Forming Method for a triple-step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package

Abstract

The present invention comprises: a step B100 in which a seed layer is first coated on the bonding surface; a step B200 in which a primary photoresist (PR) is coated on the seed layer and first patterned according to a preset pattern; a step B300 in which a primary barrier layer is coated on the seed layer exposed by the first patterning; a step B400 in which the primary photoresist (PR) is removed; a step B500 in which a secondary photoresist (PR) is coated on the seed layer and the primary barrier layer from which the primary photoresist (PR) has been removed and secondarily patterned according to a preset pattern; and a step B600 in which a secondary barrier layer is coated on the primary barrier layer exposed after patterning in the step B500. Step B700, in which the secondary photoresist (PR) is removed; Step B800, in which a tertiary photoresist (PR) is coated on the seed layer from which the secondary photoresist (PR) has been removed and tertiary patterning is performed according to a preset pattern; Step B900, in which a tertiary barrier layer is coated on the seed layer, primary barrier layer, and secondary barrier layer exposed after patterning in Step B800; Step B1000, in which a wetting layer is coated on the tertiary barrier layer; Step B1100, in which the tertiary photoresist (PR) is removed; Step B1200, in which a seed layer is removed, is performed, so that a soldering channel portion (400) having a triple step is provided, wherein a first end (Y1), a second end (Y2), and a third end (Y3) of different heights are disposed on the bonding surface.

Description

Technology Field

[0001] The present invention relates to a method for forming a triple step soldering channel portion. Specifically, it relates to a method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package. Background Technology

[0002] Examples of MEMS sensors include those that require vacuum bonding, such as MEMS infrared sensors.

[0003] MEMS infrared sensors refer to ultra-small sensors that perform the function of detecting or controlling light (optical signals) by utilizing MEMS (Micro-Electro-Mechanical Systems) technology. Using silicon-based semiconductor process technology (micro-machining), mechanical structures and electronic circuits ranging in size from several micrometers to several millimeters are integrated onto a single chip.

[0004] MEMS infrared sensors utilize the principle that temperature rises upon the absorption of infrared radiation. To minimize the influence of the surrounding environment and maximize the temperature rise caused by detected infrared radiation, it is necessary to provide thermal isolation from the surroundings and block heat transfer via conduction and convection within the package's internal gas. This is why vacuum sealing is required.

[0005] However, although vacuum bonding is performed on the bonding surface, there is a problem in that it is not easy to maintain a vacuum state due to the inflow of external air through the bonding surface. Prior art literature

[0006] (Reference 1) Korean Published Patent Application No. 10-2019-0136007 (December 9, 2019) The problem to be solved

[0007] The method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package according to the present invention has the following problem to be solved.

[0008] First, we intend to form a soldering channel section with a triple step structure on the bonding surface.

[0009] Second, by utilizing the soldering channel, the solder layer is intended to be more firmly bonded to the substrate and cover portions.

[0010] Third, it aims to prevent external air from entering the interior through the joint surface after joining.

[0011] The problems solved by the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0012] The present invention relates to a method for forming a soldering channel portion having a triple step on a bonding surface at least one of a substrate portion and a cover portion of a MEMS sensor package that is vacuum bonded by melt-filling a solder layer into the soldering channel portion, comprising: a step B100 in which a seed layer is first coated on the bonding surface; a step B200 in which a first photoresistor is coated on the seed layer and first patterned according to a preset pattern; a step B300 in which a first barrier layer is coated on the seed layer exposed by the first patterning; a step B400 in which the first photoresistor is removed; a step B500 in which a second photoresistor is coated on the seed layer and the first barrier layer from which the first photoresistor has been removed and secondly patterned according to a preset pattern; a step B600 in which a second barrier layer is coated on the first barrier layer exposed after patterning in step B500; and a step B700 in which the second photoresistor is removed. Step B800, in which a third photoresist is coated on a seed layer from which a second photoresist has been removed and a third pattern is formed according to a preset pattern; Step B900, in which a third barrier layer is coated on the seed layer, first barrier layer, and second barrier layer exposed after patterning in Step B800; Step B1000, in which a wetting layer is coated on the third barrier layer; Step B1100, in which the third photoresist is removed; and Step B1200, in which the seed layer is removed; are performed so that a soldering channel portion having a triple step is provided, wherein a first end, a second end, and a third end having different heights are disposed on the bonding surface.

[0013] In the present invention, at step B100, the seed layer may be provided as a titanium (Ti) layer or a chromium (Cr) layer.

[0014] In the present invention, at step B200, the preset pattern may be configured such that at least a portion of the seed layer is exposed.

[0015] In the present invention, at step B300, the primary barrier layer may be provided as a nickel (Ni) layer.

