INSULATING COLLOIDAL MATERIAL AND MULTILAYER CIRCUIT STRUCTURE
An insulating colloidal material and a multilayer circuit structure are provided, wherein the insulating colloidal material includes a resin, trigger particles, and an organic solvent. The trigger particles are selected from any one of the group consisting of organometallic particles and ionic compounds. The ratio of the trigger particles to the insulating colloidal material is between 0.1 wt % and 10 wt %. At least one insulating colloidal layer in the multilayer circuit structure contains the trigger particles.
This application claims the priority benefit of Taiwan application no. 104135497, filed on Oct. 28, 2015. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
TECHNICAL FIELDThe disclosure is related to an insulating colloidal material and a multilayer circuit structure for a printed circuit board.
BACKGROUNDTo meet the market demand for a light, thin, and multi-functional electronic information product, techniques such as high-density interconnect (HDI) and high-layer count (HLC) have gradually been developed in the electronic packaging techniques of a printed circuit board (PCB), such that the electronic circuit density distributed inside the PCB is higher, but the volume is smaller, thus meeting the demand for a lighter and thinner device. A smaller PCB can result in more structural space in the end product design, and more functional components can be added to achieve the design concept of multiple functions on one device.
In particular, the definition of HDI includes a circuit board for which the thickness of a copper metal conductive layer is ≦25 μm, the thickness of an insulating layer is <75 μm, a linewidth of ≦20 μm, a line spacing of ≦20 μm, and an aperture of ≦100 μm. However, the current manufacturing method of an electronic circuit includes foil ling a copper foil layer by combining sputtering and a method of electroplating or a method of lamination of copper foil on a substrate, and then forming a circuit layer via a method of patterning. Then, the above steps of circuit layer manufacture are repeated to complete a high-density multilayer circuit board.
Electrical connection between the multilayer circuit boards is achieved via vias, and the manufacturing method of the vias can be conceptually divided into the electroplating method and the lamination method. The former includes complicated via process and has higher costs; and the latter cannot achieve thinning and miniaturization since the resulting circuit layer has thicker size and greater linewidth.
SUMMARYOne of the present embodiments comprises an insulating colloidal material. The insulating colloidal material includes a resin, trigger particles, and an organic solvent. The trigger particles are selected from any one of the group consisting of organometallic particles and ionic compounds, wherein the ratio of the trigger particles to the insulating colloidal material is between 0.1 wt % and 10 wt %, and the organometallic particles includes R-M-R′ or R-M-X, wherein R and R′ are each independently an alkyl group, aromatic hydrocarbon, cycloalkyl, haloalkane, a heterocyclic ring, or carboxylic acid, and the carbon number of at least one of R and R′ is 3 or more; M is selected from one of the group consisting of silver, palladium, copper, gold, tin, and iron, or a combination thereof; and X is a halogen compound or an amine. The ionic compounds include CuCl2, Cu(NO3)2, CuSO4, Cu(OAc)2, AgCl, AgNO3, Ag2SO4, Ag(OAc), Pd(OAc), PdCl2, Pd(NO3)2, PdSO4, Pd(OAc)2, FeCl2, Fe(NO3)2, FeSO4, or [Fe3O(OAc)6(H2O)3]OAc.
Another of the present embodiments comprises a multilayer circuit structure. The multilayer circuit structure includes a substrate, a first circuit layer located on the substrate, an insulating colloidal layer covering the substrate and the first circuit layer, a via exposing the first circuit layer, and a conductive layer formed in the via. In particular, the via is disposed in the insulating colloidal layer, the insulating colloidal layer includes trigger particles therein, and the trigger particles are selected from any one of the group consisting of organometallic particles and ionic compounds, wherein the ratio of the trigger particles to the insulating colloidal layer is between 0.1 wt % and 10 wt %, and the organometallic particles includes R-M-R′ or R-M-X, wherein R and R′ are each independently an alkyl group, aromatic hydrocarbon, cycloalkyl, haloalkane, a heterocyclic ring, or carboxylic acid, and the carbon number of at least one of R and R′ is 3 or more; M is selected from one of the group consisting of silver, palladium, copper, gold, tin, and iron, or a combination thereof; and X is a halogen compound or an amine. The ionic compounds include CuCl2, Cu(NO3)2, CuSO4, Cu(OAc)2, AgCl, AgNO3, Ag2SO4, Ag(OAc), Pd(OAc), PdCl2, Pd(NO3)2, PdSO4, Pd(OAc)2, FeCl2, Fe(NO3)2,
FeSO4, or [Fe3O(OAc)6(H2O)3]OAc.
In order to make the aforementioned features of the disclosure more comprehensible, embodiments accompanied with figures are described in detail below.
The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.
