Micromachine package and method for manufacturing the same

#This application claims the priority benefit of Taiwan patent application Ser. No. 092120272, filed on Jul. 24, 2003, and the full disclosure thereof is incorporated herein by reference.

#1. Field of the Invention

#The present invention relates to a semiconductor package and a manufacturing method therefor, and more particularly, to a micromachine package with a hermetic cavity and a manufacturing method therefor.

#Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

#FIG. 1 is a schematic cross-sectional view of a micromachine package in prior art.

#FIG. 2 is a schematic cross-sectional view of another micromachine package in prior art.

#Now referring to FIG. 4, it depicts a micromachine package 100 according to an embodiment of the present invention. The micromachine package 100 comprises a micromachine chip 120 having moveable structures 122, such as micromachines or micromirrors, and a semiconductor chip 110, such as complimentary metal-oxide semiconductor (CMOS), having electrodes 112 corresponding to the moveable structures 122. The semiconductor chip 110 is fixed on the micromachine chip 120 by means of an adhesive or a spacer ring 124, and is uniformly spaced apart from the micromachine chip 120. A cavity 116 is formed between the semiconductor chip 110 and the micromachine chip 120 so that the moveable structures 122 cooperate with the electrodes 112 and freely move within the cavity 116.

#It should be noted that the moveable structures 122 and electrodes 112 are disposed on the chip 120 and the chip 110, respectively.

#The micromachine chip 120 is attached on a die pad 142 of a lead frame 140 by means of an adhesive 126. The adhesive 126 can be a conductive paste for electrically connecting the micromachine chip 120 to the die pad 142. The semiconductor package 100 is provided with a plurality of solder pads 118 disposed on the two adjacent sides thereof, which will be described hereinafter, and electrically connected to the electrodes 112. The solder pad 118 is connected to a bump 114, such as a gold bump or a solder bump. The bumps 114 are individually disposed on a plurality of leads 144 of the lead frame 140. An encapsulant 130 encapsulates the micromachine chip 120, the semiconductor chip 110, the bumps 114, and the lead frame 140. The leads 144 and the die pad 142 of the lead frame 140 respectively have lower surfaces 148 and a lower surface 146 which are exposed out of and are flush with the encapsulant 130 for being connected to an external print circuit board (not shown). Therefore, the leads 144 are referred to Quad Flat No-lead (QFN)-type leads. The lower surface 146 of the die pad 142 can also be used for grounding or dissipating heat.