JPH08244166A - Composite copper-clad laminate - Google Patents

Abstract

PURPOSE: To realize easily impregnation, generate no toxic gas and improve resistance to tracking by manufacturing a prepreg in the process of impregnating an epoxy resin composition composed of red phosphorus of specified weight %, an inorganic filler, bisphenol A type resin, novolak type epoxy resin and bisphenol A as essential components. CONSTITUTION: An epoxy resin composition, containing bisphenol A type epoxy resin (A), novolak type epoxy resin (B), bisphenol A (C), phenol novolak resin (D), red phosphorus (E) and an inorganic filler (F) as essential components and also red phosphorus (E) and the inorganic filler (F) at the ratio of 35-150wt.% to a total resin components [(A)+(B)+(C)+(D)], is prepared. In the process of impregnating a base with the composition and drying it, a prepreg is prepared by reacting bisphenol A type epoxy resin (A) and novolak type epoxy resin (B) to bisphenol A (C).

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention has excellent heat resistance, moisture resistance, impregnation property, through-hole reliability, tracking resistance and non-halogen and is excellent in flame retardancy without generation of toxic gas, and has less generation of voids. A composite copper clad laminate having good workability.

[0002]

2. Description of the Related Art In recent years, the development of electronic devices using integrated circuits such as ICs and LSIs has been remarkable, and a variety of copper clad laminates used for them have been used, and those having further excellent characteristics are required. Came. The composite copper-clad laminate that uses a glass non-woven fabric as a part of the substrate has almost the same electrical characteristics as the copper-clad laminate that uses a glass woven fabric as a substrate, and has excellent dimensional stability and through-hole reliability, and Demand is rapidly increasing due to easy punching.

Epoxy resins used in composite copper-clad laminates have undergone various improvements in order to meet excellent required properties. That is, it has been attempted to blend an inorganic filler or the like in order to reduce the curing shrinkage or the thermal expansion coefficient, the tracking resistance, or the electrical and mechanical properties, but the satisfactory results have not been obtained yet. . In order to improve the heat resistance and thermal shock resistance of the composite copper clad laminate, if a large amount of inorganic filler is added, the viscosity of the epoxy resin that impregnates the base material will increase, and if this is applied and impregnated, uneven coating will occur on the base material. However, there is a defect that causes voids and defective plate thickness. When the amount of the inorganic filler is reduced in order to reduce the viscosity, there is a drawback that properties such as heat resistance and thermal shock resistance are deteriorated.

Further, amine-based and phenol-based curing agents have been conventionally used as curing agents for epoxy resin for laminated boards. Generally, phenol-based curing agents have higher heat resistance and moisture resistance than amine-based curing agents. It has excellent migration resistance, but has the disadvantage of poor interlayer bond strength and impregnation. When a phenol-based phenol novolac resin having a large molecular weight is used, the heat resistance and the moisture resistance are excellent, but the interlayer bond strength and the impregnating property are significantly reduced. On the other hand, if the one with a small molecular weight is used, the interlayer bond strength and impregnability are improved,
Heat resistance and moisture resistance are significantly reduced. Therefore, it has been very difficult to satisfy these contradictory properties by adjusting the molecular weight of the phenol novolac resin used as the curing agent. In addition, a brominated epoxy resin obtained by previously reacting a bisphenol A type epoxy resin with tetrabromobisphenol A is used as a main resin for the epoxy resin for laminated plates for the purpose of improving flame retardancy. However, there is a drawback that hydrogen halide which is a toxic gas is generated during combustion.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is heat resistance, moisture resistance, thermal shock resistance, interlayer bonding strength, through hole reliability, tracking resistance, flame retardancy. It is intended to provide a composite copper-clad laminate that has excellent properties such as low resin viscosity, is easy to apply and impregnate, has few voids, and does not generate toxic gas during combustion because it does not use halogen. .

[0006]

Means for Solving the Problems As a result of intensive research aimed at achieving the above-mentioned object, the present inventors have reduced the resin viscosity at the time of prepreg production and added red phosphorus to increase the inorganic filler. By using a composition of the specific unreacted stage, by a composite copper clad laminate having a configuration using a prepreg that reacts in the step of coating, impregnating and drying the composition, it was found that the above object can be achieved. The present invention has been completed.

That is, according to the present invention, a plurality of prepregs obtained by impregnating and drying a glass substrate with an epoxy resin composition are laminated in a composite structure, and a copper foil is superposed on at least one surface of the prepreg to integrally mold the composite copper. A laminated laminate, (A) bisphenol A type epoxy resin, (B)
Novolac type epoxy resin, (C) bisphenol A,
(D) Phenol novolac resin, (E) Red phosphorus and (F) Inorganic filler as essential components, and (E) to the whole resin component [(A) + (B) + (C) + (D)] )
35 to 150% by weight of red phosphorus and inorganic filler (F)
In the step of impregnating and drying the epoxy resin composition contained in the ratio of (A) bisphenol A type epoxy resin and (B) novolac type epoxy resin,
(C) A composite copper-clad laminate characterized by using a prepreg made to react with bisphenol A.

