KR102536832B1 - Wafer level package and method for manufacturing the package - Google Patents

Abstract

A wafer level package according to an embodiment includes a light transmitting member having a first part and a second part adjacent to each other in a horizontal direction and first and second surfaces opposite to each other in a vertical direction, and a first part of the first part of the light transmitting member. a first wafer having a first metal portion bonded to a surface of the light transmitting member and a second wafer having a second metal portion bonded to a second surface of the second portion of the light transmitting member; The second faces do not overlap each other in the vertical direction.

Description

Wafer level package and method for manufacturing the same {Wafer level package and method for manufacturing the package}

The embodiment relates to a wafer level package and a manufacturing method thereof.

In general, Wafer Level Package (WLP), unlike the method of packaging by cutting out chips one by one after processing a wafer, performs the package process and test at once in the wafer state and then cuts the chip to simply make a finished product. It is a technique that By applying this technology, it is possible to save about 20% of the package production cost compared to the one-by-one cutting method.

A lot of research is being conducted to reduce the manufacturing cost of a wafer level package in which a plurality of wafers having low light transmittance are bonded to each other.

The embodiment provides a wafer level package that can be inexpensively and simply manufactured and a manufacturing method thereof.

A wafer level package according to an embodiment includes a light transmitting member having first and second parts horizontally adjacent to each other and first and second surfaces opposite to each other in a vertical direction; a first wafer having a first metal portion bonded to the first surface of the first portion of the light transmitting member; and a second wafer having a second metal portion bonded to the second surface of the second part of the light transmitting member, wherein the first surface of the first part and the second surface of the second part are They may not overlap each other in the vertical direction.

For example, the thickness of each of the first and second wafers in the vertical direction may be constant.

For example, the first metal part is formed on the first wafer and the third surface facing the second wafer is flat, and the second metal part is formed on the second wafer and the third surface facing the first wafer is flat. 4 sides can be flat.

For example, the first metal part may be disposed outside the third surface of the first wafer, and the second metal part may be disposed outside the fourth surface of the second wafer.

For example, the third surface of the first wafer, the fourth surface of the second wafer, and the light transmitting member may be disposed to form a cavity.

For example, the cavity may be in a vacuum state.

For example, each of the first and second wafers may be a silicon wafer.

A wafer level package according to another embodiment has first and second surfaces opposite to each other in a vertical direction, has a plurality of through-holes spaced apart from each other in a horizontal direction, and mutually interacts with each other in the horizontal direction around the plurality of through-holes. a light transmitting member having adjacent first and second portions; a plurality of first wafers each having a first metal portion bonded to the first surface of the first portion of the light transmitting member; and a plurality of second wafers each having a second metal portion bonded to the second surface of the second part of the light transmitting member, wherein a plane size of each of the plurality of first and second wafers is the plurality of second wafers. may be larger than the plane size of each of the through holes.

For example, the first portion of the light transmitting member may contact each of the plurality of through holes in the horizontal direction, and the second portion of the light transmitting member may contact the first portion in the horizontal direction.

According to another embodiment, a method of manufacturing a wafer level package including first and second wafers has a first part and a second part adjacent to each other in a horizontal direction, and first and second parts on opposite sides in a vertical direction. preparing a light transmitting member having a second surface; overlapping the first portion of the light transmitting member and the first metal portion included in the first wafer in the vertical direction; bonding a first surface of the first portion to the first metal portion by irradiating a laser beam to the first metal portion through the first portion of the light-transmitting member; overlapping the second portion of the light transmitting member and a second metal portion included in the second wafer in the vertical direction; and irradiating a laser beam to the second metal part through the second part of the light transmitting member to bond the second surface of the second part to the second metal part.

According to another embodiment, a method of manufacturing a wafer level package including a plurality of first wafers and a plurality of second wafers has first and second surfaces on opposite sides in a vertical direction and spaced apart from each other in a horizontal direction. preparing a light-transmitting member having a plurality of through-holes, and having a first portion and a second portion adjacent to each other in the horizontal direction around the plurality of through-holes; overlapping a first metal portion of each of the plurality of first wafers connected to each other by a first bridge with the first portion of the light transmitting member in the vertical direction; A laser beam is irradiated to the first metal portion of each of the plurality of first wafers through the first portion of the light-transmitting member, so that the first surface of the first portion and the first metal portion of each of the plurality of first wafers are formed. 1 bonding the metal part; removing the first bridge after bonding the first metal part; overlapping a second metal portion of each of the plurality of second wafers connected to each other by a second bridge with the second portion of the light transmitting member in the vertical direction; A laser beam is irradiated to the second metal portion of each of the plurality of second wafers through the second portion of the light-transmissive member, so that the second surface of the second portion and the second metal portion of each of the plurality of second wafers are formed. 2 bonding the metal part; and removing the second bridge after bonding the second metal part.

