DOPO derivative and composite of epoxy applied in high-frequency substrate

Abstract

A composite, a high-frequency circuit substrate using the same and method thereof are discussed. The composite includes the following solid components: a DOPO (9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide) derivative compound of 10-70 wt %, a curing agent of 10-50 wt %, one or more epoxy of 10-90 wt % and an inorganic filling material of 10-40 wt %. The non-halogen low dielectric epoxy composite uses a high-purity DOPO (9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide) derivative as tiny particles dispersing in the composite. The crosslinking yield of the composite is not reduced, while the heat resistance and flame retardancy are increased. The prepreg and copper foil covered laminate for use in printed circuit board, made from the epoxy composite, has great dielectric property and high glass transition temperature (GTT), satisfying the need of high frequency in electronic signal transmission and high speed in data processing of the industry of copper covered printed circuit board.

Claims

1. An epoxy composite, wherein based on the weight of solid contents, the composite comprises: a DOPO derivative compound of 6-15 wt %; a curing agent of 20-25 wt %; one or more epoxy resin of 10-15 wt %; and an inorganic filling material of 10-40 wt %.

2. The epoxy composite of claim 1, wherein the DOPO derivative compound has the following structure: ##STR00007## wherein R1, R2 are H. alkyl, aryl or a heterocyclic substituent group (sites on the substituent group that does not react with an aliphatic hydroxyl group); X is an oxygen atom, and m and n are respectively 4; wherein the DOPO derivative compound is prepared through a dehydration reaction between a compound (B) and a compound (C) under the presence of a catalyst, an entrainer and a solvent, at 1-6 atmosphere and at a temperature of 150-220 C.; wherein the compound has the following structure: ##STR00008## wherein R1 and R2 are defined as above; wherein the compound (C) has the following structure:
HOH.sub.2C.sub.mXH.sub.2C.sub.nOH, wherein m, n and X are defined as above, and the catalyst is a catalyst suitable for the dehydration reaction or Arbuzov reaction.

3. The epoxy composite of claim 1, wherein the DOPO derivative compound has the following structure: ##STR00009##

4. The epoxy composite of claim 1, wherein the DOPO derivative compound has the following structure: ##STR00010##

5. The epoxy composite of claim 1, wherein the curing agent is one or more of a phenolic curing agent, an amine curing agent, an acid or anhydride curing agent, a ester curing agent, and a phosphorous-containing curing agent.

6. The epoxy composite of claim 1, wherein the epoxy resin comprises at least one of the following compounds: a bifunctional epoxy resin, a novolac epoxy resin, a phosphorous-containing epoxy resin, a naphthalene-ring-containing epoxy resin, and a biphenyl-containing epoxy resin.

7. The epoxy composite of claim 1, wherein the inorganic filling material is one or more of aluminium hydroxide, zeolite, wollastonite, silicon dioxide, magnesium oxide, calcium silicate, calcium carbonate, clay, talc and mica.

8. A prepreg made of the epoxy composite of claim 1, comprising a substrate and the epoxy composite laminated onto the substrate after soaking and drying.

9. The prepreg of claim 8, wherein the substrate is a fabric or nonwoven fabric.

10. A copper foil covered laminate made of the prepreg of claim 8, comprising a plurality of laminated prepregs and a copper foil covered on one or both sides of the laminated prepregs, wherein each prepreg comprises a substrate and the epoxy composite laminated onto the substrate after soaking and drying.

Description

DETAILED DESCRIPTION

(1) In order to make the description of the present invention more detailed and more comprehensive, various aspects and embodiments of the present invention are described below illustratively. However, these illustrated aspects and embodiments are not the only way for implementing or using the embodiments of the invention. The embodiments disclosed hereinafter may be combined with or replaced by each other under beneficial situations, and alternatively other embodiments may be appended to an embodiment, without any further statement or illustration. In the following description, many specific details are illustrated so that readers can understand the following embodiments completely. However, the embodiments of the present invention may also be implemented without these specific details.

(2) The embodiment is described in details as follows, but the instant disclosure is not limited to the scope of the embodiment.

(3) The components used in the examples and comparative examples are listed as follows:

(4) Polybutadiene Epoxy:

(5) (A) polybutadiene epoxy

(6) Benzoxazine:

(7) (B) allyl-functional benzoxazine

(8) Epoxy Resin:

(9) (C-1) o-cresol formaldehyde epoxy resin

(10) (C-2) dicyclopentadiene epoxy resin

(11) Curing Agent:

(12) (D-1) styrene-maleic anhydride oligomer SMA-FE40

(13) (D-2) phosphorous curing agent AHP-60H

(14) Additive-Type Flame Retardant:

(15) (E-1) aryloxyphosphazene SPB-100

(16) (E-2) compound (A-1)

(17) (E-3) compound (A-2)

(18) (E-4) compound (A-3)

(19) Curing Accelerator:

(20) (F) 2-methyl-4-ethylimidazole

(21) Inorganic Filling Material:

