JP2003086953A - Insulator and method for forming conducting hole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means capable of efficiently forming a conducting hole even when a laser beam having a wavelength from a visible light beam region to a near infrared region is used. SOLUTION: A method for forming the conducting hole has a step of forming the conducting hole of an insulator for an interposer or an insulator for a multilayer wiring substrate. The method uses the insulator containing black or colored pigment having an absorption range in a wavelength of 350 to 1,500 nm. The method comprises the steps of irradiating the insulator with a laser beam having the wavelength of 350 to 1,500 nm, and thereby forming the conducting hole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulator having conductive holes such as through holes and via holes used in an interposer for mounting semiconductor elements and a multilayer wiring board, and a method for forming conductive holes. In particular, the present invention relates to a technique of forming a hole for conduction.

[0002]

2. Description of the Related Art In recent years, electronic devices such as mobile phones and portable information processing terminals have been rapidly reduced in size and improved in performance to process large amounts of information at high speed. Under such a background, it is necessary to increase the density of the interposer and the multilayer wiring board (multilayer printed wiring board) mounted on the electronic device. One of the means for increasing the density of the interposer and the multilayer wiring board is 1 As a result, it is necessary to reduce the diameter and the formation pitch of the conductive holes such as through holes and via holes formed in the insulating base material forming the interposer or the interlayer insulating layer forming the multilayer wiring board. There is.

[0003]

Conventionally, as a method of forming a conduction hole in an insulating base material or an interlayer insulating layer, a method of mechanically forming a conduction hole using a drill is known. However, the hole diameter of the conduction hole that can be formed using a drill is about 0.2 mm, which is not suitable for high density. Therefore, in order to reduce the diameter of the conduction holes and the formation pitch thereof, a method of forming the conduction holes using a laser beam has been studied. By using laser light, it is possible to form minute conduction holes having a hole diameter of about 25 μm.

Although it is preferable to form the hole for conduction using laser light as described above, the insulating base material of the interposer and the interlayer insulating layer of the multilayer wiring board are made of epoxy resin, phenol resin, polyimide or the like. It is composed of an organic material, which mainly absorbs light in the wavelength range from the ultraviolet region to the near-ultraviolet region. Therefore, in order to efficiently form the hole for conduction, an excimer that generates laser light in the wavelength region in the ultraviolet region is required. It was necessary to use a laser. However, the excimer laser has a short life and has a problem in handleability, and is not suitable for mass production of an interposer or a multilayer wiring board.

In addition, YAG (Yittrium Alu)
Solid-state lasers, such as a medium garnet) laser, have a longer life and are easier to handle than excimer lasers, but the wavelength of the laser light generated is, for example, 1064 nm in the near-infrared region where the first harmonic is Since the second harmonic has a wavelength such as 532 nm in the visible light region that the insulating base material of the interposer and the interlayer insulating layer of the multilayer wiring board do not have absorption, the conduction hole portion cannot be formed efficiently. I had a problem.

Therefore, the present invention has been made in view of the above circumstances, and it is possible to efficiently form the hole for conduction even when using a laser beam having a wavelength from the visible light region to the near infrared region. The purpose is to provide a means that can.

[0007]

As a result of studies to solve the above problems, the inventor of the present invention has invented the following method of forming a hole for conduction. The method for forming a hole for conduction of the present invention is a method for forming a hole for conduction in an insulator for an interposer or an insulator for a multilayer wiring board, which has an absorption region in a wavelength range of 350 to 1500 nm. An insulator containing a black or colored pigment is used, and the wavelength is 350 to 1500 nm with respect to the insulator.
It is characterized by irradiating the laser light of. In the present specification, "insulator" means an insulating base material for an interposer for mounting a semiconductor element and an interlayer insulating layer for a multilayer wiring board, and "a hole for conduction". The "portion" means a through hole, a via hole, or the like formed through the insulator.

In the method for forming a hole for conduction of the present invention, the pigment is selected from carbon black, phthalocyanine pigments, insoluble azo pigments and dioxazine pigments.
At least one kind is preferable. Further, it is preferable to use the insulator having a content of the pigment of 10% by mass or less.

The present inventor has found that the insulator has a temperature of 350 to 1500.
By incorporating a black or colored pigment capable of absorbing a wavelength of nm, that is, a wavelength in the visible light region to the near-infrared region, the main component (a component other than the pigment) of the insulator is closer to the visible light region. It has been found that the insulator can efficiently absorb the light having the wavelength from the visible light region to the near-infrared region even if the light having the wavelength in the infrared region cannot be absorbed.