A wafer level package and a manufacturing method thereof according to an embodiment have a low process cost, and limitations of process conditions can be eliminated.

1A and 1B show a combined cross-sectional view and an exploded cross-sectional view of a wafer level package according to an embodiment, respectively.
2A and 2B show a plan view and a bottom view, respectively, of a wafer level package according to another embodiment.
3A to 3F are process cross-sectional views for explaining a manufacturing method of the wafer level package shown in FIGS. 1A and 1B.
4 is a flowchart for explaining a manufacturing method of the wafer level package shown in FIGS. 1A and 1B.
5 (a) to (f) are cross-sectional views illustrating a manufacturing method of the wafer level package shown in FIGS. 2A and 2B.
6 is a flowchart for explaining a manufacturing method of the wafer level package shown in FIGS. 2A and 2B.
7 is a diagram for explaining a method of manufacturing a wafer level package according to a first comparative example in which first and second wafers are bonded to each other.
8 (a) to (d) are views for explaining a wafer level package manufacturing method according to a second comparative example using eutectic bonding.
9A and 9B are diagrams for explaining an effect of a method for manufacturing a wafer level package according to an embodiment.
10 is a diagram illustrating an infrared detection sensor including an infrared detection unit of a unit cell to which a wafer level package according to an embodiment is applied.
11 (a) and (b) show a process of bonding an electrode pad of an upper structure and an anchor portion of a lower structure by solder balls according to an embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

However, the technical spirit of the present invention is not limited to some of the described embodiments, but may be implemented in a variety of different forms, and if it is within the scope of the technical spirit of the present invention, one or more of the components among the embodiments can be selectively implemented. can be used by combining and substituting.

In addition, terms (including technical and scientific terms) used in the embodiments of the present invention, unless explicitly specifically defined and described, can be generally understood by those of ordinary skill in the art to which the present invention belongs. It can be interpreted as meaning, and commonly used terms, such as terms defined in a dictionary, can be interpreted in consideration of contextual meanings of related technologies.

In addition, terms used in the embodiments of the present invention are for describing the embodiments and are not intended to limit the present invention. In this specification, the singular form may also include the plural form unless otherwise specified in the phrase, and when described as “at least one (or more than one) of A and (and) B and C”, A, B, and C are combined. Can include one or more of all possible combinations.

Also, terms such as first, second, A, B, (a), and (b) may be used to describe components of an embodiment of the present invention. These terms are only used to distinguish the component from other components, and the term is not limited to the nature, order, or order of the corresponding component.

In addition, when a component is described as being 'connected', 'coupled' or 'connected' to another component, the component is not only directly connected to, coupled to, or connected to the other component, but also with the component. It may also include the case of being 'connected', 'combined', or 'connected' due to another component between the other components.

In addition, when it is described as being formed or disposed on the “upper (above) or lower (below)” of each component, the upper (upper) or lower (lower) is not only when two components are in direct contact with each other, but also on one A case in which another component above is formed or disposed between two components is also included. In addition, when expressed as “up (up) or down (down)”, it may include the meaning of not only the upward direction but also the downward direction based on one component.

Hereinafter, wafer level packages 100A and 100B and methods 200 and 300 for manufacturing the wafer level packages 100A and 100B according to embodiments will be described as follows with reference to the accompanying drawings. For convenience, the wafer level packages 100A and 100B and the methods 200 and 300 for manufacturing the wafer level packages 100A and 100B are described using a Cartesian coordinate system (x-axis, y-axis, z-axis), but they can also be performed using other coordinate systems. Of course it can be explained. In addition, according to the Cartesian coordinate system, the x-axis, y-axis, and z-axis are orthogonal to each other, but the embodiment is not limited thereto. That is, the x-axis, y-axis, and z-axis may cross each other.

1A and 1B respectively show a combined cross-sectional view and an exploded cross-sectional view of a wafer level package 100A according to an embodiment.

A wafer level package 100A according to an embodiment may include a light transmitting member 110A, a first wafer 120A, and a second wafer 130A.

