JP2013008720A - Electronic device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic device manufacturing method that can enhance the bond strength between members constituting an electronic device by a relatively simple method.SOLUTION: There is provided a method of manufacturing an electronic device 10 having a semiconductor substrate 2, a board 1 on which the semiconductor substrate 2 is mounted, and bonding portions 3 for bonding the semiconductor substrate 2 to the board 1 side. The bonding portions 3 are formed of a bonding material containing Au, and the bonding portion 3 side of the semiconductor substrate 2 comprises a base material formed of an element other than the element constituting the bonding material. The method comprises a contact step of heating the bonding portions 3 provided to the board 1 at the melting-point temperature thereof or more to set the bonding portions 3 to liquid-phase state and bringing the bonding material under the liquid-phase state in contact with the base material under solid-phase state, and a bonding step of heating the resultant material at a temperature which is equal to or higher than the melting-point temperature of alloy of Au and the element constituting the base material, thereby bonding the semiconductor substrate 2 to the board 1 side.

Description

  The present invention relates to a method for manufacturing an electronic device having an airtight space inside.

  Conventionally, various MEMS (Micro Electro Mechanical Systems) such as an acceleration sensor device, a gyro sensor device, and a pressure sensor device, and an electronic device such as an infrared sensor device have an internal space where functional elements are arranged as an airtight space. is there. The electronic device can prevent foreign matters from entering and protect the internal functional elements by setting the inside of the electronic device as an airtight space.

  As this type of electronic device, for example, a silicon substrate provided with a functional element, and a protective cap that covers the functional element and forms a space inside, a silicon substrate and a bonding layer comprising an Au film provided on the protective cap Are bonded to each other by heating to an AuSi eutectic temperature of 363 ° C. or higher (see, for example, Patent Document 1).

  In addition, as another electronic device, a MEMS substrate including a MEMS device as a functional element, a frame portion surrounding the MEMS device, and an IC for accommodating the MEMS device in a sealed state in a cavity surrounded by the MEMS substrate and the frame portion Also known is a substrate in which a MEMS substrate, a frame portion, and an IC substrate are bonded to each other by AuSi eutectic bonding or AuSn eutectic bonding using a metal film previously formed on a bonding surface to be overlapped. (For example, refer to Patent Document 2).

  The electronic device joins the members constituting the electronic device without using an adhesive made of an organic material that inhibits the airtightness of the airtight space inside the electronic device due to the emission of outgas.

JP-A-8-316497 JP 2009-59941 A

  By the way, in the electronic device, when the space inside the electronic device is made an airtight space by AuSi eutectic bonding between members constituting the electronic device, an unbonded region is likely to occur if the surface roughness of the bonding surface is high. In this case, it may be difficult for the electronic device to maintain the bonding with sufficient bonding strength and the airtightness of the airtight space.

  Further, when an electronic device is manufactured by AuSn eutectic bonding between members constituting the electronic device, an AuSn film is provided on one of the opposing bonding surfaces between the members, and Au or the like is provided on the other bonding surface. The metal film must be formed in advance. For this reason, the electronic device has an adverse effect of increasing the manufacturing cost.

  The present invention has been made in view of the above reasons, and provides a method for manufacturing an electronic device that can further increase the bonding strength between members constituting the electronic device by a relatively simple method. is there.

  The method of manufacturing an electronic device according to the present invention includes a semiconductor substrate, a substrate on which the semiconductor substrate is mounted, and a bonding portion for bonding the semiconductor substrate to the substrate side. A method of manufacturing an electronic device in which a part of a portion is exposed, wherein the joining portion is made of a joining material containing Au, and the joining portion side of the semiconductor substrate is made of elements other than the elements constituting the joining material A contact step made of a material and contacting the bonding material, which is heated to a temperature higher than a melting temperature of the bonding portion provided on the base body and brought into a liquid phase state, with the base material in a solid phase state, and after the contacting step And a step of joining the semiconductor substrate to the substrate side by heating to a temperature equal to or higher than the melting point of an alloy of Au and the element constituting the base material.

  In this method of manufacturing an electronic device, it is preferable that the side surface of the semiconductor substrate is bonded to the bonding portion on the substrate.

  In this method of manufacturing an electronic device, it is preferable that the base material of the semiconductor substrate is exposed by a dicing process or an etching process in advance when the semiconductor substrate comes into contact with the joint.

  In this method for manufacturing an electronic device, the bonding material containing Au is preferably Au—Sn, and the base material is preferably Si.

  The method for manufacturing an electronic device according to the present invention can increase the bonding strength between members constituting the electronic device with a relatively simple method.