[0016] In the present invention, at step B500, the preset pattern may be configured to expose a portion of the primary barrier layer and not expose the seed layer.

[0017] In the present invention, at step B600, the secondary barrier layer may be provided as a nickel (Ni) layer.

[0018] In the present invention, at step B800, the preset pattern may be configured to expose both the primary barrier layer and the secondary barrier layer, and to expose a portion of the seed layer.

[0019] In the present invention, at step B900, the third barrier layer may be provided as a nickel (Ni) layer.

[0020] In the present invention, at step B1000, the wetting layer may be provided as a gold (Au) layer.

[0021] In the present invention, at step B1200, the seed layer can be removed by etching.

[0022] In the present invention, the seed layer of step B100 is provided with a titanium (Ti) layer or a chromium (Cr) layer, the primary barrier layer of step B300 is provided with a primary nickel (Ni) layer, the secondary barrier layer of step B600 is provided with a secondary nickel (Ni) layer, the tertiary barrier layer of step B900 is provided with a tertiary nickel (Ni) layer, and the wetting layer of step B1000 can be provided with a gold (Au) layer.

[0023] In the present invention, in the triple step of the soldering channel portion formed on the bonding surface, the first end is provided by being formed by stacking a Cr layer, a tertiary Ni layer, and an Au layer in that order on the bonding surface, the second end is provided by being formed by stacking a Cr layer, a primary Ni layer, a tertiary Ni layer, and an Au layer in that order on the bonding surface, and the third end is provided by being formed by stacking a Cr layer, a primary Ni layer, a secondary Ni layer, a tertiary Ni layer, and an Au layer in that order on the bonding surface, and the first end, the second end, and the third end may be positioned higher on the bonding surface.

[0024] In the present invention, in the triple step of the soldering channel portion formed on the bonding surface, the first end is provided by being formed by stacking a Ti layer, a tertiary Ni layer, and an Au layer in that order on the bonding surface, the second end is provided by being formed by stacking a Ti layer, a primary Ni layer, a tertiary Ni layer, and an Au layer in that order on the bonding surface, and the third end is provided by being formed by stacking a Ti layer, a primary Ni layer, a secondary Ni layer, a tertiary Ni layer, and an Au layer in that order on the bonding surface, and the first end, the second end, and the third end may be positioned higher on the bonding surface.

[0025] In the present invention, the first end, the second end, and the third end may be provided to be arranged alternately in sequence.

[0026] In the present invention, the first end, the second end, and the third end may be provided to be randomly arranged.

[0027] In the present invention, the soldering channel portion may be provided continuously or discontinuously at the bonding surface.

[0028] In the present invention, the solder material of the solder layer may be provided as a eutectic alloy.

[0029] In the present invention, the eutectic alloy may be provided as any one of an Au-Sn alloy, an Au-In alloy, an Au-Si alloy, a Pb-Sn alloy, or a Sn-Ag-Cu alloy.

[0030] In the present invention, the MEMS sensor may be equipped with at least one sensor among an infrared sensor, an inertial sensor, a pressure sensor, a thermal sensor, a microbolometer, an accelerometer, or a resonant sensor.

[0032] The present invention relates to a MEMS sensor package having a soldering channel with a triple step formed therein, wherein a soldering channel portion is formed on at least one bonding surface of a substrate portion and a cover portion, and the substrate portion and the cover portion are vacuum bonded while a solder layer is melt-filled into the soldering channel portion, and the soldering channel portion is provided by a method for forming a triple step soldering channel portion provided on the bonding surface of the MEMS sensor package according to the present invention, so as to have a triple step including a first end, a second end, and a third end having different heights on the bonding surface, wherein the first end is formed by stacking a seed layer, a third barrier layer, and a wetting layer in that order on the bonding surface, the second end is formed by stacking a seed layer, a first barrier layer, a third barrier layer, and a wetting layer in that order on the bonding surface, and the third end is formed by stacking a seed layer, a first barrier layer, a second barrier layer, a third barrier layer, and a wetting layer in that order on the bonding surface, so as to have a triple step including a first end, a second end, and a third end, in that order, higher on the bonding surface. It is positioned, and the solder layer can be vacuum bonded to block the inflow of external air while being melt-filled inside the triple step of the soldering channel portion.

