JPS62200796A - Manufacture of extra-thin copper laminated board - 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 (Industrial Application Field) The present invention relates to a method for manufacturing a copper-clad laminate, which is a material for printed wiring boards. The present invention relates to a method of manufacturing an ultra-thin copper-clad laminate suitable for forming an ultra-thin copper-clad laminate.

(Conventional technology and its background) In recent years, various electronic devices and products have become lighter.

Rapid progress is being made in thinning, shortening, and miniaturization, and along with this, printed wiring boards for electronic components that are included in M1 aircraft bases and products are also becoming lighter, thinner, and smaller. There is. The specific direction for reducing the ftj of this printed wiring board is to increase the density of the wiring formed on this type of board and to make each conductor extremely thin. Moreover, since printed wiring boards are required to be produced in high-mix, low-volume production, there is also a demand for high-mix low-volume production of the substrates that form the basis of these printed wiring boards.

By the way, copper-clad laminates are often used for substrates for printed wiring boards on which electronic components are mounted. Forming minute circuits
In response to the above-mentioned demand for lighter, thinner, and shorter equipment and products, the need for copper-clad laminates spun from copper foil parts, that is, ultra-thin copper-clad laminates, is increasing.

Conventionally, such ultra-thin copper-clad laminates have been manufactured at °C as shown in FIGS. 4 to 6. That is, the fourth
Thickness as shown in 1A or 40Bm or I[l[]
5pm thick protected by pm aluminum foil (21)
Alternatively, ultra-thin copper foil (22) with a thickness of 9 mm or the like is impregnated into a non-woven glass fabric to make a completely cured epoxy resin so-called prepreg (
2) Laminated on a) and heated and pressed to integrate as shown in FIG. After that, this aluminum foil (21) is mechanically abraded or chemically removed using an etching solution consisting of sodium hydroxide and sodium gluconate to form an ultra-thin copper cladding as shown in Figure 6. This forms a laminate (2o).

(Problems to be Solved by the Invention) The conventional method for forming the ultra-thin copper-clad U-layer board (2o) described above has the following problems.

5 Of course, in order to apply this method, it is first necessary to form an ultra-thin copper foil (22) of a predetermined thickness, but this ultra-thin copper foil (22) is usually formed by electroplating. Since it is manufactured by the same method, it is not only impossible to completely eliminate the occurrence of pinholes during the manufacturing process, but also the use of aluminum foil (21) as a base material is essential. Further, since this ultra-thin copper foil (22) is usually formed as a long piece, it is rolled together with the aluminum foil (21) after completion to protect it. Therefore, according to such a manufacturing method, only the ultra-thin fM foil (22) is required, but the aluminum foil (21) is required.
), and this aluminum foil (zl) must also be taken into consideration. Furthermore, pinholes and wrinkles may occur in the ultra-thin copper foil (22) during manufacturing or when the completed ultra-thin copper foil (22) is rolled. 20) When wiring is formed on the board, there are problems such as pinholes and wrinkles causing disconnection in the wiring part of the ultra-thin copper clad laminate (20) 1:. If you try to avoid this, the yield of the ultra-thin copper foil (22) itself will deteriorate, and the price of the aluminum foil (21) mentioned above will be included in the ultra-thin copper foil (22). As a result, J1 is always expensive? ;
Therefore, the copper foil (22) must be used.

In addition, ultra-thin copper foil (
22) is formed by electroplating, so it has poor ductility properties and needs to be very thin. Therefore, prepreg (2: la ) formed by a substrate (
23), the ultra-thin copper foil (2
2) partial frX clefts may occur. This crack is a fatal defect for the wiring formed on the It is not suitable for

Furthermore, according to the conventional method, the thickness of the ultra-thin copper foil (2z) of the ultra-thin copper-clad laminate (2G) thus formed is the same as the thickness of the ultra-thin copper foil (22) that is the starting material 1. limited to.

In other words, the ultra-thin copper foil (22) of Jlu copper foil (22) has the required thickness.
When manufacturing the laminate (211), the thickness of the electrode copper foil (22) must be determined from the beginning of the manufacturing process. This means that in the current situation where this type of ultra-thin copper clad laminate (20) and the printed wiring boards used are required to be produced in high-mix, low-volume production, it is possible to respond in real time to the It makes things difficult.

