TWI439504B - Halogen-free resin composition and film and substrate produced by using the halogen-free resin composition - Google Patents

Description

Halogen-free resin composition and film and substrate prepared by using the halogen-free resin composition

The present invention relates to a halogen-free resin composition, and more particularly to a halogen-free epoxy resin composition having a composite main resin, which is composed of a bisphenol A phenolic epoxy resin and two phosphorus-containing phenolic aldehydes. Made up of epoxy resin.

At present, the range and field of application of printed circuit boards are quite extensive. The electronic components in general electronic products are inserted on printed circuit boards. Therefore, printed circuit boards are known as the "mother of electronic products", and accordingly, The quality of printed circuit boards carrying electronic components can have a considerable impact on the performance of electronic products.

The printed circuit board is fully pressed by a film of impregnated film (PP) or copper clad laminate (CCL) or copper foil by a thermal compression process; and the impregnated film is impregnated with a glass fiber cloth. A thin film formed by a subsequent process such as drying in an epoxy resin glue.

However, due to the rise of environmental awareness in recent years, many consumer electronic products have gradually used halogen-free copper foil substrates instead of halogen-free copper foil substrates. The halogen-free copper foil substrate is additionally added with a phosphorus-containing component to compensate for the flame retardant effect. Traditionally, the phosphorus-containing material may be added with a material containing a main resin or a hardener resin component, or an additional phosphorus-containing compound. The way in the resin formulation is to gain a flame retardant effect.

For example, in the prior art, a hydroxycarbonated apatite (HCA) phosphide is introduced into an epoxy resin glue, but the substrate made of a single phosphorus-containing resin described above has a problem of poor toughness.

The reason is that the inventors have felt that the above-mentioned deficiency can be improved, and proposes a present invention which is rational in design and effective in improving the above-mentioned deficiency.

The main object of the present invention is to provide a halogen-free resin composition, the main resin of which is composed of a bisphenol A phenolic epoxy resin and two phosphorus-containing phenolic epoxy resins to improve the glass conversion of the substrate produced. The temperature (Tg) does not affect the heat resistance and water absorption of the substrate, and the substrate also has better toughness.

The present invention provides a halogen-free resin composition comprising: component (A): an epoxy resin comprising a bisphenol A phenolic epoxy resin, a first phosphorus-containing novolac type epoxy resin and a second phosphorus-containing novolac type ring Composition of oxygen resin; component (B): hardener, which is a mixture of a benzoxazine ring resin and a phenolic resin hardener; component (C): flame retardant; component (D): accelerator And component (E): a filler; and the halogen-free resin composition further includes a solvent.

The present invention also provides a film formed by immersing the glass fiber cloth in the above halogen-free resin composition, curing, drying, and the like.

The present invention further provides a substrate for a printed circuit board produced by the above-described film via a press-bonding process.

The present invention has the following beneficial effects: the present invention utilizes two phosphorus-containing The phenolic epoxy resin is combined with the bisphenol A phenolic epoxy resin to form a composite main resin, and the glue of the halogen-free epoxy resin composition can improve the hardening reaction rate of the glass fiber cloth immersed in the glue; Further, by controlling the composition ratio of the above two phosphorus-containing phenolic epoxy resins, a substrate having better toughness can be obtained.

The detailed description of the present invention is to be understood by the following description of the invention.

The present invention provides a halogen-free resin composition comprising: component (A): epoxy resin, component (B): hardener, (C): flame retardant, component (D): accelerator; And component (E): a filler; the halogen-free resin composition of the present invention is a laminate material as a printed circuit board, and improves the glass transition temperature (Tg) and flame retardancy of the substrate to be produced. In addition, the present invention further proposes the composition ratio of the resin in the component (A): epoxy resin, in order to achieve good product characteristics of the substrate having high Tg, high flame retardancy, high heat resistance and high toughness; In the present invention, a proper proportion of filler is added to produce a film having better flame resistance and heat resistance.