[0034] The present invention relates to a MEMS infrared sensor package having a soldering channel portion having a triple step formed, comprising: a substrate portion having an infrared sensor mounted on one side; a cover portion spaced apart from the upper portion of the substrate portion and having a window on one side through which external infrared rays are transmitted; and a solder layer that contacts the substrate portion and the cover portion, respectively, and vacuum-bonds them on each bonding surface of the substrate portion and the cover portion. and a soldering channel portion formed with a preset step structure on a bonding surface of at least one of the substrate portion and the cover portion; wherein the soldering channel portion is provided by a method for forming a triple step soldering channel portion provided on a bonding surface of a MEMS sensor package according to the present invention, and is provided to have a triple step including a first end, a second end, and a third end having different heights on the bonding surface, wherein the first end is formed by stacking a seed layer, a third barrier layer, and a wetting layer in that order on the bonding surface, the second end is formed by stacking a seed layer, a first barrier layer, a third barrier layer, and a wetting layer in that order on the bonding surface, and the third end is formed by stacking a seed layer, a first barrier layer, a second barrier layer, a third barrier layer, and a wetting layer in that order on the bonding surface, so as to be located higher on the bonding surface in the order of the first end, the second end, and the third end, and the solder layer is melt-filled into the triple step of the soldering channel portion, thereby preventing the inflow of external air It can be vacuum bonded to block. Effects of the invention

[0035] The method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package according to the present invention has the following effects.

[0036] First, it has the effect of forming a soldering channel section with a triple step structure on the joint surface.

[0037] Second, by utilizing the soldering channel, there is an effect of bonding the solder layer more firmly to the substrate and cover portions.

[0038] Third, it has the effect of preventing external air from entering the interior through the joint surface after joining.

[0039] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description below. Brief explanation of the drawing

[0040] Figure 1 is a schematic diagram of step B100 according to the present invention. Figure 2 is a schematic diagram of step B200 according to the present invention. Figure 3 is a schematic diagram of the B300 step according to the present invention. Figure 4 is a schematic diagram of step B400 according to the present invention. FIG. 5 is a schematic diagram of the B500 step according to the present invention. FIG. 6 is a schematic diagram of the B600 step according to the present invention. FIG. 7 is a schematic diagram of the B700 step according to the present invention. FIG. 8 is a schematic diagram of the B800 step according to the present invention. FIG. 9 is a schematic diagram of the B900 step according to the present invention. FIG. 10 is a schematic diagram of the B1000 step according to the present invention. FIG. 11 is a schematic diagram of step B1100 according to the present invention. FIG. 12 is a schematic diagram of step B1200 according to the present invention. FIG. 13 is a schematic diagram of a soldering channel section (400) having a triple step structure having a first end (Y1), a second end (Y2) and a third end (Y3). FIG. 14 is a partial cross-sectional view of a MEMS sensor package equipped with a soldering channel portion (400) having a triple step structure according to the present invention. FIG. 15a is a schematic diagram of a MEMS infrared sensor package equipped with a triple step soldering channel portion (400) according to the present invention, and FIG. 15b is a partial enlarged view of area A of the bonding surface (210) of the cover portion (200). Specific details for implementing the invention

[0041] Hereinafter, embodiments of the present invention are described with reference to the attached drawings so that those skilled in the art can easily implement the present invention. As will be easily understood by those skilled in the art, the embodiments described below may be modified in various forms without departing from the concept and scope of the present invention. Where possible, identical or similar parts are indicated using the same reference numerals in the drawings.

[0042] The technical terms used in this specification are intended merely to refer to specific embodiments and are not intended to limit the invention. The singular forms used herein include plural forms unless phrases clearly indicate otherwise.

[0043] As used in this specification, the meaning of “comprising” specifies certain characteristics, regions, integers, steps, actions, elements, and / or components, and does not exclude the existence or addition of other specific characteristics, regions, integers, steps, actions, elements, components, and / or groups.

[0044] All terms used herein, including technical and scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms defined in advance are further interpreted to have meanings consistent with relevant technical literature and the present disclosure, and are not interpreted in an ideal or highly formal sense unless otherwise defined.

[0045] Expressions regarding direction used in this specification, for example, expressions of front / back / left / right, expressions of up / down, and expressions of longitudinal / transverse directions, may be interpreted by referring to the directions disclosed in the drawings.

[0047] The present invention will be described below with reference to the drawings. For reference, the drawings may be partially exaggerated to illustrate the features of the present invention. In such cases, it is preferable to interpret them in light of the entire intent of this specification.

[0049] The present invention relates to a method for forming a soldering channel portion having a triple step on a bonding surface at least one of a substrate portion and a cover portion of a MEMS sensor package that is vacuum bonded by melting and filling a solder layer into the soldering channel portion.