The light transmitting member 110A has a first portion P1 and a second portion P2 adjacent to each other in a horizontal direction (eg, a y-axis direction). In addition, the light transmitting member 110A has first and second surfaces S1 and S2 opposite to each other in a vertical direction (eg, a z-axis direction). Here, the first part P1 also has first and second surfaces S1 and S2, and the second part P2 also has first and second surfaces S1 and S2. Also, the first surface S1 of the first portion P1 and the second surface S2 of the second portion P2 may not overlap each other in a vertical direction (eg, a z-axis direction).

The light transmitting member 110A may be implemented with a material capable of transmitting light, for example, glass. Also, the light transmitting member 110A may be implemented with a material having light transmission and electrical conductivity or a material having light transmission and electrical non-conductivity.

The first wafer 120A may include a body 122 and a first metal part 124 . The first metal portion 124 may be bonded to the first surface S1 of the first portion P1 of the light transmitting member 110A. In FIGS. 1A and 1B , the first metal part 124 is shown disposed as a separate member on top of the body 122 . However, the body 122 of the first wafer 120A may include a circuit pattern (not shown) including a metal material, and the metal material may correspond to the first metal portion 124 .

The second wafer 130A may include a body 132 and a second metal part 134 . The second metal portion 134 may be bonded to the second surface S2 of the second portion P2 of the light transmitting member 110A. In FIGS. 1A and 1B , the second metal part 134 is shown disposed above the body 132 as a separate member. However, the body 132 of the second wafer 130A may include a circuit pattern (not shown) including a metal material, and the metal material may correspond to the second metal portion 134 .

In addition, each of the first and second wafers 120A and 130A may be a silicon wafer having low light transmittance, but the embodiment is not limited to a specific type or material of the wafers 120A and 130A.

In addition, the thicknesses T1 and T2 of each of the first and second wafers 120A and 130A in a vertical direction (eg, a z-axis direction) may be constant. At this time, the first metal portion 124 is formed on the first wafer 120A, and the third surface S3 facing the second wafer 130A may be flat. In addition, the second metal portion 134 is formed on the second wafer 130A, and the fourth surface S4 facing the third surface S3 of the first wafer 120A may be flat.

In addition, the first metal part 124 is disposed outside the third surface S3 of the first wafer 120A, and the second metal part 134 is disposed on the fourth surface S4 of the second wafer 130A. can be placed on the outskirts of As described above, when the first and second metal parts 124 and 134 are respectively disposed outside the first and second wafers 120A and 130A, the vertical direction of the light transmitting member 110A (eg, z When adjusting the thickness in the axial direction), an air gap (SP) may be formed. Here, the third surface S3 of the first wafer 120A, the fourth surface S4 of the second wafer 130A, and the light transmitting member 110A may be disposed to form a cavity SP. For example, the cavity SP may be in a vacuum state. To this end, the first metal part 124 and the second metal part 134 may be airtightly bonded to the light transmitting member 110A.

2A and 2B show a plan view and a bottom view, respectively, of a wafer level package 100B according to another embodiment.

A wafer level package 100B according to another embodiment shown in FIGS. 2A and 2B may include a light transmitting member 110B, a plurality of first wafers 120B, and a plurality of second wafers 130B.

In the wafer level package 100B, the plurality of first wafers 120B and the plurality of second wafers 130B may be disposed in an array form facing each other with the light transmitting member 110B interposed therebetween.

Unlike FIGS. 1A and 1B, each of the first and second wafers 120B and 130B is plural, and the plurality of first and second wafers 120B and 130B have one light-transmitting member 110B interposed therebetween, Except for being disposed with each other, the wafer level package 100B shown in FIGS. 2A and 2B is the same as the wafer level package 100A shown in FIGS. 1A and 1B.

Therefore, in the wafer level package 100B shown in FIGS. 2A and 2B, only parts different from the wafer level package 100A shown in FIGS. 1A and 1B will be described. Accordingly, the description of the wafer level package 100A shown in FIGS. 1A and 1B may also be applied to the wafer level package 100B shown in FIGS. 2A and 2B unless otherwise specified to the contrary.

The light transmitting member 110B has first and second surfaces S1 and S2 opposite to each other in the vertical direction (eg, the z-axis direction), and in the horizontal direction (eg, the x-axis direction and the y-axis direction). ) and has a plurality of through holes 140 spaced apart from each other. Here, the number of through holes 140 may be the same as the number of each of the first and second wafers 120B and 130B. That is, if the number of first wafers 120B is four, the number of through holes 140 may also be four, and the number of first wafers 120B and the number of second wafers 130B may be the same.

Also, the light transmitting member 110B may have a first portion P1 and a second portion P2 adjacent to each other in a horizontal direction around the plurality of through holes 140 .