The component (A) of the present invention: the epoxy resin is composed of a BPA Novolac Epoxy resin, a first phosphorus-containing novolac epoxy resin and a second phosphorus-containing novolac epoxy resin. By the ratio between the first phosphorus-containing novolac type epoxy resin and the second phosphorus-containing novolac type epoxy resin, or the amount of the first and second phosphorus-containing novolac type epoxy resins and the bisphenol A phenolic epoxy The ratio of the amount of resin used to increase the toughness of the substrate without causing The problem of insufficient heat resistance due to an increase in water absorption.

The first phosphorus-containing novolac type epoxy resin is a side chain type phosphorus-containing novolac type epoxy resin. In the specific embodiment, the novolac type epoxy resin is a cresol epoxy resin (o-cresol novolac). Epoxy resin, CNE), and the organic cyclic phosphide is attached to the cresol epoxy resin, for example, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (9,10) -dihydro-9-oxa-10-Phosphaphenanthrene-10-oxide, DOPO) is introduced into the structure of cresol epoxy resin to form the above-mentioned side chain type phosphorus-containing novolac type epoxy resin, and the structure of DOPO is as follows Formula I:

In other words, in the specific embodiment, the first phosphorus-containing novolac type epoxy resin is a cresol epoxy resin (CNE) using 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- The oxide (DOPO) is modified with a phosphorus-containing material. Therefore, the first phosphorus-containing novolac type epoxy resin will be abbreviated as DOPO-CNE hereinafter.

On the other hand, the second phosphorus-containing phenolic epoxy resin is obtained by attaching an organic cyclic phosphide to a phenolic epoxy resin, and the phenolic epoxy resin is a cresol epoxy resin (o). -cresol novolac epoxy resin, CNE), and the organic cyclic phosphide is attached to the cresol epoxy resin, for example, 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10- Phosphophenanthrene-10-oxide (10-(2,5-dihydroxyphenyl)-10h-9oxa-10-phosphaphenanthrene-10-oxide, DOPO-HQ) is introduced into the structure of cresol epoxy resin, while DOPO-HQ a phosphide as shown in formula II:

In other words, in the specific embodiment, the second phosphorus-containing novolac type epoxy resin is a phosphorus-containing material modified with phenol phenol epoxy resin (CNE) by using DOPO-HQ, and therefore, the second The phosphophenol novolak type epoxy resin is abbreviated as DOPO-HQ-CNE.

Further, the component (B): a curing agent in the halogen-free resin composition of the present invention is obtained by mixing a benzoxazine ring resin (Benzoxazine Resin, Bz), a phenol resin hardener, and an aromatic condensed phosphate. In this embodiment, the benzoxazine ring resin (Bz) is as shown in Formula III:

Wherein R ₁ and R ₂ are a methyl group or an ethyl group; and R ₃ is a benzene ring, a methyl group or an ethyl group. In the present embodiment, the component (C) in the halogen-free resin composition: the flame retardant is a phosphorus-containing resin compound, and its function is to increase the flame retardancy and flame retardant properties of the substrate, such as aromatic condensation. Phosphate ester, but not limited to the above.

In the present embodiment, the component (D) in the halogen-free resin composition: the accelerator is an imidazole compound, and its function is to accelerate the control of the hardening time of the glue, such as dimethylimidazole (1,2- Dimethyl Iimidazole), but not limited to the above.

The halogen-free resin composition further comprises component (E): a filler, wherein the component (E): the filler comprises aluminum hydroxide, cerium oxide or a mixture of the two.

In still another aspect, the halogen-free resin composition further comprises a component (F): a solvent, wherein the solvent of the component (F) comprises methyl ethyl ketone (MEK), propylene glycol methyl ether (PM), cyclohexanone, or both Kind or a mixture of two or more.

Hereinafter, a plurality of sets of examples will be described with respect to the above-described halogen-free resin composition to demonstrate optimum film characteristics by blending the composition ratio of the halogen-free resin composition.

Please refer to Table 1, which discusses the composition ratio between DOPO-CNE and DOPO-HQ-CNE. Among them, water absorption can also be called hygroscopicity, which is mainly to determine the water absorption characteristics of the film, because the film will be affected by the temperature and humidity of the environment to expand and deform or adsorb moisture. In the case where the moisture content and humidity of the film are too high, the printed circuit board to be pressed may cause a problem of bursting or other circuit board defects, etc., so the water absorption property is one of the important characteristics of the film. . Traditionally, IR spectroscopy or thermogravimetric analysis can be performed on this material to confirm the water absorption of the film.

