TW548310B - High frequency electrical substrate with low dielectric constant - Google Patents

Abstract

A composite material board with high rigidity and low dielectric constant is disclosed to suit for electrical substrates with high frequency. A matrix of the composite material board is provided by uniformly mixing the polytetrafluoroethylene and fluorinated ethylene-propylene. A ceramic particle filler, silica and the likes, is added into the polymer matrix for reinforcement. The ceramic particle filler weights 55 percent of the composite material board, and the fluorinated ethylene-propylene weights 0.5 to 10 percent of the composite material board. Such composite material board has a dielectric constant less than 3.5 and better stiffness than that of usual.

Description

548310 Case number 901071 V. Description of the invention (1) [Application field of the invention] The present invention relates to a high-frequency circuit substrate, and particularly to a high-frequency circuit substrate having a low dielectric constant. [Background of the Invention] There are many types of materials that have been used as circuit substrates (for example, printed circuit substrates or wafer mounting substrates). Resin-based circuit board materials are used for 5 children, which include Pan-Resin (en 〇1 丨 C), epoxy resin (epoxy), polyimide resin (polyimide), polytetrafluoroethylene (polytetrafluoroethylene; PTFE) ), And B-triazine resin (Bismaleimide Triazine; BT) and other thermosetting resins (Th ^ m ^ etted Plastic Resin). In the current printed circuit board industry, the use of circuit substrates made of epoxy resin as the matrix (matrix) is the most common. This epoxy resin is a bromine-containing resin commonly known as FR 4 tree J !. Due to the strong adhesion between FR-4 resin and copper foil, the composite material board obtained by combining 4 resin with glass fiber reinforced filler (reinf 0 rcingf 丨 1 1 er) has flexibility, cheap price, simple response and processing. The advantage of good performance is therefore widely used as a circuit board. However, because FR-4 resin has a high dielectric constant (Dk value is about 4 · 5) and has a large interference with telecommunication transmission, it is mostly used for circuit boards of electronic devices with a frequency below 2GHz. The high-frequency substrate materials used in satellite receivers, wireless communications, high-frequency microwave communications, radar equipment, and other equipment with high precision requirements can be roughly divided into BT resin, PP0 resin, and PTFE resin. series. Among them, BT resin and PPo resin are mostly used in

548310 ---- Case No. 9010715IP_Year Month Date 日 正 _ V. Description of the invention (2) Circuit board of 2 ~ 12 GHz, and most of ptfe resin is used for circuit board above 10 GHz. However, the use of PTFE resin as the base material for high-frequency circuit boards has the following disadvantages: (1) Tg is too low (about 19 ° C), the material is too soft, the scratch resistance is poor, and the drillability is poor. (2) The processing temperature is too high (700 τ), the processing force is too high (about 丨 600 ps), and the forming time is too long (about 6 hours). (3) The chemical inertness is high, and the plated through hole is high. (Piate (i Thr0Ugh Hole; PTH)), the hole wall is difficult to activate. (4) expensive (about 10 times FR-4). In order to improve the above disadvantages, one of the methods is to use PTFE resin as The base material is uniformly dispersed with a reinforcing filler (reinforcing filler) to form a composite material. The reinforcing filler may be a ceramic material, such as Si02 (US Patent 5028871, 5086548) or a molecular material such as PEEK (U.S. Patent No. 5,922,453); However, although the above-mentioned reinforcing filler is added to the PTFE resin to obtain a rigid substrate composite material, the dielectric properties of the substrate are often deteriorated due to the high dielectric constant of the reinforcing filler. An improved method is to add porous fibers or hollow fiber reinforcements to the pTFE resin (such as European patent 0 1 6041 8A2, US patents 4849284, 5 1 94326), although this method can make the composite material board High rigidity Low dielectric constant, however, will cause unwanted capillary phenomena during the process of plating through-holes of circuit substrates, that is, copper penetrates into the substrate from the hole wall. Therefore, there is still a need to provide a new suitable for high High-frequency circuit substrate composite material board to solve the above problems. [Objective and Summary of the Invention] In view of this, the purpose of the present invention is to provide a high rigidity, low dielectric

