Circuit board structure and composition for forming insulating substrate

Abstract

A composition for forming an insulating substrate includes 100 parts by weight of a modified liquid crystal polymer and 0.5 to 85 parts by weight of a dielectric filler. The modified liquid crystal polymer has a repeating unit structure shown in the specification, Ar is 1, 4-phenylene group, 1, 3-phenylene group, 2, 6-naphthyl or 4, 4 '-biphenylene group, Y is-O-or-NH-, and X is-O-or-NH-. And X is an amide group, an imino group, an amidino group, an aminocarbonylamino group, an aminothiocarbonyl group, an aminocarbonyloxy group, an aminosulfonyl group, an aminosulfonyloxy group, an aminosulfonylamino group, a carboxylic acid ester, a (carboxylic acid ester) amino group, a (alkoxycarbonyl) oxy group, an alkoxycarbonyl group, a hydroxyamino group, an alkoxyamino group, a cyanoxy group, an isocyanate group, or a combination thereof. The insulating substrate formed by using the composition can be applied to forming a circuit board structure. The composition can improve the dielectric constant of the insulating substrate and maintain a relatively low dielectric loss factor.

Description

[0001] This application is a divisional application of patent application No. 201810895875.0, filed on August 8, 2018, entitled "Circuit Board Structure and Composition for Forming Insulating Substrate". Technical Field

[0002] This invention relates to a composition for forming an insulating substrate and a circuit board structure. Background Technology

[0003] For consumer electronics, the main features of System in Package (SIP) technology should be cost savings and miniaturization. Regarding the substrate as the platform for integrating components, there are two directions. One is to use common organic material substrates or multilayer printed circuit boards (PWB); the other is inorganic material substrates, such as silicon substrates. The latter usually has the advantage of miniaturization when combined with chip circuits or processes, but cost is a consideration. For the former, in addition to its low cost, it is now possible to meet the requirements of system in package through sophisticated process technologies, such as high-density interconnect (HDI) technology, combined with special materials.

[0004] Furthermore, as information products become increasingly high-speed and high-frequency, the substrate materials required 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, all require substrate materials with high glass transition temperature (Tg), low dissipation factor (Df), and low dielectric constant (Dk). Currently, the copper foil substrates used in printed circuit boards (PCBs), both in terms of quantity and technology, are mainly made of epoxy resin FR-4 boards. However, the dielectric constant and dissipation factor of FR-4 are gradually failing to meet the requirements of high frequencies. Therefore, the industry urgently needs a substrate material with a high dielectric constant that can maintain a low dissipation factor. Summary of the Invention

[0005] One aspect of the present invention is to provide a composition for forming an insulating substrate, wherein the dielectric constant of the insulating substrate can be controlled by adjusting the composition.

[0006] The composition described above for forming an insulating substrate comprises 100 parts by weight of a modified liquid crystal polymer and 0.5 to 85 parts by weight of a dielectric filler. The modified liquid crystal polymer has a repeating unit structure. Ar is (1,4-phenylene, 1,4-phenylene), (1,3-phenylene, 1,3-phenylene), (2,6-naphthalene, 2,6-naphthyl) or (4,4′-biphenylene, 4,4′-biphenylene), Y is or And X is (Amide group) (imino) (Aminogel) (aminocarbonylamino), (Aminothiocarbonyl) (aminocarbonyloxy) (Aminosulfonyl) (aminosulfonyloxy) (Aminosulfonylamino) (Carboxylic acid esters) ((carboxylic acid ester) amino), (alkoxycarbonyl)oxy, (alkoxycarbonyl) (hydroxyamino), (alkoxyamino), (Cyanoxy) (isocyanate group) or combinations thereof, wherein R1, R2 and R3 may be C n H 2n+1 And n is a positive integer. The dielectric filler is selected from the group consisting of modified ceramic materials, conductive particles and organic materials, wherein the modified ceramic materials include silane groups.

[0007] According to certain embodiments of the present invention, the dielectric filler is an organic material selected from the group consisting of conductive polyaniline and copper titanium cyanide (CuPc).

[0008] According to certain embodiments of the present invention, the dielectric filler is an organic material, the organic material is a modified organic material, the modified organic material includes a modifying group, the modifying group being selected from the group consisting of sulfonic acid group, hydroxyl group, ether group, amino group and (p-chloromethylbenzene) vinyl group.