[0050] The present invention comprises: a step B100 in which a seed layer is first coated on the bonding surface; a step B200 in which a primary photoresist (PR) is coated on the seed layer and first patterned according to a preset pattern; a step B300 in which a primary barrier layer is coated on the seed layer exposed by the first patterning; a step B400 in which the primary photoresist (PR) is removed; a step B500 in which a secondary photoresist (PR) is coated on the seed layer and the primary barrier layer from which the primary photoresist (PR) has been removed and secondarily patterned according to a preset pattern; and a step B600 in which a secondary barrier layer is coated on the primary barrier layer exposed after patterning in the step B500. Step B700, in which the secondary photoresist (PR) is removed; Step B800, in which a tertiary photoresist (PR) is coated on the seed layer from which the secondary photoresist (PR) has been removed and tertiary patterning is performed according to a preset pattern; Step B900, in which a tertiary barrier layer is coated on the seed layer, primary barrier layer, and secondary barrier layer exposed after patterning in Step B800; Step B1000, in which a wetting layer is coated on the tertiary barrier layer; Step B1100, in which the tertiary photoresist (PR) is removed; Step B1200, in which a seed layer is removed, is performed, so that a soldering channel portion (400) having a triple step is provided, wherein a first end (Y1), a second end (Y2), and a third end (Y3) of different heights are disposed on the bonding surface.

[0052] Hereinafter, the B100 step according to the present invention will be described.

[0053] In the B100 step according to the present invention, a seed layer may be primarily coated on the bonding surface. In the present invention, the seed layer may be provided as a titanium (Ti) layer or a chromium (Cr) layer. The titanium (Ti) layer or the chromium (Cr) layer, i.e., the seed layer, may be coated by a deposition method.

[0054] FIG. 1 is a schematic diagram of the B100 step according to the present invention. It shows an embodiment in which a seed layer is first coated on the bonding surface.

[0055] For reference, to facilitate the explanation of the present invention, a chromium (Cr) layer is described as an example in these drawings. However, the present invention can be explained in the same way even if the chromium (Cr) layer is replaced with a titanium (Ti) layer.

[0056] The seed layer serves as a crystal growth nucleus for the metal thin film to be deposited in a subsequent process, such as a plating process, and provides a foundation for the subsequent metal layer to grow uniformly and in the desired crystal direction.

[0057] An adhesion layer is a layer that strengthens the adhesion between a substrate and a thin film (e.g., metal) to be deposited thereon. By improving the chemical and physical bonding between the two materials, it prevents the thin film from detaching or peeling off during subsequent processes (such as heat treatment).

[0058] The seed layer according to the present invention may also perform the function of an adhesion layer.

[0061] Hereinafter, the B200 step according to the present invention will be described.

[0062] In the present invention, the process can be carried out in various ways, such as a method in which patterning is performed after the photoresist is coated, or a method in which patterning is performed simultaneously while coating only a specific area.

[0063] Step B200 according to the present invention may have a primary photoresist (PR) coated on a seed layer and primary patterned according to a preset pattern. In the present invention, the preset pattern may be configured such that at least a portion of the seed layer is exposed.

[0064] FIG. 2 is a schematic diagram of the B200 step according to the present invention. It shows an embodiment in which a primary photoresist (PR) is coated on a seed layer and primary patterned according to a preset pattern.

[0066] Hereinafter, the B300 step according to the present invention will be described.

[0067] The barrier layer plays a role in maintaining mechanical and electrical stability by preventing the solder metal used as the solder layer from penetrating the metal on the substrate bonding surface.

[0068] In the B300 step according to the present invention, a primary barrier layer may be coated on a seed layer exposed by primary patterning. The primary barrier layer may be vacuum bonded, characterized by being provided with a nickel (Ni) layer. The nickel (Ni) layer may be coated by a plating method.

[0069] FIG. 3 is a schematic diagram of the B300 step according to the present invention. It shows an embodiment in which a primary barrier layer is coated on a seed layer exposed by primary patterning.

[0072] Hereinafter, the B400 step according to the present invention will be described.

[0073] Step B400 according to the present invention allows the primary photoresist (PR) to be removed.

[0074] FIG. 4 is a schematic diagram of the B400 step according to the present invention. It shows an embodiment in which the primary photoresist (PR) is removed.

[0077] Hereinafter, the B500 step according to the present invention will be described.

[0078] Step B500 according to the present invention may have a secondary photoresist (PR) coated on a seed layer and a primary barrier layer from which the primary photoresist (PR) has been removed, and may be secondarily patterned according to a preset pattern.

[0079] In this step, the pre-set pattern may be configured to expose a portion of the primary barrier layer and not expose the seed layer.

[0080] FIG. 5 is a schematic diagram of the B500 step according to the present invention. It shows an embodiment in which a secondary photoresist (PR) is coated on a seed layer and a primary barrier layer from which the primary photoresist (PR) has been removed, and a secondary pattern is formed according to a preset pattern.

[0083] Hereinafter, the B600 step according to the present invention will be described.

[0084] In the B600 step according to the present invention, a secondary barrier layer may be coated on the primary barrier layer exposed after panning in the B500 step. The secondary barrier layer may be provided as a nickel (Ni) layer. The nickel (Ni) layer may be coated by a plating method.