548310 __Case No. 9010715d > _ Month and Day 倏, τ_ V. Description of the invention (3) High-frequency circuit board with constant electric capacity and no copper plating through-hole phenomenon. A high-frequency circuit substrate proposed by the present invention is to uniformly disperse polymer-polytetramethylene acetate (hereinafter referred to as PTFE) and fluorinated ethylene-propylene (hereinafter referred to as FEP) uniformly. Mix as the base material (in atri X) of the composite material board, and add ceramic particle filler (ceric particle fi 1 ler), such as silicon dioxide (si 1 ica), to the molecular base material. Is a reinforcement material, wherein the ceramic particle filler accounts for 55wt% ~ 85wt% of the total weight of the composite material plate, and the FEP accounts for approximately 0.5 wt% ~ 1 0 wt% of the total weight of the composite material plate . Since FEP and PTFE are fluorine-based high-son materials, FEp and pTFE can be uniformly mixed to form a single phase. The addition of heat and sexual FEP to PTFE can improve the rigidity of this substrate and improve the problem of insufficient adhesion to circuit boards. The low dielectric constant of FEP also allows the obtained composite material board to maintain a lower overall. Dielectric constant. In order to have a clearer understanding of the features and advantages of the present invention, it will be described in detail with reference to the drawings. But it must be explained first that the present invention is protected from the following implementation exceptions, there are still other embodiments, and the following: The diagrams are not necessarily drawn in full scale. [Detailed description of the embodiment] According to the high-frequency circuit substrate disclosed in the embodiment of the present invention, the micrograph and the company refer to the electron microscope (SEM) photo diagram shown in "Fig. 1". ^ Alpha material substrate is based on the fluorine-based polymer materials pTFE and FEp. ^ The pottery-bright particles are filled t. For example, it accounts for the total weight of high-frequency circuit substrates. I _________________________

Page 8: Single-phase substrate formed by homogeneous mixing. Fill in the base material. V. Description of the invention (4) 55wt% ~ 85wt% silicon oxide particle filling material. In addition, the purpose is to strengthen the thermal expansion coefficient of the composite material plate and a porcelain particle filling material composite material plate. ; As the ceramic particles: ^ can control the ratio of complex (about 6) than PTFE dielectric constant (approximately 2) made of ceramic particle filler material to avoid more, so the overall dielectric needs to be controlled The constant is too high. X-frequency surface-frequency circuit substrate The method of this high-frequency circuit substrate is to mix the emulsion of oxidized PTFE powder and the emulsion containing FEP powder, and mix them evenly; an appropriate amount is juice-free. Oils or alcohols can also be added and added at the same time, covering the coupling: training, the coupling agent can be a siloxane coupling agent, such as ζ-"M phenyltrimethoxysilane (Phenyltrimethoxine SUane), Or a coupling agent such as NZ12, neopentyl (dially) 〇xy, tri (di〇ctyl) ph〇sphate zirconate, or a titanium coupling agent such as Ucal2, neopentyl (dially) 〇Xy5 tri (diocty1) phosphate titanate 'or Fluorine-based siloxane coupling agent; the function of the coupling agent is to improve the binding force between the silicon oxide particles and the substrate in the composite material board. Then, the ceramic particles, PTFE powder, fep powder and plasticizer are added. The mixture is' pressurized into an appropriate shape, such as a flat plate shape ', and then the molding mixture is baked to make the plasticizer contained therein 548310 Case No. 9010715 », / V. Description of the invention (5)'- ---- ^ --- send off; then Then, with about 3 6 0 ° c, w choose, good-words ^

The FFP Ba leather reconnaissance process is customized for the sintering process, so that the PTFE and F E P knives expand each other to form a ρ τ p F phase substrate, and the oxide stone is obtained as a high-frequency circuit substrate. 、 In the wire ’, you can get ^: According to the high-frequency circuit board and a commodity

Comparison of the types of high-frequency circuit board comparison test pieces The ancient watch is made according to the present invention with three different ratios of FEP ^ circuit board (represented as FEP 1 3%, FEP 3.4%, FEP 5% # = A commercially available dielectric suspension and rigidity comparison table for a high-frequency circuit substrate rib 3003 ^ on the market. The composition of R03003R contains 43.9 wt% 5 vol% of PTFE and 56.1. wt% (55 · 5 vol%) ceramic πΓ filler. The three composite materials according to the present invention have a FEP of 1.3% and 3 w. 3.4% ′ FEP 5% ′ is PTFE containing FEP-replaced portions of L 栌 Wt / ° ′ 3.4 wt% and 5 wt% of the total weight of the high-frequency circuit board, respectively. From Table 1, it can be known that the rigidity of the high-frequency circuit substrate with FEP significantly increased to 1 876 ~ 2613 a ′, which is even higher than the current commercialized equivalent 驴 300 donkey (rigidity 1 267 MPa). The aforementioned rigidity is determined by dynamic mechanical analysis test (DMA Test) at 30.29. (: Measured at temperature. In addition, the high frequency circuit

