JPS59213196A - Copper foil with adhesive - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an adhesive-coated copper foil that is bonded to a copper-clad laminate.

Copper-clad laminates are widely used as printed wiring boards by processing the copper foil bonded to the surface of the laminate, but this type of laminate is also widely used as a paper phenolic resin laminate, a paper epoxy resin laminate, It is formed by bonding a so-called adhesive-coated copper foil onto a substrate such as a polynisdel board, the surface of which is coated with an adhesive. In order to bond the above-mentioned substrate and copper foil with adhesive, a hot press method is generally used.
For example, the temperature is 170℃ and the output is 100! 7
By pressurizing and bonding under the conditions of /c1it for about 2 hours, the substrate -1 and the adhesive-coated copper; -i.1 are bonded together with sufficient adhesive strength.

However, the above-mentioned hot press method requires a huge amount of equipment, which increases production costs due to equipment investment, and the 1 nibbles method (boiled egg) is a batch system and has limited processing capacity. However, productivity is extremely poor.

Therefore, in the past, attempts have been made to continuously bond copper foils with adhesive using rolls to improve productivity, but the conventionally used butyral/phenol When the adhesive is heated with a heat-recording roll, it may not have sufficient adhesive strength, and problems such as lifting of the copper foil or 77 will occur (i5 reliability will be extremely low. It is possible to use an adhesive that exhibits good adhesion when heated with a hot roll, but this type of adhesive generally has a weak adhesive strength to copper foil, and the adhesive strength that can be used for copper-clad laminates is low. No one is known to have this.

Therefore, the present invention has been proposed in order to eliminate the drawbacks of the above-mentioned conventional methods, and it is possible to continuously bond to a substrate using a hot roll, and has sufficient adhesive strength. The purpose of the present invention is to provide adhesive-(=l-3) copper foil that can be bonded with adhesive.

As a result of intensive research, the present inventors formed a laminated layer on a copper foil with an adhesive layer having a predetermined adhesive strength to the copper foil and an adhesive layer that exhibits adhesive properties under heat. The present invention was completed by discovering that the adhesion to the copper foil is good and hot roll lamination is possible by applying a layer of 1 to 1 on the copper foil. .5
A first adhesive layer having a beer strength of kg/m or more and a second adhesive layer having thermal activation are sequentially laminated.

That is, as shown in FIG. 1, the adhesive-coated copper foil constructed according to the present invention is obtained by first coating and forming a first adhesive layer 2 having good adhesion to the copper foil on a copper foil 1; Furthermore, a second adhesive layer 3 having heat activation is formed by coating on the first adhesive layer 2. And each of these adhesive layers 2
, 3 is coated with liquid adhesive 5 or 6 using, for example, a roll 4 as shown in FIG.
A method of heating for 11 minutes is used.

The first adhesive layer 2 contains 15 kg of copper foil 1.
An adhesive having a beer strength of /ae or higher is used, and examples of such adhesives include 7-naral phenol adhesives and epoxy nitrile adhesives. For example, 30 parts by weight of phenol, 70 parts by weight of polyvinylbunaral, and epoxy resin (1
001) 2.3 kgAMr per 1 copper foil by dissolving 1 part by weight in 200 parts by weight of methyl ethyl ketone
A suitable adhesive having a beer strength of the order of b.

By the way, the above-mentioned beer strength indicates the peeling strength of the conductor (copper foil) of the cylinder wiring board, and its measurement method is JIS C5012 (7) according to the JIS standard.
81. That is, as shown in FIG.
4: 0. l TILTI+, a sample with a length of 100 wu copper foil 102 left, is prepared, and this copper foil 1
Peel off one end of the copper foil 102 to an appropriate length and place it on a support metal fitting (not shown). Then, grasp the tip of the peeled copper foil 102 with a gripping tool (not shown) to make sure that the pulling direction is copper. Approximately 56 'nun peeled in the direction perpendicular to the foil surface at a speed of 5011tj11 per minute, and the minimum value of the load during this time was determined as the peeling strength, that is, the beer strength, expressed as 1 (g/(ML). .

