TWI417594B - Wafer level lens module and method for manufacturing same - Google Patents

Description

Wafer level lens module and manufacturing method thereof

The present invention relates to a lens module, and more particularly to a wafer level lens module and a method of fabricating the same.

The general lens module mainly comprises a lens group, a lens barrel accommodating the lens group, an image sensor and a lens holder. The image sensor is disposed in the lens holder, and the lens holder accommodates the rotatable lens barrel. When the lens is formed on the image sensor, the lens barrel is rotated to change the distance between the lens group and the image sensor, so that the light is focused on the image sensor. However, the lens module is generally bulky.

With the rapid development of technology, a wafer-level lens module has appeared on the market, which includes an image sensor, a lens group and a spacer for adjusting the distance therebetween. The lens group, the spacer and the image sensor are stacked in a stacking manner. The light is made through the lens to form on the image sensor. The lens group and the image sensor are both manufactured by an integrated circuit process. Therefore, the lens module has a small volume, so that it can be applied to small electronic devices such as mobile phones.

However, due to the small size of the wafer-level lens module, it is difficult to use the Micro-Electro-Mechanism System (MEMS) or the voice coil motor (Voice coil) before the volume is increased. Motor, VCM) The mechanism is applied to cause the lens group to be displaced to focus.

In view of the above, it is necessary to provide a wafer level lens module and a method of manufacturing the same that can achieve focusing without increasing the volume.

A wafer level lens module includes an image sensor, a lens group and a piezoelectric adjustment component, wherein the piezoelectric adjustment component is superimposed on the image sensor, and the lens group is superimposed on the piezoelectric adjustment component and The piezoelectric adjusting member is in direct contact, and the piezoelectric adjusting member has a shape variable parallel to an optical axis direction of the lens group, and the piezoelectric adjusting member is used for adjusting a distance between the image sensor and the lens group.

A method for manufacturing a wafer level lens module, comprising: forming an image sensor on a wafer by using a wafer level process; providing a first electrode on the image sensor; forming a piezoelectric material on the first electrode a hollow body is formed; a second electrode is disposed on the body, the polarity of the second electrode is opposite to that of the first electrode; and the lens group formed by the wafer level process is attached to the second electrode, and the light is formed through the lens to form an image On the sensor.

The piezoelectric adjusting member of the wafer level lens module of the embodiment has a mechanical shape variable in the energized state, and the mechanical shape variable changes the distance between the lens group and the image sensor, and the piezoelectric adjusting member directly faces the lens group. Fit, without increasing the size of the lens module, allows the light to focus correctly on the image sensor.

10‧‧‧ Wafer-level lens module

11‧‧‧ lens group

12‧‧‧Image sensor

13‧‧‧ Piezoelectric adjustment parts

14‧‧‧ glass plate

111‧‧‧ first lens

112‧‧‧second lens

113‧‧‧ spacers

131‧‧‧Ontology

132‧‧‧ positive

133‧‧‧negative

1 is a schematic diagram of a wafer level lens module in accordance with an embodiment of the present invention.

The invention will be further described in detail below with reference to the accompanying drawings.

Referring to FIG. 1 , a wafer level lens module 10 according to an embodiment of the invention includes a lens group 11 , an image sensor 12 , a piezoelectric adjustment member 13 , and a glass plate 14 .

The piezoelectric adjusting member 13 is located between the lens group 11 and the image sensor 12 to adjust the distance therebetween. The glass plate 14 covers the image sensor 12, and is mainly used to protect the image sensor 12 from the outside. Pollution and water intrusion. The piezoelectric adjustment member 13 is directly attached to the lens group 11 and the image sensor 12.

The lens group 11 is fabricated on a wafer by a wafer level process, and includes a first lens 111, a second lens 112, and a spacer 113. The spacer 113 is used to separate the first lens 111 and the second lens 112. distance.

The image sensor 12 is fabricated on a wafer by a wafer level process, which is a Charge Coupled Device (CCD) or a Complementary Metal Oxide Semiconductor (CMOS).

The piezoelectric adjusting member 13 includes a body 131, a positive electrode 132 and a negative electrode 133 disposed on the body 131. The body 131 has a cylindrical shape. The positive electrode 132 and the negative electrode 133 are respectively disposed at opposite ends of the body 131. The body 131 has a shape variable of the optical axis L of the parallel lens module 10, and the material thereof is a piezoelectric crystal or a piezoelectric ceramic. Among them, the piezoelectric crystal includes quartz crystal, lithium gallate, lithium niobate, titanium niobate, lithium niobate or lithium niobate, and piezoelectric ceramics include barium titanate, lead zirconate titanate, modified lead zirconate titanate, and partial Lead citrate, lead bismuth citrate or modified lead titanate.

