TWI494363B - An epoxy resin composition and a film and a substrate made of the epoxy resin composition - Google Patents

Description

Epoxy resin composition and film and substrate prepared by using the epoxy resin composition

The present invention relates to an epoxy resin composition, and more particularly to an epoxy resin composition to which an inorganic ore powder is added.

The printed circuit board is fully pressed by a composite film of impregnated film (PP) or copper clad laminate (CCL) or copper foil by a thermal compression process; and the impregnated film is immersed in a glass fiber cloth. A thin film formed by a subsequent process such as drying in an epoxy resin glue. With the implementation of environmental protection laws (such as RoHS, WEEE), the lead-free solder process replaces the lead solder process, and the assembly temperature is increased by 30 to 40 degrees, which greatly increases the heat resistance of the substrate.

At present, the commonly used method is to increase the inorganic filler and the flame retardant materials such as cerium oxide and aluminum hydroxide filler in the resin formulation, which has obvious effects on the electronic properties of the substrate and the heat resistance or flame retardant property, so as to improve the heat resistance of the substrate. . However, the addition of the above-mentioned ceria and aluminum hydroxide fillers causes a problem that the plate hardens, making it difficult to machine; for example, during the manufacture of a printed circuit board, when the substrate is subjected to a drilling process, This causes undesirable phenomena such as delamination of the substrate, cracking of the resin layer of the substrate, breakage of the drill pin, or excessive wear of the drill pin.

In addition, the kaolin powder which is commonly used in the production of electric wires of the outer covering rubber is also used for the production of the tree-finger filler of the printed circuit board. In general, the kaolin component is composed of at least 30% by weight of alumina in addition to the cerium oxide. , Therefore, the powder has the effects of flame retardancy and flame retardancy, and the Mohs hardness of the powder is low. Compared with the generally used high hardness cerium oxide filler, the substrate made of kaolin powder as a filler has better processing. Sex, such as drilling leveling or improvement of resin cracks, has a good effect. However, the cerium oxide component in the kaolin component is low (less than 40% by weight), and it is difficult to satisfy the electrical characteristics (such as Dk and Df specifications) of the substrate to be produced, and the peeling strength of the copper foil in the substrate is inferior.

Talc powder can also be used as a resin filler to increase the electronic application characteristics of the substrate, such as the low Dk, Df communication application substrate. However, in addition to cerium oxide, talc contains a large amount of magnesium oxide. Magnesium oxide has a good effect on flame retardancy. However, since magnesium oxide will condense and suspend in an alkaline solution, the pH of the resin must be controlled. In other words, talc can only be used for resins under specific pH conditions.

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.

SUMMARY OF THE INVENTION A primary object of the present invention is to provide an epoxy resin composition using an inorganic ore powder as an inorganic filler in a resin glue to improve the processability of the film/substrate. In other words, the present invention is directed to the composition ratio of the cerium oxide and the aluminum compound of the inorganic ore powder. Further, the present invention further limits the ratio of the alkali gold and the alkaline earth metal oxide in the inorganic ore powder. The inorganic ore powder is prevented from affecting the chemical properties and physical properties of the resin glue. Therefore, the addition of the inorganic ore powder can avoid the divergence of the glue gelation time and maintain the heat resistance and water absorption of the film/substrate produced. Wait.

The present invention provides an epoxy resin composition comprising: component (A): epoxy resin; component (B): hardener; component (C): accelerator; component (D): filler, It is an inorganic ore powder in which the composition of the inorganic ore powder has 55±5 wt% of cerium oxide and 35 wt% or more of the aluminum compound.

The present invention also provides a film (prepreg) formed by immersing the glass fiber cloth in the above epoxy 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 advantageous effects: the present invention utilizes an inorganic ore powder having 55±5 wt% of ceria and 35 wt% of an aluminum compound as an inorganic filler to improve the drilling processability of the substrate. The invention further defines the alkali metal and alkaline earth metal oxides in the inorganic ore powder component to adjust the influence of the inorganic ore powder on the reactivity of the resin glue.

For a better understanding of the features and technical aspects of the present invention, reference should be made to the accompanying drawings.

The present invention provides an epoxy resin composition containing a filler of inorganic ore powder, and the filler of the inorganic ore powder can prevent the substrate formed during the drilling process. Processing cracks, Moreover, the flame retardant properties of the substrate produced are further improved.

