Patent Application
20080078493
The present invention will become more fully understood from the detailed description given herein below illustration only, and thus is not limitative of the present invention, and wherein:
The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.
Referring to
In step S1, at least one first pre-mold plate 31 with lower sintering temperature and at least two second pre-mold plates 32 with higher sintering temperature are provided. The first pre-mold plate 31 and second pre-mold plates 32 are fabricated by mixing at least one ceramic material with an inorganic adhesive. The ceramic material is a ceramic powder, a metal oxide powder, a composite metal oxide powder or combinations thereof. The inorganic adhesive has a worse chemical activity than other materials and a sintering temperature lower than that of the ceramic material. The inorganic adhesive can be the crystallized or non-crystallized glass. In addition, the first pre-mold plate 31 or the second pre-mold plate 32 further includes a polymeric adhesive, a plasticizer or an organic solvent. In the embodiment, the polymeric adhesive can be polyethylene glycol (PEG), polyvinyl butyal (PVB) or polyvinyl alcohol (PVA). The plasticizer can be dibotylphthalate (DBP). The organic solvent can be 1-Propanol extra pure, toluene or alcohol.
The fabricating processes of the ceramic of the present invention will be illustrated hereinafter. Firstly, the ceramic material with a lower sintering temperature is mixed with an inorganic adhesive to form a slurry. Herein, glass with a lower melting point temperature can be added into the slurry to lower the sintering temperature, and the liquid phase glass will help the following sintering process to obtain a denser sintered plate. In addition, in order to prepare the slurry with proper viscosity, a polymeric adhesive, a plasticizer or an organic solvent can be added into the slurry. After that, a scraper is applied to fabricate the first pre-mold plate 31 and the second pre-mold plates 32.
In the step S2, one second pre-mold plate 32, the first pre-mold plate 31 and the other second pre-mold plate 32 are stacked up in sequence. The sizes of the first pre-mold plate 31 and the second pre-mold plates 32 are substantially the same. As shown in
Further, a step S21 can be performed after the step S2 to press the stacked first pre-mold plate 31 and second pre-mold plates 32. In the step S21, the stack of the first pre-mold plate 31 and the second pre-mold plates 32 is pressed by way of hot pressing and isostatic pressing to make the stack become denser and to prevent the pre-mold plates from warping during the subsequent sintering process.
In step S3, the stacked first pre-mold plate 31 and second pre-mold plates 32 are sintered at a temperature, which is the sintering temperature of the first pre-mold plate 31. Thus, the first pre-mold plate 31 can be sintered at this lower temperature to form the ceramic thin plate, and the second pre-mold plates 32 are not sintered yet. In the sintering process, the second pre-mold plates 32 can provide a pressure to prevent the warp of the first pre-mold plate 31. In addition, the non-sintered second pre-mold plates 32 may have several holes, which can be used for air passing from the first pre-mold plate 31 during the sintering process. Furthermore, the second pre-mold plates 32 can prevent the first pre-mold plate 31 from directly contacting with the sintering mold so as to avoid the possible pollution.
A step S31 can be performed after the step S3 to remove the second pre-mold plates 32 and then obtain the thin, planar and denser ceramic thin plate. In the embodiment, the ceramic thin plate is an LTCC substrate.
The method further includes a step S32 of testing the property of the ceramic thin plate after step S31. For example, an instrument is utilized to test the dielectric property and the quality property of the sintered ceramic thin plate, which include a dielectric constant (ε) and a quality factor (Q), so that the ceramic thin plate satisfying the specification can be obtained. To be noted, the step S32 can also be performed before the step S31 and after the step S3.
With reference to
After the step S2, the method further includes a step S21′ of pressing the stacked first, second and third pre-mold plates. In addition, after the step S3, the method may further include a step S31′ of removing the second and third pre-mold plates, and a step S32′ of testing a property of the ceramic thin plate. The implementing of the steps and the fabricating of the materials are described in the first embodiment, so the detailed descriptions will be omitted.
In addition, the second and third pre-mold plates can be different, such as having different sintering temperatures, as long as the second and third pre-mold plates both have a sintering temperature higher than that of the first pre-mold plate. Under this requirement, the second and third pre-mold plates can be disposed at both opposite surfaces of the first pre-mold plate to prevent the warp of the first pre-mold plate during the sintering process.
In summary, the fabricating method of a ceramic thin plate according to the present invention is to dispose a pre-mold plate with a lower sintering temperature, such as the first pre-mold plate, between two pre-mold plates with a higher sintering temperature, such as the second and third pre-mold plates. Then, the stacked pre-mold plates are sintered at the lower sintering temperature to make the first pre-mold plate to form a ceramic thin plate, while the second and third pre-mold plates are not sintered yet. In the present invention, the second and third pre-mold plates are used to apply stress on the opposite surfaces of the first pre-mold plate during the sintering process. Accordingly, the fabricated ceramic thin plate can be planar and without a warp and have good properties such as high density, dielectric and quality.
Although the present invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 095136192 | Sep 2006 | TW | national |
