JP7243953B2 - Compositions for forming circuit board structures and insulating substrates - Google Patents

Description

The present invention relates to compositions and circuit board structures for forming insulating substrates.

For consumer electronic products, System in Package (SIP) technology should mainly exhibit the features of cost reduction and miniaturization. There are two directions for the substrate as a platform for device integration. One uses common organic material substrates or printed wiring boards (PWBs), while the other uses inorganic material substrates such as silicon substrates. The latter typically has the advantage of miniaturization combined with chip circuitry and processes, but cost is one of the considerations. In the former case, in addition to the low-cost capability, it is possible to achieve system-in-package by present-day advanced process technology such as High-Density Interconnection (HDI) technology and in combination with special materials. can be done.

In addition, as the speed and frequency of information communication products increase, high glass is used as a substrate material necessary for the development of next-generation products such as wireless communication networks, satellite communication equipment, high-power and broadband products, high-speed computers and computer workstations. It must have a glass transition temperature (Tg), a low dissipation factor (Df) and a low dielectric constant (Dk). The copper foil substrates currently used for printed circuit boards (PCBs) are FR-4 boards, both quantitatively and technically, which are mainly made of epoxy resin. However, FR-4 is no longer able to satisfy high frequency requirements due to its electrical properties such as dielectric constant and loss factor. Therefore, there is a need in the industry for substrate materials that have a high dielectric constant and can maintain a low loss factor.

One aspect of the invention provides a composition for forming an insulating substrate. By adjusting the compositional components of this composition, the dielectric constant value of the insulating substrate can be controlled.

In the composition for forming the insulating substrate,

According to some embodiments of the invention, the dielectric filler is selected from the group consisting of ceramic materials, modified ceramic materials, conductive particles, modified conductive particles, organic materials and modified organic materials.

According to an embodiment of the present invention, the ceramic material is barium titanate, lead titanate, barium strontium titanate (BST), titanium oxide, lead oxide, lead zirconate titanate (PZT), perovskite cubic structure ( CaCu ₃ Ti ₄ O ₁₂ , CCTO) and lead magnesium niobate-lead titanate (PMN-PT).

According to some embodiments of the invention, the modified ceramic material comprises modifying groups containing silyl groups.

According to some embodiments of the invention, the electrically conductive particles include carbonaceous particles and metal particles.

According to some embodiments of the present invention, the carbonaceous particles are selected from the group consisting of carbon 60 (C ₆₀ ), graphene, carbon black, carbon fibers and carbon nanotubes (CNT).

According to one embodiment of the invention, the metal particles are selected from the group consisting of silver, aluminum, copper, nickel, zinc and iron.

According to one embodiment of the present invention, the modified conductive particles comprise modified carbonaceous particles containing modifying groups selected from the group consisting of amino groups, anilino groups, carboxamide groups, carboxyl groups and hydroxyl groups.

According to one embodiment of the invention, the organic material is selected from the group consisting of conductive polyaniline and copper phthalocyanine (CuPc).

According to one embodiment of the invention, the modified organic material comprises modifying groups selected from the group consisting of sulfonic acid groups, hydroxyl groups, ether groups, amino groups and (p-chloromethylbenzene)vinyl groups.

Another aspect of the invention is to provide a circuit board structure. The circuit board structure comprises at least one insulating substrate and at least one redistribution layer. The at least one insulating substrate comprises a composition as described above for forming an insulating substrate. The at least one redistribution layer is located on the insulating substrate.

According to an embodiment of the invention, the circuit board structure further comprises an adhesive layer located between the insulating substrate and the redistribution layer.

According to an embodiment of the present invention, the adhesive layer is composed of fluorine resin, polyphenylene ether resin, aralkyl epoxy resin, epoxy resin, phenoxy resin, acrylic resin, urethane resin, silicone rubber resin, poly-p-xylene resin, It is selected from the group consisting of liquid crystal polymers, bismaleimide resins and polyimide resins.

The following description of the accompanying drawings is intended to make these and other objects, features, advantages and embodiments of the present invention more comprehensible.

FIG. 1 is a cross-sectional schematic diagram showing a circuit board structure according to several embodiments of the present invention. FIG. 2 is a cross-sectional schematic diagram showing a circuit board structure according to several embodiments of the present invention. FIG. 3 is a cross-sectional schematic diagram showing a circuit board structure according to several embodiments of the present invention. FIG. 4 is a cross-sectional schematic diagram showing a circuit board structure according to several embodiments of the present invention.