[0085] FIG. 6 is a schematic diagram of the B600 step according to the present invention. It shows an embodiment in which a secondary barrier layer is coated on the seed layer and primary barrier layer exposed after secondary panning of the B500 step.

[0088] Hereinafter, the B700 step according to the present invention will be described.

[0089] Step B700 according to the present invention allows the secondary photoresist (PR) to be removed.

[0090] FIG. 7 is a schematic diagram of the B700 step according to the present invention. It shows an embodiment in which a secondary photoresist (PR) is removed.

[0093] Hereinafter, the B800 step according to the present invention will be described.

[0094] Step B800 according to the present invention involves coating a tertiary photoresist (PR) on a seed layer from which a secondary photoresist (PR) has been removed, and then tertiarily patterning it according to a preset pattern.

[0095] In this step, the pre-set pattern may be configured to expose both the primary barrier layer and the secondary barrier layer, and to expose a portion of the seed layer.

[0096] FIG. 8 is a schematic diagram of the B800 step according to the present invention.

[0099] Hereinafter, the B900 step according to the present invention will be described.

[0100] In the B900 step according to the present invention, a third barrier layer may be coated on the seed layer, first barrier layer, and second barrier layer exposed after panning in the B800 step.

[0101] In the present invention, the third barrier layer may be provided as a nickel (Ni) layer. The nickel (Ni) layer may be coated by a plating method.

[0102] FIG. 9 is a schematic diagram of the B900 step according to the present invention.

[0105] Hereinafter, the B1000 step according to the present invention will be described.

[0106] Step B1000 according to the present invention may have a wetting layer coated on a third barrier layer. The wetting layer may be provided as a gold (Au) layer. The gold (Au) layer may be coated by a plating method.

[0107] The wetting layer ensures that the solder spreads well across the bonding surface of the substrate to facilitate a good bond, and suppresses oxidation of the metal surface to secure bonding reliability. Au, Pd, Ag, and Cu are commonly used.

[0108] FIG. 10 is a schematic diagram of the B1000 step according to the present invention. It shows an embodiment in which a wetting layer is coated on a third barrier layer.

[0111] Hereinafter, the B1100 step according to the present invention will be described.

[0112] Step B1100 according to the present invention can remove the tertiary photoresist (PR).

[0113] FIG. 11 is a schematic diagram of step B1100 according to the present invention. It shows an embodiment in which a tertiary photoresist (PR) is removed.

[0116] Hereinafter, the B1200 step according to the present invention will be described.

[0117] Step B1200 according to the present invention may remove the seed layer.

[0118] In the present invention, the seed layer can be removed by an etching method.

[0119] FIG. 12 is a schematic diagram of step B1200 according to the present invention. It shows an embodiment in which an exposed seed layer is removed.

[0122] Hereinafter, embodiments equipped with a material pre-set in each step of the present invention are described.

[0123] In the present invention, the seed layer of step B100 is provided with a titanium (Ti) layer or a chromium (Cr) layer, the primary barrier layer of step B300 is provided with a primary nickel (Ni) layer, the secondary barrier layer of step B600 is provided with a secondary nickel (Ni) layer, the tertiary barrier layer of step B900 is provided with a tertiary nickel (Ni) layer, and the wetting layer of step B1000 can be provided with a gold (Au) layer.

[0126] Below, a triple step structure according to the present invention is described.

[0127] FIG. 13 is a schematic diagram of a soldering channel section (400) having a triple step structure having a first end (Y1), a second end (Y2) and a third end (Y3).

[0128] FIG. 14 is a partial cross-sectional view of a MEMS sensor package equipped with a soldering channel portion (400) having a triple step structure according to the present invention.

[0129] In the present invention, as shown in FIG. 13, in the triple step of the soldering channel portion (400) formed on the bonding surface, the first end (Y1) is provided by being formed by stacking a Cr layer, a tertiary Ni layer, and an Au layer in that order on the bonding surface, the second end (Y2) is provided by being formed by stacking a Cr layer, a primary Ni layer, a tertiary Ni layer, and an Au layer in that order on the bonding surface, and the third end (Y3) is provided by being formed by stacking a Cr layer, a primary Ni layer, a secondary Ni layer, a tertiary Ni layer, and an Au layer in that order on the bonding surface, and the first end (Y1), the second end (Y2), and the third end (Y3) can be positioned higher on the bonding surface in that order.

