JPS6049593B2 - Aluminum base laminate for printed wiring boards and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aluminum base laminate used for manufacturing printed wiring boards (printed circuit boards) and a method for manufacturing the same.

Specifically, the present invention relates to an aluminum base laminate for printed wiring boards in which an aluminum base material and a resin layer are firmly bonded together, and a method for manufacturing the same. A printed wiring board is a single insulating board, on one or both sides of which a wiring path is formed using copper foil, and electronic components are attached to form a device.

In recent years, multilayer printed wiring boards on which electronic components are mounted at high density have been widely used, and it has been proposed to bond an aluminum plate to an insulating board in order to efficiently dissipate heat from these wiring boards. However, with the conventional adhesion method, it is not possible to firmly bond the insulating plate and the aluminum plate, and there is a risk that the insulating plate and the aluminum plate will peel off while the electronic device is in use. It had not been discovered. Therefore, the inventor of the present invention has conducted extensive research on a method for firmly adhering an insulating plate and an aluminum plate. As a result, the inventors first form irregularities under specific conditions on the surface of the aluminum plate in advance, and then apply a resin layer that will become the insulating plate. The present invention was completed by discovering that it can be bonded using a special method.

That is, an object of the present invention is to provide a laminate for a printed wiring board in which a resin layer serving as an insulating plate and an aluminum plate serving as a heat dissipation plate are firmly integrated, and a method for manufacturing the same. layers and aluminum substrates (including substrates of aluminum itself, as well as substrates of aluminum alloys).

In an aluminum base laminate for printed wiring boards, in which the aluminum base material surface is laminated with
The surface is roughened to a diameter greater than μ, and micropores with a diameter of 100 to 450A are provided on the roughened surface, and the resin layer penetrates to the inside of the micropores to connect the resin layer and the aluminum base material. This can be achieved by a method in which a laminate is firmly bonded, and in manufacturing the laminate, an adhesive thermosetting resin layer is thermocompression bonded to the surface of an aluminum base material provided with micropores. The laminate of the present invention will be explained in detail below with reference to the drawings. 1 is 2μ) or more, and the hole pitch from peak 2 to peak 2 of the unevenness (pitch S in FIG. 1) is roughened to about 10 to 500μ.

I should be 2μ or more, but the upper limit is 30p or less because the resin layer cannot sufficiently penetrate into the roughened surface by thermocompression bonding, and even if it can penetrate, the adhesive strength is insufficient. It is preferable that Moreover, if I is smaller than 2μ, the adhesive force will be insufficient. Each of the peaks 2 and valleys 3 is further provided with numerous micropores 4 having a diameter of 100 to 450A, preferably 200 to 350A.
In this case, if the pore diameter is smaller than 100A, it will be difficult for the resin layer 5 to penetrate into the inside of the micropore 4, and if it is larger than 450A, the resin layer 5 will penetrate easily, but even if it penetrates, the resin layer 5
Sufficient adhesive strength between the aluminum base material 1 and the aluminum base material 1 cannot be obtained. Note that the depth of the hole 4 is usually 0.2 to 1.0 μ. A resin layer 5 is adhered to the upper side of the aluminum base material 1 which has been roughened and has micropores 4, and as described above, a part of the resin layer 5 has micropores 4 as shown in FIG. It has invaded the inside of the body without any gaps. The resin layer 5 used here is made by impregnating glass fiber, nonwoven fabric, etc. with an adhesive thermosetting resin such as epoxy resin, phenol resin, polyester resin, polyimide, silicone resin, or polytetrafluoroethylene. used. Among these, when using an epoxy resin, it is preferable to use an aromatic amine having a molecular weight of 500 to 10,000 and an epoxy equivalent of 150 to 600 as a curing agent. The laminate having the above-mentioned structure is made into a printed wiring board by pasting copper foil on the upper surface of the resin layer 5 by a conventionally known method and etching it according to the circuit. In such a printed wiring board, a part of the resin layer 5 penetrates into the inside of the narrow micropore 4 and the resin layer 5 and the aluminum base material 1 are bonded together. No peeling, allowing electronic devices to be used safely even under harsh conditions with a lot of vibration. The laminate of the present invention as described above is manufactured, for example, as shown in FIG. First, as a degreasing step (a), surface contaminants are removed by immersing the aluminum base material 1 in a common degreasing agent. Next, the aluminum base material is roughened to an average roughness of 2 μm or more in an etching process. The etching method is not particularly limited, and includes, for example, chemical etching using NaOH, sodium dichromate, HCl, etc.; hairline, sandblasting,
Mechanical etching such as shot blasting or ball graining; electrochemical etching using alternating current or direct current in a NaCl or NH4Cl solution can be performed. The degree of surface roughening varies depending on the etching method; for example, Na
Chemical etching using OH resulted in a roughness I of approximately 2 μ and a hole pitch S of approximately 200 μ; electrochemical etching using an NHLCl solution resulted in a roughness I of approximately 4 μ and a hole pitch of approximately 100 μ; In the case of electrochemical etching, the roughness 1 is about 5μ and the hole pitch is about 10μ. In the next micropore generation step (c), micropores 4 having a diameter of 100 to 450A are provided on the uneven surface having a depth l of 2μ or more and a pitch S of about 10 to 500μ, which is generated by roughening.

