Patent Application
20050258518
The present invention relates to a CMOS image sensor module, more particularly, an image sensor package module with a leadless leadframe between chips.
CMOS image sensor chips can be integrated with other integrated circuits in a package module to reduce the footprint of the final packages and lower the cost of packaging. A conventional multi-chip CMOS image sensor package module is revealed in R.O.C. Taiwan Pat. No. 556,965. As shown in
A main purpose of the present invention is to provide an image sensor package module with a leadless leadframe between chips. The image sensor package module includes a chip carrier, an image sensor chip, an integrated circuit chip such as DSP (digital signal processor) chip, and a flexible printed circuit board. The chip carrier comprises a leadless leadframe and a pre-molded body which completely fills among a plurality of leads of the leadless leadframe, and the pre-molded body has a dam on the upper surface of the leads. The upper surfaces and the lower surfaces of the leads have a plurality of connecting regions exposed out of the pre-molded body so that the image sensor chip and the integrated circuit chip can be electrically connected to the leadless leadframe. A lower packaging cost with highly integrated the image sensor chip with the DSP chip or other integrated circuits can be achieved.
According to the present invention, an image sensor package module with a leadless leadframe between chips includes a chip carrier, an image sensor chip, an integrated circuit chip, and a flexible printed circuit board. The chip carrier comprises a leadless leadframe and a pre-molded body. The leadless leadframe has a plurality of leads. Each lead has an upper surface and a lower surface. The pre-molded body is completely filled among the leads, and comprises a dam on the upper surfaces of the leads. The upper surfaces and the lower surfaces of the leads are exposed on the pre-molded body. The image sensor chip is attached to the leads or a chip pad of the chip carrier inside the dam, and electrically connected to the upper surface of the leads by a plurality of bonding wires. A transparent cover glass is attached to the dam of the pre-molded body to seal the image sensor chip. The integrated circuit chip has a plurality of solder bumps on its active surface for electrical connection to the lower surface of the leads of the leadless leadframe. The flexible printed circuit board is connected to the leads of the leadless leadframe for outer electrical connection.
Please refer to the drawings attached, the present invention will be described by means of an embodiment below.
According to the present invention, as shown in
The image sensor chip 120 may be a charge-coupled device, CCD or a complementary metal-oxide-semiconductor, CMOS. The image sensor chip 120 has an active surface 121 and a backside surface 122. The active surface 121 includes a sensing region 123, and a plurality of bonding pads 124 are formed at periphery of the active surface 121. The image sensor chip 120 is mounted inside the circular dam 116 of the chip carrier 110 by using a die attach material 151 bonding the backside surface 122 on the chip carrier 110. In this embodiment, the image sensor chip 120 is attached to the pre-molded body 112. The bonding pads 124 of the image sensor chip 120 electrically connect to the upper surfaces 114 of the leads 113 by a plurality of bonding wires 160. A transparent cover 170 is attached to the circular dam 116 of the pre-molded body 112 to seal the image sensor chip 120. The transparent cover 170 may be an IR-cut filter. The integrated circuit chip 130 may be a CSP (chip scale package) or a flip chip, which has a mounting surface 131 on which a plurality of solder bumps 132 or the other bumps are formed. In this embodiment, the integrated circuit chip 130 is a DSP chip (digital signal processor). The solder bumps 132 are bonded to the lower surfaces 115 (connecting regions) of the leads 113 so that the integrated circuit chip 130 can be electrically connected to the leadless leadframe 111, preferably, at least a passive component 180 is mounted on the lower surface 115 of the leads 113. The flexible printed circuit board 140 is electrically connected to the leads 113 by an anisotropic conductive paste 152 (ACP) to transmit the signal of the image sensor package module 100 to the outside world.
In the present invention, the image sensor package module 100 also comprises a lens holder 191 and a lens 192. The lens 192 is supported by the lens holder 191. The lens holder 191 is connected with the circular dam 116 of the pre-molded body 112 so that the lens 192 is aligned to the sensing region 123 of the image sensor chip 120. The image sensor chip 120 is attached on the chip carrier 110 inside the circular dam 116 of the pre-molded body 112 and electrically connected to the upper surface 114 of the leads 113. Moreover, the integrated circuit chip 130 is mounted on the lower surface 115 of the lead 113. Through the internal circuit design, the signal input of the integrated circuit chip 130 can be connected with the signal output of the image sensor chip 120 by inner-connecting lead(s) 113. Moreover, the signal outputs of the integrated circuit chip 130 are connected to the flexible printed circuit board 140 by outer-connecting lead(s) 113. Therefore, the signal of the image sensor chip 120 will transmit to integrated circuit chip 130 for digital signal processing, then transmit the processed signals to outer electrical device through the flexible printed circuit board 140. The image sensor chip 120 and integrated circuit chip 130 can be highly integrated to reduce the overall packaging cost.
Referring to
The above description of embodiments of this invention is intended to be illustrative and not limiting. Other embodiments of this invention will be obvious to those skilled in the art in view of the above disclosure.
