TWI236768B - Low noise multi chip image sensor package - Google Patents

Abstract

A low noise multi chip image sensor package includes a transplant substrate, an image sensor chip, a semiconductor chip and an electrically shielding layer. The image sensor chip has a sensing surface and a back surface. A plurality of bumps are formed on the periphery of the sensing surface. The bumps connect traces of the transplant substrate. The semiconductor chip has an active surface and a passive surface. A plurality of bond pads are formed on the active surface. The passive surface of the semiconductor chip disposes the back surface of the image sensor chip. The electrically shielding layer is disposed between the image sensor chip and the semiconductor chip to reduce cross-talk between the semiconductor chip and the image sensor chip.

Description

1236768 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to a multi-chip image sensor structure, and particularly relates to a low-noise multi-chip image sensor structure. [Previous technology] With the development of technology, more and more personalized hand-held electronic products, such as mobile phones and personal digital assistants (PDAs), will integrate image sensors with original functions to enhance their functions. Function, image sensor (丨 mage sensor) is a semiconductor element that converts optical image signals into electronic signals for display or storage. When electronic products are in use, the image sensor may be subject to some unwanted Interference of extra energy. This extra energy is the interference of δoδ (η oise) 'mis§fl, which usually causes signal distortion, and its sources include the outside of the system and the system itself. In order to integrate multiple chips into an image sensor structure, a conventional image sensor structure is disclosed in China Patent Publication No. 556965 “Image Sensor Stacking Device”. Please refer to FIG. 1 for the image. The sensor system includes a transparent glass 10, an image sensing chip 20, a substrate 30, and an integrated circuit 40. The transparent glass 10 is provided with a plurality of signal output terminals and a signal input terminal. 12, the image sensing chip 20 is electrically connected to the signal input terminal 12 of the transparent glass 10, and the substrate 30 has a first surface 31 and a second surface 3 =, the transparent glass 10 The signal output terminal is electrically connected to the first surface 31 of the substrate 30, and the integrated circuit 40 is electrically connected to the second surface 3_2 of the substrate 30. The image sensor 20 and the integrated circuit The circuit 40 is electrically connected to a printed circuit board 50 by using the jt surface 32 of the substrate 30. However, there is no shieldable element between the image sensor and the integrated circuit 40. When the integrated circuit 40

Page 7 1236768 V. Description of the invention (2) The frequency generated by the circuit 40 during operation, especially at high frequencies, will affect the operation of the image sensor 20 to capture images or convert optical image signals into electronic signals. [Summary of the Invention] The main object of the present invention is to provide a low-noise multi-chip image sensor structure, which is provided between an image sensing chip and a semiconductor wafer using an electrical shielding layer to form a shielding effect. (Shielding ef fectiveness), reduce noise, so that the frequency generated during the operation of the semiconductor chip will not affect the operation of the image sensing chip to capture images or convert optical image signals into electronic signals. The low-noise multi-chip image sensor structure according to the present invention mainly includes a light-transmitting substrate, an image-sensing chip, a semiconductor wafer, and an electrical shielding layer. The light-transmitting substrate has a joint surface, A plurality of conductive lines are formed on the joint surface, the image sensing chip has a sensing surface and a back surface, the sensing surface has a sensing area, and a plurality of bumps are formed around the sensing surface. The bumps are connected to the conductive lines. The semiconductor wafer has an active surface and a non-active surface. The active surface is formed with a plurality of welding pads. The pads are electrically connected to the conductive lines. The non-active surface of the semiconductor wafer is disposed on the back of the image sensing wafer, and the electrical shielding layer is not located between the image sensing wafer and the semiconductor wafer to reduce the string between the semiconductor wafer and the image sensing wafer. Tone (cr〇ss_talk). [Embodiment] With reference to the drawings, the present invention will be described by the following embodiments. According to a first embodiment of the present invention, please refer to FIG.