In other words, the present invention uses an inorganic ore powder to define the applicability of the inorganic ore powder in proportion to its composition. In the composition of the inorganic ore powder, the cerium oxide component represents the cerium content in the crystal, and the aluminum compound (represented by the chemical formula Al ₂ O ₃ ) represents alumina, aluminum hydroxide or aluminide containing water of crystallization (hydrogen) Alumina or alumina), wherein the above-mentioned ceria component is limited to 55±5 wt%, to control the hardness of the inorganic ore powder, and to provide a suitable hardness for use in the filler to reduce the resin of the substrate The layer has a problem of drilling cracks; and the composition of the aluminum compound in the inorganic ore powder component is at least greater than 35 wt%, so that the substrate produced has excellent flame retardant properties.

Hereinafter, the above-mentioned epoxy resin composition will be subjected to a combination of a plurality of sets of examples to explain parameters such as composition and particle size of the inorganic ore powder, so that the present invention can achieve optimum film characteristics. Accordingly, the present invention mainly provides an epoxy resin composition comprising: component (A): epoxy resin; component (B): hardener; component (C): accelerator; component (D) : Filler, which is an inorganic ore powder. Table 1 shows an epoxy resin composition of a plurality of different compositions, wherein in Example 1, the main resin (i.e., the epoxy resin of the component (A)) is 100 parts by weight, and the epoxy resin may be: a ring The oxygen resin is a brominated phenolic epoxy resin, a bisphenol A phenolic epoxy resin, a tetrafunctional epoxy resin (FR4 epoxy resin), or a mixed resin of two or more of the above, but not limited to the above And component (B): the hardener is a phenolic hardener, such as bisphenol A phenolic hardener, in an amount of 30 parts of the component (A), in other words, the amount of the bisphenol A phenolic hardener is 30 parts, which is part by weight relative to the epoxy resin of the component (A).

While the first embodiment of Table 1 and the controls 1 to 3 mainly change the conditions of the filler, for example, the first embodiment uses the muscovite powder as the above component (D): the filler; and the control 1 to 3 Kaolin is the above component (D): a filler. In contrast, the conventional quartz powder is used as the inorganic filler. Finally, the film is made of epoxy resin composition with different compositions, and then the upper and lower layers of the film are made of 1Oz copper foil and hot pressed to copper. Various characteristics analysis tests were performed after the substrate.

Please refer to the experimental data in Table 1:

In addition, in Example 1 and Controls 1 to 4, the epoxy resin composition The accelerator of the component (C) is a 2-ethyl-4-methylimidazole in an amount of 0.1 part by weight of the component (A).

In another aspect, the epoxy resin composition further comprises: component (E): an additive, for example, the additive can be one or more intervening agents, such as a coupling agent or other additive, and the like. In the above specific examples, in order to improve the compatibility of the cerium oxide and the resin in the filler component, the present invention firstly oxidizes cerium oxide by using a silane coupling agent having a relative amount of 0.04. In order to improve the compatibility of the ruthenium dioxide and the resin, the physical properties of the film/copper substrate to be produced can be improved by generating silanized silica. The decane coupling agent is an interface agent applied to a resin and a baseless filler, which has a function of increasing the surface activity of the baseless filler, thereby increasing the physical properties of the composite material such as strength, abrasion resistance and the like. In terms of chemical structure, the decane coupling agent has two or more different reactive organic atomic monomers in the molecule, one of which is a reactive group bonded to the baseless filler, and the other is combined with an organic resin material. The reaction group allows the inorganic filler to be combined with the organic resin material to improve the release property, flame resistance and processability of the formed film (prepreg).

The epoxy resin composition further comprises: component (F): solvent, the solvent of the component (F) is used in an amount of 100 parts of the component (A), in the embodiment 1 of the present invention In Controls 1 to 4, the solvent may include methyl ethyl ketone (MEK), propylene glycol methyl ether (PM), cyclohexanone, or a mixture of two or more of them.

According to Table 1, different compositions of epoxy resin composition glue made into film After that, eight sheets of film were placed on top of each other with 1Oz copper foil, and then hot pressed into a copper-clad substrate, and various characteristic analysis tests were performed, such as the gelation time of the glue and the water absorption rate and flame resistance of the film produced.

Among them, the water absorption (rate) can also be referred to as hygroscopicity, which is mainly to determine the water absorption characteristics of the copper-clad substrate, and the copper-clad substrate is swelled or adsorbed by the influence of temperature and humidity of the environment. In the case where the water content and the humidity of the copper-clad substrate are too high, the problem of the explosion plate or the defects of other circuit boards is easily generated, and the water absorption property is one of the important features of the film/copper substrate. Conventionally, IR spectral analysis or thermal weight loss analysis can be performed on the material to confirm the water absorption of the copper-clad substrate.

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 copper-clad substrate in the 288 ° C tin furnace to the explosion board (minutes).

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 requirements for the UL 94 V-0 rating are 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.