FIG. 3 is a schematic cross-sectional view of a main part showing the method for manufacturing the electronic device of Embodiment 1. It is a schematic sectional drawing of another principal part which shows the manufacturing method of an electronic device same as the above. It is a schematic sectional drawing of the electronic device same as the above. The principal part of the electronic device in the same as above is shown, (a) is a partial plan view, (b) is a partially enlarged view of (a), and (c) is an AA 'schematic sectional view of (b). It is a schematic sectional drawing of the principal part which shows the manufacturing method of the other electronic device same as the above. It is a schematic sectional drawing of the principal part which shows the manufacturing method of another electronic device same as the above. It is a schematic sectional drawing of the principal part which shows the manufacturing method of the electronic device of Embodiment 2. It is a schematic sectional drawing of another principal part which shows the manufacturing method of an electronic device same as the above. It is a schematic sectional drawing of the principal part which shows the manufacturing method of the other electronic device same as the above. It is a schematic sectional drawing of the principal part which shows the manufacturing method of the electronic device of Embodiment 3. It is a schematic sectional drawing which shows the manufacturing method of the electronic device of Embodiment 4. It is another schematic sectional drawing which shows the manufacturing method of an electronic device same as the above.

(Embodiment 1)
As an example of the manufacturing method of the electronic device 10 of the present embodiment, a manufacturing method of the infrared sensor device 10A that is the electronic device 10 having the structure shown in FIG. 3 will be described. First, the structure of the infrared sensor device 10A will be described with reference to FIG. The infrared array sensor 2a disposed in the airtight space 10a inside the infrared sensor device 10A will be described with reference to FIG.

  An infrared sensor device 10A shown in FIG. 3 includes a concave ceramic package 1a. The package 1a uses the joint portion 3 to mount the infrared array sensor 2a on the inner bottom surface 1ab of the concave package 1a. That is, in the infrared sensor device 10 </ b> A that is the electronic device 10, the infrared array sensor 2 a that is the semiconductor substrate 2 and the package 1 a that is the substrate 1 on which the infrared array sensor 2 a is mounted are bonded by the bonding portion 3.

  In addition, the infrared sensor device 10A includes a lid 1b in which a through hole 1ba is provided in a metal lid. Infrared sensor device 10A joins lid 1b with infrared passage part 2c formed of a semiconductor material so that joint 3 may be used to cover penetration hole 1ba. In other words, in the infrared sensor device 10 </ b> A, the infrared transmitting member 2 c that is the semiconductor substrate 2 and the lid 1 b that is the substrate 1 on which the infrared transmitting member 2 c is mounted are bonded by the bonding portion 3.

  The infrared transmitting member 2c is made of Si and is formed in a plano-convex lens shape so that infrared rays from the outside can be collected and irradiated to the infrared array sensor 2a. The infrared transmitting member 2c includes a filter 2ca formed of a dielectric multilayer film that transmits predetermined infrared rays on the infrared incident surface side of the infrared transmitting member 2c. Similarly, the infrared transmitting member 2c includes a filter 2cb formed of a dielectric multilayer film that transmits predetermined infrared rays on the infrared emitting surface side of the infrared transmitting member 2c.

  The infrared sensor device 10A is seam welded so that a lid 1b provided with an infrared transmitting member 2c covers a concave package 1a. In the infrared sensor device 10A, a space surrounded by the lid 1b including the infrared transmitting member 2c and the concave package 1a is defined as an airtight space 10a. The infrared sensor device 10A is joined to the airtight space 10a inside the infrared sensor device 10A, a part of the joint part 3 that joins the infrared array sensor 2a to the package 1a side, and the infrared transmitting member 2c to the lid 1b side. Part of the part 3 is exposed.

  Infrared sensor device 10A electrically connects infrared array sensor 2a and a circuit pattern (not shown) on package 1a by wire 6 (for example, a gold wire or an aluminum wire). The infrared sensor device 10A is configured so that the detection output of the infrared array sensor 2a can be output to the outside of the infrared sensor device 10A via the wire 6 or a circuit pattern.

  Hereinafter, each configuration of the infrared sensor device 10A used in the present embodiment will be described in detail.

The package 1a of the infrared sensor device 10A is, for example, one in which the infrared array sensor 2a can be mounted on the inner bottom surface 1ab side of the package 1a, and can be made of ceramic or the like. The package 1a can be formed of, for example, a ceramic mainly composed of alumina. The package 1a uses not only ceramics mainly composed of alumina but also LTCC (Low Temperature Co-fired Ceramics) fired at a lower temperature of 900 ° C. or lower by adding a glass-based material to alumina. it can. For the package 1a, as an LTCC material, specifically, an aluminosilicate-based (Na ₂ O—Al ₂ O ₃ —Ba ₂ O ₃ —SiO ₂ -based) glass composition can be used.

  The package 1a is required to have a high gas barrier property for hermetic sealing such as sealing with an inert gas or evacuation. Therefore, it is more preferable that the package 1a uses aluminum nitride, alumina, or silica-based ceramic as the material of the package 1a. The package 1a may be formed of metal or silicon material. The package 1a is not limited to the configuration of the concave ceramic package 1a, and may be a stem used for a can package or a semiconductor wafer.