1236768 V. Description of the invention (3) Miscellaneous §fl Multi-chip image sensor 1000 structure, which mainly includes a light-transmitting substrate 1 1 0, an image-sensing chip 1 2 0, and a semiconductor wafer 1 3 0 and an electrical shielding layer 1 40, the transparent substrate 1 10 may be a glass sheet having a bonding surface 111, and a plurality of conductive lines 112 are formed on the bonding surface 111, and the conductive lines 112 The outer side is connected with a plurality of solder balls 150, and the far-image sensing chip 120 is a first sensing chip (〇ptica 1 sensing chip), a charge coupled device (CCD), and a complementary type A metal oxide semiconductor (complementary metal oxide serai conductor, CMOS) or a photodiode. The image sensing chip 1 20 has a sensing surface 1 2 1 and a back surface 1 2 2. The sensing surface 1 2 Series 1 has a sensing area 1 2 3, and a plurality of bumps 1 24 are formed around the sensing surface 12 1 without affecting the sensing area 1 23. The image is captured, and these bumps 1 2 4 are connected The conductive circuit 112 of the transparent substrate 110 is covered with a sealant 160; the sealant 160 It surrounds the sensing area 123 and does not cover the sensing area 1 23, so that a closed space is formed between the sensing area 1 23 and the transparent substrate 110. The semiconductor wafer 1 30 is selected from a radio frequency ( One of Radio Frequency (RF) chip and Application Specific Integrated Circuit chip, the semiconductor chip 130 has an active surface 131 and a non-active surface 132, and the active surface 131 is formed with a plurality of The bonding pads 133 are connected with the bonding pads 133 and the transparent substrate 110 through the conductive lines 112 by a plurality of bonding wires 170, so that the bonding pads 133 are electrically connected with the conductive lines 112, and according to the conductive Circuit 11 2. The image sensing chip 120 and the design of the semiconductor chip 130. The pads 133 can be simultaneously connected to the bumps 124 and the

Page 9 1236768 V. Description of the invention (4) The solder balls 150 are electrically connected, or are only electrically connected to the solder balls 150 and not electrically connected to the bumps 1 24, or only connected to the bumps. The block 124 is electrically connected without being electrically connected to the fresh balls 150 ′, and the non-active surface 1 3 1 of the semiconductor chip 130 is disposed on the back surface 1 2 2 of the image sensing chip 1 2 0. The electrical shielding layer 140 is disposed between the image sensing chip 120 and the semiconductor wafer 130. The electrical shielding layer 140 may be a metal plate or a metal cover. In this implementation, For example, the electrical shielding layer 140 is a metal cover, which has a flat portion 1 41 and a plurality of bent extension portions 1 42. The flat portion 141 is attached with a first adhesive layer 181. On the back surface 122 of the image detection insect sheet 120, and the extensions 142 are attached to the side of the image sensing chip 120, the semiconductor chip 130 is provided with a second adhesive layer; [8 2 is attached to the other side of the flat portion 1 41. In addition, a piece of colloid 1 90 covers the image sensing wafer 120, the semiconductor wafer 130, the electrical shielding layer 140, and The bonding wires 1 7 0. The low-noise multi-chip image sensor 100 uses the electrical shielding layer 1 40 to be disposed between the image sensing chip 120 and the semiconductor chip i 30 to form a shielding effectiveness and reduce shielding effectiveness. Noise, reducing cross-talk between the semiconductor chip 130 and the image sensing chip i20, so that the frequency generated during the operation of the semiconductor chip 130 will not affect the acquisition of the image sensing chip 120 The operation of converting images or optical image signals into electronic signals. According to a second specific embodiment of the present invention, please refer to FIG. 3, a structure of a low-noise multi-chip image sensor 2000, which mainly includes a light-transmitting substrate 210, an image-sensing chip 220, a Semiconductor wafer 2 30 and a power

Page 10 1236768 V. Description of the invention (5) ---

The transparent substrate 240 may be a glass sheet. A plurality of conductive lines 211 are formed on the transparent substrate 210. A plurality of solder balls 250 are connected to the outer side of the conductive lines 211. The image sensing chip 22 has a sensing surface 221 and a back surface 222. The sensing surface 221 has a sensing area 223. A plurality of bumps 2 24 are formed around the sensing surface 221 without affecting the sensing surface 221. The sensing area 1 2 3 takes images, the bumps 2 2 4 are connected to the conductive circuit 212 of the transparent substrate 210, and the semiconductor chip 230 is selected from a radio frequency (RF) chip and special applications One of the application specific integrated circuit chips, 'The semiconductor wafer 230 has an active surface 231 and a non-active surface 2 3 2' The active surface 2 31 is formed with a plurality of fresh 塾 2 3 3, A plurality of bonding wires 260 are used to connect the bonding pads 233 and the conductive lines 212 of the transparent substrate 210 so that the bonding pads 233 are electrically connected to the conductive lines 212. The non-active surface 231 of the semiconductor wafer 230 is Corresponding to the back surface 22 2 of the image sensing chip 220, and An adhesive layer 270 is attached to the electrical shielding layer 240. The electrical shielding layer 240 is disposed between the image sensing wafer 220 and the semiconductor wafer 230. In this embodiment, the electrical shielding layer 240 is a metal layer formed by a sputtering method and includes Gold (Au) is first formed on the back surface 222 of the image sensing chip 220, or the non-active surface 231 of the semiconductor wafer 230, or a preform (preform). After the semiconductor wafer 230 and the image sensing wafer 220 are combined, the electrical shielding layer 240 may include silicon (Si) to become an eutectic bonding layer. In addition, a piece of colloid 280 covers the image sensing chip 220, the semiconductor wafer 230, and the

Page 11 1236768 V. Description of the invention (6) Fresh line 2 6 0. The protection scope of the present invention shall be determined by the scope of the appended patent application. Any changes and modifications made by those skilled in the art without departing from the spirit and scope of the present invention shall fall within the protection scope of the present invention. .