In order to make the description of the content of the present invention more detailed and complete, the following provides an illustrative description of the embodiments and specific examples of the present invention, which are specific examples of the present invention. is not the only form of implementation or operation of Each of the embodiments disclosed below may be combined or replaced with each other where beneficial, and may be added to other embodiments in one embodiment without further description or explanation.

For a more detailed and complete description of this disclosure, reference may be made to the accompanying drawings and the various embodiments described below, in which like numbers indicate the same or similar elements.

The terms used herein generally represent their ordinary meaning, and specific definitions of specific terms are provided below to further guide the practitioner. For convenience, certain terms may be specially labeled, such as by italics and/or quotation marks. Such terms are not in any way affected by their scope and meaning, regardless of whether they are specifically labeled, and have the same scope and meaning as that of ordinary terms. It is understood that the same may be described in one or more forms. Accordingly, alternative language and synonyms for one or more terms may be used herein, but no particular meaning is given to the term in the context discussed herein. is not intended to imply that While synonyms are used for a term, repeated use of one or more synonyms does not preclude use of other synonyms. Any examples discussed herein are illustrative and not intended to limit the scope or significance in any way. Likewise, the invention is not limited to the various embodiments described herein.

As used herein, singular terms include plural referents unless the content clearly dictates otherwise. References to specific instructions such as "in one embodiment" indicate certain features, structures or characteristics in at least one of the embodiments of the present disclosure, and thus terms such as "in one embodiment" are used everywhere. appearing as specific indications need not refer to the same embodiment, and furthermore, one or more embodiments may combine these particular features, structures and characteristics as appropriate.

One aspect of the present invention is a composition for forming an insulating substrate, in which 100 parts by weight of a modified liquid crystal polymer having a repeating unit having the structure of the following formula (1) and 0.5 to 85 parts by weight of a dielectric and a body filler.

According to various embodiments of the present invention, any one of Ar above may be combined with any Y and any X together. Different combinations may have the same or different technical effects.

More specifically, the above modified liquid crystal polymer can be dissolved in a particular solvent to form a modified liquid crystal polymer solution. By way of example, this particular solvent may be selected from the group consisting of N-methyl-2-pyrrolidone, N,N-dimethylacetamide, γ-butyrolactone, dimethylformamide, 2-butoxyethanol and 2-ethoxyethanol. Compared with conventional liquid crystal polymers, the solubility of soluble liquid crystal polymers in certain solvents is higher. It should be understood that the modified liquid crystalline polymer solution can be formed on a support plate by a similar process such as coating and a heating process to evaporate the solvent until dry to form an insulating substrate containing the modified liquid crystalline polymer. .

Ａｒは、１，４－フェニレン基、１，３－フェニレン基、２，６－ナフタレン基又は４，４′－ビフェニレン基であり、Ｙは、－Ｏ－又は－ＮＨ－であり、且つＸは、カルボキサミド基、イミド基、アミジノ基、アミノカルボニルアミノ基、アミノノチカルボニル基、アミノカルボニルオキシ基、アミノスルホニル基、アミノスルホニルオキシ基、アミノスルホニルアミノ基、カルボキシルエステル、（カルボキシルエステル）アミノ基、（アルコキシカルボニル）オキシ基、アルコキシカルボニル基、ヒドロキシアミノ基、アルコキシアミノ基、シアナト基、イソシアナト基又はそれらの組み合わせである。 By way of example, the modified liquid crystalline polymer solution may be an aromatic liquid crystalline polyester solution comprising one of the above solvents and an aromatic liquid crystalline polyester. The weight percentage of the solid content of the aromatic liquid crystalline polyester is 1 wt% to 85 wt%, and may be, for example, 5 wt%, 15 wt%, 25 wt%, 35 wt%, 45 wt%, 55 wt%, 65 wt% or 75 wt%. . If the weight percentage of the solid content of the aromatic liquid crystalline polyester is less than a certain value, such as less than 1 wt%, multiple coating processes are required to achieve the required thickness of the insulating substrate, which can take a considerable amount of time. or costly. Conversely, when the weight percentage of the solid content of the aromatic liquid crystalline polyester is greater than a certain value, for example, greater than 85 wt%, the solid content of the aromatic liquid crystalline polyester is difficult to dissolve in the solvent and gelatinization occurs. . Specifically, the aromatic liquid crystalline polyester has the following repeating units,

