WO2003030599A1

WO2003030599A1 - Copper foil with carrier and printed board comprising this copper foil

Info

Publication number: WO2003030599A1
Application number: PCT/JP2002/008358
Authority: WO
Inventors: Atsushi Okuno; Takashi Natsume
Original assignee: Japan Rec Company, Limited; Nikko Materials Company, Limited
Priority date: 2001-09-26
Filing date: 2002-08-20
Publication date: 2003-04-10
Also published as: JP2003101189A; TW558915B

Abstract

A piece of copper foil with a carrier characterized by comprising a resin layer having an area smaller than that of the piece of copper foil in such a way that the periphery of the piece of copper foil is not provided with the resin layer and a printed board using such copper foil are disclosed. The resin layer having an area smaller than that of the copper foil piece is formed on the copper foil piece by screen-printing. The handlability of the copper foil is improved. Contaminants such as resin powder do not adhere to the copper foil during cutting. Further, scratches by foreign matters, dents, damages, creases, and breakage during cutting, packing, and transportation are effectively prevented.

Description

Copper sheet with copper foil and printed circuit board using the copper foil

In the present invention, a resin layer is provided on the surface of the copper foil to improve the handling property of the copper foil and to prevent the contaminants such as the resin powder from adhering to the surface of the copper foil. The present invention relates to a copper foil with a carrier provided with a resin layer effective for preventing nicks and a substrate using the copper foil. Background art

Conventionally, a build-up wire board has a printed wiring board on which a circuit network is formed as an inner layer core material, a copper foil for an outer layer circuit in the form of a collar with resin immersion base or a copper foil with resin After stacking, they are manufactured by forming interlayer connections and networks.

Note that, by repeating the above steps, stacking of outer layer circuits is performed according to the number of required layers. Generally, when pressing copper foil using a press or laminating device, foreign matter such as copper chips generated during cutting of copper foil or shelf powder of prepreder adheres to the shiny side (S side) of copper foil, etc. If this is the case, there is a problem that the glossy surface is scratched or foreign matter adheres. In addition, even when laminating, the copper-clad laminates can be taken out of the machine.

In recent years, the demand for miniaturization of electronic devices has made the circuit width significantly smaller, and the thickness of copper foil used in copper-clad laminates has become less than 1 and the demand for copper foil with a reduced thickness has It is getting bigger.

However, when the thickness of the copper foil is reduced to 18 or less, the handling property is extremely deteriorated. In addition to the pressing and laminating processes described above, scratches, foreign substances may be mixed in, wrinkles, breakage, etc. often occur during normal cutting, packing, and transportation, and in particular, the gloss of the copper foil On the other hand, there is a problem that it is strongly susceptible to that. If such scratches, wrinkles, or breaks occur, especially on the shiny side, they cause circuit disconnection or short circuit, which further causes defects in printed circuit boards and electronic devices, resulting in serious problems. ing.

Several proposals have been made to prevent such scratches, wrinkles and breakages on the surface of the copper foil and to improve the handling properties. As one example, for example, there is a proposal of using a carrier of aluminum foil or copper foil and adhering to the copper foil with an adhesive.

This reinforces the above-mentioned ultra-thin copper foil and improves the handling property of the copper foil, and also protects the copper foil surface, particularly the shiny side (S-face) of the copper foil during cutting, It prevents contaminants such as resin powder from adhering to the surface, and also prevents scratches and dents caused by foreign matter. In this case, the one with an aluminum carrier is generally referred to as a C A (Copper Al umi num) foil.

Usually, such a CA foil is laminated with a resin-impregnated base material in the next step, and subjected to heating and pressing processes using a breathing apparatus to form a copper-clad laminate used for printed circuit boards. It is a thing. Finally, the aluminum carrier is peeled off to serve as a support and a contaminant protection layer.