1236768 on page 12 [Simplified illustration on the drawing] Fig. 1: Schematic cross-sectional view of the Republic of China Patent Publication No. 55 6965 "Image Sensor Stacking Device"; Fig. 2: First implementation of the present invention For example, a schematic cross-sectional view of a low-noise multi-chip image sensor structure; and FIG. 3: a cross-sectional schematic view of a low-noise multi-chip image sensor structure according to a second specific embodiment of the present invention. Simple explanation of component symbols 10 Transparent glass 11 Signal output terminal 12 Signal input terminal 20 Image sensing chip 30 Substrate 31 First surface 32 Second surface 40 Integrated circuit 50 Printed circuit board 100 Multi-chip image sensor 110 Transmissive substrate 111 bonding surface 112 conductive line 120 image sensing chip 121 sensing surface 122 back surface 123 sensing area 124 bump 130 semiconductor wafer 131 active surface 132 non-active surface 133 solder pad 140 electrical shielding layer 141 flat portion 142 extending portion 150 160 170 Fresh Ball Sealant Fresh Line

Page 13 1236768 Brief description of the drawings 181 Section—adhesive layer 182 second adhesive layer 190 sealing compound 200 multi-chip image sensor 210 transparent substrate 211 conductive circuit 220 image sensor chip 221 sensing surface 222 back surface 223 sensor Measurement area 224 Bump 230 Semiconductor wafer 231 Active surface 232 Non-active surface

2 3 3 Rod 塾 240 Electrical shielding layer 2 5 0 Solder ball 2 6 0 Welding wire 270 Adhesive layer 280 Sealant

Page 14

Claims (1)

1236768 [Scope of patent application] 1. A low-noise multi-chip image sensor structure, including a transparent substrate 'which is formed with a plurality of conductive lines; a scene > image sensing chip' which has a sense A measuring surface and a back surface, the measuring surface has a sensing area, and a plurality of bumps are formed around the sensing surface g = the bumps are connected to the conductive lines; a semiconductor wafer has an active surface And an inactive surface, the active surface is formed with a plurality of pads, the pads are electrically connected to the conductive lines, and the inactive surface of the semiconductor chip is disposed on the back surface of the image sensing chip; and. An electrically shielding layer is disposed between the image sensing chip and the semiconductor wafer. 2. The low-noise multi-chip image sensor structure described in item 丨 of the patent application scope, wherein the electrical shielding layer is a metal cover having a flat portion and a plurality of bent extensions The flat portion is attached to the back surface of the image sensing chip, and the extended portions are attached to a side surface of the image sensing chip. 3. The low-noise multi-chip image sensor structure described in item 1 of the patent application scope, wherein the electrical shielding layer is a metal layer, which is formed on the back surface of the image sensing chip. 4. The low-noise multi-chip image sensing Is structure described in item 3 of the scope of the patent application, wherein the metal layer is formed on the back surface of the image sensing wafer by a sputtering method. 1236768 6. Scope of patent application-structure, wherein the electrical shielding layer is a pre-shaped sheet metal plate. 6. The low-noise multi-chip image sensor structure as described in item j of the scope of the patent application, wherein the semiconductor chip is selected from the group consisting of a Radio Frequency (RF) chip and a special application integrated circuit (Appi icati On Specific Integrated Circuit) chip. 7. The low-noise multi-chip image sensor structure described in item 丨 of the declared patent scope further includes a sealant that covers the bumps. 8. The low-noise multi-chip image sensor structure m, as described in item 丨 of the patent application scope, includes a plurality of bonding wires, which are connected to the pads of the semiconductor wafer and the conductive lines. Second plug: Application: The low-noise multi-chip image sensing structure described in item 8 of the patent scope, which further includes a colloid, which covers the bonding wires. 3 ΜΪ1Ϊ, the low-noise multi-chip image sensing as described in Item 1 It: Dao several solder balls, which are provided on the transparent substrate and connected to the conductive lines. ^ Structure: Application: The low-noise multi-chip image sensing device described in item 1 of f 3 t is a structure, in which the electrical shielding layer contains 12. For example, the jth scope of the patent application: Head I The low-noise multi-chip image sensing of Shenggan Afu 1 or 11 is structured as: ^, where the electrical shielding layer 13, as in the scope of patent application ^ 3 Aikawa " ¥ Μ # ， i ϋ Z The low-noise multi-chip image sensing as described in the above item, wherein the electrical shielding layer is _… bonding layer) 〇 16 page 16