1/To the second adhesive layer 3, heat 1"-
The heat from the metal causes the temperature to rise above the softening point, resulting in stickiness.
A so-called heat-activated adhesive that can be bonded is used,
Examples of such adhesives include epoxy/acrylic adhesives and epoxy/polyamide adhesives. for example,
30 parts by weight of acrylic rubber (manufactured by Teikoku Kagaku Co., Ltd.), 21 parts by weight of flotated bisphenol, 21 parts by weight of cresol novolak epoxy, 28 parts by weight of polyphenol, and a catalyst, 100 parts by weight of methyl ethyl ketone, 10 parts by weight of toluene.
0 parts by weight and ethyl alcohol 200? 10 parts by weight of acrylic rubber (manufactured by Teikoku Kagaku Co., Ltd.), epoxy resin (
Shell Kagaku Co., Ltd. 1 (101) 20 parts by weight and Unten Imixol 0. A solution of l 5 :fifft part in 50 parts by weight of methyl ethyl ketone and 20 parts by weight of 1-toluene has the above-mentioned thermal activity and is suitable for use in the second adhesive layer 3.

As shown in Figure 4, the adhesive layered copper foil as described above is
The copper-clad laminate is easily laminated to the substrate 10 by a pair of hot rolls 8.9, and a copper-clad laminate having sufficient adhesive strength is obtained. As the substrate 10, all kinds of substrate materials can be used, such as a paper phenolic resin laminate, a paper epoxy resin laminate, a glass epoxy resin substrate, an aluminum plate or a steel plate coated with an insulating layer on the surface. .

In addition, after the above roll lamination 1, 130 ° C., 2 to 5
After post-curing for about an hour, each of the adhesive layers 2,
To make the curing state of No. 3 more reliable. Further, it is preferable that the substrate 10 be heated in advance in order to drive out unreacted components and volatile components such as organic solvents remaining in the substrate 10.

As mentioned above, the adhesive bonded copper foil is easily laminated onto the substrate 10 with hot rolls 8, 9 due to the thermal activation of the second adhesive layer 3, and It is reliably joined to the base 10 due to the adhesive strength of No. 2 to the copper foil 1.

By the way, by using the above-mentioned adhesive-coated copper foil in a multilayer wiring board that was previously proposed by the applicant of the present application, it becomes possible to significantly improve the reliability of this multilayer wiring board.

Hereinafter, a manufacturing process for manufacturing the multilayer wiring board using the adhesive-coated copper foil according to the present invention will be described with reference to the drawings.

FIGS. 5 to 11 show the process order of the multilayer wiring board. In this example, first, as shown in FIG. 5, a conductive foil, e.g. A copper-clad laminate coated with foil is prepared, and the copper foil is heated to form a first conductive foil pattern F'lJ-wiring pattern 22. At this time, in order to improve the adhesion between the wiring pattern 22 and an insulating layer to be formed next, the wiring pattern 22 may not be subjected to surface treatment. As for surface treatment, in addition to blackening treatment, C is applied to the surface.
There are chemical surface roughening treatments that form an oxide film such as LIO and CLI 20 , mechanical surface roughening treatments such as sandblasting. Next, first wiring pattern 2
As shown in FIG.
It is formed by printing except for the connecting portion 22a (approximately circular in the illustrated example). The insulating layer 23 is formed by so-called reciprocating printing in which a squeegee is moved back and forth.

According to this method, even if the shoulder portion of the first wiring pattern is in the shadow, the shadow portion is sufficiently coated due to the reciprocating coating, and an insulating layer 23 without pinholes is formed.

Next, as shown in FIG.
Roll the copper foil 1 laminated with
, and the wires at a speed of 5 m/min) to stack and combine on the substrate 21. Since the adhesive needs to be in a semi-cured state for laminating the copper foil 1, it is difficult to use a hot press method, and conventionally, thermally activated adhesives with poor adhesion to the copper foil 1 Since it was not possible to use an agent, the adhesive strength of the copper foil 1 was low and reliability was poor. However, by using the adhesive-based copper foil according to the present invention, the above-mentioned roll lamination 1.
During bonding by the device, the second adhesive layer 3 is not thermally activated, so that the substrate 21 remains in a semi-cured state with good adhesion.
In addition, it becomes possible to bond the copper foil 1 to the substrate 21 with a predetermined adhesive strength due to the beer strength of the first adhesive layer 2 in the curing process described later.

