a structure of a high heat-resistant separable copper foil according to a third embodiment of the present invention. As shown in the figure, the high heat-resistant separable copper foil structure 1 of the present embodiment differs from the first embodiment in that a fine roughened particle layer 40 is further formed on the first copper foil surface 30a of the copper foil layer 30.

As in the second embodiment, the finely roughened particle layer 40 is an alloy finely roughened particle layer in which the composition settings can be adjusted according to the process requirements. Further, in the present embodiment, the finely roughened particle layer 40 may be further subjected to a rustproofing treatment and/or a coupling agent (decane coupling agent) treatment. That is, the fine roughened particle layer 40 for increasing the interlayer bonding force in the present embodiment is an alloy finely roughened particle layer to which the rustproofing treatment is applied or an alloy finely roughened particle to which the rustproofing treatment and the coupling agent are applied. Floor.

Accordingly, when the high heat-resistant separable copper foil structure 1 of the present embodiment is used to manufacture a multilayer printed circuit board by the coreless build-up method, the carrier foil 10 and a subsequent PCB plating layer (not shown) can be added. The bonding force, that is, the bonding force of the copper pillar (Copper Pillar).

[Fourth embodiment]

Please refer to FIG. 4, which is a schematic diagram of a structure of a high heat-resistant separable copper foil according to a fourth embodiment of the present invention. As shown in the figure, the high heat-resistant separable copper foil structure 1 of the present embodiment differs from the first embodiment in that the second bonding surface 10b of the carrier foil 10 and the first copper foil surface 30a of the copper foil layer 30 are A finely roughened particle layer 40 is formed. Since its specific features have been described in detail in the second and third embodiments, it will not be described herein.

Accordingly, when the high heat-resistant separable copper foil structure 1 of the present embodiment is used for coreless When the multilayer printed circuit board is produced by the build-up method, the bonding force between the carrier foil 10 and a support substrate (not shown) composed of a highly insulating material can be increased, and at the same time, the copper foil layer 30 and a subsequent PCB plating are added. The bond between layers (not shown).

[Application Example]

Please refer to FIGS. 5 to 7 for a schematic diagram of a manufacturing process of a multilayer printed circuit board. When the high heat-resistant separable copper foil structure 1 of the present invention is used for manufacturing a multilayer printed circuit board by a coreless build-up method, the following steps can be roughly taken: First, as shown in FIG. 5, two high heat-resistant separable copper foil structures 1 are bonded to a supporting substrate 50 by a bonding method, wherein the fine roughened particle layer 40 on the second bonding surface 10b of the carrier foil 10 is They are respectively in contact with opposite surfaces of the support substrate 50. In actual implementation, the high heat-resistant separable copper foil structure 1 can utilize all the conditions and methods for bonding the metal foil commonly used in the manufacturing process of the printed circuit board to the support material composed of the highly insulating material.

Next, as shown in FIG. 6, a copper plating layer 60 is formed on the fine roughened particle layer 40 on the first copper foil surface 30a of the copper foil layer 30 in the two high heat-resistant separable copper foil structures 1, The two copper plating layers 60 are formed into a line pattern by a process such as exposure and development.

Thereafter, as shown in FIG. 7, a build-up wiring layer 70 is simultaneously formed on the wiring pattern made of the copper plating layer 60. Specifically, the build-up wiring layer 70 can be formed by first forming an insulating resin layer on each of the wiring patterns by using a laminated resin film or a coating resin composition, and then on each of the insulating resin layers. Make inner and outer lines (not shown). It is worth noting that the above steps can be repeated a plurality of times depending on the product requirements, and the multilayer build-up wiring layer 70 is formed in this manner.

Finally, as shown in FIG. 7, the carrier foil 10 and the copper foil layer 30 are separated from the support substrate 50 by the release layer 20, and thereby two multi-layer laminates (not shown) are obtained, and the process is not at all An additional step of removing the heat resistant metal layer is required. The above two multi-layer laminates are formed into a multilayer printed circuit board after being subjected to necessary processing such as plating, exposure development, etching, and the like.