Each of the plurality of first wafers 120B may have a first metal portion (not shown) bonded to the first surface S1 of the first portion P1 of the light transmitting member 110B. Although the first metal part is hidden by the first wafer 120B shown in FIG. 2A and cannot be seen, it may be disposed between the first wafer 120B and the first portion P1 of the light-transmissive substrate 110B.

Referring to FIG. 2B , each of the plurality of second wafers 130B may have a second metal portion (not shown) bonded to the second surface S2 of the second portion P2 of the light transmitting member 110B. . For ease of understanding, the first portion P1 is also indicated in FIG. 2B.

Although the second metal part is hidden by the second wafer 130B shown in FIG. 2B and cannot be seen, it may be disposed between the second wafer 130B and the second part P2 of the light-transmissive substrate 110B.

The first part P1 of the light transmitting member 110B is in contact with each of the plurality of through holes 140 in the horizontal direction (eg, x-axis and y-axis directions), and the second part P2 of the light transmitting member 110B ) may contact the first portion P1 in a horizontal direction (eg, x-axis and y-axis directions). Here, the second part P2 is disposed farther from the through hole 140 than the first part P1, but unlike the first part P1 is farther from the through hole 140 than the second part P2. It can also be placed further away.

In addition, the plane size of each of the plurality of first and second wafers 120B and 130B may be larger than the plane size of each of the plurality of through holes 140 .

Hereinafter, a manufacturing method 200 of a wafer level package 100A according to an embodiment shown in FIGS. 1A and 1B will be described as follows with reference to the accompanying drawings.

3A to 3F are cross-sectional views illustrating a method 200 of manufacturing the wafer level package 100A shown in FIGS. 1A and 1B.

FIG. 4 is a flowchart for explaining a manufacturing method 200 of the wafer level package 100A shown in FIGS. 1A and 1B.

First, as shown in FIG. 3A, the first part P1 and the second part P2 are adjacent to each other in the horizontal direction (eg, the y-axis direction), and the vertical direction (eg, the z-axis direction ), a light transmitting member 110A having first and second surfaces S1 and S2 opposite to each other is prepared (step 210).

After operation 210, as shown in FIG. 3B, the first portion P1 of the light transmitting member 110A and the first metal portion 124 included in the first wafer 120A are moved in a vertical direction (eg, z axial direction) (step 220).

After step 220, as shown in FIG. 3C, the first part P1 of the light transmitting member 110A and the first metal part 124 included in the first wafer 120A are moved in a vertical direction (eg, z-axis direction), the laser beam LL is irradiated to the first metal part 124 through the first part P1 of the light-transmitting member 110A, so that the first part P1 The first surface S1 and the first metal part 124 are bonded (operation 230).

After step 230, as shown in FIG. 3D, after the result obtained in step 230 is overturned, as shown in FIG. 3E, the second part P2 of the light-transmissive member 110A and the second wafer 130A are The included second metal part 134 is overlapped in a vertical direction (eg, a z-axis direction) (operation 240).

After step 240, as shown in FIG. 3F, the second part P2 of the light transmitting member 110A and the second metal part 134 included in the second wafer 130A are moved in a vertical direction (eg, z axial direction), and then irradiates the second metal part 134 with a laser beam LL through the second part P2 of the light-transmitting member 110A, thereby forming the second part P2 of the light-transmitting member 110A. The wafer level package 100A shown in FIGS. 1A and 1B is completed by bonding the surface S2 and the second metal part 134 (operation 250).

Hereinafter, a manufacturing method 300 of a wafer level package 100B according to another embodiment shown in FIGS. 2A and 2B will be described as follows with reference to the accompanying drawings.

5 (a) to (f) are cross-sectional views illustrating a method 300 of manufacturing the wafer level package 100B shown in FIGS. 2A and 2B.

FIG. 6 is a flowchart for explaining a manufacturing method 300 of the wafer level package 100B shown in FIGS. 2A and 2B.

First, as shown in FIG. 5 (a), the first and second surfaces S1 and S2 are opposite to each other in the vertical direction (eg, z-axis direction), and in the horizontal direction (eg, x-axis direction). A first portion having a plurality of through-holes 140 spaced apart from each other in the axial and y-axis directions) and adjacent to each other in a horizontal direction (eg, in the x-axis and y-axis directions) around the plurality of through-holes 140 A light transmitting member having (P1) and a second part (P2) is prepared (operation 310).