Ar is a 1,4-phenylene group, 1,3-phenylene group, 2,6-naphthalene group or 4,4′-biphenylene group, Y is —O— or —NH—, and X is , carboxamide group, imide group, amidino group, aminocarbonylamino group, aminonoticarbonyl group, aminocarbonyloxy group, aminosulfonyl group, aminosulfonyloxy group, aminosulfonylamino group, carboxyl ester, (carboxyl ester) amino group, ( alkoxycarbonyl)oxy group, alkoxycarbonyl group, hydroxyamino group, alkoxyamino group, cyanato group, isocyanato group, or a combination thereof.

When the content of the dielectric filler exceeds a certain value, for example, 85 parts by weight, the dielectric fillers communicate with each other, so that the material changes from an insulator to a conductor, and the dielectric constant and conductivity of the material change drastically. , further loses its performance as an insulating substrate. In embodiments, the dielectric filler is selected from the group consisting of ceramic materials, modified ceramic materials, conductive particles, modified conductive particles, organic materials and modified organic materials. More specifically, in some examples, the ceramic material includes Barium Titanate (BT), Lead Titanate, Barium Strontium Titanate (BST), Titanium Oxide, Lead Oxide, Zircon Titanate. It is selected from the group consisting of lead acid (Pb(ZrTi)O ₃ ; PZT), perovskite cubic structure (CaCu ₃ Ti ₄ O ₁₂ ; CCTO) and lead magnesium niobate-lead titanate (PMN-PT). In some examples, the modified ceramic material comprises a modifying group, wherein the modifying group of the modified ceramic material comprises a silyl group. In some examples, the conductive particles include carbonaceous particles and metal particles. For example, the carbonaceous particles are selected from the group consisting of carbon 60 (C ₆₀ ), graphene, carbon black, carbon fiber and carbon nanotube (CNT). Metal particles are selected from the group consisting of silver, aluminum, copper, nickel, zinc and iron. In some examples, the modified conductive particles comprise modified carbonaceous particles containing modifying groups. The modifying group of the modified carbon particles is selected from the group consisting of amino group, anilino group, carboxamide group, carboxyl group and hydroxyl group. In some examples, the organic material is selected from the group consisting of conductive polyaniline and Copper Phthalocyanine (CuPc). In some examples, the modified organic material includes modifying groups selected from the group consisting of sulfonic acid groups, hydroxyl groups, ether groups, amino groups, and (p-chloromethylbenzene)vinyl groups. It should be understood that the dielectric filler is formed on the support plate by a similar process such as coating in addition to a solution of the modified liquid crystal polymer described above, and the dielectric constant is enhanced by a heating process to evaporate the solvent until dry. forming an insulating substrate. It should be noted that the dielectric filler is not dissolved in the modified liquid crystal polymer solution, but is uniformly dispersed in the modified liquid crystal polymer solution.

In one embodiment, the dielectric filler has an average particle size of 0.1 to 20 μm. According to several examples, when the average particle size of the dielectric filler is smaller than a certain value, for example, 0.1 μm, the effect of improving the dielectric constant is not significant. Conversely, if the average particle size of the dielectric filler is larger than a certain value, for example, 20 μm, it is difficult to control the dispersibility of the dielectric filler particles, and it becomes easy to communicate between the dielectric filler particles. Later insulating substrates lose their insulating properties. Therefore, the average particle size of the dielectric filler is, for example, 0.5 μm, 1.0 μm, 1.5 μm, 2.0 μm, 2.5 μm, 3.0 μm, 3.5 μm, 4.0 μm, 4.5 μm, 5.5 μm, 0 μm, 5.5 μm, 6.0 μm, 6.5 μm, 7.0 μm, 7.5 μm, 8.0 μm, 8.5 μm, 9.0 μm, 9.5 μm, 10.0 μm, 12.0 μm, 14.0 μm, It may be 16.0 μm or 18.0 μm.