In summary, the high heat-resistant separable copper foil structure of the present invention does not require a heat-resistant metal layer (thermal diffusion layer) to prevent high-temperature environment or long-time heat compared to the conventional copper foil structure with a carrier foil. The heat diffusion between the carrier foil and the copper foil layer caused by the press-bonding, so the process of manufacturing the multilayer printed circuit board by the core-less Build-up method of the present invention can eliminate the step of removing a heat-resistant metal layer. Further, a multilayer printed circuit board can be manufactured in a low cost manner.

Furthermore, in the high heat-resistant separable copper foil structure of the present invention, roughened copper tumors are formed on at least one side of the carrier foil and the copper foil layer, and the roughened copper tumor on one side thereof can increase the surface between the substrate and the substrate. The combination of the roughened copper on the other side can increase the bonding force with the surface of the subsequent PCB plating layer. Therefore, the core-less Build-up method is used to fabricate the multilayer printed circuit board. The process can produce high quality multilayer printed circuit boards.

The above description is only an embodiment of the present invention, and is not intended to limit the scope of patent protection of the present invention. Anyone who is familiar with the art of the artist, within the spirit and scope of the creation, the equivalent of the changes and retouching, still fall within the scope of the patent protection of this creation.

1‧‧‧High heat-resistant separable copper foil structure

10‧‧‧Carrier foil

10a‧‧‧first joint

10b‧‧‧second joint

20‧‧‧ peeling layer

30‧‧‧copper layer

30a‧‧‧First copper foil surface

30b‧‧‧Second copper foil surface

Claims (10)

A high heat-resistant separable copper foil structure suitable for manufacturing a multilayer printed circuit board by a coreless build-up method, the high heat-resistant separable copper foil structure comprising: a carrier foil having a first joint surface and a first a second bonding surface, the second bonding surface is formed with a layer of fine roughened particles; a peeling layer capable of mutually interdiffusion between the layers is formed on the first bonding surface of the carrier foil; and a copper foil layer having an opposite one a surface of the first copper foil and a surface of a second copper foil, a surface of the first copper foil of the copper foil layer is formed with another layer of fine roughened particles, and a peeling layer is formed between the surface of the second copper foil and the protective layer The surfaces are connected. The high heat-resistant separable copper foil structure according to claim 1, wherein the peelable layer intertwined between the protective layers is a quaternary alloy layer containing molybdenum, nickel, chromium and potassium. The high heat-resistant separable copper foil structure according to claim 1, wherein the peeling layer which mutually diffuses between the protective layers is an alloy metal oxide layer containing molybdenum, nickel, chromium and potassium. The high heat-resistant separable copper foil structure according to claim 1, wherein the fine roughened particle layer on the second joint surface of the carrier foil is an alloy finely roughened particle layer. The high heat-resistant separable copper foil structure according to claim 1, wherein the fine roughened particle layer on the second joint surface of the carrier foil is an alloy finely roughened particle layer to which the rustproof treatment is applied. The high heat-resistant separable copper foil structure according to claim 1, wherein the fine roughened particle layer on the second joint surface of the carrier foil is an alloy finely roughened particle layer which is subjected to a rustproof treatment and a coupler treatment. The high heat-resistant separable copper foil structure according to any one of claims 4 to 6, wherein the other finely roughened particle layer on the surface of the first copper foil of the copper foil layer is an alloy finely roughened particle layer. The high heat-resistant separable copper foil structure according to any one of claims 4 to 6, wherein the other finely roughened particle layer on the surface of the first copper foil of the copper foil layer is a fine alloy for imparting rustproof treatment The particle layer is roughened. The high heat-resistant separable copper foil structure according to any one of claims 4 to 6, wherein the another layer of finely roughened particles on the surface of the first copper foil of the copper foil layer is a rust-preventing treatment and a coupling agent The treated alloy finely coarsens the particle layer. The high heat-resistant separable copper foil structure according to claim 1, wherein the carrier foil has a thickness of between 12 μm and 70 μm, and the copper foil layer has a thickness of between 3 μm and 5 μm.