When resin-coated copper foil is applied to the above-mentioned copper foil with a caliper, measurement dust is generated from the resin layer end face when slitting the resin-coated copper foil or the resin layer end face when cut after being subjected to the carriage. And contamination of products and processes is a problem. Disclosure of the invention

The present invention has been made in view of the above problems, and the object of the present invention is to prepare a resin layer by screen printing on the copper surface of a copper foil with a carrier cut into a predetermined size. There is no need to cut the resin layer portion, and by suppressing the generation of resin powder, it is possible to prevent the contamination of the process and the product, improve the handling of the copper foil, and further prevent scratches and dents due to foreign matter, The present invention is intended to obtain a copper foil with a carrier provided with a resin layer capable of effectively preventing scratches, wrinkles, breakage and the like during cutting, packing and transportation, and a printed board using the copper foil. From the above, the present invention

1. A copper foil with a carrier comprising a resin layer having an area smaller than the area of the copper foil, leaving a peripheral edge of the copper foil, and a copper foil with a carrier and a printed substrate using the copper foil

2. A copper foil with a carrier according to the above 1 characterized in that the resin layer is an insulating resin layer and a printed circuit board using the copper foil

3. A coated copper foil according to the above 1 or 2, characterized in that a resin layer is applied by printing, and a printed circuit board using the copper foil

4. The copper foil with carrier according to any one of the above 1 to 3 characterized in that the carrier is a metal plate or metal foil or a resin film and a printed circuit board using the copper foil

5. The carrier copper foil and the printed circuit board using the copper foil as described in each of the above 1 to 4, characterized in that the bonding surface with the carrier is the shiny surface (S surface) of the copper foil. . Embodiment of the Invention

As the carrier of the present invention, a resin film such as aluminum, copper, copper alloy, stainless steel plate or foil, or PET can be used. Alternatively, a plate or foil of aluminum, copper, a copper alloy, or stainless steel, which has been previously coated with a thermosetting resin and heat-cured may be used.

Although it may be something other than the above-mentioned carrier, it is desirable to use a material which is easy to peel off in a later step and which can be obtained at low cost. It is also possible to use an oxide film or other surface-treated material to facilitate peeling.

For example, when using an aluminum foil or sheet as a support (an aluminum foil or sheet is a particularly preferable material as a carrier), a normal aluminum rolled foil can be used, and in particular, the thickness (thinness) of aluminum used. There is no need to limit to. However, in terms of cost, it is desirable to use thinner aluminum foil. However, if it is too thin, it can not be used as a carrier, so a certain thickness or more is necessary. The preferred aluminum material for such a carrier is as follows. The soft type has a weak "strain" and needs to be thick, so it is preferable to use the hard type. However, transfer of rolling oil and aluminum powder remaining on the aluminum foil to the copper foil may occur. In order to prevent this, the thermosetting resin can be prevented by coating in advance on an aluminum foil.

As the thermosetting resin to be coated on the aluminum foil, thermosetting resins such as epoxy resin, polyester resin, acrylic resin and urethane resin can be used. Such a thermosetting resin has good adhesion to aluminum foil, and after heat curing, it has the property that it does not change its properties even by heat and pressure with a press and laminate, and does not transfer to the other material. .

A thinner aluminum foil can be used as a carrier to improve the "strain" of the aluminum foil. In particular, epoxy resins are suitable. The thickness of the thermosetting resin coating is not particularly limited, but thin is preferable in terms of cost.

Bonding of aluminum foil coated with thermosetting resin and copper foil is carried out using thermosetting resin such as epoxy resin, acrylic resin, urethane resin and the like. As a result, the strength of the aluminum foil complements the strength of the copper foil, and the occurrence of flaws, wrinkles, and folds can be effectively suppressed.

In addition, the covering of aluminum can prevent foreign matter from directly mixing in or adhering to the surface of the copper foil.

Where the aluminum foil is bonded to the copper foil, if the copper foil is a rectangular sheet, it is applied to at least one side edge but may be applied to both side edges or all four side edges of the rectangular sheet.

In addition, the aluminum foil and the copper foil can be laminated continuously at both side edges of the sleeve. Peeling is easier as there are fewer points to be joined, but it is necessary to increase the joining points and area in order to achieve effective joining. The form of bonding can be appropriately selected according to the purpose of use.

