CS199175B1 - Method of clad material expressions for preparing printed circuit boards - Google Patents

Abstract

The invention relates to the production of printed circuits by direct pressing of a metal foil onto a plastic substrate made of polyphenylene oxide or its mixture with other polymers. Good adhesion of the metal foil to the substrate is achieved if the substrate material contains 0.1 to 5 parts by weight of guanidine or biguanidine derivatives per 100 parts of polyphenylene oxide.

Description

BACKGROUND OF THE INVENTION The present invention relates to a process for the production of printed circuit boards by direct compression of a metal foil onto a plastic backing of polyphenylene oxide and mixtures thereof with other polymers. ,

The use of polyphenylene oxide as a support for the production of printed circuit boards is known. Its advantageous mechanical and electrical properties are exploited here, of which the low value of the lossy sintering and permittivity remains stable over a wide temperature and frequency interval. Polyphenylene oxide is particularly suitable for the above application because of its low thermal expansion and applicability over a wide temperature range (from -170 to f190 ° C). However, the method of applying the conductive layer to the material is tedious and laborious, since the direct pressing of the metal foil has not proved to be insufficient in cohesion, manifested in particular at the temperatures required for brazing.

Surprisingly, it has now been found that these disadvantages do not occur with polyphenylene oxide and mixtures thereof with other polymers. No. 185031 uses substituted guanidines or biguanidines as a component in the composition to suppress unwanted changes in the polyphenylene oxide properties during thermal treatment.

SUMMARY OF THE INVENTION The present invention provides a process for producing a clad printed circuit board by directly pressing a metal foil onto a plastic backing of polyphenylene oxide or mixtures thereof with other polymers and optionally other additives such as stabilizers, pigments, lubricants, fillers, wherein the metal foil is pressed at 300 ° C and a pressure of 5 to 25 MPa per powder, granulate or sheet of polyphenylene oxide or mixtures thereof with other polymers and, where appropriate, other additives, containing 0 to 1 parts by weight per 100 parts by weight of polyphenylene oxide of guanidine derivatives of the general formula I (1)

R-Ο-

or a biguanidine of the formula R ¹ t R ⁴ | 2 ¹ R - N N - R ^{5 x} 0 - N - 3 R ⁱ - N t ^X H - R ⁶

(II) wherein R ¹ to R ⁷ is hydrogen, methyl, ethyl, phenyl, tolyl or zylyl.

The basic component of the mixture is a polyphenylene oxide of the general formula. As a rule, polyphenyl oxide is understood to mean poles (2,6-dimethyl-1,4-phenylene oxide), which may optionally contain poles (1,2-phenylene oxides).

The other component of the polyphenylene oxide blend may be any of the following polymers or combinations thereof: styrene plastic, e.g. clear polystyrene, tough polystyrene or acrylonitrile, butadiene and styrene terpolymer, polyolefins, e.g. polyethylene, polypropylene, ethylene-propylene thermoplastic or elastomers), polyisobutylene, ethylene-propyl-diene rubber, butyl rubber or polysiloxane. The total content of these modifying polymers may range from 0 to 50% by weight, based on the blend with polyphenylene oxide. In addition, the material may contain other commonly used additives such as stabilizers, pigments, lubricants, fillers and the like.

By using guanidine and biguanidine derivatives as modifying additive, better adhesion of the metal foil to the surface of the material is achieved, while maintaining excellent mechanical, thermal and electrical properties. The field can be molded in a single operation by pressing a powder, granulate or pre-prepared plate at temperatures of 250 to 300 ° C, pressure of 5 to 25 MPa for 2 to 40 minutes. The array may be aluminum or copper, preferably with a surface adapted for use in the manufacture of conventional laminated printed circuits. The peel strength is increased by an average of 50% compared to polyphenylene oxide and its mixtures prepared with the addition of nitrogen bases along the axes. No. 159032. Common types of tin solders (for example Sn 60%, Pb 40%) with optimally set temperature and soldering time can be used for soldering. For serial PCB production, wave soldering can also be used technically - even after testing the most suitable conditions.

The following examples illustrate the invention. The parts shown in the examples are by weight.

Example 1 - Comparative

Ir, N, N-dimethylhexamethylenediamine (according to the author's certificate No. 159032) was added to the poly (2,6-dimethyl-1,4-phenyleneexide) powder in an amount of 2 parts per 100 parts of polymer. To ensure homogeneity of the mixture, the powder material was impregnated with the additive solution, mixed thoroughly and dried. A single batch of powdered polyphenylene oxide, whose viscosity number was 56.5 ml / g measured in chloroform at a concentration of 0.3 g / 100 ml, was used to prepare this and all other samples. solution, at 25 ^G e.