After step 310, as shown in FIG. 5(b), the first metal parts (not shown) of each of the plurality of first wafers 120B connected to each other by the first bridge 128 are attached to the light transmitting member 110B. It overlaps with the first part P1 in the vertical direction (eg, the z-axis direction) (operation 320). The first metal part is not visible because it is covered by the first wafer 120B shown in FIG. 5( b ), but may be disposed between the first wafer 120B and the first part P1 of the light-transmitting substrate 110B.

After step 320, as shown in FIG. 5(c), a laser beam is irradiated to the first metal part of each of the plurality of first wafers 120B through the first part P1 of the light transmitting member 110B. , the first surface S1 of the first part P1 and the first metal parts of each of the plurality of first wafers 120B are bonded (operation 330).

After step 330, the first bridge 128 shown in FIG. 5(c) is removed (step 340).

After step 340, as shown in FIG. 5(d), the results obtained in step 340 are turned over, and a plurality of second wafers connected to each other by a second bridge 138 as shown in FIG. 5(e). After preparing 130B, the second metal portion of each of the plurality of second wafers 130B is perpendicular to the second portion P2 of the light transmitting member 110B (eg, the z-axis direction) in FIG. 5(f). ) as shown in (step 350). The second metal portion is not visible because it is covered by the second wafer 130B shown in FIG. 5(e), but may be disposed between the second wafer 130B and the second portion P2 of the light-transmitting substrate 110B.

After step 350, a laser beam is irradiated to the second metal portion of each of the plurality of second wafers 130B through the second portion P2 of the light-transmitting member 110B shown in FIG. The second surface S2 of the portion P2 and the second metal parts of each of the plurality of second wafers 130B are bonded (Operation 360).

For example, the laser beam used in step 230 or 250 shown in FIG. 4 and step 330 or 360 shown in FIG. 6 may be an infrared (IR) beam having a wavelength of 1 μm, but the embodiment It is not limited to a specific wavelength or type of the laser beam LL used.

After step 360, the second bridge 138 is removed to complete the wafer level package 100B shown in FIGS. 2A and 2B (step 370).

In the above-described embodiment, step 340 may be performed after any one of steps 350 to 370.

Hereinafter, a method of manufacturing a wafer level package according to comparative examples and embodiments will be described as follows with reference to the accompanying drawings.

FIG. 7 is a diagram for explaining a method of manufacturing a wafer level package according to a first comparative example in which first and second wafers 20 and 30 are bonded to each other.

It is assumed that the first wafer 20 and the second wafer 30 shown in FIG. 7 perform roles respectively corresponding to the first wafers 120A and 120B and the second wafers 130A and 130B according to the embodiment. .

If each of the first wafer 20 and the second wafer 30 is made of silicon material, in order to bond the metal parts 40 of each of the first and second wafers 20 and 30, the silicon material Since an expensive special laser capable of penetrating the first wafer 20 must be used, process costs may increase and process conditions may be restricted.

On the other hand, according to the embodiment, each metal layer ( The first wafers 120A and 120B and the second wafers 130A and 130B may be bonded by bonding the light transmitting members 110A and 110B to the light transmitting members 122 and 132 . Therefore, since a general-purpose laser device may be used without the need to use a special and expensive laser device as in the first comparative example, process costs may be reduced and limitations of process conditions may be eliminated.

8 (a) to (d) are diagrams for explaining a method of manufacturing a wafer level package according to a second comparative example using eutetic bonding.

The first wafer 21 and the second wafer 31 shown in (a) to (d) of FIG. 8 correspond to the first wafers 120A and 120B and the second wafers 130A and 130B according to the embodiment, respectively. Assume that the role of

According to the wafer level package manufacturing method according to the second comparative example, the first wafer 21 is prepared as shown in FIG. 8(a).

Thereafter, as shown in FIG. 8( b ), a cavity C is formed by etching one surface of the first wafer 21 by a conventional photolithography process.

Then, as shown in FIG. 8(c) , electrodes 41 are formed around the cavity C in the first wafer 21 .

Then, as shown in FIG. 8( d ), the electrode 41 may be coupled to the second wafer 31 to form a cavity SP.

As described above, in the case of forming the cavity SP by eutectic bonding according to the second comparative example, a manufacturing process such as a photolithography process is complicated, resulting in an increase in cost.

On the other hand, in the case of the embodiment, by adjusting the thickness of the light transmitting member (110A, 110B) disposed between the first wafer (120A, 120B) and the second wafer (130A, 130B) to irradiate the laser, the second Since the photolithography process or the like of the comparative example is unnecessary, since the cavity SP can be simply formed between the first wafers 120A and 120B and the second wafers 130A and 130B, the manufacturing process is simple and the cost can be reduced. can

9A and 9B are diagrams for explaining an effect of a method for manufacturing a wafer level package according to an embodiment.