Processability: Holes were drilled on the above-mentioned copper-clad substrate, and the number of holes in which the resin layer was cracked among the 27 drill holes was calculated. The smaller the number of crack holes in the resin layer, the better the workability of the substrate.

Embodiment 1 is a preferred embodiment of the present invention. In the composition of Embodiment 1, the inorganic ore powder in the filler of the component (D) is a mica powder (or muscovite), and the system thereof R1R2[AlSi ₃ O ₁₀ ](OH) _{2 is a} main crystalline component, wherein R1 and R2 are respectively metal ions, and R1 and R2 are sodium, potassium or magnesium, and the cerium oxide in the muscovite powder component The ratio is 55 ± 5 wt%, and the particle size of the muscovite powder is 2 ± 1 μm.

From the data in Table 1, the resinized adhesive time, peel strength and water absorption of the copper-clad substrate can satisfy the specifications of the substrate; and the glass transition temperature (Tg) is 158.5 ° C, indicating that the reactivity is also good; It can be known that the film/copper substrate prepared by the glass fiber cloth impregnation operation by the epoxy resin composition glue proposed by the invention has high heat resistance, so the time required for the explosion of the plate is long and conforms to the test specification. (greater than 10 minutes); at the same time, no cracking of the resin layer occurs in the hole of the substrate, so the ratio of cerium oxide in the muscovite powder added in Example 1 can improve the hardness of the powder (powder Since the Mohs hardness is about 3 or less, the resin layer crack at the time of drilling the substrate is reduced, and the workability and product quality of the substrate are improved.

On the other hand, due to the aluminum compound in the muscovite powder (including aluminum hydroxide, aluminum hydroxide containing crystal water, alumina or water containing crystal water) The proportion of the component of the alumina component, but not limited to the above, is 35 wt% or more, and therefore, the resulting substrate has excellent flame retardant properties.

Furthermore, the ratio of the alkali metal (IA) to the alkaline earth (IIA) metal oxide (such as sodium oxide, potassium oxide, magnesium oxide, etc.) in the muscovite powder is less than 5 wt% to avoid powder Reacts with other components in the resin. In the present embodiment, the present invention limits the ratio of sodium oxide (Na ₂ O) and potassium oxide (K ₂ O) to less than 3% by weight to avoid unnecessary reaction.

Comparative 1 differs from Example 1 in that Control 1 uses a kaolin powder having a ceria component as low as 45 wt%. According to the experimental results shown in Table 1, the film/copper substrate prepared by the resin composition of the control 1 has markedly poor peel strength and low heat resistance (driving tin result) because of the added filling. The cerium oxide component in the feed is too low. Similarly, since the content of cerium oxide is too low, the dielectric constant (Dk) and the dissipation factor (also known as the dissipation factor, Df) of the fabricated substrate cannot satisfy the application of the communication substrate. Further, the water absorption property and the reactivity (the size of the Tg value) of the substrate prepared in Comparative Example 1 could not satisfy the requirements of the substrate specifications.

In addition, the control 2 differs from the first embodiment in that the control 2 uses a kaolin powder having a higher ceria component but a lower aluminum compound component, that is, the control 2 uses a ceria component of 75 wt%, and an aluminum compound component. It is a 15% by weight kaolin powder. According to the experimental results shown in Table 1, the crack of the resin layer on the copper-clad substrate has occurred because the increase in the composition of the cerium oxide increases the hardness of the kaolin powder, which in turn leads to the hardness of the copper-clad substrate. rise. In addition, according to the results of the flame resistance test, Although the flame resistance of the substrate is still in the V-0 grade, since the composition ratio of the aluminum compound is lowered, the burning time of the substrate is already quite close to the upper limit of the standard; in other words, the ratio of the aluminum compound which is too low will cause a decrease in the flame resistance of the substrate.

Further, Control 3 differs from Example 1 in that Control 3 uses a kaolin powder having a ratio of alkali metal group metal oxide (Na ₂ O, K ₂ O) of more than 10% by weight. According to the experimental results shown in Table 1, since the kaolin powder has high reactivity, it is easy to interfere with the hardening reaction of the resin, so that the resinizing time is greatly prolonged, resulting in insufficient hardening reaction of the substrate, insufficient heat resistance of the substrate, and water absorption. The physical properties of the substrate such as deterioration and peeling strength are deteriorated.

The difference between the control 4 and the first embodiment is that the control 4 uses a conventional quartz powder (cerium oxide > 99 wt%) as an inorganic filler, and the physical properties of the copper-clad substrate prepared by the resin composition of the control 4 can be satisfied. Product specifications, but due to the large amount of cerium oxide, the hardness of the substrate produced is too high, resulting in a large number of cracks in the resin layer during the drilling of the substrate.

