JPS6227368A - Non-oxide ceramic green sheet and manufacture - 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 [Technical Field of the Invention] The present invention relates to a non-oxide ceramic green sheet and a method for manufacturing the same.

[Technical background of the invention and its problems] In recent years, in order to miniaturize electronic devices, circuits 7. % A board that efficiently dissipates heat is required to cope with the increase in heat generation from electrical elements due to the high density packaging of electrical elements (ICs, etc.) on boards and the use of power semiconductors, etc. ing. Conventionally used circuit boards are made of alumina (A
There are ceramic substrates such as i203) and resin substrates.

Among these, alumina substrates in particular have excellent mechanical strength and electrical insulation properties, and can be easily formed into green sheets, making it possible to perform high-density wiring such as multilayer wiring, and are widely used. On the other hand, this alumina substrate has a low thermal conductivity (K (w/m-k)) of about 20, so it cannot be expected to dissipate heat from the substrate side, which is required when high-density wiring etc. are applied. It has its drawbacks.

Furthermore, with recent advances in fine ceramics technology, attempts have been made to use ceramic materials with excellent thermal conductivity and mechanical strength, such as silicon carbide (SiC) and aluminum nitride (A4N), for circuit boards. however,
SiC has a high dielectric constant and low dielectric strength, so it has the problem that it cannot be used as it is as a substrate for a terminal device to which high frequency or high voltage is applied.

On the other hand, AnN has excellent thermal conductivity.

If the dielectric strength is large and the dielectric constant is as small as A203, it has excellent properties and is a promising material for circuit boards, and representative examples are shown in Table 1.

Table 1 Now, when considering application to circuit boards, multilayer wiring, weight reduction, etc., clean sheeting is an essential technology.

Conventionally, green sheeting technology using PVB (polyvinyl butyral) etc. as a binder has been established for A203, but since AIN has fundamentally different characteristics from Au203, the Ax2o3 sheeting technology can be applied as is. I can't. For example, A i2 is used to form non-oxide ceramic green sheets such as An N green sheets.
If a general PVB binder was used in 03, cracks would occur in the sheet.

However, as mentioned above, the basic characteristics of <AL;LH are A sentence 203. It is far superior to SiC, etc., and it has been desired to establish a sheet-forming technology.

[Object 1-1 of the invention] The present invention solves the above-mentioned problems and provides a non-oxide ceramic green seaweed which is excellent in terms of cracking and deformation, as well as a method for producing the same. The purpose is to

[Keystones of Civilization] As a result of extensive research, the inventors of the present invention achieved the above objective by blending acrylic resin, polyester thread/plastic agent into non-oxide ceramic powder in a specific ratio and forming it into a sheet. The inventors have discovered that it is possible to accomplish the following, and have completed the present invention.

That is, 1 the present invention has the following features: a) Weight average molecular weight: 5.0 x 103 to 4.0 x 10
5 to 20 parts by weight of organic solvent-soluble acrylic resin of No. 5 b)
Weight i11 average molecular weight e, ox 1o2~8.0×10
The present invention relates to a non-oxide ceramic green sheet comprising 1 to 10 parts by weight of the polyester plasticizer of No. 3 and C) 100 parts by weight of non-oxide ceramic powder, and a method for producing the same.

In the green sheet of the present invention, aluminum nitride powder (AM
N), and in addition to IN, if necessary, alkaline earth metals (Ca, Sr and Ba'7), a.

Thoria and rare earth elements (La, Ce, Pr, Nd
, Sm, Gd, DY, etc.) or carbonates may be used. A green sheet obtained by containing such an oxide or carbonate can not only be sintered under pressure but also have high If and resistance to the metal of the IN substrate.

Therefore, the low wettability of A-FN to metals, which has been a problem for some time, can be improved by incorporating the above-mentioned oxides and the like. Therefore, in the A-pattern N green sheet containing -1- oxide, etc., Ag-P
d, Ag-based paste such as Ag, Cu paste and A
It is also possible to form the conductor path using a commonly used thick film paste such as U-paste. ” - The blend Jj1 of the oxide or carbonate, etc. is not particularly limited, but is usually 0 in terms of metal element with respect to the blended amount of A-mono N.
,011 parts or more. In addition, the additive form f
The gas may be an oxide, such as carbonate, which becomes an oxide during sintering. In this case, if the oxide etc. are contained in large quantities, the high thermal conductivity of AiN may decrease, so 1
It is particularly preferable that the hair content is 5% or less.

The Afl N powder used preferably has an average particle size of 08 to 2.5 μm.

