JPH01299836A - Production of laminate - Google Patents

Abstract

PURPOSE:To obtain a laminate retaining a low permittivity, a low dielectric loss tangent and high heat resistance and having increased flame retardancy, by laminate-molding prepregs formed from a varnish containing a specified poly(aromatic cyanate), a flame retardant and a catalyst and base materials. CONSTITUTION:A varnish is prepared by mixing a poly(aromatic cyanate) of formula I with a flame retardant of formula II, a flame retardant of formula III and a reaction catalyst for the poly(aromatic cyanate). Prepregs prepared by using this varnish are laminate-molded to obtain the purpose laminate. In the formulas, Ar is an aromatic group, B is a 7-20C polycyclic aliphatic group, D is an active hydrogen-free substituent, q, r and s are each 0, 1, 2 or 3, q+r+s>=2, t is 0-4, x is 0-5, R and R' are each an active hydrogen-free aromatic or brominated aromatic substituent, n is a positive number, and n is 0, 1 or 2.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for manufacturing a laminate used as a printed wiring board.

[US technology] ``In recent years, the frequencies used in fields such as the electronic industry, communications, and computers have shifted to the ``high frequency'' region, such as MH and GH. In the insulating layer of printed wiring boards used in high frequency tilting systems,
A smaller dielectric constant is desired in order to shorten signal propagation delay, and a smaller dielectric loss tangent is desired in order to reduce power loss. For this reason, polyethylene oxide N (Teflon) and polyphenylene oxide (P P
Attempts have been made to form an insulating layer using resins such as O).

[Problem to be solved by the invention]

However, when forming an insulating layer using these resins, the glass transition temperature (Tg) is low at about 180 to 200°C, and the heat resistance is insufficient, and the reliability of the through hole may be affected, such as the occurrence of smear during through hole processing. There was a problem that it could not be formed into a multilayer printed wiring board because it could not be obtained at a high price. The present invention has been made in view of the above points, and provides a method for manufacturing a laminate that can maintain low dielectric constant, dielectric loss tangent, and high heat resistance, and can also improve flame retardancy. The purpose is to

[Means to solve the problem]