Therefore, in combination with the above various examples, the present invention does not limit the type of inorganic ore powder. For example, it is only necessary to adjust the composition ratio of the kaolin of the control 1 to the control 3 to the composition of the present invention, and the kaolin of the control 1 to the control 3 It can also be used in the present invention.

The present invention further provides a method of producing a film using the above epoxy resin composition and a formed film. The method employs the above epoxy resin composition comprising component (A): epoxy resin; component (B): hardener; component (C): accelerator; component (D): filler, It is none The machine ore powder, the composition of the inorganic ore powder has 55±5 wt% of cerium oxide, and 35 wt% or more of the aluminum compound. Dipping a glass fiber cloth into the glue of the epoxy resin composition to form an impregnated film (PP) or a copper clad laminate (CCL) having better flame resistance and heat resistance. Or other film, and the above film can be applied to a substrate for a printed circuit board (such as a copper-clad substrate in the embodiment), and the substrate can have relatively good workability when subjected to a drilling process.

In summary, the present invention has the following advantages:

1. The present invention mainly utilizes an inorganic ore powder having 55±5 wt% of ceria as an inorganic filler in a resin composition to improve the processability of a film/substrate prepared by using the resin glue.

2. On the other hand, the present invention further defines that the proportion of the aluminum compound in the inorganic ore powder is more than 35 wt% to achieve better flame resistance of the substrate; and the ratio of the metal oxide of the alkali gold to the alkaline earth is also Restriction is made to avoid unnecessary reaction between the inorganic ore powder and the resin glue. Therefore, the present invention can achieve both specifications of low water absorption and heat resistance of the film/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)

An epoxy resin composition for a circuit substrate comprising: component (A): epoxy resin; component (B): hardener; component (C): accelerator; and component (D): a filler, which is a mica powder, wherein the composition of the mica powder has 55±5 wt% of cerium oxide, and 35 wt% or more of an aluminum compound, wherein the alkali gold group in the composition of the mica powder The proportion of the metal oxide of the alkaline earth group is less than 5% by weight, and the particle size of the mica powder is 2 ± 1 μm. The epoxy resin composition for a circuit substrate according to claim 1, wherein the mica powder is mainly composed of R1R2[AlSi ₃ O ₁₀ ](OH) ₂ , wherein R1 and R2 are respectively Metal ion. The epoxy resin composition for a circuit substrate according to claim 2, wherein R1 and R2 in the main crystalline component are sodium, potassium or magnesium. The epoxy resin composition for a circuit substrate according to claim 1, wherein the mica powder of the component (D) is used in an amount of 30 parts of the component (A). The epoxy resin composition for a circuit substrate according to claim 1, wherein the aluminum compound is composed of aluminum hydroxide, aluminum hydroxide containing crystal water, aluminum oxide or water containing crystal water. A compound of an alumina component. Epoxy tree for circuit substrate as described in claim 1 a fat composition, wherein the component (A): the epoxy resin is a brominated phenolic epoxy resin, a bisphenol A novolac epoxy resin, a tetrafunctional epoxy resin, or a mixed resin of two or more of the above . An epoxy resin composition for a circuit substrate according to claim 1, wherein the component (B): the hardener is a phenolic hardener. The epoxy resin composition for a circuit substrate according to claim 7, wherein the phenolic hardener is a bisphenol A phenolic hardener. The epoxy resin composition for a circuit substrate according to claim 8, wherein the bisphenol A phenolic hardener is used in an amount of 30 parts of the component (A). The epoxy resin composition for a circuit substrate according to claim 1, wherein the component (C): the accelerator is 2-ethyl-4-methylimidazole, and the 2-ethyl- The amount of 4-methylimidazole used was 0.1 part of the component (A). The epoxy resin composition for a circuit substrate according to claim 1, further comprising: component (E): an additive, wherein the additive of the component (E) comprises a decane coupling agent, and the group The amount of the component (E) is 0.04 parts of the component (A). The epoxy resin composition for a circuit substrate according to claim 1, further comprising: component (F): a solvent, wherein the solvent of the component (F) comprises methyl ethyl ketone (MEK), propylene glycol Methyl ether (PM), cyclohexanone, or a mixture of two or more of them, and The solvent of the component (F) is used in an amount of 100 parts of the component (A). The epoxy resin composition for a circuit substrate according to claim 1, wherein the inorganic ore powder is a kaolin powder. A film obtained by dipping a glass fiber cloth to a film produced in an epoxy resin composition for a circuit substrate according to any one of claims 1 to 13. A substrate for a printed circuit board, which is a substrate for a printed circuit board made of the film of claim 14.