TWM514176U - Pre-drilling wet plating metal substrate - Google Patents

Description

Pre-drilled wet-plated metal substrate

The present invention relates to a pre-drilled wet-plated metal substrate, in particular to a FCCL which is drilled at a predetermined position before metallization work, and then metallized, which can effectively reduce production cost and reach fine lines and micro Holes and high density requirements.

Flexible copper clad laminate (FCCL) is widely used in the electronics industry as a circuit board (PCB). In addition to its advantages of lightness, thinness and flexibility, FCCL also has a polyimide film. In addition to the excellent electrical properties, thermal properties and heat resistance, its low dielectric constant (Dk) makes the electrical signal transfer quickly, good thermal performance, easy to cool components, high glass transition temperature (Tg) allows the assembly to operate well at higher temperatures.

Flexible copper foil substrates are divided into two categories, one is the traditional adhesive type three-layer soft board substrate (3FCCL), and the other is the new type of non-adhesive two-layer soft board substrate (2FCCL). Material materials, their manufacturing methods are different, their application products are also different, three-layer soft board substrate is generally applied to bulk soft board products, and the second-layer soft board substrate has the advantages of lightness, thinness and shortness, and can be applied to higher-order soft board manufacturing. on. As for the manufacturing method of the existing two-layer soft board substrate, it can be divided into a coating type. (Casting Type), Lamination, Sputtering, and Wet-plating, all of which form a metal layer on a dielectric material to complete the fabrication of a flexible metal substrate. The methods are all known techniques and will not be described here.

In the conventional flexible circuit board, the flexible copper foil substrate is drilled first, and as shown in the first and second figures, the substrate 12 having the copper layer 10 is first drilled. The operation is such that a plurality of through holes 14 are formed on the substrate 12, and a conductive medium 16 (such as a metallized micro hole such as a conventional copper, an electroplated copper or a conventional conductive graphite to form a conductive medium 16) is formed in the through hole 14, and finally, The secondary copper 18 is plated on the flexible metal substrate 12 to form a secondary copper 18 above the copper layer 10 and in the through hole 14, so that the upper and lower circuits of the substrate 12 are turned on. Such a conventional flexible circuit board The manufacturing is cumbersome and costly, and the secondary copper 18 is formed on the copper 10 of the substrate 12, which will increase the thickness of the circuit board, which is not conducive to the demand for thin wires and high density, and the tradition in the through hole 14 The way in which the conductive via 16 is fabricated (such as conventionalized copper, electroplated copper, and metallized micropores such as conventional conductive graphite) has a large thickness and is also disadvantageous for microporation.

In order to solve the above-mentioned shortcomings of the flexible circuit board and the fabrication, the creator created the creation.

The present invention is a pre-drilled wet-plated metallized substrate comprising a polyimine film; a plurality of through holes are formed on the polyimide film; a first metal layer is formed on the surface of the polyimide film And a second metal layer is formed on the first metal layer, wherein the first metal layer is deposited by electroless plating a nickel layer, and a copper layer is electroplated on the nickel layer.

10‧‧‧ copper layer

12‧‧‧Substrate

14‧‧‧through holes

16‧‧‧Electrical medium

18‧‧‧Second copper

20‧‧‧ Polyimine film

22‧‧‧through holes

24‧‧‧First metal layer

26‧‧‧Second metal layer

Fig. 1 is a cross-sectional view showing a conventional flexible circuit board.

Figure 2 is a cross-sectional view of the first figure drilled.

Figure 3 is a manufacturing flow chart of the creation.

Figure 4 is a cross-sectional view of the present polyimine film.

Figure 5 is a cross-sectional view of the pre-drilled polyimine film.

Fig. 6 is a cross-sectional view showing the first metal layer in Fig. 5.

Fig. 7 is a cross-sectional view showing the second metal layer in Fig. 6.

Figure 8 shows the case where the film surface is directly cleaned without being cleaned.

Figure 9 shows the case where the film surface is directly cleaned without being cleaned, and the pre-drilled hole is leak-plated.

