TWI675795B - Electronic element and manufacturing method thereof - Google Patents

Abstract

An electronic component includes a MEMS wafer; a substrate connected to the MEMS wafer; a cover wafer disposed on the MEMS wafer; and a bond pad formed on the MEMS wafer The MEMS wafer is connected to the substrate.

Description

Electronic component and manufacturing method thereof

The present invention relates to an electronic component and a method for manufacturing the same, and more particularly, to an electronic component that increases the shrinkability of a micro-electromechanical system component and a method for manufacturing the same.

As shown in FIG. 1, the existing micro-electro-mechanical system (MEMS) device 10 is mainly composed of a MEMS wafer 102 and a complementary metal-oxide semiconductor (CMOS) crystal. Circle 104 and a cap wafer 106. The complementary metal-oxide-semiconductor wafer 104 can be provided with an element structure 110. The element structure 110, the MEMS wafer 102, and the cover wafer 106 together form a micro-electromechanical system element 10. Among them, a bond pad 108 is disposed on the complementary metal oxide semiconductor wafer 104 for subsequent packaging processes for wire connection, thereby forming a signal transmission path between the MEMS element 10 and the outside.

In the packaging process, limited by the wire bonding process, a safety distance D1 (about 140 to 160 microns) must be maintained between the cover wafer 106 and the bonding pad 108 of the MEMS element 10 in a lateral direction X. In order to avoid hitting the MEMS element 10 when a solder pin having a pyramidal structure is displaced in a longitudinal direction Y during the wire bonding process, thereby affecting the production yield. However, in order to prevent the MEMS element 10 from being damaged by the impact of the solder pin during the wire bonding process, the wafer 106 and the bonding pad 108 are covered. However, the safety distance D1 between them limits the size of the MEMS element 10, which leads to an increase in the difficulty of scaling the MEMS element 10, and increases the production cost.

Therefore, how to effectively reduce the safety distance between the bonding pad 108 and the cover wafer 106 to increase the shrinkability of the MEMS device and effectively reduce the production cost has become an issue that the industry is eager to discuss.

In order to solve the above problems, the present invention provides an electronic component and a manufacturing method thereof.

An embodiment of the present invention discloses an electronic component including a MEMS wafer; a substrate connected to the MEMS wafer; a cap wafer (Cap Wafer) disposed on the MEMS wafer; and A bond pad is formed on the MEMS wafer and connected to the substrate.

Another embodiment of the present invention discloses a method for manufacturing an electronic component, wherein the electronic component includes a MEMS wafer, a substrate, a cover wafer, and a bonding pad. The manufacturing method includes a wafer bonding process. Connecting the MEMS wafer and the substrate; forming the bonding pad on the MEMS wafer; and setting the cover wafer on the MEMS wafer.

10, 20‧‧‧ electronic components

102, 202‧‧‧ MEMS wafers

104, 204‧‧‧ substrate

106, 206‧‧‧ covered wafers

108, 208‧‧‧Joint pads

110, 210‧‧‧ Element Structure

30‧‧‧Manufacturing Process

302, 304, 306, 308, 310‧‧‧ steps

D1, D2‧‧‧Safety distance

H1‧‧‧First height

H2‧‧‧Second Height

HD‧‧‧ height difference

X‧‧‧Horizontal direction

Y‧‧‧longitudinal direction

FIG. 1 is a schematic cross-sectional view of a conventional MEMS component.

FIG. 2 is a schematic cross-sectional view of an electronic component according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of a manufacturing process according to an embodiment of the present invention.