The mixture was remelted on a laboratory screw extruder and the extruded string was granulated. Plates were pressed from the granulate and test specimens were prepared from them by mechanical machining to determine the basic mechanical, electrical and thermal properties. Furthermore, plates clad with Cu - foil were prepared, from which the printed circuit boards were made in the usual way. In this case and the following, 35 / were used on Clevit® - Metali thick films and G - 2 treatment.

Table i tensile strength, micro bodies with cross section 1 mm 72 deform. speed 50 mm / min. · 23 ° G MPa notch toughness, .SN 640612, test. Type 3, 23 ° CJ / cm ² , - 0.55 Vicat softening temperature, CSN 640521, method B ° C 201 loss factor, CSN 346466, 50 Hz, 23 ° 0 5,1.10 ^-4 internal resistivity, CSN 346460 ,. 23 ° C cm 1,1.10 ¹⁸ Peel strength, ČSN 644810 N / pm 7.2 Solder temperature ° 0 180 - 200

Example 2

Dimethyl ethyl guanidine was transferred to the poly (2,6-dimethyl-1,4-fexiylone oxide) in an amount of 2 parts per 100 parts of polymer by the same procedure as in Example 1. Further processing of the material was also carried out under the same conditions as in the previous case. pressed directly to the granulate. The measurement results are shown in Table II.

Tensile strength, 23 ° G MPa - 67 notched toughness, 23 ° 0 J / cm ² 0.56 Vicat softening temperature ° C 203 loss factor, 50 Hz, 23 ° G 5.8.10 ^-4 resistivity, 23 ° C cm 8.9.10 ¹ ^ Peel strength N / om 12.3 Solder temperature ° C 190 - 210

From the same material, the test bodies were pressed from the powder mixture for comparison, i.e. without remelting and granulating, also the copper foil was pressed directly onto the powder. The measured properties differed from the results given in Table II only in terms of measurement error.

Example 3 1.

4.5 parts of o-tolylbiguanidine were added to a mixture of 90 parts of poly (2, S-dimethyl-1,4-phenylene oxide) and 10 parts of ethylene-propylene rubber. The mixture was further processed as in the previous examples, the copper foil being pressed onto a plate previously prepared from the granulate. The measurement results are included in Table III.

Table III tensile strength, 23 ° C MPa 54.7 notched toughness, 23 ° CJ / crn ^ 2.67 Vicat softening temperature ° C 198 loss factor, 50 Hz, 23 ° C 5.9.10 internal resistivity, 23 ° C cm 2.1.10 ¹ ^ Peel strength N / cm -1 13.2 Solder temperature ° G 190-210

Example 4

To a mixture of 65 parts of poly (2,6-dimethyl-1,4-phenylene oxide), 10 parts of clear polystyrene Krasten 127 and 5 parts. 2.5 parts of ethylguanidine were added to the butyl rubber and the mixture was worked up in the same manner as in the previous examples. Table IV summarizes the material properties.

Table IV tensile strength, 23 ° C MPa 65.7 notched toughness, 23 ° 0 J / cm ^ 1.7 Vicat softening temperature ° G 187 loss factor, 50 Hz, 23 ° C 5.4.10 "^ specific internal resistance, 23 ° C 1.5.10 ¹⁸ Peel strength N / cm 11.2 Solder temperature- ° C 200

Example 5

To a mixture of 50 parts of poly (2,6-dimethyl-1,4-phenyl-oxide), 45 parts of tough polystyrene and 5 parts of ethylene-propylene rubber was added 1.5 parts of phenyl-o-tolylxylylguanidine, part of TiO ₂ -a stabilizer. The mixture was worked up and evaluated as in the previous examples, the results are shown in Table IV. The deterioration of the electrical properties, the lower heat resistance and the need to lower the brazing temperature are due to the presence of a considerable amount of tough polystyrene in the mixture.

Table V tensile strength, 23 ° C MPa 54.2.

notch toughness, 23 ° CJ / cm 1.14 Vicat softening temperature ° C. 146 loss factor, 50 Hz, 23 ° C 7.4.10 "^ resistivity, 23 ° C cm 6.2.10 ^ peel strength H / cm '. 10.5 Solder temperature ° C .180

Object of the invention

Claims (1)

Object of the invention Process for the production of clad material for the preparation of printed circuit boards by direct pressing of a metal foil onto a plastic backing of polyphenyleneexide or mixtures thereof with other polymers and optionally other additives such as stabilizers, pigments, lubricants, fillers, characterized in that the metal foil is pressed at temperature 250 to 300 ° 0 and a pressure of 5 to 25 MiPa per powder, granulate or sheet of polyphenylene oxide or mixtures thereof with other polymers or other additives, containing 0.1 to 5 parts by weight per 100 parts by weight of polyphenylene oxide of guanidine derivatives of the general formula I