Page 10 548310 __Case No. 9010715 黍 &_; yyyyyyyyyyyyyyyyyyy: Five, description of the invention (6) The dielectric properties of the board are also quite good, the overall dielectric constant is only 3. 〇 卜 3. 〇8 or so , Lower than 3.16 of R03 00 3R, so it can be applied to high frequency circuit substrates

The composite material plate according to the present invention also has a high bending modulus (f 1 6 X ^ Β 1 modulus). Taking the above-mentioned FEP 1.3% high frequency circuit substrate as an example, its bending modulus can reach 272 X 1 03 psi; Compared with US Patent No. 5,922,453, adding 10 v〇U (6 wt%) of pEEK reinforced particles to R03003R instead of pTFE is a high-frequency circuit substrate board (the bending invention only added 1.3 wt% of FEP to achieve the effect.) Ceramic particle

It accounts for 0.5wt% to 10wt% of the total weight. FEP has the advantages of high rigidity and low dielectric constant, or it may cause copper through-hole penetration problems. The above are only covered by the present invention and are not intended to limit the implementation model of the present invention. The spirit of the present invention should be covered by the equivalent scope of appropriate patent application. The modulus of curvature is 218 X 103 psi), which can be obtained in the south. The reinforced PTFE composite material plate is added with the “acquired composite material plate at the same time” and does not significantly increase the cost of production. The preferred embodiment is included in the description, and those familiar with the technology will be able to modify and retouch without departing from it. ; Therefore, any changes and modifications in accordance with the present invention are patent models of the present invention

Page 11 548310 Case No. 901071511 Modification Brief Description of Drawings Figure 1 is an electron microscope (SEM) photograph of one of the high frequency circuit substrates of the present invention. iBii Page 12

Claims (1)

548310 This month ’s amendment, the scope of patent application_ 1 · A high-frequency circuit substrate with low dielectric constant, which includes: a fluorine-containing polymer substrate, which is composed of at least a mixture of PTFE and FEP 'Where the FEP accounts for 0.5 wt% to 10 wt% of the total weight of the composite material plate; at least one ceramic particle filler is dispersed in the polymer substrate: and a coupling agent covering the surface of the ceramic particle filler Composed of. 2. The high-frequency circuit substrate having a low dielectric constant as described in item 丨 of the patent application range, wherein the ceramic particle filling material is silica. 3. The high-frequency circuit substrate having a low dielectric constant as described in item 2 of the scope of the patent application, wherein the ceramic particle filler accounts for 55wt% to 85wt% of the total weight of the composite material plate. 4. The high-frequency circuit substrate with a low dielectric constant as described in item 2 of the scope of the patent application, wherein the coupling agent is added in an amount less than 3% by weight of the ceramic filler. 5. The high-frequency circuit substrate having a low dielectric constant as described in item 1 of the scope of the patent application, wherein the coupling agent is a siloxane series. 6. The high-frequency circuit substrate having a low dielectric constant as described in item 5 of the scope of the patent application, wherein the coupling agent is phenyltrimethoxystone. 7. The high-frequency circuit substrate having a low dielectric constant as described in item 1 of the scope of the patent application, wherein the coupling agent is a fluorine-based siloxane series. 8. The high-frequency circuit substrate having a low dielectric constant as described in item 1 of the scope of the patent application, wherein the coupling agent is a titanium series. 9. The high-frequency circuit substrate having a low dielectric constant as described in item 8 of the scope of the patent application, wherein the coupling agent is neopentyl (dially) oxy, Lical2, tri (dioctyl) phosphate titanate. 548310 _Case No. 9010715V_ Year Month Revision_ VI. Patent Application Range 10. The high-frequency circuit substrate with low dielectric constant as described in item 1 of the patent application range, wherein the coupling agent is a zirconium series. 11. The high-frequency circuit substrate with a low dielectric constant as described in item 10 of the scope of patent application, wherein the coupling agent is NZ1 2, neopentyl (dially) oxy, tri (dioctyl) phosphate zirconate o Page 14