Heat resistance: the result of floating tin, the heat resistance test is based on the industry standard IPC-TM-650 Method 2.4.13.1, the time required to soak the heat-dissipating film in the 288 ° C tin furnace to the blasting plate, which can be known by the present invention The film produced by the proposed epoxy resin composition glue after the glass fiber cloth impregnation operation has high heat resistance, so the time required for the explosion of the plate is long and conforms to the test specification.

Flame resistance: that is, flame retardant, measured according to UL 94 method, refers to the flame resistance test of plastic materials. It is based on the self-ignition time, spontaneous combustion speed and falling particle state of the plastic material standard test piece after flame burning. The flame resistance rating. According to the quality of the fire resistance, the order is HB, V-2, V-1, V-0, and the highest is 5V. The UL 94 test method refers to the fact that the plastic material burns on the flame in a vertical manner. The test cycle is performed every ten seconds. The steps are as follows: Step 1: Put the test piece into the flame for ten seconds and then remove it, and measure the test piece to continue burning time (T1) after the removal; Step 2: Test piece flame After extinction, put it into the flame for ten seconds and then remove it, then measure the sample to continue burning time (T2) after removal; Step 3: Repeat several experiments and take the average value; Step 4: Calculate T1+T2 total. The requirement of UL 94 V-0 is that the average of the single burning time T1 and the average T2 of the test piece shall not exceed 10 seconds, and the total of T1 and T2 shall not exceed 50 seconds to meet the requirements of UL 94 V-0. .

Due to the incorporation of DOPO-HQ, there is an effect of improving the toughness of the substrate, but it may also cause an increase in the water absorption of the substrate, so the amount of addition must be controlled. As shown in Table 1, please refer to Control 2 and Control 4, wherein Control 2 has only DOPO-HQ-CNE, and without DOPO-CNE, its water absorption value is as high as 0.35; while Control 4 has DOPO-CNE and DOPO-HQ. The ratio of -CNE is 0.11, but the water absorption value is as high as 0.26, which lowers the Tg of the substrate. Therefore, according to Control 2 and Control 4, DOPO-HQ-CNE cannot be added excessively, and DOPO-CNE and DOPO-HQ-CNE should be used. The proportional control is 0.11 or more. In addition, please refer to Control 1 and Control 3, in which only a small amount of DOPO-HQ-CNE is added to the component (A). In the two comparative examples, the ratio of DOPO-CNE to DOPO-HQ-CNE is 1.54 and 1.02, respectively. However, it is known from the toughness characteristics of the substrate that a small amount of DOPO-HQ-CNE cannot effectively improve the toughness of the substrate. Therefore, according to Control 1 and Control 3, the ratio of DOPO-CNE to DOPO-HQ-CNE should be controlled to 1.02 or less. .

However, according to Examples 1 to 3 of Table 1, the ratio of DOPO-CNE to DOPO-HQ-CNE is 0.43, 0.68 and 0.25, respectively, and the characteristics of Examples 1 to 3 can be found in the above ratio range. The amount added by DOPO-HQ-CNE can effectively improve the toughness of the substrate, and the water absorption of the substrate is controlled between 0.15 and 0.21, and the flame resistance is also controlled quite well. In other words, through the experimental data of Table 1, The invention provides a halogen-free resin composition, wherein the ratio of DOPO-CNE to DOPO-HQ-CNE in component (A) is between 0.25 and 0.68, and the substrate toughness and glass transition temperature (Tg) are effective. It is improved, and its water absorption and flame resistance are also excellent. In addition, from the comparison of Examples 1 and 3, it can be found that when the ratio of DOPO-CNE to DOPO-HQ-CNE is close to 0.25, the substrate has better toughness characteristics, that is, DOPO-CNE in component (A) and The optimum ratio of DOPO-HQ-CNE is 0.29 to 0.43, so that the toughness, water absorption and flame resistance of the substrate are balanced.