The present invention will be described in detail below.

The prepreg used in the present invention is obtained by reacting an epoxy resin composition in the step of impregnating and drying a glass substrate.

The epoxy resin composition is (A) bisphenol A type epoxy resin, (B) novolac type epoxy resin, (C) bisphenol A, (D) phenol novolac resin, (E) red phosphorus and (F) inorganic filler. Is an essential component.

The bisphenol A type epoxy resin (A), which is a component of the epoxy resin composition, has an epoxy equivalent of 170 to 340 and is not particularly limited and can be widely used. These bisphenol A type epoxy resins can be used alone or in combination of two or more. The bisphenol A type epoxy resin generally has an epoxy equivalent of 170 or more, and when it exceeds 340, impregnating property is deteriorated, which is not preferable.

The novolak type epoxy resin (B) which is a component of the epoxy resin composition includes phenol type, cresol type, bisphenol A type, etc. These can be used alone or in combination of two or more kinds. .

As the (C) bisphenol A which is a component of the epoxy resin composition, a usual bisphenol A can be used, and the compounding amount thereof is the whole resin component [(A) +
(B) + (C) + (D)] is preferably contained in a proportion of 10 to 50% by weight. If the blending ratio of bisphenol A is less than 10% by weight, a sufficient interlayer bond strength cannot be obtained,
Further, if it exceeds 50% by weight, the thermal shock resistance and the moisture resistance are deteriorated, which is not preferable.

Examples of the phenol novolac resin (D), which is a component of the epoxy resin composition, include phenol type, alkyl-modified phenol type, and bisphenol A type. These are used alone or in combination of two or more. be able to.

As the red phosphorus (E) which is a component of the epoxy resin composition, the red phosphorus usually used as a flame retardant can be used. Further, red phosphorus coated with aluminum hydroxide, titanium oxide or the like can be mentioned, and these can be used alone or in combination of two or more kinds. Further, (E) red phosphorus is preferably blended in a proportion of 1 to 20% by weight based on the whole resin composition [(A) + (B) + (C) + (D)]. If it is less than 1% by weight, flame retardancy does not occur, and if it exceeds 20% by weight, the insulating property is lowered.

Examples of the inorganic filler (F) which is a component of the epoxy resin composition include talc, silica, alumina, aluminum hydroxide, antimony trioxide and the like, and these are used alone or in combination of two or more. can do.
The present invention is characterized in that (E) red phosphorus and (F) inorganic filler are used in combination. The blending ratio of the inorganic filler is 35 to 150% by weight including the red phosphorus (E) with respect to the entire resin composition [(A) + (B) + (C) + (D)]. ,
It is desirable to mix them. If the amount is less than 35% by weight,
The heat resistance and the thermal shock resistance are poor, and when it exceeds 150% by weight, the viscosity increases, and coating unevenness occurs on the base material, resulting in voids and poor plate thickness. A material consisting of these components is dissolved in a solvent to form a varnish, which is then impregnated into the substrate.

The prepreg used in the present invention is not a resin composition prepared by pre-reacting each of the above components to be coated, impregnated and dried on a glass substrate, but an epoxy containing the above components as essential components. A prepreg is prepared by reacting (A) bisphenol A type epoxy resin and (B) novolac type epoxy resin with (C) bisphenol A in a step of impregnating and drying a resin composition on a glass substrate.

The glass substrate and copper foil used in the present invention are
Both can be used without particular limitation as long as they are usually used for glass epoxy copper clad laminates. Examples of the glass substrate include woven glass cloth, non-woven glass cloth, and glass mat.

The manufacturing process of the copper clad laminate according to the present invention is carried out by laminating a plurality of prepregs prepared as described above in a composite structure, stacking copper foils and molding them under heat and pressure to form a composite copper clad laminate. Plates can be manufactured.

[0020]

The present invention comprises (A) a bisphenol A type epoxy resin and (B) a novolac type epoxy resin in a step of impregnating and drying an epoxy resin composition on a glass substrate.
(C) A prepreg is produced by reacting with bisphenol A. Conventionally, a resin composition for a laminated board has been produced by reacting an epoxy resin and a divalent bisphenol A in a reaction vessel to polymerize, and then coating, impregnating and drying the glass base material to produce a prepreg. On the other hand, in the present invention, each low-molecular component before the reaction is applied as it is to improve the impregnating property to the glass cloth and the like, the occurrence of coating unevenness is prevented, the inorganic filler is increased, and the halogen-free It was possible to improve heat resistance and flame retardancy by adding red phosphorus. In addition, by advancing the reaction of each component during the production of prepreg, the competitive reaction between the epoxy resin, bisphenol A and the curing agent is controlled to improve the interlayer bond strength and thermal shock resistance. Moisture resistance,
It was possible to manufacture a composite copper-clad laminate that also maintained through-hole reliability.

[0021]

EXAMPLES The present invention will now be described with reference to examples. The invention is not limited by these examples.
In the following Examples and Comparative Examples, "part" means "part by weight".