The method for producing a non-oxide ceramic green sheet of the present invention has a weight average molecular weight of 5.0 x 103 to 4.0 x 105.
5 to 20 parts by weight of an organic solvent-soluble acrylic resin, 1 to 100 parts by weight of a polyester plasticizer with an average molecular weight of 6.0 x 102 to 8.0 x 103, and 100 parts by weight of a non-oxide ceramic. The process consists of a step of boiling the slurry by mixing A FjR, and a step of forming the prepared slurry into a sheet.

First, the slurry is prepared using a non-oxide ceramic, such as A.
n N powder, if necessary, oxides or carbonates of the above alkaline earth metals, toluene, methyl ethyl ketone,
A predetermined amount of an organic solvent such as methyl acetate is mixed and kneaded. Thereafter, the above-mentioned acrylic resin and polyester plasticizer are added, mixed, and R-kneaded to sufficiently disperse the IN powder. Next, a green sheet is manufactured from the slurry according to the doctor blade method.

A substrate can be obtained by firing the green sheet obtained in this way.

The acrylic resin used in the present invention is mainly composed of acrylic ester and/or methacrylic ester,
An acrylic resin obtained by adding a small amount of other polymerizable monomers as necessary and performing solution polymerization or suspension polymerization using an organic peroxide catalyst, and having a weight average molecular weight of 5.0×
103 to 4.0 x 105, and is usually dissolved in an organic solvent. Among them, the weight average molecular weight is 5
．． 0x104 to 2.0x10' is preferred.

If the weight average molecular weight of the acrylic resin is less than 5,000, the strength, elasticity, etc. of the obtained green sheet will be significantly reduced. On the other hand, if the weight average molecular weight exceeds 400,000, the viscosity will be significantly increased and the dispersibility and coating suitability will be significantly reduced.

Examples of acrylic esters used here include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, inbutyl acrylate, tert-butyl acrylate, amyl acrylate, and n-lactyl acrylate-1, 2. -Ethylhexyl acrylate, lauryl acrylate-1, I-lysosyl acrylate, stearyl acrylate, cyclohexyl acrylate, etc.Methacrylic acid esters include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n- Butyl methacrylate, 5ec-butyl methacrylate, tert
-butyl methacrylate-1, inbutyl methacrylate, cyclohexyl methacrylate, phenylmesyl methacrylate-1, 2-ethylhexyl methacrylate, n
-octyl methacrylate, lauryl methacrylate,
Examples include tridecyl methacrylate, stearyl methacrylate, and cyclohexyl methacrylate.

Other polymerizable monomers include acrylic acid, methacrylic acid, itaconic acid, and β-hydroxyethyl (meth)
Acrylate, N-methoxyethyl (meth)acrylamide, N-ethoxyethyl (meth)acrylamide,
Examples include N-butoxymethyl (meth)acrylamide and styrene.

The polyester polymeric agent used in the present invention is:
It is obtained by esterifying glycol and dibasic acid, and has a weight average molecular weight of 8.0×
102 to 8.0 x 103, and preferably 8.0 x 102 to 4.0 x 103. The weight average molecular weight of polyester plasticizer is 600
If it is less than 20%, the releasability from the carrier film will be extremely poor. On the other hand, if the weight ratio of the product is less than 8,000, the plasticizer will ooze out from the front surface of the green sheet, making it more likely that cracks will occur.

Glycols used here include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butylene glycol,
1.5-bentanediol, trimethylene glycol,
1,3-butylene glycol, 1,2-butylene glycol, 1,4-bentanediol, 1,6-hexamethylene diol, 2-ethyl-1,3-butanediol, etc., especially diethylene glycol, 1,3- Butylene glycol, 1.4-butylene glycol, 1.6-
Glycols having 3 to 6 carbon atoms such as butylene glycol are preferred. Also used 21! Base acids include cepacic acid, azelin ugly, pimelic acid, adipic acid, glutaric acid, succinic acid, incepacic acid, dimethyl adipic acid, malonic acid, phthalic acid, inphthal ugly, tetradecalic acid, 3-methylphthalic acid, 4- Among these are methyl phthalic acid, 3,4-dimethyl phthalic acid, 6-acid and similar acids, adipic acid, phthalic acid, 1-sebacic acid are particularly preferred from both economical and technical standpoints.

The following alcohol or alkanol is used to adjust the degree of polymerization when esterifying a diglycol and a difj4 acid. For example, butanol.

hexanol, inhexanol, amyl alcohol,
Decanol, octatool, inoctatool, dodecanol, isodecanol, 3-ethyl-2-pentanol, indridecanol, 3-methyl-1-butanol, tetradecanol, hexadecanol, 2-ethylhexanoltanol , 4-ethyl-4-methyl-3-hexanol, pentadecanol, and alcohols similar to these.