Please refer to Table 2, wherein the ratio of DOPO-CNE to DOPO-HQ-CNE in Examples 1, 4, and 5 and Controls 5 and 6 is 0.43, and the amount of DOPO-CNE and DOPO-HQ-CNE is The proportion of the amount of bisphenol A phenolic epoxy resin is discussed.

As shown in Table 2, the ratio of the amount of DOPO-CNE and DOPO-HQ-CNE to the amount of the bisphenol A phenolic epoxy resin is 2, resulting in an increase in water absorption of the substrate and a decrease in Tg; The ratio of the amount of DOPO-CNE and DOPO-HQ-CNE to the amount of the bisphenol A phenolic epoxy resin is 0.5, and the flame retardancy of the substrate is only V1 grade, in other words, when the proportion of the component of the phosphorus-containing epoxy resin is biased Low (ie, the total amount of DOPO-CNE and DOPO-HQ-CNE is low), that is, the flame resistance of the substrate cannot be improved, and when the proportion of the phosphorus-containing epoxy resin is excessive (ie, DOPO-CNE and DOPO-HQ-CNE) Too much total), which causes a problem of increased water absorption of the substrate.

According to the first, fourth, and fifth embodiments of Table 2, wherein the ratio of the amount of DOPO-CNE and DOPO-HQ-CNE to the amount of the bisphenol A phenolic epoxy resin is 1, 1.4 and 0.72, respectively, and by Example 1, 4, 5 characteristics of the experiment can be found that in the above ratio range, the amount of DOPO-CNE and DOPO-HQ-CNE can effectively improve the toughness of the substrate, and the water absorption of the substrate is controlled between 0.16 ~ 0.17, and The flame resistance is also controlled to be quite suitable. In other words, through the experimental data of Table 2, the present invention provides a halogen-free resin composition, the amount of DOPO-CNE and DOPO-HQ-CNE in the component (A) and the double The ratio of the amount of phenol A phenolic epoxy resin is between 0.72 and 1.4, and the substrate toughness and glass transition temperature (Tg) can be effectively improved, and the water absorption and flame resistance are also excellent. In addition, from the data of Example 1, it is known that the optimum ratio of the amount of DOPO-CNE and DOPO-HQ-CNE in the component (A) to the amount of the bisphenol A phenolic epoxy resin is 1, so that the substrate is Toughness, water absorption, and flame resistance have a balanced performance.

Therefore, according to the experimental results shown in the above Tables 1 to 2, the halogen-free resin compositions of Examples 1 to 5 were blended with the phosphorus-containing compounds DOPO and DOPO-HQ to enhance the reactivity and heat resistance of the substrate. The glass transition temperature (Tg) of the substrate prepared by the invention is obviously increased to about 175 ° C, and the Tg point is higher, in accordance with the general FR4 pressing process (the hot pressing temperature is 195 ° C or more for at least 30 minutes). It means that it has better reactivity and higher bridging density under the same hardening conditions. In still another aspect, the flame-retardant resin composition of the present invention has a flame resistance rating in accordance with UL 94 V-0, and the toughness of the substrate is improved by adjusting the ratio of DOPO to DOPO-HQ.

The present invention further proposes a method of producing a film using the above halogen-free resin composition and a formed film. The method uses the above halogen-free resin composition comprising component (A): an epoxy resin comprising a bisphenol A novolac epoxy resin, a first phosphorus-containing novolac type epoxy resin and a second phosphorus-containing novolac type ring Composition of oxygen resin; component (B): hardener, which is a mixture of benzoxazine ring resin and phenolic resin hardener; component (C): flame retardant: aromatic condensed phosphate; component (D): accelerator and component (E): a filler, wherein the filler comprises aluminum hydroxide, cerium oxide or a mixture of the two; and component (E): a solvent. A glass fiber cloth is dipped in the glue of the halogen-free resin composition to form an impregnated film (PP) or a copper clad laminate (Copper clad laminate) having better flame resistance, heat resistance and high toughness. CCL), or other film, and the above film can be applied to a substrate for a printed circuit board, and the substrate can have a relatively good reactivity when passed through a press-bonding process.