Please refer to FIG. 2, which is a schematic cross-sectional view of an electronic component 20 according to an embodiment of the present invention. The electronic component 20 includes a micro-electro-mechanical system (MEMS) wafer 202, a substrate 204, a cap wafer 206, and a bond pad 208. The electronic component 20 may include various components related to MEMS, such as a movable component or a non-movable component such as an inertial sensor, a pressure sensor, an accelerometer, or an angular rate sensor. The substrate 204 is made of a semiconductor material, glass, or other materials. For example, the substrate 204 may include a complementary metal-oxide semiconductor (CMOS) wafer. The substrate 204 may be The MEMS wafer 202 is connected according to a wafer bonding process, such as a Fusion Bonding process. However, depending on the material or surface material of the substrate 204 and the MEMS wafer 202, the substrate 204 can also be through an anodic bonding, adhesive bonding, direct bonding, or glass dielectric bonding ( Glass-frit Bonding) and other processes connect the MEMS wafer 202. The cover wafer 206 may be disposed on the MEMS wafer 202 according to an eutectic bonding process. Similarly, the cover wafer 206 may be disposed on the MEMS wafer 202 through other processes.

In addition, the bonding pad 208 is formed on the MEMS wafer 202 and is connected to the substrate 204 via a via (Via) or at least one wire (such as a metal wire). An element structure 210 may be formed on the substrate 204, and the element structure 210 may be composed of a multilayer structure such as a metal wiring layer and an insulating layer. It is worth noting that, as shown in FIG. 2, the cover wafer 206 and the substrate 204 have a first height H1 in a longitudinal direction Y, and the cover wafer 206 and the bonding pad 208 have a second height in the longitudinal direction Y. Height H2. Since the bonding pad 208 is formed on the MEMS wafer 202, the second height H2 will be smaller than the first height H1, and the first height H1 and the second height H2 have a height difference HD. In this way, compared with the conventional technology in which the bonding pad 108 is provided on the complementary metal oxide semiconductor wafer 104, the electronic component 20 according to the embodiment of the present invention can effectively form the bonding pad 208 on the MEMS wafer 202, which can effectively The distance between the bonding pad 208 and the covering wafer 206 in the longitudinal direction Y is reduced, thereby preventing the solder pins from hitting the MEMS element 20 and the metal wiring during the wire bonding process, thereby improving the production yield.

In detail, since the bonding pads 208 of the MEMS element 20 are formed on the structure of the MEMS wafer 202, in this way, the MEMS element 20 can effectively reduce the distance between the bonding pads 208 and the covering wafer 206 to increase wire bonding. Operating space of the welding pin during the manufacturing process. In an embodiment, the thickness of the MEMS wafer 202 (equivalent to the aforementioned height difference HD) is between 20 and 40 micrometers (Micrometer), which can reduce the aforementioned second height H2 to between 100 and 120 micrometers. It is roughly equivalent to the thickness of the cover wafer 206. Therefore, compared to the prior art, the bonding pad 208 of the embodiment of the present invention is formed on the MEMS wafer 202 structure, and indeed effectively reduces the distance between the bonding pad 208 and the cover wafer 206, which can greatly shorten the bonding pad 208 and the cover. A safety distance D2 of the wafer 206 in a lateral direction X. The safety distance may be 80 to 120 micrometers, and preferably 90 to 110 micrometers, which is smaller than that between the covering wafer 106 and the bonding pad 108 in the prior art. Safety distance D1 (approximately 140 to 160 microns). In this way, the electronic component 20 of the present invention can not only prevent the solder pins from hitting the MEMS component 20 and the metal wiring during the wire bonding process, thereby improving the production yield, but also reducing the size of the MEMS component 20 by the bonding pad 208 and the cover crystal. The safety distance D2 between the circles 206 is limited by the magnitude, so as to achieve the effect of reducing the difficulty of shrinking the MEMS device 20 and the production cost.

Further, the embodiments of the present invention do not limit the internal structures of the MEMS wafer 202 and the substrate 204, but may be adjusted according to the application of the electronic component 20. For example, in one embodiment, the MEMS element 20 may include an accelerometer. Since the accelerometer is a movable element, the MEMS wafer 202 may include a movable cavity corresponding to the accelerometer. According to this, according to the actual needs of different electronic products or electronic components, this embodiment can appropriately adjust the structure of the electronic components to facilitate subsequent product manufacturing, which all belong to the scope of the present invention.

