Low-temperature-cofired-ceramic (LTCC) tape structures including cofired ferromagnetic elements, drop-in components and multi-layer transformer
US5312674A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 1992 |
| Grant date | May 17, 1994 |
| Priority date | — |
| Expiry date | Jul 31, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24926
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A ferromagnetic material (18,20) in ink or tape form is sinterable using a same firing profile as and has approximately the same thermal shrinkage characteristics as low-temperature-cofired-ceramic (LTCC) tape, and is chemically non-reactive therewith. The ferromagnetic material (18,20) is applied to the surfaces of LTCC tape sheets (12,14,16) to form desired elements such as cores for inductors (22) and transformers and magnetic shields. Ferromagnetic vertical interconnects (vias) (54) can be formed by punching holes (56) through tape sheets (46) and filling them with ferromagnetic ink. The tape sheets (12,14,16) and ferromagnetic elements (18,20) are laminated together and cofired to form an integral structure (10). Ferromagnetic and non-magnetic components (114) can be fabricated separately and inserted into cavities (104a, 106a,108a) in tape sheets (104,106,108) prior to cofiring. A multi-layer transformer (250) includes primary (254b, 256b,258b,254d,256d,258d) and secondary (254c,256c,258c) coils, each being formed of vertically aligned, arcuate conductors which are printed on separate tape sheets (254,256,258) and vertically interconnected at their ends to form continuous ele…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.