[0009] According to certain embodiments of the present invention, the dielectric filler is a conductive particle, the conductive particle is a modified conductive particle, the modified conductive particle includes modified carbon particles, the modified carbon particles include modifying groups, and the modifying groups are selected from the group consisting of amino, aniline, amide, carboxyl and hydroxyl groups.

[0010] According to certain embodiments of the present invention, the dielectric filler is a conductive particle, which includes carbon particles and metal particles.

[0011] According to certain embodiments of the present invention, the carbon particles are selected from carbon sixtypin (C6) particles. 60 It is a group consisting of graphene, carbon black, carbon fiber, and carbon nanotubes (CNTs).

[0012] According to certain embodiments of the invention, the metal particles are selected from the group consisting of silver, aluminum, copper, nickel, zinc and iron.

[0013] According to certain embodiments of the present invention, X is , , , , , , or .

[0014] According to certain embodiments of the present invention, Ar is .

[0015] Another aspect of the present invention provides a circuit board structure. This circuit board structure includes at least one insulating substrate and at least one redistribution layer. The at least one insulating substrate includes the composition for forming the insulating substrate as described above. The at least one redistribution layer is located on the insulating substrate. Attached Figure Description

[0016] To make the above and other objects, features, advantages and embodiments of the present invention more apparent and understandable, the accompanying drawings are described in detail below:

[0017] Figures 1 to 4 A cross-sectional schematic diagram illustrating a circuit board structure according to various embodiments of the present invention is shown;

[0018] The symbols are explained as follows:

[0019] 10: Circuit board structure; 12: Insulating substrate

[0020] 14: Rewiring layer, 16: Adhesive layer

[0021] 18: Conductive blind hole. Detailed Implementation

[0022] To make the description of this disclosure more detailed and complete, illustrative descriptions of embodiments and specific examples of the present invention are provided below; however, these are not the only forms of implementing or applying the specific examples of the present invention. The various embodiments disclosed below can be combined or substituted with each other where advantageous, and other embodiments can be added to one embodiment without further description or explanation.

[0023] To make the description of this disclosure more detailed and complete, reference can be made to the accompanying drawings and the various embodiments described below, in which the same numbers represent the same or similar elements.

[0024] Throughout this document, the vocabulary used generally represents its ordinary meaning. Certain specific terms will be defined below to provide additional guidance to practitioners. For convenience, some terms may be specially marked, for example, using italics and / or quotation marks. Regardless of whether they are specially marked, their scope and meaning remain unchanged and are the same as ordinary terms. It is understood that the same thing can be described in more than one way. Therefore, alternative language and synonyms for one or more terms may be used herein, without implying that a term has any special meaning in the context of this discussion. Synonyms for certain terms will be used, and repeated use of one or more synonyms does not preclude the use of other synonyms. Any examples discussed in this specification are for illustrative purposes only and do not limit the scope or meaning of the invention or its examples in any way. Similarly, the invention is not limited to the various embodiments presented in this specification.

[0025] Unless otherwise clearly indicated in the text, the singular as used herein includes plural referents. By referring to a specific reference such as "in one embodiment," a particular feature, structure, or characteristic is indicated in at least one embodiment of the present invention. Therefore, when phrases such as "in one embodiment" appear in various places by specific reference, it is not necessary to refer to the same embodiment. Furthermore, in one or more embodiments, these particular features, structures, or characteristics may be combined with each other as appropriate.

[0026] One aspect of the present invention is to provide a composition for forming an insulating substrate, comprising 100 parts by weight of a modified liquid crystal polymer and 0.5 to 85 parts by weight of a dielectric filler. The modified liquid crystal polymer has a repeating unit structure of the following formula (1).

[0027] Equation (1).

[0028] Ar in formula (1) can be 1,4-phenylene, with the chemical formula: ; 1,3-phenylene, chemical formula is ; 2,6-naphthalene, chemical formula is ; or 4,4′-biphenylene, with the chemical formula […]. .

[0029] In equation (1), Y can be... or .

[0030] In formula (1), X can be an amide group (Carboxamido), with the chemical formula being Imino (Imido / Imino), chemical formula is Amidino, chemical formula: Aminocarbonylamino, chemical formula is Aminothiocarbonyl, chemical formula: Aminocarbonyloxy, chemical formula is Aminosulfonyl, chemical formula: Aminosulfonyloxy, chemical formula is Aminosulfonylamino, chemical formula: Carboxyl ester, chemical formula: (Carboxyl ester)amino, chemical formula is ; (alkoxycarbonyl)oxy, chemical formula is The chemical formula for alkoxycarbonyl is: Hydroxyamino, chemical formula is Alkoxyamino, chemical formula: ; Cyanoxy group, chemical formula is Isocyanate group, chemical formula is ; or combinations thereof, wherein the general formula of alkoxy groups R1, R2 and R3 is C n H 2n+1 And n is a positive integer.