The present invention provides a polyaromatic cyanate represented by the following formula (1), (wherein ^" is aromatic, B is a C2-2° polycyclic aliphatic group, and D each independently contains active hydrogen. No substituent -Qy",
Each s is independently an integer of 0.1.2 or 3, provided that the sum of q*r@S is greater than or equal to 2. t
are each independently an integer from 0 to 4. X is l from 0 to 5
) A flame retardant represented by the following formula (n), (wherein R and R' are aromatic or brominated aromatic substituents that do not contain active hydrogen, n is a positive number) and a flame retardant represented by the following formula (1). A varnish is prepared by blending a flame retardant and a polyaromatic cyanate reaction catalyst (where n is an integer of 0, 1, or 2), and the varnish is impregnated into a base material to create a prepreg. The present invention relates to a method for manufacturing a laminate, which is characterized by laminating and molding. The present invention will be explained in detail below. As the polyaromatic cyanate represented by formula (1), those disclosed in Patent Application Publication No. 1988-500434 can be used. That is, this polyaromatic cyanate provides an aromatic polytrianone (polyaromatic cyanate resin) which is more stable against hydrolytic action and has excellent thermal stability than conventional polytriazine. In the polyaromatic cyanate of formula (1) used in the present invention, the aromatic group Ar means any group containing an aromatic group, such as benzene, naphthalene, 7-enanthracene, anthracene, or biaromatic group. group, two or more aromatic groups bridged by alkylene moieties. Preferred are benzene, naphthalene, biphenyl, binaphthyl, and diphenylfulkylene groups, and the polycyclic aliphatic group B with Ct~2°, which is particularly preferably a benzene group, is an aliphatic group containing two or more rings. The polycyclic aliphatic group may contain one or more double or triple bonds. Suitable polycyclic aliphatic groups include the following: There is. O is present, and Dl is a C5~ alkyl group. ) inside 6
(a) (b) (e) (d) (e) (f) (g) or (1
) is preferred, more preferably (aHb) (c)
(d) (ρ), and (a) is particularly preferred. D in formula (1) means all substituents that can be substituted on the organic hydrocarbon group, but substituents containing active hydrogen atoms are excluded. The active hydrogen atom means a hydrogen atom bonded to an oxygen, sulfur, or nitrogen atom.Each of the six formulas (1) is defined independently, for example,
Alkyl, alkenyl, alkynyl, aryl, alkaryl, aralkyl, halo, alkoxy, nitro, carboxylate, sulfone, sulfide, carbonate, etc., and preferably 01 to . . alkyl, C1-1
° Alkenyl, nitro, halo, 01~. Most preferred are alkyl, alkynyl, bromo, and chloro. In addition, 1 in formula (1) is an integer from O to 4, preferably a y number of 60.1 or 2, more preferably 0 or 1, and optimally O, which is 0 formula (1 ) is independently defined. s qSr%S is an integer of 0.1.2 or 3, and optimally 1. ql'', S are each defined independently, but the sum of these is set to be 2 or more. Furthermore, X is a positive number from 0 to 5. Polyaromatic cyanate of formula (1) is found as a mixture of compounds where x is θ~5*, and X is defined as the average number of this mixture. Preferred polyaromatic cyanates of formula (I) An embodiment is represented by the following formula: Thus, the aromatic polytrianone (polyaromatic cyanate tree WI) obtained from the polyaromatic cyanate of formula (I)
) has a low dielectric constant (Ct around 2,78), low dielectric loss tangent (tan δ around 0,003), and high heat resistance (Fuss transition temperature Tg 250 or higher, oven heat resistance around 300℃)
It has excellent properties as a resin constituting the insulating substrate of a printed wiring board. Therefore, in the present invention, a flame retardant represented by formula (II) and a flame retardant represented by formula (III) are further blended to impart flame retardant properties required for printed wiring boards. It is. In the carbonated oligomer of the formula (IN phenoxy-terminated tetrapromopis)-A, R and R' are aromatic or brominated aromatic substituents containing no active hydrogen, for example, Br (R, is Br , CH3, C2Hs, etc., or a combination of these, and the theory is an integer of 1, 2, or 3), and in formula (II), 1 is a positive number that is not particularly limited, but it is currently available. Those that can do n;10