In order to provide the micropores 4, for example, porous alumite (corrosion-resistant oxide film) may be produced, and if phosphoric acid is used as the electrolyte, porous alumite having micropores 4 with a pore diameter of approximately 330A is produced, and chromium Approximately 240A when using acid
, about 170A when using oxalic acid, about 1 when using sulfuric acid.
Porous alumite having micropores 4 of 20A is produced respectively. Next, in the resin layer pressure bonding step 2, the aluminum base material 1
A resin layer 5 serving as an insulating material is firmly bonded thereon by thermocompression bonding.

Thermocompression bonding is performed until the adhesive thermosetting resin, which is a component of the resin layer 5, melts and penetrates into the inside of the micropores 4. For example, when glass fiber impregnated with epoxy resin is used as the resin layer 4, The process is carried out at a temperature of 120 to 180°C and a pressure of 50k91cIt for 60 to 12 minutes. Note that it is preferable to treat the resin layer 5 with a silane coupling agent before this resin layer pressure bonding step 2, since the resin layer 5 can be bonded more tightly. Silane coupling agents that can be used include:
vinyltrichlorosilane, vinyltrithioxysilane,
Vinyltris(β-methoxyethoxy)silane, β-(
3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyl? trimethoxysilane,
N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, etc. can be used, and these can be mixed with alcohol and water at 100% by weight. Part 5
~1 part of saliva may be added, applied as a primer to the surface of the base material 1, and sufficiently air-dried. As described above, the laminate of the present invention can be produced by the method described above, and this laminate exhibits excellent properties.

Example base material: Length 300TI0rL1 Width 1071Un1 Thickness 2? Using an aluminum plate JISAAlO5O-H24, the surface was degreased by immersing it in a 3% aqueous solution of the degreaser "Dipsol AI-47" at 50°C for 3 minutes, and the surface was roughened under the conditions shown in the table below. A resin layer with a thickness of 100 μm obtained by impregnating glass fiber with an epoxy resin trade name “Epicote 1001” (Shell Chemical Co., Ltd.) having a molecular weight of 900 and an epoxy equivalent of 450 to 500 and hardening it was heated at 150°C and a pressure of 50k91C71f for 12 minutes. It was crimped and its adhesive strength was measured.

The adhesive strength after treatment with a silane coupling agent is also shown. In order to measure the adhesive strength, the same aluminum plate was laminated on the upper side of the resin layer under the same conditions as shown in FIG.

[Brief explanation of the drawing]

FIG. 1 is a partially enlarged sectional view showing the laminate of the present invention, FIG. 2 is a further enlarged sectional view of FIG. 1, FIG. 3 is a partially enlarged sectional view showing the method of the present invention, and FIG. 4A 1 is a cross-sectional view of an aluminum plate laminated on the upper side of the resin layer in order to measure adhesive strength in an example, and B is an enlarged cross-sectional view. 1... Aluminum base material, 4... Fine pores, 5... ■ Fat layer.

Claims (1)

[Scope of Claims] 1. In an aluminum base laminate for printed wiring boards in which a resin layer and an aluminum base material are laminated, the surface of the aluminum base material is roughened to an average roughness of 2μ or more, and the surface roughness is further increased. A printed wiring characterized in that micropores with a diameter of 100 to 450 Å are provided on the planarized surface, and the resin layer penetrates into the inner side of the micropores to firmly bond the resin layer and the aluminum base material. Aluminum base laminate for use. 2. The aluminum base laminate for a printed wiring board according to claim 1, wherein the resin layer is glass fiber impregnated with an adhesive thermosetting resin. 3 The surface of the aluminum base material is degreased and etched to roughen it to an average roughness of 2 μ or more, and then porous alumite having micropores with a pore diameter of 100 to 450 Å is generated on the roughened surface, and then adhesive A thermosetting resin layer is thermocompression bonded to the surface of an aluminum base material, and the thermosetting resin penetrates into the inside of the micropores to firmly integrate the aluminum base material and the thermosetting resin layer. A method for manufacturing an aluminum base laminate for printed wiring boards. 4. The method for producing an aluminum base laminate for a printed wiring board according to claim 3, wherein the adhesive thermosetting resin layer is glass fiber impregnated with epoxy resin. 5 The surface of the aluminum base material is degreased and etched to roughen the surface to an average roughness of 2μ or more, and then porous alumite having micropores with a pore diameter of 100 to 450 Å is generated on the roughened surface, and then a silane cup is formed. After treatment with a primer containing a ring agent or a silane coupling agent, an adhesive thermosetting resin layer is thermocompression bonded to the surface of the aluminum base material, and the thermosetting resin penetrates into the inside of the micropores to form the aluminum base material. 1. A method for manufacturing an aluminum base laminate for printed wiring boards, characterized by strongly integrating a thermosetting resin layer and a thermosetting resin layer.