[0031] According to various embodiments of the present invention, any of the above-described Ar can be combined with any Y and any X. Different combinations may have the same or different technical effects.

[0032] More specifically, the aforementioned modified liquid crystal polymer can be dissolved in a specific solvent to form a modified liquid crystal polymer solution. For example, this specific solvent can be selected from the group consisting of N-methyl-2-pyrrolidone, N,N-dimethylacetamide, γ-butyrolactone, dimethylformamide, 2-butoxyethanol, and 2-ethoxyethanol. Compared to conventional liquid crystal polymers, the solubility of the soluble liquid crystal polymer in the specific solvent is higher. It is understood that the modified liquid crystal polymer solution can be formed on a substrate through processes such as coating, and then the solvent can be evaporated through a heating process to form an insulating substrate containing the modified liquid crystal polymer.

[0033] For example, the modified liquid crystal polymer solution can be an aromatic liquid crystal polyester solution, comprising one of the aforementioned solvents and the aromatic liquid crystal polyester. The weight percentage of the solid component of the aromatic liquid crystal polyester is from 1 wt% to 85 wt%, for example, 5 wt%, 15 wt%, 25 wt%, 35 wt%, 45 wt%, 55 wt%, 65 wt%, or 75 wt%. When the weight percentage of the solid component of the aromatic liquid crystal polyester is less than a certain value, such as 1 wt%, multiple coating processes are required to achieve the required thickness of the insulating substrate, which is quite time-consuming and costly. Conversely, when the weight percentage of the solid component of the aromatic liquid crystal polyester is greater than a certain value, such as 85 wt%, the solid component of the aromatic liquid crystal polyester is not easily soluble in the solvent, thus resulting in gelatinization. Specifically, the aromatic liquid crystal polyester has a repeating unit structure as follows:

[0034]

[0035] Wherein Ar is 1,4-phenylene, 1,3-phenylene, 2,6-naphthyl or 4,4′-biphenylene, Y is -O- or -NH-, and X is amide, imino, amidin, aminocarbonylamino, aminothiocarbonyl, aminocarbonyloxy, aminosulfonyl, aminosulfonyloxy, aminosulfonylamino, carboxylic ester, (carboxylic ester)amino, (alkoxycarbonyl)oxy, alkoxycarbonyl, hydroxyamino, alkoxyamino, cyanoxy, isocyanate or a combination thereof.

[0036] If the content of the dielectric filler exceeds a certain value, such as 85 parts by weight, the dielectric fillers will interconnect, causing the material to change from an insulator to a conductor. This will drastically alter the material's dielectric constant and conductivity, thus causing it to lose its performance as an insulating substrate. In several 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 several examples, the ceramic material is selected from barium titanate (BT), lead titanate, barium strontium titanate (BST), titanium oxide, lead oxide, lead zirconate titanate (Pb(ZrTi)O3, PZT), and perovskite cubic crystal structure (CaCu3Ti4O3). 12 The group comprises lead magnesium niobate-lead titanate (PMN-PT). In several examples, the modified ceramic material includes a modifying group, which contains a silane group. In several examples, the conductive particles include carbon-based particles and metal particles. For example, the carbon-based particles are selected from carbon-60 (C60-C60) materials. 60 The modified conductive particles are selected from the group consisting of graphene, carbon black, carbon fibers, and carbon nanotubes (CNTs); while the metal particles are selected from the group consisting of silver, aluminum, copper, nickel, zinc, and iron. In several examples, the modified conductive particles include a modified carbon particle containing a modifying group selected from the group consisting of amino, aniline, amide, carboxyl, and hydroxyl groups. In several examples, the organic material is selected from the group consisting of conductive polyaniline and copper phthalocyanine (CuPc). In several examples, the modified organic material contains a modifying group selected from the group consisting of sulfonic acid, hydroxyl, ether, amino, and (p-chloromethylbenzene)vinyl groups. It is understood that the dielectric filler is added to the solution of the modified liquid crystal polymer and formed on a carrier plate by a coating or similar process, and then the solvent is evaporated by a heating process to form an insulating substrate with improved dielectric constant. It is worth noting that the dielectric filler does not dissolve in the modified liquid crystal polymer solution, but is uniformly dispersed in the modified liquid crystal polymer solution.