~20 mixtures. Other values of n can also be used. The flame retardant effect of formula (II) or formula (II[) flame retardant formulation depends on the amount of Br, and the UL standard 94■-
In order to obtain a flame retardant level of 0, the content of Br must be 5% relative to the total amount of the polyaromatic cyanate of formula (I) and the flame retardant of formulas (II) and The flame retardant of formula (n) is added so that the content of Br is 5 to 10% by weight.
The flame retardants of formula (I The compounding amount as a compound is 10 to 20% by weight, and the formula (I[[
) To blend the flame retardant of B so that the content is 5 to 10% by weight, the amount to be blended as a compound is 10 to 20% by weight.
It is common to set each. Too much flame retardant may cause problems with heat resistance, so
It is best to set the upper limit to the above value. As a reaction catalyst for polymerizing the polyaromatic cyanate of formula (1), organic metal salts such as imidazoles, tertiary amines, organic cobalt salts such as cobalt naphthenate and cobalt octylate can be used, Although organic cobalt salts are particularly preferred, the amount of the reaction catalyst to be blended is not particularly limited. For example, when organic cobalt salts are used as a reaction catalyst, the amount of formula (1) The weight ratio of cobalt ions to the weight of polyaromatic cyanate is 10 to 700 p. It is blended within a range of about 50%. And the polyaromatic cyanate of the above formula (1'), the formula (I
A varnish is prepared by dissolving a flame retardant of formula I) and formula 1 (I[), a reaction catalyst, etc. in an organic solvent. The organic solvent may be aromatic hydrocarbons, alcohols, etc. as long as it dissolves the polyaromatic cyanate of formula (I) and the flame retardant of formula (II) and formula 1 (I[[) and does not have a negative effect on the reaction. Ketones are not particularly limited. For example, toluene, 7
Setone, methyl ethyl ketone, trimethylformamide,
Methyl cellosolve and the like can be used alone or in combination of two or more. The concentration of the varnish is generally adjusted to a solids content of 50 to 70% by weight. However, when preparing prepreg, the base material is not particularly limited, but it is common to use a woven or non-woven fabric made of plus fibers, and this base material is impregnated with varnish and dried by heating. do. The amount of varnish impregnated into the base material is such that the ratio of solid content (compound of formula (1) and compounds of formula (It) and formula (III)) to the base material is 45% by weight.
It is preferable to set the dielectric constant as above.The level of dielectric constant is affected by the resin content.If the base material is made of Elf lath cloth, the dielectric constant will be increased by impregnation of 45% by weight or more. A dielectric constant of 4.0 or less can be achieved, and when the base material is made of Dlf lath cloth, a dielectric constant of 3.5 or less can be achieved with impregnation of 45% by weight or more. The heating and drying conditions when preparing prepreg are influenced by the amount of reaction catalyst mixed, etc., but for example, the heating temperature is 160°C.
In this case, the desired prepreg stroke del time can be obtained by adjusting the heating time for about 3 to 10 minutes. The stroke del time of prepreg varies depending on molding conditions, etc., but it is 2 at 170℃.
~10 minutes is common. The polyaromatic cyanate in the prepreg is then polymerized and hardened by layering multiple sheets of prepreg prepared in this way, then layering metal foil such as #L foil on both or one side of the top and bottom, and molding this under heat and pressure. A double-sided metal foil-clad laminate or a single-sided metal foil-clad laminate can be produced by laminating and bonding metal foil on both sides or one side of an insulating substrate configured by the above method. By etching the metal foil of this laminated board to form a circuit, it is possible to create an inner layer printed wiring board.In addition, by stacking a plurality of these five inner layer printed wiring boards via a plurality of the prepregs, and forming a circuit on the outermost layer. A multilayer printed wiring board can be created by stacking metal foils and molding them under heat and pressure. The molding conditions are a heating temperature of 170°C to 230°C and a maximum pressure of 30 to 40 kg.
/em" and the time is generally set to about 90 to 120 minutes. When performing 77 Turkey Air at a temperature of about 220 to 230 ° C after molding, the molding temperature is