[0131] In addition, as an embodiment in which a chromium (Cr) layer is replaced with a titanium (Ti) layer, the present invention is provided such that in a triple step of a soldering channel portion (400) formed on a bonding surface, a first end (Y1) is formed by stacking a Ti layer, a tertiary Ni layer, and an Au layer in that order on the bonding surface, a second end (Y2) is formed by stacking a Ti layer, a primary Ni layer, a tertiary Ni layer, and an Au layer in that order on the bonding surface, and a third end (Y3) is formed by stacking a Ti layer, a primary Ni layer, a secondary Ni layer, a tertiary Ni layer, and an Au layer in that order on the bonding surface, and the first end (Y1), the second end (Y2), and the third end (Y3) can be positioned higher on the bonding surface in that order.

[0134] Below, the arrangement of each end formed in the soldering channel section is described.

[0135] Each end according to the present invention, namely the first end (Y1), the second end (Y2), and the third end (Y3), may be provided to be arranged alternately in sequence.

[0136] In addition, each end according to the present invention, namely the first end (Y1), the second end (Y2), and the third end (Y3), may be provided to be arranged randomly. The embodiment of FIG. 13 shows an embodiment arranged randomly.

[0139] In the following, the continuous and discontinuous arrangement of the soldering channel section will be described.

[0140] In the present invention, the soldering channel portion (400) may be provided continuously or discontinuously at the bonding surface.

[0141] FIG. 13 shows an embodiment in which the soldering channel portion (400) is provided continuously at the bonding surface. FIG. 14 shows an embodiment in which the soldering channel portions (400a) and (400b) are provided discontinuously, that is, spaced apart, at the bonding surface. When provided discontinuously, the bonding surface may be exposed, and the first end, second end, and third end may be distinguished from the exposed surface. When provided continuously, the bonding surface may be provided so as not to be exposed, or the bonding surface may be provided so as to be partially exposed.

[0144] Below, the material of the solder layer is described.

[0145] In the present invention, the solder material of the solder layer may be provided as a eutectic alloy.

[0146] In the present invention, the eutectic alloy may be provided as any one of an Au-Sn alloy, an Au-In alloy, an Au-Si alloy, a Pb-Sn alloy, or a Sn-Ag-Cu alloy.

[0147] Eutectic refers to a mixture or the phenomenon in which two or more substances have the lowest melting point (eutectic point) when mixed.

[0148] A eutectic alloy refers to an alloy in which two or more types of metals are mixed in specific proportions and melt at a temperature lower than the melting point of each metal. In such alloys, the two phases do not separate but form a superlattice (eutectic structure) as a single solid mixture, and they can be utilized in various fields such as soldering and bonding.

[0151] Below, MEMS sensors are described.

[0152] In the present invention, the MEMS sensor may be equipped with at least one sensor among an infrared sensor, an inertial sensor, a pressure sensor, a thermal sensor, a microbolometer, an accelerometer, or a resonant sensor.

[0153] The MEMS sensor applied to the present invention is preferably a MEMS sensor that requires vacuum bonding.

[0156] Meanwhile, the present invention can be implemented as a MEMS sensor package.

[0157] A MEMS sensor package having a soldering channel with a triple step formed according to the present invention has a soldering channel formed at least at one bonding surface of a substrate portion and a cover portion, and the substrate portion and the cover portion are vacuum bonded as a solder layer is melt-filled into the soldering channel portion, and the soldering channel portion (400) is provided by a method for forming a triple step soldering channel portion provided on the bonding surface of the MEMS sensor package according to claim 1, so as to have a triple step including a first end (Y1), a second end (Y2), and a third end (Y3) having different heights on the bonding surface, wherein the first end is formed by stacking a seed layer, a third barrier layer, and a wetting layer in that order on the bonding surface, the second end is formed by stacking a seed layer, a first barrier layer, a third barrier layer, and a wetting layer in that order on the bonding surface, and the third end is formed by stacking a seed layer, a first barrier layer, a second barrier layer, a third barrier layer, and a wetting layer in that order on the bonding surface, so as to have a first In the order of the end, the second end, and the third end, they are positioned higher on the joint surface, and vacuum bonding can be performed so as to block the inflow of external air while the solder layer is melt-filled inside the triple step of the soldering channel portion.

[0159] Meanwhile, the present invention can be implemented as a MEMS infrared sensor package.

