Patent Application
20110143922
This application claims the benefits of Taiwan Patent Application No. 098142670, filed on Dec. 14, 2009 and Taiwan Patent Application No. 099106436, filed on Mar. 5, 2010, which are hereby incorporated by reference for all purposes as if fully set forth herein.
1. Field of the Invention
The present invention relates to a composition, and specifically to a composition with catalyst particles for making a circuit pattern.
2. Description of Related Art
Multilayer boards, which includes not only a plurality of circuit patterns but also at least one conductive blind via, have been developed, and the conductive blind via is electrically connected with at least two layers.
During manufacturing of the multilayer board, the circuit patterns are usually formed by lithography and etching of a copper foil on a dielectric layer. The conductive blind via is formed in the dielectric layer by following processes: laser drilling, desmear, chemical plating (also called electroless plating) and electroplating.
An object of the invention is to provide a composition with catalyst particles for making a circuit pattern.
A composition with catalyst particles in accordance with the present invention is provided for making a circuit pattern. The composition with catalyst particles includes an insulation material and a plurality of catalyst particles. The catalyst particles are distributed in the insulation material and not made of metal. When the composition with catalyst particles is bathed in a chemical plating solution, a redox reaction (shorthand for reduction-oxidation reaction) may take place between some of the catalyst particles and the chemical plating solution so as to deposit a conductive pattern on the composition with catalyst particles.
Based on the above, the conductive pattern can be formed on the composition by the catalyst particles. Accordingly, the composition of the present invention can be applied to make a circuit pattern and suitable for making a circuit board and a molded interconnect device (MID).
To further understand the above features and advantages of the present invention, please refer to the following detailed description and drawings related the present invention.
Particularly, the catalyst particles 120 may be boron particles, silicon particles, germanium particles, arsenic particles, antimony particles and tellurium particles. In addition, the catalyst particles 120 may also be metalloid complex compound particles, such as metalloid nitride particles or metalloid oxide particles; moreover, the components of the catalyst particles 120 may simultaneously contain metalloid complex compounds and metalloids.
In a preferred embodiment, the diameter of the catalyst particles 120 may be greater than 100 nm, and the mass percentage of the catalyst particles 120, that is, the mass ratio of the catalyst particles 120 to the composition 100, may be between 5% and 40%. Besides, the dielectric constant of the composition 100 may be between 2.5 (1 MHz) and 4.7 (1 MHz), which is approximate to that of general epoxy resin.
The insulation material 110 may be a polymer or a ceramic, and the polymer may include epoxy resin, modified epoxy resin, polyester, acrylic ester, fluoro-polymer, polyphenylene oxide, polyimide (PI), phenolicresin, polysulfone, silicone polymer, bismaleimide triazine modified epoxy (BT resin), cyanate ester, polyethylene, polycarbonate (PC), acrylonitrile-butadiene-styrene copolymer (ABS copolymer), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), liquid crystal polymers (LCP), polyamide 6 (PA 6), Nylon, polyoxymethylene (POM), polyphenylene sulfide (PPS), cyclic olefin copolymer (COC) or any combination thereof.
In addition, the insulation material 110 may be a solid material or a liquid material, so that the composition 100 is in the solid or liquid states such as a bulk/a film or a coating.
The catalyst particles 120 are incorporating into the insulation material 110 and mixing them together to form the composition 100. During the mixing stage, the catalyst particles 120 are stirred such that the catalyst particles 120 can be evenly distributed in the insulation material 110. Moreover, the composition 100 may also be formed by mixing the catalyst particles 120 with a dispersant (not shown) into a slurry in advance and then incorporating the slurry into the insulation material 110. It must be understood that the dispersant is not a required material for forming the composition 100, such that the dispersant may be used to mix with catalyst particles 120 in a preferred embodiment but not limited to the invention.
The composition 100 can be applied to make a circuit pattern for a circuit board such as a single-side circuit board, a double-side circuit board or a multilayer circuit board. In addition, the circuit pattern may also include at least one conductive blind via.
Referring to
The substrate 200 may also be a circuit substrate, a metal core layer or a resin layer. When the substrate 200 is a circuit substrate, the substrate 200 has at least one circuit pattern. Taking the substrate 200 shown in
In
Referring to
The recessed pattern 220 can be formed by several methods such as laser ablation, plasma etching or mechanical processing. A laser source used for the laser ablation may emit a laser beam with the wavelength range of visible light, infrared light or ultraviolet light. The mechanical processing may include water jet cutting, sandblasting or profile cutting such as V-cutting or routing.
It should be noted that after the recessed pattern 220 is formed by laser ablation, a desmear process is performed on the recessed pattern 220 to desmear the blind via 226 for eliminating the residues of the insulation material 110 and the impurities remained on the surface of the pad 212. Generally, the pre-process solutions used in the desmear process may slightly corrode metal surfaces, so that the pre-process solutions may slightly damage the surface of the pad 212.