All of these can be used in the present invention. Since the copper foil with carrier such as aluminum is extremely good in handling property, the occurrence of wrinkles and breakage can be effectively prevented, and the covering of aluminum or the like can prevent the foreign matter from directly adhering to the surface of the copper foil.

Furthermore, after lamination on a resin substrate, carriers such as aluminum are peeled off, and a circuit network is formed by a process such as etching. However, copper-clad laminates are protected by carriers such as aluminum until just before circuit formation. It is effective in preventing scratches and dents caused by foreign substances, and also effectively prevents scratches, wrinkles and breakage during cutting, packing and transportation.

The copper foil surface to be bonded to aluminum foil etc. should be provided on the shiny side (S 1) side, but it may be provided on other side, ie the roughened side (M side). Also, it may be applied to the glossy surface (S surface) which has been subjected to surface treatment such as plating. It can select suitably according to a use.

In the present invention, in such a copper foil with carrier, a resin layer having an area smaller than that of the copper foil is formed on the surface opposite to the bonding surface with the carrier, leaving the peripheral edge of the copper foil. This is a major feature of the present invention.

The resin layer on the surface of the copper foil with carrier can be formed by screen printing on the copper surface of the copper foil with carrier cut into a predetermined size.

If a resin-coated copper foil is applied to a copper foil with a carrier and the resin layer is cut simultaneously with the copper foil with a carrier, there is a risk that resin fragments may adhere to the copper foil. Such fragments are undesirable as contamination in the next step. Therefore, a resin layer having an area smaller than that of the copper foil is formed by screen printing on the copper surface of the copper foil with a caliper cut into a predetermined size as described above. The width of the peripheral edge of the copper foil can be arbitrarily set according to the inner layer core material size. Next, the copper foil with carrier on which the resin layer is formed and the inner layer core material on which the circuit is formed are laminated to form a copper-clad laminate.

As an example of this copper foil lamination process, heating and pressure are applied, for example, at a press pressure of about 10 to 3 kgz cm ² and a press temperature of about 170 ° C. for 60 to 100 minutes. Stack.

Thus, the copper foil with carrier on which the resin layer is formed and the inner layer core material can be sufficiently joined. In addition, the copper foil with carrier has extremely good handleability, and no wrinkles or breakages occur. W

6 In particular, when the thickness of the copper foil is 18 m or less, the handling property is significantly improved. Furthermore, there is an effect that no damage occurs during normal cutting, packing, and transportation, as well as the above-described pressing process, and foreign matter is not mixed in, wrinkles, and breakage occur. As a result, cutting and shorting of printed circuit boards can be reduced, defects in electronic devices can be suppressed, and product yield can be improved.

After the above lamination, the carrier such as aluminum can be peeled off and removed. Aluminum foil or sheet for carriers can be recycled.

This improves the handling of ultra-thin copper foils and prevents the adhesion of resin powder and other contaminants on the surface of the copper foils, and prevents scratches due to foreign matter and marks, as well as scratches during cutting, packing, and transportation, A printed circuit board can be easily obtained without causing wrinkles or breakage. Example and comparative example

Next, Examples and Comparative Examples of the present invention will be described. The present embodiment is merely an example, and the present invention is not limited to this example. That is, within the scope of the technical idea of the present invention, all aspects or modifications other than the present embodiment are included.

(Example 1)

A 50 mm thick hard type aluminum foil roll with a width of 500 mm and a 9 m thick electrolytic copper foil roll (with a width of 500 mm) glossy side (S side) with a 10 mm area on both sides It bonded together using a resin adhesive and obtained an aluminum carrier attached copper foil.

Next, this aluminum carrier copper foil is cut to a length of 500 mm, and then the insulating resin is applied by screen printing to a square of 400 mm on a side and dried. An insulating layer of zm was formed. The edge (peripheral edge) of the copper foil without resin is 5 mm. ,

In order to observe the occurrence of wrinkles at the time of lamination of the copper foil with an aluminum carrier, and to observe the foreign matter adhesion to the copper foil after the lamination process of the copper foil, the press pressure is 20 kgz cm ² , The aluminum foil was peeled for 1 hour at a pressing temperature of 170 ° C., and the copper foil surface from which the aluminum foil was peeled was observed with an optical microscope. As a result, in Example 1, the handling property was good, no occurrence of wrinkles, and no deposit residue after pressing was observed at all.