In each of FIGS. 9A and 9B , the wafer 420 may correspond to the first wafers 120A and 120B or the second wafers 130A and 130B, and the metal part 410 may correspond to the first metal part 124 or It corresponds to the second metal portion 134, and the light transmitting member 110 may correspond to the light transmitting member 110A or the light transmitting member 110B.

When the laser beam LL is irradiated to the metal part 410 through the light-transmissive member 110 by the wafer-level package manufacturing method according to the embodiment, when the intensity of the beam LL is weakened, as shown in FIG. 9A As described above, a blind hole BH may be formed in the metal part 410 . Alternatively, when irradiating the laser beam LL to the metal part 410 through the light transmitting member 110, when the intensity of the beam LL is increased, as shown in FIG. 9B , the through hole in the metal part 410 (TH) can be formed. Therefore, in step 230 or 250 shown in FIG. 4 and step 330 or 360 shown in FIG. 6 , the first or second metal parts 124 and 134 are formed by radiating a laser beam to the light transmitting members 110A and 110B. ), the first or second metal parts 124 and 134 may be patterned by adjusting the intensity of the irradiated laser beam LL. Accordingly, separate patterning processes may be simultaneously performed to further reduce manufacturing process costs.

The wafer level package and its manufacturing method according to the above-described embodiments may be used in various fields. For example, a wafer level package according to an embodiment may include an infrared sensor or the like.

10 is a diagram illustrating an infrared detection sensor including an infrared detection unit of a unit cell to which a wafer level package according to an embodiment is applied.

As shown in FIG. 10 , the infrared detection sensor 500 according to the embodiment may include an upper structure 510 and a lower structure 520 .

The upper structure 510 includes an upper layer 512, an infrared sensor 514, an electrode wire 516, and an electrode pad 518, and the lower structure 520 electrically connected to the upper structure 510 is a lower layer. 522 , an anchor portion 524 and a reflective layer 526 .

For convenience of explanation, the upper layer 512, the infrared sensor 514, the electrode wire 516, and the electrode pad 518 are shown spaced apart, but preferably, the infrared sensor 514 is below the upper layer 512. The electrode wiring 516 and the electrode pad 518 may be deposited and formed on the lower surface of the upper layer 512 to be tightly adhered to each other.

The upper layer 512 serves to transmit only infrared rays having a specific wavelength selected from among infrared rays condensed by a lens unit (not shown).

The upper layer 512 may include a resistance element, a thermoelectric element, and the like, and preferably may include a PVDF film, but the material of the upper layer 512 is exemplary and is not limited thereto.

The infrared sensor 514 performs a function of receiving and detecting infrared rays of a specific wavelength that have selectively passed through the upper layer 512 .

The infrared sensor 514 may have a characteristic in which an electrical resistance value decreases when infrared rays are absorbed. For example, when infrared rays are absorbed, the temperature rises due to the energy of the infrared rays absorbed, and by this temperature change The electrical resistance value may decrease. Therefore, the amount of reduced electrical resistance changes according to the amount of infrared rays absorbed. Using these characteristics, the infrared sensor 514 can detect infrared rays.

The material used for the infrared detector 514 has a high temperature coefficient of resistence (TCR), low resistivity, connectivity with an integrated circuit (IC) process, inexpensiveness and simplification of the manufacturing process, High reproducibility and the like are required. In particular, a semiconductor that responds sensitively to a slight temperature increase, a material with a high negative (-) resistance temperature coefficient, or a material whose resistance varies according to the degree of absorption of infrared rays can be used for the infrared sensor 514, and the infrared rays that are sensed can be used. resistance changes as the temperature of the infrared sensor 514 changes.

For example, the infrared sensor 514 may include a metal such as titanium (Ti), amorphous silicon (a-Si), vanadium oxide (VOx), which is a type of metal oxide, or an oxide resistive thin film. This is an example, and it is obvious to those skilled in the art that the specific material of the infrared sensor 514 is not limited thereto.

The temperature coefficient of resistance refers to the rate at which the resistance value changes as the temperature rises. A material whose electrical resistance decreases as the temperature rises has a negative (-) temperature coefficient of resistance, and a material whose electrical resistance increases has a positive (+) temperature coefficient. has a temperature coefficient of resistance of The temperature of the upper layer 512 that absorbs the infrared radiant energy increases, and the temperature of the infrared sensor 514 disposed under the upper layer 512 may also increase. This reduction in electrical resistance of the infrared sensor 514 leads to an increase in output voltage, and the increased voltage causes current to flow through the lower structure 520 through the electrode wiring 516 . Vanadium oxide (VOx), which has a high negative temperature coefficient of resistance, has a large rate of decrease in electrical resistance with increasing temperature, so that a temperature difference between objects can be easily distinguished.