Therefore, according to the method of forming the hole for conduction of the present invention, the amount of the laser beam absorbed by the insulator is increased even when the laser beam having the wavelength from the visible light region to the near infrared region is used. Therefore, the hole for conduction can be efficiently formed. Further, as described above, the solid-state laser that emits laser light having a wavelength in the visible light region to the near-infrared region has a longer life and is easier to handle than the excimer laser, and therefore the conduction hole of the present invention is used. The method of forming the portion is also excellent in mass productivity. Also,
In the method of forming a hole for conduction of the present invention, since the hole for conduction is formed by using a laser beam, it is possible to reduce the diameter of the hole for conduction formed, and it is possible to cope with high density. is there.

By using the above-described method of forming a hole for conduction of the present invention, the following insulator of the present invention can be provided. The insulator of the present invention is an insulator for an interposer or an insulator for a multilayer wiring board, and has a wavelength of 3
It is characterized by containing a black or colored pigment having an absorption region in the range of 50 to 1500 nm. Further, in the insulator of the present invention, it is preferable that the pigment is at least one of carbon black, a phthalocyanine pigment, an insoluble azo pigment, and a dioxazine pigment. Further, the content of the pigment is preferably 10% by mass or less.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The insulator of the present invention is an insulator for an interposer or an insulator for a multilayer wiring board, and has a wavelength of 350 to 15
It is characterized by containing a black or colored pigment having an absorption region in the range of 00 nm. The insulating material that constitutes the insulator of the present invention is not particularly limited as long as it has excellent insulating properties, but a glass epoxy resin cured product, a phenol resin cured product, an epoxy resin /
Phenol resin cured product, epoxy resin / melamine resin cured product, modified epoxy resin cured product, epoxy resin / phenol resin / elastomer cured product, bismaleimide / triazine resin cured product, bismaleimide / amine cured product, polyimide resin, Examples thereof include polyetherimide resin, polyamideimide resin, siloxane-modified polyimide resin, polyester resin and the like.

The black or colored pigment contained in the insulator of the present invention preferably has an absorption region in the range of 350 to 1500 nm and is electrically, chemically and thermally stable. Carbon black can be illustrated as a black pigment which has such performance. As carbon black, HCC and H for color
Carbon black such as CF grade or high conductivity Ketjenblack EC (manufactured by Lion Akzo) can be used. Examples of the colored pigment having the above performance include phthalocyanine-based pigments such as phthalocyanine blue and phthalocyanine green, insoluble azo pigments such as permanent red, fast yellow and brilliant carmine, and dioxazine-based pigments.

Thus, the insulator of the present invention is
Since it contains a black or colored pigment having an absorption region in the range of 1500 nm, the insulator of the present invention can efficiently absorb light having a wavelength from the visible light region to the near infrared region. Therefore, when forming a hole for conduction in the insulator of the present invention, even when using a laser beam having a wavelength of the visible light region to the near-infrared region, the amount of laser light absorbed by the insulator is increased. Therefore, the hole for conduction can be efficiently formed. In addition, the solid-state laser that emits laser light having a wavelength in the visible light region to the near-infrared region has a longer life and is easier to handle than an excimer laser. Therefore, the insulator of the present invention can be mass-produced. Are better. In addition, since the hole for conduction can be formed by using laser light, the diameter of the hole for conduction can be reduced, and high density can be dealt with.

Further, among the exemplified black or colored pigments, it is particularly preferable to use a pigment capable of absorbing light having a wide wavelength. For example, carbon black
This is preferable because it can absorb light having a wavelength in the near-ultraviolet region to the near-infrared region. In this way, by using a pigment that can absorb a wide range of wavelengths of light,
This is preferable because the range of types of laser light that can be used when forming the hole for conduction in the insulator of the present invention is widened.

Further, as described above, since the black or colored pigment is contained in the insulator in order to improve the absorption effect of the laser light, the insulator for the interposer (insulating base material). ) Or an insulating material for a multilayer wiring board (interlayer insulating layer) must be added within a range that does not impair the characteristics. Specifically, the content of the black or colored pigment is preferably 10% by mass or less, and 2% by mass is preferable.
The following is more preferable. If the content of the black or colored pigment is more than 10% by mass, the mechanical strength of the insulator may be lowered and may become brittle, or the electrical characteristics may be deteriorated, which is not preferable.