【Example】

The present invention will be explained in detail below with reference to Examples. A mixture of 75 parts by weight of polyaromatic cyanate (XU-71787, manufactured by Gutsu Chemical Co., Ltd.) shown by the following formula, K (salmon), where R and R' are formula (b) in formula (n), and n is 10 to 20. 12.5 parts by weight of a flame retardant (brominated carbonate oligomer; BC-58 manufactured by Great Lakes), a flame retardant with n=0 in formula (I[) (tetrabromobisphenol A: T
Take 12.5 parts of BBA) (total B content is 13% by weight) and add these to a 1:1 mixed solvent of methyl ethyl ketone and trimethylformamide so that the solid content is 6.
The mixture was stirred and dissolved to a concentration of 0% by weight, and cobalt heptathenate was added thereto as a reaction catalyst at a weight ratio of 150 ppm of cobalt ions to the polyaromatic cyanate to prepare a varnish. This varnish was impregnated into a 2116 type E lath cloth base material (Nitto Boseki! I!116E) so that the solid content (polyaromatic cyanate and flame retardant) was 45% by weight.
A prepreg was prepared by heating and drying at a temperature of 4 minutes. Next, four sheets of this prepreg were stacked, and 70 μ thick double-sided roughened copper foil was stacked on both the top and bottom sides, and the molding temperature was 170°C.
Laminate molding was carried out under the conditions of a molding pressure of 40 kg/e spade 2 and a molding time of 90 minutes, and after-curing in an electric oven for 2 hours at 230°C, an inner layer printed wiring board with a thickness of 0.41 was obtained. A double-sided copper-clad laminate was obtained. Same as Example 1, except that n = 1 (tetrabromobisphenol A bis(2-hydroxyl ether); manufactured by Great Lake) was used as the flame retardant of the Hashimu type (l[[)]. A varnish was prepared and a prepreg was prepared, followed by lamination molding and after-curing in the same manner as in Example 1 to obtain a double-sided copper-clad laminate for an inner layer printed wiring board having a thickness of 0.4 m. Dai J "Shin" - A varnish was prepared in the same manner as in Example 1, except that n=2 (Dai-Kogyo Seiyaku Co., Ltd.!! GX-6107) was used as the flame retardant of the formula (I[[)] At the same time as preparation, a prepreg was created, and further laminated molding and 7
A double-sided copper-clad laminate for an inner layer printed wiring board having a thickness of 0.4 mm was obtained by carrying out a 7-turn test. K (Soup 1) Poly7minobismaleimide resin (Kelimide 601 manufactured by Nippon Polyimide Co., Ltd.) was mixed with N so that the solid content was 60% by weight.
-Dissolve polyimide resin varnish in methyl-2-pyrrolidone! It was 91 years old. This varnish was coated with the same E as in the example.
〃The terrace base material was impregnated with a resin content of 45% by weight and dried in the same manner as in the example to create a prepreg.Four sheets of this prepreg were then stacked and 7 layers were applied on both the top and bottom sides.
Double-sided roughened copper foils with a thickness of 0μ were stacked and laminated under the same conditions as in Example 1, and further heated at 200°C in an electrical open circuit.
, the thickness was 0.41 after 77 turquoise under the conditions of 2 hours.
A double-sided copper-clad laminate for inner-layer printed wiring boards was obtained. An inner layer printed wiring board was created by etching the copper foil of the double-sided copper-clad laminate obtained in this way to form a circuit. Layered with prepreg, and layered 18μ thick copper foil on top and bottom of it with three sheets of prepreg interposed, laminated and molded under the same conditions as above, and further 2
A multilayer printed wiring board having a circuit configuration of 8 chips and having a thickness of 2.41 was obtained by performing 77-turn heating at 00° C. for 2 hours. The polyaromatic cyanate (XU-71787 manufactured by Dow Chemical Company) used in the K19 example was used (no flame retardant was used), and the solid content was dissolved in a 1:1 mixed solvent of methyl ethyl ketone and trimethylformamide. The varnish was dissolved by stirring to a concentration of 60% by weight, and cobalt heptotenate was added thereto as a reaction catalyst at a weight ratio of 200ppm of cobalt ion to the polyaromatic cyanate resin. Manufactured. Thereafter, a prepreg was prepared in the same manner as in the example, and lamination molding and after-curing were performed in the same manner as in the example to obtain a double-sided copper-clad laminate for an inner layer printed wiring board having a thickness of 0.4 Irm. Examples 1 to 3 and 1 Comparative Examples 1 and 2 obtained as above
The electrical and thermal properties of the laminates are measured, and the results are shown in the zero-order table, which shows the dielectric constant,
Dielectric loss tangent, flame resistance, and oven heat resistance are JIS C64.
Measurements were made based on 81. In addition, as shown in the results of the viscoelasticity table, the positive transition temperature is for each example in which the insulating substrate is formed of aromatic polytrianone (polyaromatic cyanate resin) obtained by polymerizing polyaromatic cyanate. It is confirmed that the dielectric constant and dielectric loss tangent of Comparative Example 1 are lower than that of Comparative Example 1 in which the insulating substrate is formed of polyimide resin, and each of the examples in which a flame retardant is blended with polyaromatic cyanate In this case, it was confirmed that the flame retardancy increased from the HB level of Comparative Example 2, which did not contain II flame retardant, to the level of 94V-0, and the positive transition temperature and heat resistance temperature levels were also maintained at high levels without deterioration. It is confirmed that

【Effect of the invention】

As described above, in the present invention, a laminate is manufactured by blending the polyaromatic cyanate of the formula (1-) with the flame retardants of the formula (n) and the formula (I[[). Therefore, the low dielectric constant and dielectric loss tangent of the polyaromatic cyanate polymer can ensure high high frequency characteristics of the laminate, and the flame retardant grade of the laminate can be increased by adding a flame retardant. It is important to maintain a high level of heat resistance.

Claims (1)

[Claims] (1) The polyaromatic cyanate shown in the following formula (I) has ▲mathematical formulas, chemical formulas, tables, etc.▼...Formula (I) (In the formula, A_r is aromatic. B is a polycyclic ring of C_7_ to_2_0 Formula aliphatic group. D is each independently a substituent containing no active hydrogen. q, r, and s are each independently an integer of 0, 1, 2, or 3, provided that the sum of q, r, and s is less than 2. is greater than or equal to 2. t is each independently an integer from 0 to 4. x is 0 to 4.
5) Flame retardants shown in the following formula (II), ▲There are mathematical formulas, chemical formulas, tables, etc.▼...Formula (II) (In the formula, R and R' are aromatic or Brominated aromatic substituent. n is a positive number) The flame retardant shown in the following formula (III), ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼...Formula (III) (in the formula, n is 0, 1 or an integer of 2) and a polyaromatic cyanate reaction catalyst to prepare a varnish, impregnating a base material with this varnish to create a prepreg, and laminating and molding this prepreg. Production method.