The electrode wiring 516 includes metal, and transmits an electrical signal according to a change in resistance value to the lower structure 520 through the anchor portion 524 by infrared rays absorbed by the infrared sensor 514 .

The infrared detection unit 514 of the infrared detection sensor 500 absorbs infrared radiant energy and the temperature must rise in response thereto, but the heat generated by the infrared detection unit 514 absorbing the infrared radiant energy is several nanowatts ( nW), it is necessary to minimize heat loss escaping to the outside in order to effectively convert the heat into an electrical signal.

In other words, the infrared sensor 514 requires a thermal isolation structure to minimize heat conduction with the outside and suppress heat loss, and to improve the performance of the thermal isolation structure, the infrared sensor 514 and the lower structure 520 The electrode wire 516 electrically connecting the ) may be formed of a material having a small cross-sectional area, a long shape, and low thermal conductivity.

The electrode pad 518 transmits a detection signal from the infrared detector 514 to the lower layer 522, and corresponds to a conductive metal disposed in a pad region of a diagonal corner of the quadrangular infrared detector 514. On the other hand, it is apparent to those skilled in the art that the shape of the infrared sensor 514 is not limited thereto, and may include a shape such as a circle, a triangle, and a trapezoid.

Meanwhile, the lower structure 520 may include a lower layer 522, an anchor portion 524 for transmitting a predetermined electrical signal to the lower layer 522, and a reflective layer 526 contributing to increasing infrared absorption efficiency.

The lower layer 522 may include a silicon substrate, and a readout integrated circuit (ROIC) for driving the infrared sensor 514 may be formed on the silicon substrate. An electrical signal according to a change in resistance value is input to a readout integrated circuit (ROIC) embedded in the lower layer 522 .

Although not shown, the lower layer 522 is an insulating layer such as silicon oxide (SiO2) or silicon nitride (SiNx) as a protective layer on the silicon substrate to prevent damage to the silicon substrate from a subsequent process or short circuit with the device. (not shown) may be included.

An anchor portion 524 such as aluminum (Al) electrically connected to the upper structure 510 and a reflective layer 526 may be disposed on the surface of the lower layer 522 as shown.

The anchor unit 524 may transmit a predetermined electrical signal to the lower layer 522 or receive it from the upper structure 510, and serves to structurally support the upper structure 510. Accordingly, the readout integrated circuit (ROIC) of the upper structure 510 and the lower structure 520 may be structurally connected to each other to configure the infrared detection sensor 500 .

In other words, the anchor unit 524 may be used as a plug that electrically connects the readout integrated circuit (ROIC) of the lower layer 522 to the upper structure 510, and a predetermined electrical signal is transmitted to the lower layer 522. A current flows through the readout integrated circuit (ROIC). Hereinafter, a process in which the upper structure 510 and the lower structure 520 are bonded while forming a resonance structure will be described with reference to FIG. 11 .

11 (a) and (b) show a process of bonding an electrode pad of an upper structure and an anchor portion of a lower structure by solder balls according to an embodiment.

The upper layer 512, the infrared detector 514, the lower layer 522, and the reflective layer 526 shown in FIG. 11 are the upper layer 512, the infrared detector 514, the lower layer 522, and the reflective layer shown in FIG. Since it corresponds to (526), the same reference numerals are used, and overlapping descriptions thereof are omitted.

In addition, the upper layer 512, the electrode pad 518A, the light transmitting member 100, the anchor portion 524A, and the lower layer 522 shown in FIG. 11 are the aforementioned first wafers 120A and 120B, the light transmitting member 100A. , 100B) and the second wafers 130A and 130B, respectively.

Referring to FIG. 11 , the electrode pad 518A of the upper structure 510 and the anchor portion 524A of the lower structure 520 may be bonded by the light transmitting member 100 .

In the process of connecting the electrode pad 518A and the anchor portion 524A by the light transmitting member 100, the first metal part 124 and the second metal part 134 are connected by the light transmitting members 100A and 100B. Since it is the same as the process of connecting to each other, a redundant description thereof will be omitted.

In this case, in order to electrically connect the electrode pad 518A and the anchor portion 524A to each other, the light transmitting member 110 may be implemented as a light transmitting material having a conductivity type.