[0017]

EXAMPLES Next, examples and comparative examples according to the present invention will be described. (Example 1) Epoxy resin (trade name: EPOMIC R
-301, manufactured by Mitsui Petrochemical Co., Ltd., 40 parts by mass, rubber-modified epoxy resin (trade name: EPOTOHTO YR-10)
2, Toto Kasei Co., Ltd.) 20 parts by mass, polyvinyl acetal resin (trade name: Denka Butyral # 5000A, manufactured by Denki Kagaku Kogyo Co., Ltd.) 30 parts by mass, melamine resin (trade name: Uban 20SB, manufactured by Mitsui Toatsu Kagaku Co., Ltd.) 10 Parts by mass, latent epoxy resin curing agent (dicyandiamide: reagent) 2 parts by mass (however, added with a dimethylformamide solution having a solid content of 25% by mass), curing accelerator (trade name: Cureazole 2)
E4MZ, Shikoku Kasei Co., Ltd.) 0.5 parts by mass, carbon black (HCF grade, # 2600, Mitsubishi Chemical Co., Ltd.) 5
Part by mass was dissolved in a mixed solvent in which toluene and methanol were mixed at a mass ratio of 1: 1 to prepare a composition having a solid content of 25% by mass. This composition was applied on a 38 μm-thick polyester film, air-dried, and then heated at 150 ° C. for 7 minutes. Then, after peeling from the polyester film, using a press machine in which both press surfaces are fluorinated, the pressure is 30 kg / cm ² and the temperature is 170 ° C.
Press cured for 60 minutes. As described above, an insulator having a thickness of 40 μm, which can form the insulating base material of the interposer or the interlayer insulating layer of the multilayer wiring board, was formed.

(Example 2) 2,2-bis [4- (aminophenoxy) phenyl] propane, 3,3'-dicarboxy-4,4'-diaminodiphenylmethane, and an aminopropyl-terminated dimethylsiloxane octamer. And 2,
100 parts by mass of a siloxane-modified polyimide having an average molecular weight of 25,000 and containing 3 ', 3,4'-biphenyltetracarboxylic dianhydride (siloxane modification rate 8%);
69 parts by mass of 4,4′-bismaleimidediphenylmethane, 24 parts by mass of dimethallyl bisphenol A, and 2 parts by mass of carbon black (HCF grade, # 2600, manufactured by Mitsubishi Chemical Corporation) were dissolved in tetrahydrofuran to obtain a solid content of 30% by mass. A composition was prepared. This composition was applied on a polyester film having a thickness of 38 μm, air-dried, and
Heated at 140 ° C. for 7 minutes. Then, after peeling from the polyester film, press-curing was performed for 60 minutes at a pressure of 30 kg / cm ² and a temperature of 190 ° C. by using a press machine in which both press surfaces were subjected to fluorine processing. As described above, an insulator having a thickness of 40 μm, which can form the insulating base material of the interposer or the interlayer insulating layer of the multilayer wiring board, was formed.

(Example 3) 26.4 parts by mass of dicyclo type epoxy resin (trade name: HP-7200, manufactured by Dainippon Ink and Chemicals, Inc.), resole phenol resin (trade name: Shonor CKM2400, manufactured by Showa High Polymer Co., Ltd.) ) 12.3 parts by mass, Epofriend A1020 (manufactured by Daicel Chemical Industries, Ltd.) 56.3 parts by mass, carbon black (HCF grade, # 260).
0, manufactured by Mitsubishi Chemical) 2 parts by mass of tetrahydrofuran 2
It was dissolved in 03 parts by mass to prepare a composition having a solid content of 32%. This composition was applied on a polyester film having a thickness of 38 μm, air-dried, and then heated at 150 ° C. for 3 minutes.
Then, after peeling from the polyester film, press-curing was performed for 60 minutes at a pressure of 30 kg / cm ² and a temperature of 190 ° C. by using a press machine in which both press surfaces were subjected to fluorine processing. As described above, an insulator having a thickness of 40 μm, which can form the insulating base material of the interposer or the interlayer insulating layer of the multilayer wiring board, was formed.