The amount of acrylic resin and polyester polymer plasticizer to be mixed with the non-oxide ceramic powder depends on the blending ratio of the two, but the acrylic resin should be 5 to 20 parts by weight per 100 parts by weight of the non-oxide ceramic powder. part, preferably 8 to 20 parts by weight, and the polyester polymer plasticizer is usually 1 to 10 parts by weight, preferably 2 to 8 parts by weight.

If the amount of acrylic resin mixed is less than 11 parts, cracks will occur in the green sheet, and on the other hand, if it exceeds 20 parts, the green sheet surface will be blistered, the edges will curl, the surface will be wavy during degreasing, and the size of the green sheet will be affected. There is a big problem with stability, etc. Also, 1g of polyester polymer plasticizer! ．． If the green sheet is less than 30 mm, cracks may occur in the green sheet, the edges of the sheet may curl up, the yield rate may be poor, and the surface may not be smooth.

If the green sheet exceeds the +oH position, the green sheet becomes soft and has a major problem in dimensional stability and punching during punching. 2. The plasticizer oozes out onto the sheet surface, and a tank remains forever.

Further, the organic solvents used in the present invention include commonly used toluene, methyl ethyl ketone, methyl acetate, and the like.

By using such an acrylic resin and a polyester plasticizer, it is possible to obtain an lN green sheet, which has been difficult to obtain in the past.

[Embodiments of the invention] The present invention will be explained in detail below.

First, an acrylic resin and a plasticizer were manufactured.

Take 80 parts by weight of ethyl acetate into a reactor equipped with a stirrer, reflux condenser, dropping device and thermometer, and separately add 20 parts by weight of methyl methacrylate and 2-ethyl. A monomer mixture containing 30 parts by weight of xyl methacrylate and 50 parts by weight of n-butyl methacrylate is prepared.

Separately, a catalyst is prepared in which 1 part by weight of BPO (benzoyl peroxide) is dissolved in 10 parts of ethyl acetate.

The mixture was heated to 80°C, and the mixture amount and catalyst were dropped over 2 hours. After the dropwise addition was completed, the mixture was held at the same temperature for about 10 hours.
Complete the polymerization. After adjusting the nonvolatile content with toluene, the resin was cooled to obtain an acrylic resin (A-1). The obtained acrylic resin (A-1) had a nonvolatile content of 49.3%, a viscosity of 1,000 cps, and a c. p. c. The weight average molecular weight measured by the method was 90,000.

・A-2 n-butyl methacrylate instead of A-1(7) monomer
50 parts by weight, 25 parts by weight of n-butyl acrylate,
The reaction was carried out in the same manner except that a mixed monomer containing 25 parts by weight of methyl methacrylate was used and a catalyst prepared by dissolving 3 parts by weight of BPOO in 10 parts by weight of ethyl acetate was used in place of the catalyst in A-1. -2) was obtained. The obtained acrylic resin (A-2) had a nonvolatile content of 40%, a viscosity of 3,000 cps, and a weight average molecular weight of 170,000.

・A-3 A-1 except that a catalyst prepared by dissolving 0.2.5 parts by weight of B, P, and 0.2.5 parts by weight in 10 parts by weight of ethyl acetate was used instead of the catalyst in A-1.
The reaction was carried out in the same manner as above to obtain an acrylic resin (A-3). The obtained acrylic resin (A-3) had a nonvolatile content of 53
%, viscosity 300 cps, and weight average molecular weight 60,000. A-4 (comparative example) 200 parts by weight of water containing 2 parts by weight of sodium polyacrylate was placed in a reactor, and 15 parts by weight of methyl methacrylate, n -30 parts by weight of butyl methacrylate, 30 parts by weight of ethyl methacrylate, 1 and 2 parts of n-butyl acrylate
Prepare 5 parts by weight of mixed monomers.

The mixture is heated to 80° C., 0.5i parts of B and P are added, and then the above mixed monomers are added dropwise. After dropping, hold at the same temperature for 3 hours to complete the first reaction, cool,
Pearl-like particles were produced at the bottom of the reaction vessel. The obtained pearl-like particles were dried and dissolved in ethyl acetate, and an acrylic resin (A
-, 4) was obtained. The weight average molecular weight measured by the G, P, C method was 450,000.

Φ A-5 The same procedure was carried out except that 0.1.0 parts by weight of B and P were used instead of the catalyst in A-4. Acrylic resin (A-5) dissolved in ethyl acetate with a non-volatile content of 30% and a viscosity of 300 cps.
I got it.

As measured by CTPC, the weight average molecular weight was 300,000.

Polyester, Rho-B-1 58 parts by weight of propylene glycol and 152 parts by weight of adipic acid are charged into a reaction vessel, heated to 200°C, and an esterification reaction is carried out at the same temperature. To adjust the degree of polymerization, 96 parts by weight of 2-ethylhexanol was added to stop the polymerization.
A polyester plasticizer (B-1) was obtained. The obtained plasticizer (B-1) had a weight average molecular weight of 1,200 and an acid value of 2.0.
, the viscosity was 500 cps.