[0037] In some embodiments, the average particle size of the dielectric filler is between 0.1 and 20 micrometers. According to several embodiments, when the average particle size of the dielectric filler is less than a certain value, such as 0.1 micrometers, the effect on improving the dielectric constant is not significant. Conversely, when the average particle size of the dielectric filler is greater than a certain value, such as 20 micrometers, it is difficult to control the dispersion of the dielectric filler particles, and the dielectric filler particles are prone to interconnection, thereby causing the subsequently formed insulating substrate to lose its insulating properties. Therefore, the average particle size of the dielectric filler can be, 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, 5.0 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, 16.0 μm, or 18.0 μm.

[0038] Generally, due to the good processability, heat resistance, low water absorption, low dielectric constant (Dk) (e.g., between 2 and 4), and low loss factor (Df) (e.g., between 0.003 and 0.008) inherent properties of modified liquid crystal polymers, the compositions of the present invention for forming insulating substrates contain the aforementioned dielectric fillers that can increase the dielectric constant to between 3 and 200, while maintaining the loss factor between 0.003 and 0.008. Typically, dielectric materials can be classified into high dielectric constant (e.g., greater than 4) and low dielectric constant (e.g., less than or equal to 4) based on their dielectric constant. High dielectric materials are mainly used in fields such as gate dielectric materials, energy storage materials, and wireless communication materials to reduce the power consumption of electronic products; low dielectric materials are mainly used to prepare electronic packaging materials to reduce the adverse effects caused by RC delay.

[0039] In other alternative embodiments, the composition for forming the insulating substrate may comprise a modified polyimide (PI) and a dielectric filler. Specifically, the modified polyimide comprises aromatic monomers and / or other functional monomers that help reduce water absorption. For example, the aromatic monomers may comprise aromatic diamines, aromatic dianhydrides, aromatic polyamides, polyphenylene terephthalamide (PPTA), 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)). The characteristics and examples of the dielectric filler have been described in detail above and will not be repeated here.

[0040] Another aspect of the present invention is to provide a circuit board structure 10. Figures 1 to 4 A cross-sectional schematic diagram of a circuit board structure according to various embodiments of the present invention is shown. Please refer to [the relevant documentation / reference]. Figure 1 The 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 includes the composition for forming the insulating substrate as described above. Specifically, the composition forming the at least one insulating substrate 12 includes 100 parts by weight of a modified liquid crystal polymer and 0.5 to 85 parts by weight of a dielectric filler. The characteristics 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. The at least one redistribution layer 14 is located on the insulating substrate.

[0041] In some instances, the material of the redistribution layer 14 may comprise copper, aluminum, iron, silver, palladium, nickel, chromium, molybdenum, tungsten, zinc, chromium, manganese, cobalt, gold, tin, lead, or stainless steel, or an alloy of at least two of the above metals. More specifically, the redistribution layer 14 may be formed by etching metal foil, such as copper foil, aluminum foil, silver foil, tin foil, and / or gold foil. In some embodiments, the surface of the redistribution layer 14 may be coated with a coating layer (not shown), such as a nickel-gold layer, a zinc layer, or a cobalt layer.

[0042] Please see Figure 2In several embodiments, the circuit board structure 10 may further include an adhesive layer 16 located between the insulating substrate 12 and the redistribution layer 14. More specifically, the adhesive layer 16 has the same pattern as the redistribution layer 14. The formation of the adhesive layer 16 allows for better adhesion between the insulating substrate 12 and the redistribution layer 14. In several examples, the adhesive layer 16 is selected from the group consisting of fluoropolymers, polyphenylene oxide resins (PPO / PPE), aryl epoxy resins, epoxy resins, phenoxy resins, acrylic resins, urethane resins, silicone rubber resins, poly(p-cycloxylene) resins, liquid crystal polymers, bismaleimide resins, and polyimide resins. For example, fluoropolymers may include polytetrafluoroethylene (PTFE), polyfluoroalkoxy (PFA), fluoroethylene-hexafluoropropylene (FEP), and ethylene-tetrafluoroethylen (ETFE); aryl epoxy resins may include biphenyl epoxy resins. According to... Figure 1 and Figure 2 The schematic diagram of the circuit board structure 10 shown is a single-sided circuit board structure.