(Comparative Example 1) A thickness capable of forming an insulating base material of an interposer or an interlayer insulating layer of a multilayer wiring board in the same manner as in Example 1 except that the composition was prepared except for carbon black. A 40 μm insulator was formed. (Comparative Example 2) Insulation having a thickness of 40 μm that can form an insulating base material of an interposer or an interlayer insulating layer of a multilayer wiring board in the same manner as in Example 2 except that the composition was prepared except for carbon black. Formed body. (Comparative Example 3) Insulation having a thickness of 40 µm that can form an insulating base material of an interposer or an interlayer insulating layer of a multilayer wiring board in the same manner as in Example 3 except that the composition was prepared except for carbon black. Formed body.

(Evaluation Method) Shots required to form one through hole using the second harmonic (wavelength 532 nm) of a YAG laser on the insulator obtained in each of the examples and comparative examples. The number was measured. Moreover, the hole diameter of the formed through hole was measured.

(Results) Table 1 shows the number of shots required to form one through hole and the diameter of the formed through hole in each of the examples and comparative examples. As shown in Table 1, in Examples 1 to 3, 2 to 3 shots resulted in 2
A conduction hole having a diameter of 5 μm could be formed. On the other hand, in Comparative Examples 1 to 3, it was found that 4 to 8 shots are required to form one through hole, which is a large number of shots as compared with Examples 1 to 3. Further, as a result of requiring a large number of shots, it was found that the hole diameter of the formed through hole was 30 to 40 μm, which was larger than those of Examples 1 to 3.

From the above results, by including carbon black in the insulator, the absorption efficiency of laser light can be improved even when the laser light in the visible light region is used, and the efficiency of the hole for conduction can be improved. It turned out that it can be formed well. Further, as a result of being able to efficiently form the conduction hole portion, the hole diameter of the formed conduction hole portion can be made substantially equal to the diameter of the laser beam, and a minute conduction hole portion having a small hole diameter is formed. It turned out to be possible.

In the above-mentioned Examples 1 to 3, only the case where carbon black, which is a black pigment, is contained in the insulator has been described, but the present inventor has found that the phthalocyanine pigment, the insoluble azo pigment, and the dioxazine pigment. It has been confirmed that the same effect can be obtained even if a colored pigment such as the above is included.

[0025]

[Table 1]

[0026]

As described above in detail, according to the method of forming the hole for conduction of the present invention, an insulator containing a black or colored pigment having an absorption region in the wavelength range of 350 to 1500 nm is used. Since the configuration is adopted, the amount of laser light absorbed by the insulator can be increased even when using laser light having a wavelength in the visible light region to the near infrared region, and the conduction hole can be formed efficiently. can do. Moreover, by using the method of forming the hole for conduction of the present invention, it is possible to provide a high density insulator and an insulator excellent in mass productivity.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05K 3/00 H01L 23/14 R (72) Inventor Naoshi Suzuki 3-1, Soba-cho, Shizuoka-shi, Shizuoka No. 3 in the Electronic Materials Division, Tomoegawa Paper Co., Ltd. (72) Inventor Yasuhiro Yoshii No. 3 Somune-cho for Shizuoka City, Shizuoka Prefecture F-term in the Electronic Materials Division, Tomoegawa Paper Co., Ltd. (reference) 5E346 AA12 CC08 CC09 CC10 GG15 HH33

Claims (6)

[Claims] 1. An insulator for an interposer or an insulator for a multilayer wiring board, the wavelength of which is 350 to 1500.
An insulator containing a black or colored pigment having an absorption region in the range of nm. 2. The insulator according to claim 1, wherein the pigment is at least one of carbon black, a phthalocyanine pigment, an insoluble azo pigment, and a dioxazine pigment. 3. The insulator according to claim 1, wherein the content of the pigment is 10% by mass or less. 4. A method for forming a hole for conduction in an insulator for an interposer or an insulator for a multilayer wiring board, comprising a black or colored pigment having an absorption region in a wavelength range of 350 to 1500 nm. A method for forming a hole for conduction, which comprises forming a hole for conduction by irradiating the insulator with a laser beam having a wavelength of 350 to 1500 nm while using the contained insulator. 5. The method according to claim 4, wherein the pigment is at least one of carbon black, a phthalocyanine pigment, an insoluble azo pigment, and a dioxazine pigment. 6. The method for forming a hole for conduction according to claim 4, wherein the insulator having a content of the pigment of 10% by mass or less is used.