The mechanical deformation of the body 131 is proportional to the electric field strength E applied thereto, and the ratio of the mechanical deformation of the body 131 to the electric field strength E can be expressed by the following simple formula. :S=dE, S is the shape variable of the body 131 at a certain electric field strength E, and d is the piezoelectric constant of the body 131. It can be seen from the above formula that if a certain deformation S is to be caused to the body 131, an electric field having an electric field intensity E of S/d can be applied.

When an electric field of the same (or opposite) direction as the polarization direction is applied to the body 131, since the direction of the electric field is the same as (or opposite to) the polarization direction, the polarization intensity is increased (or decreased), so that the body 131 is made. Causes mechanical deformation that grows (or shortens) in the direction of polarization.

An electric field is applied to the positive electrode 132 and the negative electrode 133 such that the length of the body 131 in the direction parallel to the optical axis L changes, and the change in the length of the body 131 causes the piezoelectric adjusting member 13 to generate a mechanical deformation, which causes the lens group 11 and the image sensing The distance between the devices 12 changes, and the piezoelectric adjusting member 13 directly fits the lens group 11 without increasing the volume of the lens module 10, so that the light is focused on the image sensor 12.

In the process of manufacturing the wafer level lens module 10, first, a plurality of image sensors 12 are formed on the wafer by a wafer level process, and the glass plate 14 is covered on the image sensor 12, and then on the glass plate 14. A metal layer is deposited as the negative electrode 133, and then a hollow cylindrical body 131 made of a piezoelectric material is stacked on the negative electrode 133, a metal layer is deposited on the body 131 as a positive electrode 132, and finally a lens group 11 formed by a wafer level process is attached. The positive wafer 132 is formed to form a plurality of wafer level lens modules 10, which are cut into individual wafer level lens modules 10.

Of course, the metal piece may be attached to the image sensor 12 and the body 131 as the negative electrode 133 and the positive electrode 132; or the fabricated piezoelectric adjustment member 13 may be superposed on the image sensor 12.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

10‧‧‧ Wafer-level lens module

11‧‧‧ lens group

12‧‧‧Image sensor

13‧‧‧ Piezoelectric adjustment parts

14‧‧‧ glass plate

111‧‧‧ first lens

112‧‧‧second lens

113‧‧‧ spacers

131‧‧‧Ontology

132‧‧‧ positive

133‧‧‧negative

Claims (10)

A wafer level lens module comprising an image sensor and a lens group, wherein the wafer level lens module further comprises a piezoelectric adjustment member superimposed on the image sensor, wherein the lens group is superimposed on the image sensor a piezoelectric adjusting member is directly in contact with the piezoelectric adjusting member, and the piezoelectric adjusting member has a shape variable parallel to an optical axis of the lens group, wherein the piezoelectric adjusting member is used for adjusting a distance between the image sensor and the lens group . The wafer level lens module of claim 1, wherein the piezoelectric adjustment member comprises a hollow cylindrical body and electrodes disposed at both ends of the body. The wafer level lens module of claim 2, wherein the material of the body is a piezoelectric crystal or a piezoelectric ceramic. The wafer level lens module of claim 3, wherein the piezoelectric crystal comprises a quartz crystal, lithium gallate, lithium niobate, titanium niobate, lithium niobate or lithium niobate. The wafer level lens module according to claim 3, wherein the piezoelectric ceramic comprises barium titanate, lead zirconate titanate, modified lead zirconate titanate, lead metasilicate, lead bismuth ruthenate Or modified lead titanate. The wafer level lens module according to any one of claims 1 to 5, wherein: the image sensor and the piezoelectric adjustment member have a glass plate. The wafer level lens module of claim 6, wherein the image sensor is a charge coupled device or a complementary metal oxide semiconductor device. A method for manufacturing a wafer level lens module, comprising: forming an image sensor on a wafer by using a wafer level process; and providing a first electrode on the image sensor; Forming a hollow body made of a piezoelectric material on the first electrode; providing a second electrode on the body, the second electrode having a polarity opposite to the first electrode; and bonding the lens group formed by the wafer level process to the second electrode On the electrode, light passes through the lens to form an image sensor. The method of manufacturing a wafer level lens module according to claim 8, wherein a metal layer is deposited as a first electrode and a second electrode on the image sensor and the body, respectively. The method for manufacturing a wafer level lens module according to claim 9, wherein the method for manufacturing the wafer level lens module further comprises covering the glass plate on the image sensor and depositing on the glass plate. The metal layer serves as a first electrode.