On the other hand, since the catalyst particles 120 are not made of metal, the pre-process solutions are unable to damage the catalyst particles 120 exposed on the recessed pattern 220. Therefore, the catalyst particles 120 can be remained without any change in chemical properties after the desmear process.
Referring to
In detail, the chemical plating solution includes at least one type of metal ion, such as copper ions or nickel ions and so on. A redox reaction may take place between the surface atoms of the catalyst particles 120 and the metal ions, such that the metal ions are reduced to metal atoms which attach to the catalyst particles 120. The metal atoms are combined together to form the conductive pattern 230. Accordingly, the conductive pattern 230 is formed by the metal ions and connected with some catalyst particles 120, as shown in
To easily deposit the conductive pattern 230 on the composition 100 and improve electrical quality of the conductive pattern 230, in a preferred embodiment, the mass percentage of the catalyst particles 120 may be between 20% and 30%, and the diameter of the catalyst particles 120 may be between 300 nm and 400 nm. Furthermore, when the catalyst particles 120 are silicon particles used as an example, the preferred purity of the silicon particles may be more than 97%, so that the conductive pattern 230 may easily deposit on the composition 100 and the electrical quality of the conductive pattern 230 can also be improved.
However, it should be emphasized that the invention is not limited to any particular purity of the silicon particles. The preferred purity of the silicon particles may also be less than 97% in other preferred embodiments. Moreover, when the catalyst particles 120 are silicon particles, the catalyst particles 120 may be prepared commercially available silicon powder or ground silicon powder ground in a ball grinder.
The chemical plating solution may be an alkaline solution or an acid solution, and the alkaline solution or the acid solution can dissociate the surface atoms in the catalyst particles 120 to produce a plurality of electrons. The electrons combine with the metal ions in the chemical plating solution to produce metal atoms, thereby promoting the deposition of the conductive pattern 230 on the composition 100.
It is to be noted that after the desmear process, the catalyst particles 120 exposed on the recessed pattern 220 are still remained without any change in chemical properties, so that the deposition of the conductive pattern 230 won't be affected even if the desmear process has been performed. Besides, after the desmear process, the residues of the insulation material 110 and the impurities remained on the surface of the pad 212 are removed to ensure that the conductive pattern 230 can tightly connect to the pad 212, and the electrical connection quality of the conductive pattern 230 and the pad 212 is improved.
After the conductive pattern 230 is formed, a circuit board 20 is essentially complete, wherein the conductive pattern 230 is a circuit pattern of the circuit board 20 and may include a circuit pattern 232 and a conductive blind via 234. The circuit pattern 232 includes a plurality of traces (not labeled) and at least one pad (not labeled), and the traces are disposed in the trench 222 and the pad is disposed in the notch 224. The conductive blind via 234 is disposed in the blind via 226 and may be a hollow conductive column.
In detail, during the process of making the molded interconnect device, a plurality of trenches 322 and at least one notch 324 are formed on the composition 100, and the insulation material 110 of the composition 100 is a bulk. In addition, the composition 100 may be made into a sheet or a shell for electronic apparatuses such as mobile phones, laptop computers or personal digital assistants (PDAs). The method for forming the trenches 322 and the notch 324 is the same as that of forming the recessed pattern 220 as shown in
Referring to
The conductive pattern 330 is a circuit pattern, and the conductive pattern 330 includes traces (not labeled) disposed in the trenches 322 and a pad (not labeled) disposed in the notch 324. After the conductive pattern 330 is formed on the composition 100, a molded interconnect device 30 is essentially complete. Additionally, when the composition 100 is made into a sheet, the molded interconnect device 30 may be a single-side circuit board.
To sum up, a redox reaction may take place between the chemical plating solution and the catalyst particles so as to deposit the conductive pattern such as circuit patterns or conductive blind vias on the composition. The composition of the invention can be applied to make a circuit pattern and suitable for making a circuit board or a molded interconnect device.
Additionally, the conductive pattern is only formed on the area where the catalyst particles and the chemical plating solution are brought in contact, that is, where the catalyst particles are exposed. Therefore, the invention can omit the processes of lithography and etching, and fabricate a circuit pattern completely without lithography and etching based on utilizing the composition of the invention in making circuit patterns. As a result, the invention can reduce the requirements for photoresists, developing agents and etching solutions and omit photo masks during making circuit boards, thereby reducing costs in manufacturing circuit boards.
What are disclosed above are only the specification and the drawings of the best embodiments of the present invention and it is therefore not intended that the present invention be limited to the particular embodiments disclosed. It will be understood by those skilled in the art that various equivalent changes may be made depending on the specification and the drawings of the present invention without departing from the scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 098142670 | Dec 2009 | TW | national |
| 099106436 | Mar 2010 | TW | national |