Generally, the modified liquid crystal polymer itself has excellent processability, heat resistance, low water absorption, low dielectric constant (Dk) (eg, between 2 and 4) and low loss factor (Df) (eg, between 0.003 0.008), the composition for forming the insulating substrate of the present invention contains a dielectric filler capable of increasing the dielectric constant, and increases the dielectric constant between 3 and 200. , and the loss factor may be between 0.003 and 0.008. Typically, dielectric materials are classified into high dielectric constants (eg, greater than 4) and low dielectric constants (eg, 4 or less) depending on the dielectric constant. High dielectric materials are mainly used in fields such as gate dielectric materials, energy storage materials and wireless communication materials, so as to reduce the power consumption of electronic products, while low dielectric materials are mainly used for resistive It is used in the preparation of electronic packaging materials to reduce the adverse effects of RC delay.

In another alternative embodiment, a composition for forming an insulating substrate may include a modified polyimide (PI) and a dielectric filler. Specifically, the modified polyimide includes aromatic monomers and/or other functional monomers that help reduce water absorption. Examples of aromatic monomers include aromatic diamines, aromatic dianhydrides, aromatic polyamides, polyphenylene terephthalamide (PPTA), poly-p-phenylenebenzoxazole ((poly(p-phenylene-2,6 -benzobisoxazole; PBO) and a copolymer of p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid (poly(p-hydroxybenzoic acid-co-2-hydroxy-6-naphthoic acid)). Features and embodiments of the dielectric filler have been described in detail above and will not be repeated here.

Another aspect of the invention provides a circuit board structure 10 . 1-4 are schematic cross-sectional views showing circuit board structures according to several embodiments of the present invention. Please refer to FIG. 1 first. Circuit board structure 10 includes at least one insulating substrate 12 and at least one redistribution layer 14 . The at least one insulating substrate 12 comprises a composition for forming an insulating substrate as described above. That is, the composition forming the at least one insulating substrate 12 includes 100 parts by weight of modified liquid crystal polymer and 0.5 to 85 parts by weight of dielectric filler. Features and embodiments of both the modified liquid crystal polymer and the dielectric filler have been described in detail above and will not be repeated here. This at least one redistribution layer 14 is located on the insulating substrate.

In some instances, the material of redistribution layer 14 is copper, aluminum, iron, silver, palladium, nickel, chromium, molybdenum, tungsten, zinc , manganese , cobalt, gold, tin, lead, or stainless steel, or at least two of them. It may include alloys of mixed species. More specifically, the rewiring layer 14 is formed by etching a metal foil such as copper foil, aluminum foil, silver foil, tin foil and/or gold foil. In one embodiment, the surface of the redistribution layer 14 is covered with a coating layer (not shown), such as a nickel-gold layer, a zinc layer, or a cobalt layer, on the surface of the redistribution layer 14 through a coating process.

Referring to FIG. 2, in some embodiments, circuit board structure 10 may further include an adhesive layer 16 located between insulating substrate 12 and redistribution layer 14 . More specifically, the adhesive layer 16 has the same pattern as the rewiring layer 14 . The formation of the adhesive layer 16 provides better bonding between the insulating substrate 12 and the redistribution layer 14 . In some examples, the adhesive layer 16 is made of fluorine resin, polyphenylene ether resin (PPO/PPE), aralkyl epoxy resin, epoxy resin, phenoxy resin, acrylic resin, urethane resin, silicone rubber resin, poly-p-xylene resin. , liquid crystal polymer, bismaleimide resin and polyimide resin. Examples of fluororesins include polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (Polyfluoroalkoxy; PFA), tetrafluoroethylene-hexafluoropropylene copolymer (Fluorinated Ethylene Propylene; FEP ), ethylene-tetra-fluoro-ethylene (ETFE). Aralkyl epoxy resins may include biphenyl-type epoxy resins. The schematic diagram of the circuit board structure 10 shown in FIGS. 1 and 2 is a single sided circuit board structure.

However, the invention is not limited to the single-sided circuit board described above. The circuit board structure 10 may be a multilayer circuit board structure where the required line layout determines the respective number of layers of the insulating substrate 12 and the redistribution layer 14 . A circuit board structure 10 shown in FIG. 1, in that it differs from the circuit board structure 10 shown in FIG. It should be understood that signal transmission between any two redistribution layers 14 is accomplished through conductive blind holes 18 provided in the insulating substrate 12 . Accordingly, circuit board structure 10 may further include at least one conductive blind hole 18 through insulating substrate 12 . In some embodiments, the material of conductive blind hole 18 may be similar to the material of redistribution layer 14 .