Therefore, in view of the current state of the prior art including the various problems mentioned above, the inventor has developed a method that does not require the conventional aluminum # (21) at all to manufacture the ultra-thin copper-clad laminate (20). Koto■J4ii
'I Prevent pinholes, wrinkles, etc. from occurring in the copper foil (22) itself. (3) The ultra-thin copper foil (22) should have sufficient ductility to make it flexible and (ultra-thin copper suitable for plates). Tension laminate (20
) (4) And we need high-mix, low-volume production! The present invention was completed with the aim of creating an ultra-thin copper-clad laminate (20) that can respond to the current situation in just one minute.

(Means for solving the problems) The means taken by the present invention to solve the above problems are as follows.
This will be explained with reference to the 11th to 4th sections corresponding to the embodiments.

At least one of mechanical polishing, electrochemical polishing, and chemical etching is applied to the copper foil (12) with a thickness of 18 ILm or more laminated on at least one side of the substrate (11).

This is a method for producing an ultra-thin copper-clad laminate (lO), characterized in that the thickness of the copper foil (12) is 127 Lm or less.

The mechanical polishing in this case may be any one of Hough polishing, belt polishing, swing polishing, spin polishing, scrub polishing, and blast polishing. Further, in the case of electrochemical polishing, it is specifically preferable to use electrolytic polishing. Additionally, for chemical etching, sulfuric acid-hydrogen peroxide, persulfates, ferric chloride, ferric chloride (g)1 or ammonium complex! Any etching solution containing at least one of the following may be used.

Next, the method according to the present invention will be explained for jJ single weight.

That is, first, as shown in FIGS. 1 and 2, a prepreg (II), which will become the board (II), is made of paper phenolic resin, glass epoxy resin, or glass polyimide resin.
A) is laminated with a copper foil (12) formed by electrolysis or rolling with a thickness of 18 lm or 25 lm. Thereafter, 40 to 100 kg was heated at a temperature of 160°C to 260°C according to a conventional method, and a pressure of 1 to 100 cm/c nv' was applied.
Press for 2 hours.

A laminate as shown in FIG. 2 is formed.

Next, the copper foil (12) formed as this laminated board (Ill) is etched using an etching solution such as ferric chloride.
At ~55°C, the copper foil is etched to a thickness of 12 Bm or less by immersion method, 11G flow method, spray method, &Y or oscillating spray Z. As a result, as shown in Figure 3, the copper foil (1
2) is ultra-thin copper clad with ultra-thin copper foil! ! The i-layer board (10) is completed.

This is because the copper foil (12) used in this method does not need to be extremely thin from the beginning.

It does not need to be lined with aluminum foil or the like as in the case of using conventional ultra-thin copper foil.

For example, if the copper foil (12) is rolled and provided with an anchor on one side to ensure strong adhesion to the substrate (11), the copper foil (12) itself has a predetermined strength. Usually 18pm, 25pm.
Alternatively, you can use a 35 mm thick 6 mm. The copper foil used in this case has a so-called anchor part, and the thickness including this anchor part is 1-81Lm.
, 25 gm or 351 Lm. In other words, while ensuring quality stability and reliability, we are saving resources by omitting the use of aluminum foil as a backing material, and reducing roll winding work when using ultra-thin copper foil from the beginning. In order to avoid waste and thereby reduce material costs, the copper foil (12) used in the present invention may be one with a thickness of 18 gm or more, which is currently commonly used. be.

In addition, prepreg (ll) used as the substrate (11)
Examples of a) are not limited to the paper phenolic resin, glass epoxy resin, or glass polyimide resin described in 1). In other words, as such prepreg,
In addition to the above, various resins such as paper epoxy resin, glass triazine resin, glass diallyl phthalate resin, Kevlar polyimide resin, glass bismaleimide triazine vA resin, etc. impregnated with paper, glass nonwoven fabric, Kevlar nonwoven 11i, etc. are used. Then it comes.

In addition, as the group & (II) in L, rigid or flexible substrates formed by adding thermosetting resins to the skeletons of the various paper-glass nonwoven fabrics, Kevlar nonwoven fabrics, etc. described above, thermosetting Rigid or flexible substrates made only of resin, polyamide resin, Teflon resin, polyester resin, polyether sulfon resin, polyether ether ketone resin, or aramid resin. Polyester 8111'f reinforced with a
Rigid or flexible substrates made of thermoplastic resin such as L, aluminum plates, copper plates, etc., whose surfaces are insulated in whole or in part with one or at least two of epoxy resin, epoxy-modified polyimide resin, or polyimide resin. Also included are metal core substrates, ceramic substrates such as alumina, and glass substrates '9. Of course, this substrate (11) may also be a composite body made by appropriately combining these materials.