In the following, the embodiments of the disclosure are described in detail. These descriptions are intended to explain the structure or the step process of the disclosure, and are not intended to limit the disclosure, and therefore the disclosure is not limited thereto.
In an embodiment of the disclosure, an insulating colloidal material contains a resin, trigger particles, and an organic solvent.
The resin is, for instance, an epoxy resin, polyphenylene oxide (PPO), bismaleimide triazine (BT), a cyclo olefin copolymer (COC), polyimide (PI), or a liquid crystal polymer (LCP).
The trigger particles are selected from any one of the group consisting of organometallic particles and ionic compounds. The organometallic particles includes R-M-R′ or R-M-X, wherein R and R′ are each independently an alkyl group, aromatic hydrocarbon, cycloalkyl, haloalkane, a heterocyclic ring, or carboxylic acid. The carbon number of at least one of R and R′ is 3 or more. The more the carbon number, the greater the solubility with the organic solvent, and thus it is easier to dissolve in the polymer colloid (i.e. the resin and the organic solvent). However, if the carbon number is insufficient, the trigger particles are only miscible with a high-polar solvent and not easy to dissolve in the polymer colloid. M is selected from one of the group consisting of silver, palladium, copper, gold, tin, and iron, or a combination thereof. X is a halogen compound or an amine. The ionic compounds include CuCl2, Cu(NO3)2, CuSO4, Cu(OAc)2, AgCl, AgNO3, Ag2SO4, Ag(OAc), Pd(OAc), PdCl2, Pd(NO3)2, PdSO4, Pd(OAc)2, FeCl2, Fe(NO3)2, FeSO4, or [Fe3O(OAc)6(H2O)3]OAc. The organometallic particles and the ionic compounds can be used alone or in a combination of two or more.
The organic solvent may be a low-polar organic solvent, in particular an organic solvent miscible with the trigger particles and the resin, such as methanol, acetone, toluene, methyl ethyl ketone, dipropylene glycol methyl ether (DPM), or propylene glycol monomethyl ether acetate. For instance, the solubility of the trigger particles in the organic solvent is greater than 0.1 wt %. Since the trigger particles are completely miscible with the organic solvent, and are therefore completely miscible with the resin, the ratio of the trigger particles to the insulating colloidal material is 10 wt % or less, thus facilitating the use of the insulating colloidal material in a high-frequency circuit board system.
Moreover, the viscosity coefficient of the insulating colloidal material is, for example, between 10,000 and 200,000, therefore facilitating the use of the insulating colloidal material in the coating process of a general multilayer circuit.
Moreover, when the insulating colloidal material is to be in contact with a chip and a device, and the contact area is large, the coefficient of thermal expansion between different materials can be reduced and the modulus of rigidity thereof can be increased by adding particles of silicon dioxide, aluminum oxide, or aluminum nitride to prevent peeling or warping of the resulting film layer.
Moreover, in the insulating colloidal material, other components such as an absorbent, a colorant, or a fiber material can also be added. The absorbent is, for instance, methylbenzene dithiol or pyridine containing Co, Ni, or Fe for increasing the reaction of the resin in the insulating colloidal material and a laser light, whereby reducing the laser wattage needed for the vaporization of the insulating colloidal material by the laser. The colorant, for example, is a general dye, such as an inorganic colorant or an organic colorant. The inorganic colorant is, for instance, carbon black or titanium dioxide; and the organic colorant is, for instance, an azo pigment (—N═N—), copper phthalocyanine blue (C32H16N8Cu), or phthalocyanine green (C32HCl 15N8Cu). The fiber material can be, for instance, glass fiber or carbon fiber for improving the mechanical strength of the molded product of the insulating colloidal material.
In an embodiment, the additive amount of the absorbent is, for instance, 0.1 wt % to 10 wt % of the total amount of the insulating colloidal material, and the additive amount of the colorant is, for instance, 1 wt % to 45 wt % of the total amount of the insulating colloidal material.
Referring to
When the via 112 and the trench 114 are formed in the insulating colloidal layer 106 via laser processing, the trigger particles around the via 112 and the trench 114 are activated, and the conductive layer 108 and the second circuit layer 110 can be formed directly by, for instance, a method of non-electroplating process according to the exposed and activated trigger particles, and therefore a complicated process such as sputtering is not needed. In the present embodiment, the material of the conductive layer 108 and/or the second circuit layer 110 is, for instance, copper, nickel, or silver.
In the following, the manufacturing process of the multilayer circuit structure of
First, a substrate 200 (as shown in
Then, a first circuit layer 202 (as shown in
Then, an insulating colloidal layer 204 (as shown in
Then, a plurality of vias 206 and a plurality of trenches 208 are formed in the insulating colloidal layer 204 through laser (as shown in
Then, a metal material is deposited on the walls of the vias 206 and the trenches 208 via the activated trigger particles 207 in
Moreover, the second circuit layer 110 in
Experimental examples are described below to verify the efficacy of the disclosure. However, the disclosure is not limited to the following content.