[0160] A MEMS infrared sensor package having a soldering channel portion with a triple step formed according to the present invention comprises: a substrate portion (100) having an infrared sensor (S) mounted on one side; a cover portion (200) spaced apart from the upper portion of the substrate portion (100) and having a window (W) on one side through which external infrared rays are transmitted; and a solder layer (300) that vacuum-bonds by contacting the substrate portion and the cover portion, respectively, on each bonding surface (110) (210) of the substrate portion (100) and the cover portion (200). The soldering channel portion (400) is formed with a preset step structure on a bonding surface of at least one of the substrate portion and the cover portion; wherein the soldering channel portion (400) is provided by a method for forming a triple step soldering channel portion provided on a bonding surface of a MEMS sensor package according to claim 1, and is provided to have a triple step including a first end (Y1), a second end (Y2), and a third end (Y3) having different heights on the bonding surface, wherein the first end is formed by stacking a seed layer, a third barrier layer, and a wetting layer in that order on the bonding surface, the second end is formed by stacking a seed layer, a first barrier layer, a third barrier layer, and a wetting layer in that order on the bonding surface, and the third end is formed by stacking a seed layer, a first barrier layer, a second barrier layer, a third barrier layer, and a wetting layer in that order on the bonding surface, and is positioned higher on the bonding surface in the order of the first end, the second end, and the third end. The above solder layer can be vacuum bonded to block the inflow of external air while being melt-filled into the triple step of the soldering channel portion.

[0161] FIG. 15a is a schematic diagram of a MEMS infrared sensor package equipped with a triple step soldering channel portion (400) according to the present invention, and FIG. 15b is a partial enlarged view of area A of the bonding surface (210) of the cover portion (200).

[0163] The embodiments described in this specification and the accompanying drawings are merely illustrative of a part of the technical concept included in the present invention. Accordingly, since the embodiments disclosed in this specification are intended to explain, not limit, the technical concept of the present invention, it is obvious that the scope of the technical concept of the present invention is not limited by these embodiments. All variations and specific embodiments that can be easily deduced by a person skilled in the art within the scope of the technical concept included in the specification and drawings of the present invention should be interpreted as being included within the scope of the rights of the present invention. Explanation of the symbols

[0164] 100 : Substrate part 110 : Joint surface 200 : Cover part 210 : Bonding surface 300 : Solder layer 400 : Soldering channel section S: MEMS infrared sensor W : Windows