Next, as shown in FIG. 8, selective etching is performed on the copper foil 1 using an aqueous solution of ferrous chloride (enoting solution) to form a second conductive foil pattern, that is, a wiring pattern 26. At this time, the connecting portion 26a of the second wiring pattern 26 with the first wiring back 22 does not have a shape having a closed inner circumferential surface (so-called "snap-shape"), but is connected to the first wiring pattern 22 as shown in the figure. For example, in the illustrated example, the copper foil 1 is formed into a substantially semicircular shape so as to partially overlap the connecting portion 22a of the copper foil 1.
During selective etching, the adhesive layers 2, 3 on the back 1 are not removed.

Next, as shown in FIG. 9, both connecting portions 22J1 and 26a
A Nork-resist layer 27 is deposited by printing except for the portions corresponding to . As this sinter resist layer 27, an ultraviolet curing resin such as Evogin Acrylay 1 type can be used, and the peeling of the adhesive layers 2 and 3 can be carried out.
It has the property of not being affected by the organic solvent used in IilI. Then, using the solder resist layer 21 and the connecting portion 26a of the second wiring pattern 26, that is, the copper foil as a mask, each adhesive layer 2 in a semi-cured state exposes the portion corresponding to the connecting portion 22a of the first wiring pattern 22. , 3 in an organic solvent (
For example, a solution of methylene chloride) can be used to selectively dissolve and peel off.
(C) Expose the surface of the connection part 2221.

Next, the base is formed by mechanical means such as pressing so that the center part of the connection part 22a of the first wiring pattern 22 includes at least a part 33 where the connection part 26M+ of the second wiring pattern 726 does not overlap. An electrical component insertion hole 28 is formed so as to pass through the material 21.

Then, each adhesive layer 2, 3 in a semi-cured state is cured with an electron beam,
Alternatively, the multilayer wiring board 29 shown in FIG. 10 is obtained by thermosetting. Although the insertion holes 28 were formed in the process shown in FIG. 10, the insertion holes 28 may also be formed in advance before the selective etching of the copper foil shown in FIG. This is to prevent the adhesive strength of the connecting portion 22a to the base 4A21 from decreasing due to the impact when drilling with a press, and
If press holes are punched when the entire surface of the adhesive is adhered, a decrease in adhesive strength can be avoided.

Thereafter, as shown in FIG.
- The wire 31 is inserted into the wire entry 128, and the lead wire 31 and both connecting portions 22a and 26a are electrically connected by the conductive material 32. As the conductive substance 32, half H'' (
Solder flow, manual soldering, reflow with Norder cream, Norter coater leveler), gallium alloy (which initially forms a paste-like form at working temperature and then becomes alloyed and solidifies over time), silver paint, carbon A conductive phase of paint, copper paint, etc. may be used.

As mentioned above, by using the copper foil with adhesive according to the present invention, the copper foil 1 can be bonded with high adhesive strength even when the adhesive is first used in a semi-cured state and is completely cured at the end. This makes it possible to improve the reliability of the multilayer wiring board 29.

As described above, according to the present invention, it is possible to obtain an adhesive-coated copper foil that has sufficient adhesive strength and can be bonded to a substrate with good productivity.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a main part showing an adhesive-coated steel foil according to the present invention, and FIG. 2 is a schematic diagram showing a method of forming each adhesive layer.
FIG. 3 is a perspective view showing a method of measuring beer strength, and FIG.
・This is a schematic diagram showing the method... Figures 5 to 11 are partially sectional perspective views showing the sequence of steps in the manufacturing process of a multi-layer wiring board. 1... ...Copper foil 2...First adhesive layer 3...Second adhesive layer Patent applicant Sony Corporation representative Patent attorney Kodo Koike 1) Sakae Mura - Figure 1 Figure 3 Figure 4

Claims (1)

[Claims] With an adhesive formed by sequentially laminating on a copper foil a first adhesive layer having a beer strength of 5 kg 10 m or more with respect to the copper foil and a second adhesive layer having thermal activation. Copper foil.