Further, please refer to FIG. 3, which is a schematic diagram of a manufacturing process 30 according to an embodiment of the present invention. The manufacturing process 30 is used to manufacture the electronic component 20, which can be compiled into a code and stored in a storage device of a manufacturing machine. The manufacturing process 30 may include the following steps: Step 302: forming an element structure 210 on a substrate 204.

Step 304: Use a wafer bonding process (such as a fusion bonding process) to connect a MEMS wafer 202 to the substrate 204; Step 306: Form a bonding pad 208 on the MEMS wafer 202; Step 308: Set a cover wafer 206 on the MEMS crystal Circle 202.

Step 310: The thickness of the cover wafer 206 is thinned by a grinding process.

According to the manufacturing process 30, in step 304, for example, the MEMS wafer 202 and the substrate 204 are connected by a fusion bonding process to form a first composite wafer. Next, in step 306, a bonding pad 208 is formed on the MEMS wafer 202 of the first composite wafer, and the bonding pad 208 is connected to the substrate 204 via a via or a wire. In step 308, for example, the cover wafer 206 and the first composite wafer (ie, the MEMS wafer 202 and the substrate 204) are bonded to each other in a eutectic bonding process, thereby forming a second composite wafer.

Before performing step 304, a step 302 may be further included to form the element structure 210 on the substrate 204. Furthermore, after step 308, the thickness of the cover wafer 206 can be reduced by a grinding process to separate the components of the MEMS device 20 in a step 310.

It is worth noting that according to the actual needs of different electronic products, the first composite wafer and The bonding mode of the second composite wafer can be adjusted and modified according to the electronic products or electronic components, and is not intended to limit the scope of the present invention.

In summary, the embodiment of the present invention forms a bonding pad on a MEMS wafer to reduce The height difference between the bonding pad and the cover wafer increases the operating space of the solder pin when the electronic component is performing a wire bonding process. In other words, the safety distance between the bonding pad and the cover wafer can be greatly shortened, thereby effectively reducing the size of the electronic component and reducing the production cost.

The above is only a preferred embodiment of the present invention. All modifications and modifications should fall within the scope of the present invention.

Claims (10)

An electronic component includes: a MEMS wafer; a substrate connected to the MEMS wafer; a cap wafer (Cap Wafer) disposed on the MEMS wafer; and a bonding pad (Bond Pad) formed on the MEMS wafer and connected to the substrate; wherein the cover wafer and the substrate have a first height, and the cover wafer and the bonding pad have a second height, the The first height is greater than the second height. The electronic component according to claim 1, wherein the second height is between 100 and 120 microns. The electronic component according to claim 1, wherein the first height and the second height have a height difference, the height difference is the same as the thickness of the MEMS wafer, and the thickness of the MEMS wafer is between Between 20 and 40 microns. The electronic component according to claim 1, wherein the bonding pad is connected to the substrate through a via or at least one wire. The electronic component according to claim 1, wherein the substrate includes a complementary metal oxide semiconductor wafer, and an element structure is formed on the substrate. An electronic component manufacturing method, wherein the electronic component includes a MEMS wafer, a substrate, a cover wafer, and a bonding pad. The manufacturing method includes: connecting the MEMS wafer with a wafer bonding process And the substrate; forming the bonding pad on the MEMS wafer; and setting the cover wafer on the MEMS wafer; wherein the cover wafer and the substrate have a first height between the cover and the substrate There is a second height between the wafer and the bonding pad, and the first height is greater than the second height. The manufacturing method according to claim 6, wherein the second height is between 100 and 120 microns. The manufacturing method according to claim 6, wherein the first height and the second height have a height difference, the height difference is the same as the thickness of the MEMS wafer, and the thickness of the MEMS wafer is between Between 20 and 40 microns. The manufacturing method according to claim 6, further comprising forming an element structure on the substrate. The manufacturing method according to claim 6, further comprising thinning the thickness of the cover wafer by a grinding process.