EXPERIMENTAL EXAMPLE 1First, an insulating colloidal material was prepared. In detail, 0.5 wt % of CuCl2 was dissolved in methanol, and then the mixture was uniformly mixed with 50 wt % of an epoxy resin, wherein 1 wt % of a colorant (carbon black) was further added. Then, referring to
Then, the second insulating colloidal layer 406 was directly patterned by using argon gas laser having a wavelength of 1064 nm as the laser source, such that a via 408 was formed and the trigger particles inside the second insulating colloidal layer 406 were exposed. Thereafter, a non-electroplating copper process was performed red via the exposed trigger particles to complete the manufacture of a conductive layer 410. The thickness of the resulting conductive layer 410 is about 10 μm. The second circuit layer 410 in
Other than respectively using 1 wt %, 3 wt %, 10 wt %, and 13 wt % of CuCl2 as the trigger particles, insulating colloidal materials were prepared and multilayer circuit structures were made according to the steps of experimental example 1.
COMPARATIVE EXAMPLE 1Other than using 20 wt % of CuCl2, an insulating colloidal material was prepared and a multilayer circuit structure was made according to the steps of experimental example 1.
COMPARATIVE EXAMPLE 2Except for the absent of CuCl2, an insulating colloidal material was prepared and a multilayer circuit structure was made according to the steps of experimental example 1.
The testing shows that the resistances of both the first circuit layer 404 and the conductive layer 410 of experimental example 1 are 1.5 Ω or less.
Moreover, the dielectric constant Dk and the dielectric loss Df of the second insulating colloidal layers of experimental examples 1 to 5 and comparative examples 1 to 2 were tested, and the results are shown in Table 1 below.
It can be known from Table 1 that, since the amount of the trigger particles (CuCl2) in experimental examples 1 to 5 is small, the dielectric constant Dk and the dielectric loss Df of the second insulating colloidal layer formed after curing still retain the original characteristics of the insulating material, and Dk and Df are not significantly increased. However, once the amount of the trigger particles exceeds the scope of the disclosure, Dk and Df of the insulating colloidal layer are significantly increased.
Referring to
In
Based on the above, the insulating colloidal material of the disclosure includes a resin, trigger particles, and an organic solvent. After the organic solvent is removed by curing the insulating colloidal material, drilling is performed via laser, and since the exposed trigger particles are suitable for a subsequent non-electroplating copper deposition process of copper after the resin is removed by the high temperature of the laser, in the disclosure, a multilayer circuit structure having fine conductive wires and small vias can be formed via a simple process, so as to meet the market demand for a lighter and thinner device. Moreover, the insulating colloidal layer of the multilayer circuit structure of the disclosure contains 0.1 wt % to 10 wt % of the trigger particles therein, such that the dielectric constant Dk and the dielectric loss Df of the insulating colloidal layer still retain the original characteristics of the insulating material. As a result, during the manufacture of circuits, the circuits can be the insulating layers in the multiple layers of circuit at the same time. Moreover, by using laser drilling and a non-electroplating copper process, fine conductive wires and small vias can be formed. Therefore, the insulating colloidal layer above can be used as a dielectric layer and used as a base layer for forming a conductive layer at the same time. More specifically, the volume of the multilayer circuit structure can be significantly reduced, thus meeting the market demand for a lighter and thinner device.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims and their equivalents.
Claims
1. An insulating colloidal material, comprising:
- a resin;
- trigger particles selected from one of the group consisting of organometallic particles and ionic compounds, wherein a ratio of the trigger particles to the insulating colloidal material is between 0.1 wt % and 10 wt %, and
- an organic solvent, wherein the organometallic particles comprise R-M-R′ or R-M-X, wherein R and R′ are each independently an alkyl group, aromatic hydrocarbon, cycloalkyl, haloalkane, a heterocyclic ring, or carboxylic acid, and a carbon number of at least one of R and R′ is 3 or more; M is one selected from the group consisting of silver, palladium, copper, gold, tin, and iron, or a combination thereof; and X is a halogen compound or an amine;
- the ionic compound comprises CuCl2, Cu(NO3)2, CuSO4, Cu(OAc)2, AgCl, AgNO3, Ag2SO4, Ag(OAc), Pd(OAc), PdCl2, Pd(NO3)2, PdSO4, Pd(OAc)2, FeCl2, Fe(NO3)2, FeSO4, or [Fe3O(OAc)6(H2O)3]OAc.
2. The insulating colloidal material of claim 1, wherein the resin comprises polyphenylene oxide (PPO), bismaleimide triazine (BT), a cyclo olefin copolymer (COC), a liquid crystal polymer (LCP), polyimide (PI), or an epoxy resin.