Example 1 Bisphenol A type epoxy resin (epoxy equivalent 187)
173 parts, cresol novolac epoxy resin (epoxy equivalent 210, solid content 70% by weight) 23 parts, bisphenol 41
Part, bisphenol A type novolac resin (hydroxyl value 11
(8, solid content 70% by weight) 108 parts, red phosphorus 10 parts, 306 parts aluminum hydroxide as an inorganic filler, 0.1 parts 2-ethyl-4-methylimidazole and methylcellosolve are added to obtain an epoxy resin having a solid content of 80% by weight. A resin varnish was prepared.
A glass non-woven fabric was continuously impregnated with this epoxy resin varnish and dried for 6 minutes in a drier kept at 165 ° C to obtain a prepreg (I). Six pieces of this prepreg (I) were overlaid, and a varnish containing no inorganic filler prepared separately was impregnated and dried on both sides of the prepreg (II) and overlaid on both sides with a thickness of 18 μm. Copper foils were layered and heat-pressed integrally at a temperature of 170 ° C and a pressure of 4.9MPa for 90 minutes to form a composite copper-clad laminate.

Example 2 A varnish was prepared in the same manner as in Example 1, except that 204 parts of aluminum hydroxide and 102 parts of talc were used as the inorganic fillers in the varnish formulation of Example 1, and then the varnish was further prepared. A composite copper clad laminate was manufactured in the same manner as in.

Comparative Example 1 Epoxy resin (epoxy equivalent 420, solid content 75% by weight) 24
0 part, cresol novolac epoxy resin (epoxy equivalent 210, solid content 70% by weight) 26 parts, bisphenol A type novolac resin (hydroxyl value 118, solid content 70% by weight) 87 parts,
As an inorganic filler, 259 parts of talc, 0.1 part of 2-ethyl-4-methylimidazole and methyl cellosolve were added,
An epoxy resin varnish having a resin solid content of 80% by weight was prepared.
Further, a composite copper-clad laminate was produced in the same manner as in Example 1.

Comparative Example 2 A varnish was prepared in the same manner as in Comparative Example 1 except that talc was replaced with aluminum hydroxide as the inorganic filler in the varnish formulation of Comparative Example 1, and further the same as in Comparative Example 1. To produce a composite copper clad laminate.

Using the composite copper clad laminates produced in Examples 1-2 and Comparative Examples 1-2, solder heat resistance, thermal shock resistance, through-hole reliability, tracking resistance, flame retardancy, and generation of voids. Since the situation was tested, the results are shown in Table 1.
It was shown to. The present invention is excellent in all characteristics, and the effects of the present invention could be confirmed.

Solder heat resistance is a composite copper clad laminate 2
A 5 mm × 25 mm test piece was floated in a solder bath at 260 ° C. and 280 ° C., and the time until blistering occurred was tested. Thermal shock resistance is a 50 mm × 50 mm test piece obtained by etching copper foil.
Ten pieces were pretreated under the conditions of 122 ° C., 0.1 MPa, 7 hours, and then dipped in a solder bath at 260 ° C. for 30 seconds, and the presence or absence of blistering was tested. Through-hole reliability is achieved by making a 200-hole conductive through-hole substrate and using it at 260 ° C oil.
After soaking for 10 seconds, soaking in oil at 20 ° C for 10 seconds is one cycle, and the conduction resistance is measured at each cycle.
The number of cycles until disconnection was measured. Flame retardant is UL9
It tested based on 4 test methods. For the occurrence of voids, the number of voids in 30 composite copper-clad laminates was examined. Tracking resistance was tested by the IEC electrolytic drop method.

[0028]

[Table 1]

[0029]

As is clear from the above description and Table 1, the composite copper-clad laminate of the present invention has heat resistance, moisture resistance, thermal shock resistance, interlayer bonding strength, tracking resistance, flame retardancy, and through. It is excellent in hole reliability, low in resin viscosity, easy to apply and impregnate, does not generate toxic gas because it is non-halogen, and generates few voids, which is suitable for electronic equipment.

Front page continuation (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location C08K 3/02 NKU C08K 3/02 NKU C08L 63/00 NJW C08L 63/00 NJW

Claims (1)

[Claims] 1. A composite copper-clad laminate in which a plurality of prepregs obtained by impregnating and drying a glass substrate with an epoxy resin composition are laminated in a composite structure, and copper foils are laminated on at least one surface of the prepregs and integrally molded. And (A) bisphenol A type epoxy resin, (B) novolac type epoxy resin, (C) bisphenol A, (D) phenol novolac resin, (E) red phosphorus and (F) inorganic filler as essential components, All components [(A) + (B) +
(C) + (D)], a step of impregnating a base material with an epoxy resin composition containing 35 to 150% by weight of red phosphorus of (E) and an inorganic filler of (F) and drying. 2. A composite copper-clad laminate, comprising: (A) a bisphenol A type epoxy resin and (B) a novolac type epoxy resin, and (C) a prepreg obtained by reacting with bisphenol A.