Please refer to FIG. In some embodiments, circuit board structure 10 may further include an adhesive layer 16 positioned between insulating substrate 12 and redistribution layer 14 . More specifically, the conductive blind holes 18 pass through the adhesive layer 16 and are electrically connected to the two adjacent rewiring layers 14 . Features and embodiments of adhesive layer 16 have been described in detail above and will not be repeated here. In another embodiment of the invention, the circuit board structure may include two or more layers of insulating substrates and a redistribution layer between the insulating substrates.

In short, the composition for forming the insulating substrate of the present invention contains a modified liquid crystal polymer and a dielectric filler. Insulating substrates with a dielectric constant (eg, 4 to 200) have a low dielectric loss factor (eg, 0.003 to 0.008) even in high frequency signal transmission, reducing the delay or loss of signal transmission, thereby increase the speed and/or frequency of Furthermore, the composition for forming the insulating substrate of the present invention can ensure the quality and stability of signal transmission in severe environments of high temperature and high humidity.

Although the present invention has been disclosed above by way of example, it is not intended to limit the invention and various changes and modifications may be made by anyone skilled in the art without departing from the spirit and scope of the invention. can be done. Therefore, the protection scope of the present invention should be based on what is specified in the following claims.

10 Circuit Board Structure 12 Insulating Substrate 14 Rewiring Layer 16 Adhesive Layer 18 Conductive Blind Hole

Claims (12)

A composition for forming an insulating substrate, having a repeating unit having the following structure,

or a combination thereof, wherein R ₁ , R ₂ and R ₃ are C _n H _2n+1 and n is a positive integer, 100 parts by weight of a modified liquid crystalline polymer; a dielectric filler, wherein the dielectric filler has an average particle size of 0.1 to 20 μm, the modified liquid crystal polymer is soluble, and the dielectric filler is a ceramic material, a modified ceramic A composition selected from the group consisting of materials, conductive particles, modified conductive particles, organic materials and modified organic materials. Said ceramic materials are barium titanate, lead titanate, barium strontium titanate (BST), titanium oxide, lead oxide, lead zirconate titanate ( _PZT ), perovskite cubic structure ( _CaCu3Ti4O12 , CCTO ₎ . and lead magnesium niobate-lead titanate (PMN-PT). 2. The composition of claim 1, wherein the modified ceramic material comprises modifying groups containing silyl groups. 2. The composition of claim 1, wherein the conductive particles comprise carbonaceous particles and metal particles. 5. The composition according to claim 4, wherein the carbonaceous particles are selected from the group consisting of carbon 60 ( _C60 ), graphene, carbon black, carbon fibers and carbon nanotubes. 5. The composition of claim 4, wherein said metal particles are selected from the group consisting of silver, aluminum, copper, nickel, zinc and iron. 2. The composition according to claim 1, wherein said modified conductive particles comprise modified carbon particles containing modifying groups selected from the group consisting of amino groups, anilino groups, carboxamide groups, carboxyl groups and hydroxyl groups. 2. The composition of claim 1, wherein said organic material is selected from the group consisting of conductive polyaniline and copper phthalocyanine (CuPc). The composition of claim 1, wherein said modifying organic material comprises modifying groups selected from the group consisting of sulfonic acid groups, hydroxyl groups, ether groups, amino groups and (p-chloromethylbenzene)vinyl groups. A circuit board structure comprising: at least one insulating substrate comprising the composition for forming the insulating substrate of claim 1; and at least one redistribution layer located on the insulating substrate. 11. The circuit board structure of claim 10 , further comprising an adhesive layer positioned between said insulating substrate and said redistribution layer. The adhesive layer includes fluorine resin, polyphenylene ether resin, aralkyl epoxy resin, epoxy resin, phenoxy resin, acrylic resin, urethane resin, silicone rubber resin, poly-p-xylene resin, liquid crystal polymer, bismaleimide resin and polyimide. 12. The circuit board structure of claim 11 , selected from the group consisting of resins.

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