3. The insulating colloidal material of claim 1, wherein a solubility of the trigger particles in the organic solvent is greater than 0.1 wt %.
4. The insulating colloidal material of claim 1, further comprising an absorbent or a colorant.
5. The insulating colloidal material of claim 4, wherein the colorant comprises carbon black, titanium dioxide, or an organic colorant.
6. The insulating colloidal material of claim 1, further comprising a fiber structure.
7. The insulating colloidal material of claim 1, further comprising particles of silicon dioxide, aluminum oxide, or aluminum nitride.
8. The insulating colloidal material of claim 1, wherein the organic solvent comprises methanol, acetone, toluene, methyl ethyl ketone, dipropylene glycol methyl ether, or propylene glycol monomethyl ether acetate.
9. The insulating colloidal material of claim 1, wherein a ratio of the trigger particles to the insulating colloidal material is between 0.5 wt % and 10 wt %.
10. The insulating colloidal material of claim 1, wherein a viscosity coefficient of the insulating colloidal material is between 10,000 and 200,000.
11. A multilayer circuit structure, comprising:
- a substrate;
- a first circuit layer located on the substrate;
- an insulating colloidal layer covering the substrate and the first circuit layer, wherein the insulating colloidal layer comprises a via, and the via exposes the first circuit layer; and
- a conductive layer formed in the via,
- wherein the insulating colloidal layer comprises trigger particles therein, and the trigger particles are selected from one of the group consisting of organometallic particles and ionic compounds, wherein a ratio of the trigger particles to the insulating colloidal layer is between 0.1 wt % and 10 wt %, and the organometallic particles comprises R-M-R′ or R-M-X, wherein R and R′ are each independently an alkyl group, aromatic hydrocarbon, cycloalkyl, haloalkane, a heterocyclic ring, or carboxylic acid, and a carbon number of at least one of R and R′ is 3 or more; M is one selected from the group consisting of silver, palladium, copper, gold, tin, and iron, or a combination thereof; and X is a halogen compound or an amine; the ionic compounds comprise CuCl2, Cu(NO3)2, CuSO4, Cu(OAc)2, AgCl, AgNO3, Ag2SO4, Ag(OAc), Pd(OAc), PdCl2, Pd(NO3)2, PdSO4, Pd(OAc)2, FeCl2, Fe(NO3)2, FeSO4, or [Fe30(OAc)6(H2O)3]OAc.
12. The multilayer circuit structure of claim 11, wherein the substrate comprises glass, sapphire, silicon, silicon germanium, silicon carbide, gallium nitride, or a polymer material.
13. The multilayer circuit structure of claim 11, wherein a material of the insulating colloidal layer comprises polyphenylene oxide (PPO), bismaleimide triazine (BT), a cyclo olefin copolymer (COC), a liquid crystal polymer (LCP), polyimide (PI), or an epoxy resin.
14. The multilayer circuit structure of claim 11, wherein a material of the conductive layer comprises copper, nickel, or silver.
15. The multilayer circuit structure of claim 11, wherein the insulating colloidal layer further comprises a trench formed on the via.
16. The multilayer circuit structure of claim 15, further comprising a second circuit layer formed in the trench on the conductive layer.
17. The multilayer circuit structure of claim 16, wherein the second circuit layer further extends from within the trench to a surface of the insulating colloidal layer.
18. The multilayer circuit structure of claim 16, wherein the first circuit layer, the conductive layer, and the second circuit layer form an inductor.
19. The multilayer circuit structure of claim 16, wherein the first circuit layer, the insulating colloidal layer, and the second circuit layer form a capacitor.
20. The multilayer circuit structure of claim 16, further comprising: a dielectric layer formed on the second circuit layer; and a third circuit layer formed on the dielectric layer, wherein the second circuit layer, the dielectric layer, and the third circuit layer form a capacitor.
21. The multilayer circuit structure of claim 11, wherein the insulating colloidal layer further comprises an absorbent or a colorant.
22. The multilayer circuit structure of claim 21, wherein the colorant comprises carbon black, titanium dioxide, or an organic colorant.
23. The multilayer circuit structure of claim 11, wherein the insulating colloidal layer further comprises a fiber structure.
24. The multilayer circuit structure of claim 11, wherein the insulating colloidal layer further comprises particles of silicon dioxide, aluminum oxide, or aluminum nitride.
25. The multilayer circuit structure of claim 11, wherein a ratio of the trigger particles to the insulating colloidal material is between 0.5 wt % and 10 wt %.
Type: Application
Filed: Dec 17, 2015
Publication Date: May 4, 2017
Inventors: Meng-Chi Huang (Taoyuan City), Tune-Hune Kao (Hsinchu City)
Application Number: 14/972,112