・B-2 (comparative example) Polyester type with weight average molecular weight 500, acid value 1.5, and viscosity 200 cps in the same manner as B-1 except that the amount of the polymerization modifier 2-ethylhexanol used was changed to 150 parts by weight. A polymer plasticizer (B-2) was obtained.

・B-3 (Comparative example) 60 parts by weight of propylene glycol and 150 parts by weight of sepacic acid were charged into a reaction vessel, and the esterification reaction was carried out in the same manner as in B-1. Weight average molecular i 9,000, acid value 2, viscosity A polyester polymer plasticizer (B-3) of 130,000 cps was obtained.

・B-4 1 --/''2 1. -I 8' II
-I Il, lnn number It
Q Ro-tsu 1 Go Shie-7 Ugly 150
Part by weight was placed in a reaction vessel and subjected to an esterification reaction in the same manner as in B-1 to obtain a polyester polymer plasticizer (with a weight average molecular weight of 5,000, an acid value of 1.7, and a viscosity of 18,000 cps).
B-4) was obtained.

Next, a green sheet was created using this acrylic resin and plasticizer.

(Example-1) 20 parts by weight of methyl ethyl ketone and 15 parts by weight of n-butanol were blended and mixed with 100 parts by weight of An N powder containing 3% by weight of Y2O2. after that.

Acrylic resin (A-
2) 12 parts by weight and 2 parts by weight of a polyester plasticizer (B-1) having a weight average molecular weight of 1,200 were blended.

Mixed. The viscosity of this slurry was 2,500 cps. Next, adjust the viscosity by vacuum defoaming etc. to +5,00
It was set to 0 cps.

Using such a slurry, a sheet was formed on a polyester film using a doctor blade device so that the thickness was adjusted to 40 μm. This sheet 5X 5
(cm), stacked 4 sheets, and weighed 100 kg.
/cm2.Thermocompression bonding was performed at 100° C. for 30 minutes, followed by firing.

Various properties of the green sheet and various properties after sintering are also shown in Table 2.

(Examples 2 to 9) Sheets were manufactured in the same manner as in Example 1 by changing the AnN powder, acrylic resin, and polyester plasticizer. The results are shown in Table 2. Table 2 also shows comparative examples other than those of the present invention.

In addition, Example 9 contained only A-N as the aluminum nitride powder, and Examples 1, 3 to 8, and Comparative Examples 1 to 9 contained 3% by weight of Y2O3. In addition, in Example g42, 1% by weight of CaCO3 was included.

As is clear from Table 2, all the examples of the present invention exhibited good characteristics. The boundary surface is calculated as 71+11 by SEH.
However, all showed good bonding conditions.

On the other hand, Comparative Examples 1, 2, 4, and 5.7 cannot be sheet-formed, and Comparative Examples 3, 6, and 8.9 can be sheet-formed, but cracks occur and they are not practical at all. There is no sex. In addition, Comparative Examples 8 and 9 are binders that are generally used for alumina-based products, but if the amount added is increased to prevent cracking, the tensile strength will further decrease, and the degreasing conditions will also deteriorate. inferior to sex.

[Effects of the Invention] As is clear from the explanation below, according to the present invention,
It is possible to provide a green sheet with extremely excellent properties such as mechanical strength, electrical insulation, pressure resistance, and high thermal conductivity. Furthermore, according to the present invention, the formed green sheet does not suffer from cracks or deformation. Therefore, the green sheet according to the present invention is particularly suitable for circuit boards requiring high-density wiring, can be widely used, and has extremely high industrial value.

Claims (1)

[Claims] 1. a) Weight average molecular weight 5.0×10^3 to 4.0×
10^5 organic solvent soluble acrylic resin 5 to 20 parts by weight b) Weight average molecular weight 6.0 x 10^2 to 8.0 x 10^
A non-oxide ceramic green sheet comprising 1 to 10 parts by weight of the polyester plasticizer of No. 3 and c) 100 parts by weight of non-oxide ceramic powder. 2. Weight average molecular weight 5.0 x 10^3 - 4.0 x 10^
5 to 20 parts by weight of the organic solvent-soluble acrylic resin No. 5, 1 to 10 parts by weight of a polyester plasticizer having a weight average molecular weight of 6.0 x 10^2 to 8.0 x 10^3, and non-oxide ceramic powder. 1. A method for producing a non-oxide ceramic green sheet, comprising the steps of: mixing 100 parts by weight to prepare a slurry; and forming the obtained slurry into a sheet.