(22) (G) spherical silica powder

(23) Formula of the Glue Composite:

(24) TABLE-US-00001 TABLE 1 Comparative Comparative Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 1 Example 2 A 15 26 35 25 20 50 45 B 42 34 25 25 30 22 35 C-1 10 30 C-2 12 10 24 D-1 18 15 D-2 25 22 16 23 25 40 E-1 5 5 6 E-2 8 8 8 9 E-3 15 E-4 E-5 10 17 10 F appropriate appropriate appropriate appropriate appropriate appropriate appropriate appropriate G 30 30 30 30 30 30 30 30

(25) TABLE-US-00002 TABLE 2 Comparative Comparative Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Example 3 Example 4 A 25 20 30 22 25 30 15 30 B 25 30 22 28 25 25 60 35 C-1 10 10 15 10 C-2 10 10 15 D-1 20 15 15 D-2 18 20 20 25 20 E-1 10 10 9 9 E-2 E-3 12 18 6 E-4 10 15 6 E-5 15 F appropriate appropriate appropriate appropriate appropriate appropriate appropriate appropriate G 30 30 30 30 30 30 30 30

(26) Evaluation Table of Physical Properties:

(27) TABLE-US-00003 TABLE 3 Comparative Comparative Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 1 Example 2 Glass 175 172 165 165 173 150 161 155 Transition Temperature Peel 8.72 8.75 8.71 8.72 8.8 7.3 8.71 8.75 Strength Flame V-0 V-0 V-0 V-0 V-0 V-1 V-0 V-0 Retardancy Thermal >60 >60 >60 >60 >60 >45 >60 >60 Stability Water 0.12 0.22 0.18 0.13 0.11 0.35 0.15 0.35 Absorption PCT 2 HR 5 MIN 5 MIN 5 MIN 5 MIN 5 MIN 5 MIN 3 MIN 5 MIN 288 C. Dk 3.5 3.8 3.6 3.7 3.6 3.4 4.1 4.0 Df 0.002 0.005 0.003 0.005 0.006 0.002 0.012 0.01

(28) TABLE-US-00004 TABLE 4 Comparative Comparative Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Example 3 Example 4 Glass 168 171 169 170 168 171 189 175 Transition Temperature Peel 8.71 8.68 8.75 8.8 8.77 8.8 8.61 8.76 Strength Flame V-0 V-0 V-0 V-0 V-0 V-0 V-1 V-0 Retardancy Thermal >60 >60 >60 >60 >60 >60 >60 >60 Stability Water 0.15 0.18 0.16 0.15 0.18 0.17 0.14 0.25 Absorption PCT 2 HR 5 MIN 5 MIN 5 MIN 5 MIN 5 MIN 5 MIN 2 MIN 3 MIN 288 C. Dk 3.7 3.8 3.5 3.7 3.8 3.72 4.0 4.4 Df 0.008 0.009 0.005 0.009 0.008 0.009 0.015 0.016

(29) The measuring methods of the aforementioned physical properties are as follows:

(30) (1) glass transition temperature:

(31) The temperature rising rate=20 C./min, as measured by a differential scanning calorimeter (DSC).

(32) (2) peel strength:

(33) The test piece is cut into a rectangle and put into a testing device, so as to test the peel strength of the metal covering layer with a certain speed and pulling force

(34) (3) flame retardancy:

(35) The test piece is cut into a rectangle of 0.5 in4.7 in, then fired for 10 seconds with a blue flame having a flame height of 2 cm, and then the flame is removed, where the test piece is fired twice to record the automatic quench time after the flame is removed.

(36) (4) thermal stability:

(37) The test piece is cut and grounded flush, and then put into a thermogravimetric analyzer (TMA) for testing.

(38) (5) water absorption:

(39) The test piece is heated in a pressure cooker of 2 atm at 120 C. for 30 min.

(40) (6) electrical properties:

(41) The etched substrate is cut into a square test piece of 5 cm.sup.2, baked for 2 h in an oven at 105 C., taken out and then is tested by a plate thickness tester to obtain the plate thicknesses at three positions thereon. Then the test piece is clamped in a dielectric tester to test the data of three positions and then obtain a mean value.

(42) (7) T288 board angle damafe:

(43) The test piece is heated in a pressure cooker of 2 atm at 120 C. for 120 min, soaked in a solder bath at 288 C. for 20 seconds, and then observed to find whether delaminating occurs.

(44) In view of the results of the aforementioned test, properties of low-dielectric, great flame retardancy, low water absorption can be achieved according to the present invention. The present invention also sufficiently uses the synergistic effect among the polybutadiene epoxy, benzoxazine, epoxy resin and curing agent, and satisfies the requirement of environment protection by applying a non-halogen board material. The aforementioned descriptions are only preferred embodiments of the present invention, and other corresponding variations falling into the scope of claims of the present invention can be made according to the technical solutions and ideas of the present invention by those of ordinary skills in the art.