(Comparative example 1)

By the same process as in Example 1, a copper foil with an aluminum carrier having a width of 500 mm was obtained. Next, an insulating resin was applied continuously to a width of 400 mm on the copper foil with an aluminum carrier and dried to form an insulating layer with a coating thickness of 40 / im.

Next, after cutting this aluminum carrier attached copper foil to a length of 500 mm, the conditions similar to those of Example 1 are used to see how foreign matter adheres to the copper foil after the copper foil lamination step. After laminating the aluminum and peeling off the aluminum, the copper foil surface was observed with an optical microscope.

As a result, although the handling property of the aluminum carrier attached copper foil is good and no wrinkles are generated, a part of the resin layer is peeled off at the time of cutting in the process of producing the laminated substrate, and thereby the copper foil on the copper foil is obtained. Deposit debris was observed.

(Comparative example 2)

Insulating resin was continuously applied and dried to a width of 40 0 mm on a 9 m thick electrolytic copper foil roll (width 50 0 mm) to form an insulating layer with a coating thickness of 40 / im. . Next, according to the same process as in Example 1, a copper foil with an aluminum carrier having a width of 500 mm was obtained.

Next, after cutting this aluminum carrier-added copper foil to a length of 50 O mm, in order to observe the state of foreign matter adhesion to the copper foil after the lamination process of this copper foil, under the same conditions as in Example 1. After laminating and peeling off the aluminum, the copper foil surface was observed with an optical microscope.

As a result, although the handling property of the aluminum carrier attached copper foil is good and no wrinkles are generated, a part of the resin layer is peeled off at the time of cutting in the process of producing the laminated substrate, and thereby the copper foil on the copper foil is obtained. Adherent residue was observed. (Comparative example 3)

An insulating resin is applied continuously to a width of 400 mm on a 9 m thick electrolytic copper foil (width 500 mm) and an insulating layer with a thickness of 40 m is applied. It formed. Next, after cutting this copper foil to a length of 500 mm, in order to observe the appearance of foreign matter adhesion to the copper foil after the lamination step of this copper foil, lamination was performed under the same conditions as in Example 1. The copper foil surface was observed with an optical microscope. As a result, it was confirmed that some wrinkles occurred. In addition, during cutting in the process of producing the laminated substrate, a part of the resin layer was peeled off, and a deposit residue on the copper foil was recognized.

From the above, it was found that forming the resin layer having an area smaller than the area of the copper foil while leaving the peripheral edge of the copper foil is extremely effective in terms of preventing the contamination by the resin at the time of cutting. Also, in the above, the results of investigations on copper foil with aluminum carrier were made, but similar results were obtained when other carriers were used. Effect of the invention

Improves handling of ultra-thin copper foil and prevents contaminants such as resin powder from adhering to the surface of the copper foil, prevents scratches due to foreign substances, prevents scratches, and cuts, packs, scratches during transportation, wrinkles, breaks, etc. It has an excellent effect that a printed circuit board can be easily obtained without generation.

Claims

The scope of the claims

1. A copper foil with a carrier comprising a resin layer having an area smaller than the area of the copper foil with the peripheral edge of the copper foil remaining, and a copper foil with a carrier and a printed circuit board using the copper foil.

2. A copper foil with a caliper according to claim 1, wherein the resin layer is an insulating resin layer, and a printed circuit board using the copper foil.

3. A resin layer is applied by printing, A copper foil with a carrier according to claim 1 or 2 and a printed circuit board using the copper foil.

4. A range of claims characterized in that the carrier is a metal plate or a metal foil or a resin film, and the copper foil with carrier described in each of the items 1 to 3 and the copper foil

5. The range of claims characterized in that the bonding surface with the carrier is the shiny side (S side) of the copper foil, and the copper foil with carrier described in each of paragraphs 1 to 4 and the copper foil > Substrate.