MULTI-LAYER SUBSTRATE STRUCTURE USING DOUBLE MATERIALS

PURPOSE: A multi-layer board and junction method thereof is provided to increase package density and reduce permittivity loss by using junction material having a low permittivity. CONSTITUTION: An FR-4 film(100) is prepared. A prepreg film(200), a Teflon film(300), a bonding film(400) and a ceramic film(500) are stacked on the FR-4 film(100) in sequence. The RF-4 film(100) and the Teflon film(300) are bonded by the prepreg film(200) composed of bonding material. The Teflon film(300) and the ceramic film(500) are bonded by the bonding film(400) composed of bonding material. Each films(100,300,500) is coated in both sides with copper foils. Preferably, the prepreg film(200) has a permittivity of about 3.2 to 7.7 F/m, and is used in the frequency range of about 1 to 20 GHz. Preferably, the bonding film(400) has a thickness of about 35 to 70 mic and a permittivity of about 2.1 to 3.7 F/m, and is used in the frequency range of about 1 to 20 GHz.