On the other hand, when the electrode pads 518A and 518B of the upper structure 510 and the anchor portions 524A and 524B of the lower structure 520 are bonded by the light transmitting member 100, the reflective layer 526 and the infrared sensor ( 514), a cavity SP may be formed between them.

Although the above has been described with reference to the embodiments, these are only examples and do not limit the present invention, and those skilled in the art to which the present invention belongs will not deviate from the essential characteristics of the present embodiment. It will be appreciated that various variations and applications are possible. For example, each component specifically shown in the embodiment can be modified and implemented. And the differences related to these modifications and applications should be construed as being included in the scope of the present invention as defined in the appended claims.

100A, 100B: wafer level package 110A, 110B: light transmitting member
120A, 120B: first wafer 130A, 130B: second wafer

Claims (11)

a light transmitting member having first and second portions adjacent to each other in the horizontal direction and first and second surfaces opposite to each other in the vertical direction;
a first wafer having a first metal portion bonded to the first surface of the first portion of the light transmitting member; and
a second wafer having a second metal portion bonded to the second surface of the second portion of the light transmitting member;
The wafer level package of claim 1 , wherein the first surface of the first portion and the second surface of the second portion do not overlap each other in the vertical direction. The wafer level package of claim 1 , wherein a thickness of each of the first and second wafers in the vertical direction is constant. According to claim 1,
The first metal part is formed on the first wafer and a third surface facing the second wafer is flat,
The second metal part is formed on the second wafer, and a fourth surface facing the first wafer is flat. According to claim 3,
The first metal part is disposed outside the third surface of the first wafer,
The second metal part is disposed outside the fourth surface of the second wafer. 5. The wafer level package of claim 4, wherein the third surface of the first wafer, the fourth surface of the second wafer, and the light transmitting member are arranged to form a cavity. 6. The wafer level package of claim 5, wherein the cavity is in a vacuum state. The wafer level package of claim 1 , wherein each of the first and second wafers is a silicon wafer. A first part and a second part having first and second surfaces opposite to each other in a vertical direction, having a plurality of through holes spaced apart from each other in a horizontal direction, and adjacent to each other in the horizontal direction around the plurality of through holes. a light transmitting member having;
a plurality of first wafers each having a first metal portion bonded to the first surface of the first portion of the light transmitting member; and
including a plurality of second wafers each having a second metal portion bonded to the second surface of the second portion of the light transmitting member;
A wafer level package wherein a plane size of each of the plurality of first and second wafers is larger than a plane size of each of the plurality of through holes. The method of claim 8, wherein the first portion of the light transmitting member contacts each of the plurality of through holes in the horizontal direction,
The second portion of the light transmitting member contacts the first portion in the horizontal direction. In the manufacturing method of a wafer level package including first and second wafers,
preparing a light-transmitting member having a first portion and a second portion adjacent to each other in a horizontal direction and first and second surfaces opposite to each other in a vertical direction;
overlapping the first portion of the light transmitting member and the first metal portion included in the first wafer in the vertical direction;
bonding a first surface of the first portion to the first metal portion by irradiating a laser beam to the first metal portion through the first portion of the light-transmitting member;
overlapping the second portion of the light transmitting member and a second metal portion included in the second wafer in the vertical direction; and
and irradiating a laser beam to the second metal part through the second part of the light-transmissive member to bond the second surface of the second part and the second metal part. In the manufacturing method of a wafer level package including a plurality of first wafers and a plurality of second wafers,
A first part and a second part having first and second surfaces opposite to each other in a vertical direction, having a plurality of through holes spaced apart from each other in a horizontal direction, and adjacent to each other in the horizontal direction around the plurality of through holes. preparing a light transmitting member having;
overlapping a first metal portion of each of the plurality of first wafers connected to each other by a first bridge with the first portion of the light transmitting member in the vertical direction;
A laser beam is irradiated to the first metal portion of each of the plurality of first wafers through the first portion of the light-transmitting member, so that the first surface of the first portion and the first metal portion of each of the plurality of first wafers are formed. 1 bonding the metal part;
removing the first bridge after bonding the first metal part;
overlapping a second metal portion of each of the plurality of second wafers connected to each other by a second bridge with the second portion of the light transmitting member in the vertical direction;
A laser beam is irradiated to the second metal portion of each of the plurality of second wafers through the second portion of the light-transmissive member, so that the second surface of the second portion and the second metal portion of each of the plurality of second wafers are formed. 2 bonding the metal part; and
and removing the second bridge after bonding the second metal part.

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