To glue the copper foil (12) to the board (II),
J double prepreg (lla) may be used as is, or phenol adhesive, epoxy adhesive, polyimide adhesive, etc. may be used.

In addition, as a method of making the copper foil (12) extremely thin,
In addition to the chemical etching method, mechanical polishing such as eight polishing, belt polishing, rocking polishing, spin polishing, one scrub polishing, or blast polishing as described above, or electrochemical Mn such as electrolytic polishing may be used. In this case, polishing may be performed by using only one of the polishing methods listed in I-1, or at least -J4 of these polishing methods may be used in combination.

In this case, the order of combination can be arbitrarily chosen, but in terms of accuracy and productivity, chemical etching with an oscillating spray is slightly superior.

Heretofore, in the production of printed wiring boards, puff polishing, belt polishing, soft etching, etc. have been commonly used as pre-treatment or post-treatment for each process. The internalization of the copper foil (I2) in the present invention is similar to these techniques in terms of [υ]. However, polishing and etching, which are conventionally used in 1IJ processing and post-processing, are
In contrast, the present invention aims to prevent the occurrence of defects during production, ensure product reliability, and control quality.
Using polishing or etching, remove the copper foil (I2) on the substrate (11) in place 9! The technical ideas of the two methods are completely different.

Furthermore, in applying the present invention, it goes without saying that when each of the copper foils (12) described in 1- is formed on one side of the substrate (II),
Ultra-thin copper clad laminates can also be made by forming on both sides (10)
It is possible to manufacture

Next, the present invention will be explained with reference to examples.

(Example) Example 1 - Manufacturing method of single-sided ultra-thin copper-clad laminate (10) Thickness: 18 gm
Electrolytic copper foil (HTE manufactured by Mitsui Kinzoku Sawgyo Co., Ltd.)
Prepreg (lla) with pm thickness (R manufactured by Matsushita Dencho Co., Ltd.)
-1705) Add 1,400 to 6 pieces of 1-4 and apply pressure 4.
0kg/c vinegar, temperature 170℃, hot breath for 1 hour, cut, size 340 Ila+it1. Thickness 11
A single-sided copper-clad laminate of No. 111 was formed.

In contrast, cupric chloride and I'i! Etching solution consisting of acid (group Q: Cu Cl, 2 H, 01711
gra- and HCl (20” B e ) 0.1
(equivalent to the solution made by adding water to ii to make 141)
Etching was carried out at ~55° C. using an oscillating spray method to form an ultra-thin copper-clad laminate (+ 11 ) having a copper foil (12) with a thickness of 111 μm on one side.

When we attempted to form a circuit by coating the resulting ultra-thin copper-clad laminate (Ill) with a liquid photosensitive resin, we were able to create a pattern with a minimum conductor of 111 or 30 pm.

Example 2 - Manufacturing method of double-sided ultra-thin copper-clad laminate (10) Thickness: 25 m
Rolled copper foil (11☆ 0FC-A (:E
) was placed on the lowest and lowest parts of six 180 gm thick prepreg (lla) (R-1705 manufactured by Matsudo Dencho Co., Ltd.), and the pressure was set to +r/c rr+' and the temperature was set to 17.
After hot pressing at 0°C for 1 hour, cut and size
A double-sided copper-clad frame board of 340 mm square and 1 mm thick was formed.

On the other hand, etching was carried out using an oscillating spray method at 50 to 556 C using an etching solution consisting of cupric chloride and hydrochloric acid similar to that used in Example 1, and an ultra-thin film having a copper foil (12) with a thickness of 12 Bm on both sides was used. A copper clad laminate (lO) was formed.

After drilling holes in this double-sided ultra-thin copper-clad laminate (10) and applying a deplating catalyst to the entire surface, chemical copper plating was applied to create a double-sided printed wiring board using the solder through-hole method. Ta. As a result, a circuit pattern with a conductor in the through hole and a minimum conductor of 1rJ or 501Lm was formed.

(Effects of the Invention) As explained below, the present invention is as exemplified in each of the embodiments in Section L.