Figure 10 shows the situation of plating after film surface cleaning.

The manufacturing method of the wet-plated metal substrate of the pre-drilled hole of the present invention, as shown in FIG. 3 and FIG. 4, includes providing a polyimide film 20 (S1), in this embodiment The monomer composition and preparation method thereof are not particularly limited, and may be carried out by a usual technique in the art, and may have a thickness of 7 to 50 μm.

Referring to FIG. 3, a polythene film 20 (S1) is provided, and a pre-drilling operation (S2) is performed on a Polyimide film 20 to form a plurality of surfaces of the polyimide film 20 Through holes 22.

The pre-drilled polyimide film 20 is subjected to a bonding operation (S3), and a surface cleaning treatment is performed to remove impurities/dirt on the polyimide film 20, wherein the surface cleaning treatment includes Performing a dry treatment (S4), followed by a wet treatment (S5), which may be a physical high energy treatment such as corona, plasma or UV irradiation. This not only cleans the membrane surface, but also has different degrees of table modification to increase the membrane surface. Adhesion, and corona mode can activate the hydrophilicity of the membrane surface, which is beneficial to subsequent wet treatment. The wet treatment is a chemical liquid cleaning, which further includes a super-wave shock, which can promote the treatment efficiency of the chemical liquid on the membrane surface.

The polyimine film 20 which has been subjected to the cleaning treatment is subjected to an electroless plating process to form a first metal layer 24 (S6) on the surface and the wall surface of the through hole 22. In this embodiment, the first metal layer 24 is made of nickel metal. The thickness can be from 0.05 to 0.2 microns.

The polyimine film 20 of the first metal layer 24 is subjected to a heat treatment (S7), and the heat treatment can improve the adhesion force between the conventional metal layer and the polyimide film (ie, peeling between the two) The high temperature reliability of the strength is insufficient). Through the heat treatment, the peeling strength of the metal layer and the polyimide film can be maintained, the yield of the copper layer plating can be improved, and the handleability of the copper layer plating can be improved.

Referring to FIG. 6, the polyimide film 20 after the heat treatment is subjected to a process of plating the second metal layer 26 to form a second metal layer 26 over the first metal layer 24 (S8).

Furthermore, in the present invention, the polyimide film 20 is pre-drilled prior to metallization, and after the cleaning process, the metal layer is formed by wet plating, which can improve the process of the conventional flexible circuit board shown in the first figure. Complexity, and can meet the needs of fine lines, micropores and high density products.

The pre-drilled wet-plated metal substrate of the present invention, as shown in FIG. 7, includes a polyimine film 20 having a plurality of through holes 22 formed therein; and a polyimine film 20 is provided with a The first metal layer 24 is located on the surface thereof and the wall surface of the through hole 22, which may be nickel metal, may have a thickness of 0.05-0.2 micrometers, and a second metal layer 26 is disposed on the first metal layer 24, and the second metal layer 26 is Copper has a thickness of 0.2 to 12 microns.

The table below shows that corona treatment improves the quality of nickel work.

Please refer to Figure 8 for the direct plating of the film surface without cleaning.

Please refer to Fig. 9 for the direct plating of the film surface without cleaning, and the pre-drilling is leak plating.

Please refer to Figure 10 for the plating after film surface cleaning.

20‧‧‧ Polyimine film

22‧‧‧through holes

24‧‧‧First metal layer

26‧‧‧Second metal layer

Claims (2)

A pre-drilled wet-plated metal substrate comprising a polyimide film; forming a plurality of through holes on the polyimide film; depositing a nickel layer on the surface of the polyimide film by electroless plating; And a copper layer is deposited on the nickel layer by electroplating to form a nickel layer and a copper layer on the surface of the polyimide film and the through-hole wall. The pre-drilled wet-plated metal substrate according to claim 1, wherein the nickel layer has a thickness of 0.05 to 0.2 μm and the copper layer has a thickness of 0.2 to 12 μm.