Claims

Claim 1 A method for forming a soldering channel portion having a triple step on a bonding surface at least one of a substrate portion and a cover portion of a MEMS sensor package that is vacuum bonded by melt-filling a solder layer into the soldering channel portion, comprising: a step B100 in which a seed layer is first coated on the bonding surface; a step B200 in which a first photoresistor is coated on the seed layer and first patterned according to a preset pattern; a step B300 in which a first barrier layer is coated on the seed layer exposed by the first patterning; a step B400 in which the first photoresistor is removed; a step B500 in which a second photoresistor is coated on the seed layer and the first barrier layer from which the first photoresistor has been removed and secondly patterned according to a preset pattern; a step B600 in which a second barrier layer is coated on the first barrier layer exposed after patterning in step B500; and a step B700 in which the second photoresistor is removed. A method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package, characterized by performing the following steps: a step B800 in which a third photoresist is coated on a seed layer from which a second photoresist has been removed and a third pattern is formed according to a preset pattern; a step B900 in which a third barrier layer is coated on the seed layer, first barrier layer, and second barrier layer exposed after patterning in the step B800; a step B1000 in which a wetting layer is coated on the third barrier layer; a step B1100 in which the third photoresist is removed; and a step B1200 in which the seed layer is removed; wherein a soldering channel portion having a triple step is provided on the bonding surface, wherein a first end, a second end, and a third end having different heights are disposed thereon. Claim 2 A method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package, characterized in that, in step B100, the seed layer is provided as a titanium (Ti) layer or a chromium (Cr) layer. Claim 3 A method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package, wherein, in step B200, the preset pattern is provided such that at least a portion of the seed layer is exposed. Claim 4 A method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package, characterized in that, in step B300, the primary barrier layer is provided as a nickel (Ni) layer. Claim 5 A method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package, characterized in that, in step B500, the preset pattern exposes a portion of the primary barrier layer and does not expose the seed layer. Claim 6 A method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package, characterized in that, in step B600, the secondary barrier layer is provided as a nickel (Ni) layer. Claim 7 A method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package, characterized in that, in step B800, the preset pattern is configured to expose both the primary barrier layer and the secondary barrier layer, and expose a portion of the seed layer. Claim 8 A method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package, characterized in that, in step B900, the third barrier layer is provided as a nickel (Ni) layer. Claim 9 A method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package, characterized in that, in step B1000, the wetting layer is provided as a gold (Au) layer. Claim 10 A method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package, characterized in that, in step B1200, the seed layer is removed by an etching method. Claim 11 A method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package, characterized in that, in claim 1, the seed layer of step B100 is provided as a titanium (Ti) layer or a chromium (Cr) layer, the primary barrier layer of step B300 is provided as a primary nickel (Ni) layer, the secondary barrier layer of step B600 is provided as a secondary nickel (Ni) layer, the tertiary barrier layer of step B900 is provided as a tertiary nickel (Ni) layer, and the wetting layer of step B1000 is provided as a gold (Au) layer. Claim 12 A method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package according to claim 11, wherein, in the triple step of the soldering channel portion formed on the bonding surface, the first end is provided by being formed by stacking a Cr layer, a tertiary Ni layer, and an Au layer in that order on the bonding surface, the second end is provided by being formed by stacking a Cr layer, a primary Ni layer, a tertiary Ni layer, and an Au layer in that order on the bonding surface, and the third end is provided by being formed by stacking a Cr layer, a primary Ni layer, a secondary Ni layer, a tertiary Ni layer, and an Au layer in that order on the bonding surface, and the first end, the second end, and the third end are positioned higher on the bonding surface. Claim 13 A method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package according to claim 11, wherein, in the triple step of the soldering channel portion formed on the bonding surface, the first end is provided by being formed by stacking a Ti layer, a tertiary Ni layer, and an Au layer in that order on the bonding surface, the second end is provided by being formed by stacking a Ti layer, a primary Ni layer, a tertiary Ni layer, and an Au layer in that order on the bonding surface, and the third end is provided by being formed by stacking a Ti layer, a primary Ni layer, a secondary Ni layer, a tertiary Ni layer, and an Au layer in that order on the bonding surface, and the first end, the second end, and the third end are positioned higher on the bonding surface. Claim 14 A method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package, characterized in that, in claim 12 or claim 13, the first end, the second end, and the third end are arranged to be alternately arranged sequentially. Claim 15 A method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package, characterized in that, in claim 12 or claim 13, the first end, the second end, and the third end are provided to be randomly arranged. Claim 16 A method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package, wherein, in claim 1, the soldering channel portion is provided continuously or discontinuously on the bonding surface. Claim 17 A method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package, wherein, in claim 1, the solder material of the solder layer is provided as a eutectic alloy. Claim 18 A method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package, wherein, in claim 17, the eutectic alloy is provided as any one of an Au-Sn alloy, an Au-In alloy, an Au-Si alloy, a Pb-Sn alloy, or a Sn-Ag-Cu alloy. Claim 19 A method for forming a triple step soldering channel portion provided on the bonding surface of a vacuum-bonded MEMS sensor package, wherein, in claim 1, the MEMS sensor is provided as at least one sensor selected from an infrared sensor, an inertial sensor, a pressure sensor, a thermal sensor, a microbolometer, an accelerometer, or a resonant sensor. Claim 20 A soldering channel portion is formed on at least one bonding surface of a substrate portion and a cover portion, and the substrate portion and the cover portion are vacuum bonded as a solder layer is melted and filled into the soldering channel portion. The soldering channel portion is provided by a method for forming a triple step soldering channel portion provided on the bonding surface of a MEMS sensor package according to claim 1, and is provided to have a triple step including a first end, a second end, and a third end having different heights on the bonding surface. The first end is formed by stacking a seed layer, a third barrier layer, and a wetting layer in that order on the bonding surface. The second end is formed by stacking a seed layer, a first barrier layer, a third barrier layer, and a wetting layer in that order on the bonding surface. The third end is formed by stacking a seed layer, a first barrier layer, a second barrier layer, a third barrier layer, and a wetting layer in that order on the bonding surface. The first end, the second end, and the third end are positioned higher on the bonding surface in that order, and the solder layer is melted inside the triple step of the soldering channel portion. A MEMS sensor package having a soldering channel portion with a triple step formed therein, characterized by being vacuum-bonded to block the inflow of external air while being filled. Claim 21 A substrate portion having an infrared sensor mounted on one side; a cover portion spaced apart from the upper portion of the substrate portion and having a window on one side through which external infrared rays are transmitted; and a solder layer that vacuum-bonds by contacting the substrate portion and the cover portion, respectively, on the bonding surfaces of the substrate portion and the cover portion. and a soldering channel portion formed with a preset step structure on a bonding surface of at least one of the substrate portion and the cover portion; wherein the soldering channel portion is provided by a method for forming a triple step soldering channel portion provided on a bonding surface of a MEMS sensor package according to claim 1, and is provided to have a triple step including a first end, a second end, and a third end having different heights on the bonding surface, wherein the first end is formed by stacking a seed layer, a third barrier layer, and a wetting layer in that order on the bonding surface, the second end is formed by stacking a seed layer, a first barrier layer, a third barrier layer, and a wetting layer in that order on the bonding surface, and the third end is formed by stacking a seed layer, a first barrier layer, a second barrier layer, a third barrier layer, and a wetting layer in that order on the bonding surface, so as to be located higher on the bonding surface in the order of the first end, the second end, and the third end, and as the solder layer is melt-filled into the triple step of the soldering channel portion, the external air A MEMS infrared sensor package having a soldering channel portion with a triple step formed, characterized by being vacuum-bonded to block inflow.

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