1 Apply at least one of mechanical polishing, electrochemical polishing, or chemical etching to the copper foil (12) with a thickness of 182 m or more laminated on at least one side of the plate (+1). Its feature lies in the fact that the thickness of the copper foil (12) is less than 12m, which makes it possible to produce an ultra-thin copper-clad laminate (10) at a low price, which is suitable for manufacturing extremely small printed wiring boards with conductor + tJ. Moreover, it can be easily manufactured.

Zunawa, unreleased I! According to II, there is no need for aluminum foil (21), which was indispensable in the conventional method, and the ultra-thin copper-clad laminate (IO) is at least as expensive as the aluminum foil (21). It can be manufactured cheaply. In addition, in carrying out the present invention, there is no reason to use ultra-thin copper foil from the beginning, so pinholes, wrinkles, etc., which conventionally occur during the production of ultra-thin copper foil, etc. This problem can be avoided and the yield of the ultra-thin copper clad laminate (10) itself can be improved. Moreover, if it is an ultra-thin copper foil, it would be necessary to protect it by lining it, and it would also be necessary to prepare for the occurrence of wrinkles since it is rolled up, but according to the present invention, such things are not necessary at all. Therefore, this also makes it possible to reduce the price of the ultra-thin copper-clad laminate (10).

In addition, in one aspect of the present invention, a copper foil (12
) can be used as is.

It is suitable not only for rigid type substrates but also for flexible type substrates. That is,
This allows it to be used as a highly versatile ultra-thin copper clad laminate (10).

Furthermore, according to the present invention, the required thickness of the outer four foil portions is not limited by the initial material 1; in other words, a relatively thick copper foil (12) is used. By doing this, (the thickness of the copper foil (12) formed on the plate (II) can be arbitrarily determined by appropriately selecting the etching process, the copper foil of the required thickness can be formed. The ultra-thin copper clad laminate (10) can be formed freely, and this is an improvement in the current situation where high-mix, short-dose production is required.
- minutes can be accommodated.

In addition to the above effects, the present invention also has the following effects. That is, it is possible to use an inexpensive copper foil of ordinary thickness instead of the expensive J4i thin copper foil, the reliability of the anchor part of the copper foil itself to the substrate (II) is high, and there is no need for an etching device for aluminum foil. In addition, there is no need for a pretreatment process on the surface of the copper foil for pattern formation, and it is possible to use rolled copper foil with fewer pinholes.

Therefore, the productivity of internal copper-clad laminates (lO) is improved.

[Brief explanation of drawings]

11.21 to 3 are diagrams for explaining the manufacturing method according to the present invention, where D'S11'id is a partially enlarged sectional view showing the state before lamination, and FIG. 2 is a partially enlarged sectional view showing the state before lamination. FIG. 3 is a partially enlarged sectional view of an ultra-thin copper-clad laminate after the copper foil has been subjected to polishing or etching treatment. Also, the 4th I5! Figures 6 to 6 are diagrams for explaining the conventional method. Figure 4 is a partially enlarged sectional view showing the state of the surface on which ultra-thin copper foil backed by aluminum foil is laminated, and Figure 5 is Partially enlarged sectional view after laminating these, No. 6
The figure is a partially enlarged sectional view showing the ultra-thin copper-clad laminate after completion. Explanation of code: IO...Ultra-thin copper clad laminate, 1]...Substrate, 12...
·Copper foil.

Claims (1)

[Claims] 1) Applying at least one of mechanical polishing, electrochemical polishing, and chemical etching to a copper foil with a thickness of 18 μm or more laminated on at least one side of the substrate, A method for producing an ultra-thin copper-clad laminate, characterized in that the thickness of the copper foil is 12 μm or less. 2) The mechanical polishing according to claim 1, wherein the mechanical polishing uses at least one of buff polishing, belt polishing, rocking polishing, spin polishing, scrub polishing, and blast polishing. A method for manufacturing ultra-thin copper-clad laminates. 3) The method for manufacturing an ultra-thin copper-clad laminate according to claim 1, wherein the electrochemical polishing is electrolytic polishing. 4) A patent claim characterized in that the chemical etching is performed with an etching solution containing at least one of sulfuric acid-hydrogen peroxide, persulfate, ferric chloride, cupric chloride, or ammonium double salt. A method for producing an ultra-thin copper-clad laminate according to item 1.