[0043] However, the present invention is not limited to the single-sided circuit board described above. The circuit board structure 10 can also be a multilayer circuit board structure, and the number of layers of the insulating substrate 12 and the redistribution layer 14 can be determined according to the required circuit layout. Figure 3 The illustrated circuit board structure 10 and Figure 1 The difference in the illustrated circuit board structure 10 is that: Figure 3 The illustrated circuit board structure 10 includes two insulating substrates 12 and three redistribution layers 14, with each of the two insulating substrates 12 sandwiched between two adjacent redistribution layers 14. It is understood that signal transmission between any two redistribution layers 14 is implemented via conductive blind vias 18 disposed in the insulating substrates 12. Therefore, the circuit board structure 10 may also include at least one conductive blind via 18 penetrating the insulating substrate 12. In some embodiments, the material of the conductive blind via 18 may be similar to the material of the redistribution layers 14.

[0044] Please see Figure 4In several embodiments, the circuit board structure 10 may further include an adhesive layer 16 located between the insulating substrate 12 and the redistribution layer 14. More specifically, a conductive blind via 18 penetrates the adhesive layer 16 and electrically connects two adjacent wiring layers 14. The features and embodiments of the adhesive layer 16 have been described in detail above and will not be repeated here. In other embodiments of the invention, the circuit board structure may also include two or more insulating substrates and a redistribution layer between the insulating substrates.

[0045] In summary, the composition for forming an insulating substrate of the present invention comprises a modified liquid crystal polymer and a dielectric filler. By adjusting the composition, the dielectric constant of the insulating substrate is significantly increased, enabling the high dielectric constant (e.g., 4 to 200) insulating substrate to maintain a low dielectric loss factor (e.g., 0.003 to 0.008) even under high-frequency signal transmission, thereby reducing signal transmission delay or loss and improving signal transmission speed and / or frequency. Furthermore, the composition for forming an insulating substrate of the present invention can ensure the quality and stability of signal transmission under harsh environmental conditions of high temperature and high humidity. In addition, the composition for forming an insulating substrate of the present invention can also form an insulating substrate with a low dielectric constant (e.g., less than or equal to 4), which can be combined with the aforementioned insulating substrate with a high dielectric constant to stack new multifunctional electronic products.

[0046] Although the present invention has been disclosed above with reference to embodiments, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any person skilled in the art can make various equivalent changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications should be included within the scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the appended claims.

Claims

1. A composition for forming an insulating substrate, characterized in that, Include: The modified liquid crystal polymer, in a quantity of 100 parts by weight, has a repeating unit structure as follows: Where Ar is , , or Y is or And X is , , , , , , , , , , , , , , , , Or a combination thereof, wherein R1, R2 and R3 are C n H 2n+1 And n is a positive integer; and The dielectric filler is in the range of 0.5 to 85 parts by weight, wherein the dielectric filler is selected from the group consisting of modified ceramic materials, conductive particles and organic materials, wherein the modified ceramic materials include silane groups.

2. The composition according to claim 1, characterized in that, The dielectric filler is an organic material selected from the group consisting of conductive polyaniline and titanium copper cyanide.

3. The composition according to claim 1, characterized in that, The dielectric filler is an organic material, which is a modified organic material containing a modifying group selected from the group consisting of sulfonic acid, hydroxyl, ether, amino and (p-chloromethylbenzene) vinyl groups.

4. The composition according to claim 1, characterized in that, The dielectric filler is the conductive particle, which is a modified conductive particle. The modified conductive particle includes modified carbon particles, which contain modifying groups selected from the group consisting of amino, aniline, amide, carboxyl, and hydroxyl groups.

5. The composition according to claim 1, characterized in that, The dielectric filler is the conductive particle, which includes carbon particles and metal particles.

6. The composition according to claim 5, characterized in that, The carbon particles are selected from a group consisting of C60, graphene, carbon black, carbon fiber, and carbon nanotubes.

7. The composition according to claim 5, characterized in that, The metal particles are selected from the group consisting of silver, aluminum, copper, nickel, zinc and iron.

8. The composition according to claim 1, characterized in that, Where X is , , , , , , or .

9. The composition according to claim 1, characterized in that, Where Ar is .

10. A circuit board structure, characterized in that, Include: At least one insulating substrate, comprising a composition for forming an insulating substrate as described in claim 1; and At least one wiring layer is located on the insulating substrate.

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