In summary, the present invention has the following advantages:

1. The present invention mainly utilizes two phenolic epoxy resins modified with a phosphorus-containing compound and a bisphenol A phenolic epoxy resin to form a composite main resin to form a halogen-free epoxy resin composition glue. In order to improve the flame resistance, low water absorption and heat resistance of the film produced by using the glue, the substrate produced has better toughness characteristics.

2. On the other hand, in the halogen-free resin composition of the present invention, a composite epoxy resin hardener comprising a benzoxazine ring resin, a phenolic resin hardener and an aromatic condensed phosphate ester, wherein the hardener is used The aromatic condensed phosphate ester can increase the electrical properties of the substrate and further increase the peel strength of the substrate.

The above is only the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Therefore, the equivalents of the present invention and the equivalents of the drawings are all included in the present invention. Within the scope of protection, it is given to Chen Ming.

Claims (15)

A halogen-free resin composition comprising: component (A): an epoxy resin, which is composed of a bisphenol A phenolic epoxy resin, a first phosphorus-containing novolac type epoxy resin and a second phosphorus-containing novolac type epoxy resin. a composition in which the ratio of the total amount of the first phosphorus-containing novolac type epoxy resin and the second phosphorus-containing novolac type epoxy resin to the amount of the bisphenol A phenolic epoxy resin is 0.72 to 1.4, and the first phosphorus content The ratio of the amount of the phenolic epoxy resin to the amount of the second phosphorus-containing phenolic epoxy resin is 0.25 to 0.68; and the component (B): the hardener which is hardened by the benzoxazine ring resin and the phenolic resin. Mixture; component (C): flame retardant; component (D): accelerator; and component (E): filler. The halogen-free resin composition according to claim 1, wherein the first phosphorus-containing novolac type epoxy resin in the component (A) is a side chain type phosphorus-containing novolac type epoxy resin. The halogen-free resin composition according to claim 2, wherein the first phosphorus-containing novolac type epoxy resin in the component (A) is linked to the phenolic epoxy resin by an organic cyclic phosphide. Producer. The halogen-free resin composition according to claim 3, wherein the first phosphorus-containing novolac type epoxy resin in the component (A) is 9,10-dihydro-9-oxa-10- The phosphophenanthrene-10-oxide is valenced to a cresol epoxy resin, and the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is as shown in Formula I: The halogen-free resin composition according to claim 4, wherein the second phosphorus-containing phenolic epoxy resin in the component (A) is linked to the phenolic epoxy resin by an organic cyclic phosphide. Producer. The halogen-free resin composition according to claim 5, wherein the second phosphorus-containing novolac type epoxy resin in the component (A) is obtained by attaching a phosphide of the formula II to a cresol epoxy resin. Producer The halogen-free resin composition according to claim 1, wherein the sum of the first phosphorus-containing novolac type epoxy resin and the second phosphorus-containing novolac type epoxy resin in the component (A) is the same as the double The ratio of the amount of the phenol A phenolic epoxy resin is 1. A halogen-free resin composition as described in claim 1, wherein The ratio of the amount of the first phosphorus-containing novolac type epoxy resin in the component (A) to the amount of the second phosphorus-containing novolac type epoxy resin is 0.29 to 0.43. The halogen-free resin composition according to claim 8, wherein the benzoxazine ring resin in the component (B) is as shown in the formula III: Wherein R ₁ and R ₂ are a methyl group or an ethyl group; and R ₃ is a benzene ring, a methyl group or an ethyl group. The halogen-free resin composition according to claim 9, wherein the flame retardant in the component (C) is a phosphorus-containing resin. The halogen-free resin composition according to claim 10, wherein the phosphorus-containing resin in the component (C) is an aromatic condensed phosphate. A halogen-free resin composition as described in claim 1, wherein The component (E) in the middle part comprises aluminum hydroxide, cerium oxide or a mixture of the two. The halogen-free resin composition according to claim 1, further comprising a component (F): a solvent, wherein the solvent of the component (F) comprises methyl ethyl ketone, propylene glycol methyl ether, cyclohexanone, or both Kind or a mixture of two or more. A film produced by immersing a glass cloth in a halogen-free resin composition according to any one of items 1 to 13 of the application. A substrate for a printed circuit board, which is a substrate for a printed circuit board made of the film of claim 14.