  The infrared sensor device 10A uses the lid 1b including the infrared transmitting member 2c as a lid, and the lid 1b and the package 1a on which the infrared array sensor 2a is mounted are joined and hermetically sealed, whereby the infrared sensor device 10A. The inside is an airtight space. In order to firmly join the metal lid 1b and the ceramic package 1a with good airtightness, for example, resistance seam welding may be performed. Therefore, the package 1a is provided with a seam ring (not shown) made of, for example, Kovar so that the lid 1b and resistance seam welding can be performed on the package 1a. When the package 1a is resistance seam welded to the lid 1b, a seam welding metal film (for example, W film, Ni plating film, Au plating film, etc.) is formed in advance on the package 1a in contact with the seam ring. It is preferable.

  Next, the infrared array sensor 2a is used for an infrared image sensor or the like. In the plan view of FIG. 4A, m × n (2 × 2 in the illustrated example) thermal infrared detectors. 40a is arranged in a two-dimensional array. As shown in the sectional view of FIG. 4C, the thermal infrared detector 40a includes a silicon oxide film 42a formed on one surface side of the silicon substrate 41 and a silicon nitride film formed on the silicon oxide film 42a. 42b, the sensing element 20 formed on the silicon nitride film 42b, the interlayer insulating film 42g formed so as to cover the sensing element 20 on the surface side of the silicon nitride film 42b, and the interlayer insulating film 42g. The infrared sensor thin film 42 is formed by patterning the laminated structure with the passivation film 42i.

  Here, a part of the infrared sensor thin film 42 is spatially separated from the silicon substrate 41 by a cavity 45 formed from one surface side of the silicon substrate 41. The infrared sensor thin film 42 is provided with a slit 44 communicating with the cavity 45 in the thickness direction of the infrared sensor thin film 42. The thermal infrared detector 40a constitutes an infrared absorber 21 in which a portion of the infrared sensor thin film 42 spatially separated from the silicon substrate 41 absorbs infrared rays.

  The thermal infrared detector 40a includes an interlayer insulating film 42g made of a BPSG (Boro-Phospho Silicate Glass) film. The thermal infrared detecting unit 40a forms a passivation film 42i by a laminated film of a PSG (PhosphoSilicate Glass) film and an NSG (Non-doped Silicate Glass) film on the PSG film. In the thermal infrared detector 40a, the laminated film of the interlayer insulating film 42g and the passivation film 42i also serves as the infrared absorption film 22.

  Here, when the refractive index of the infrared absorption film 22 is n and the center wavelength of the infrared ray to be detected is λ, the thermal infrared detection unit 40a sets the thickness t of the infrared absorption film 22 to λ / 4n. The absorption efficiency of infrared rays having a wavelength to be detected (for example, 8 to 12 μm) can be increased, and high sensitivity can be achieved. For example, when n = 1.4 and λ = 10 μm, the infrared absorption film 22 may be t≈1.8 μm, the interlayer insulating film 42 g has a thickness of 0.8 μm, and the PSG film has a thickness of 0.8 μm. The film thickness of 0.5 μm and the NSG film is 0.5 μm. The passivation film 42i is not limited to the stacked film of the PSG film and the NSG film, and may be formed of, for example, a silicon nitride film.

  The sensing element (temperature sensing part) 20 of the thermal infrared detecting unit 40a includes a thermopile. The thermopile includes a p-type polysilicon layer 42e and an n-type polysilicon layer 42c formed across the infrared absorption portion 21 on the center side and the silicon substrate 41 surrounding the cavity 45 on the outer peripheral side in FIG. have. The thermopile is a metal material (for example, Al-Si or the like) in which one end portion of the p-type polysilicon layer 42e and one end portion of the n-type polysilicon layer 42c are electrically joined on the infrared incident surface side of the infrared absorbing portion 21. ). Here, in the thermopile, the other end of the p-type polysilicon layer 42e of the thermocouple and the other end of the n-type polysilicon layer 42c adjacent to each other on one surface side of the silicon substrate 41 are made of a metal material (for example, Al- Four thermocouples are connected in series by bonding with a wiring 42h made of Si or the like.

  In the thermopile, one end portion of the n-type polysilicon layer 42c, one end portion of the p-type polysilicon layer 42e, and the connection portion 23 constitute a hot junction on the infrared absorbing portion 21 side, and the other end portion of the p-type polysilicon layer 42e. The other end of the n-type polysilicon layer 42c and the wiring 42h constitute a cold junction on the silicon substrate 41 side.

  The connecting portions 23 are electrically connected to the n-type polysilicon layer 42c and the p-type polysilicon layer 42e through contact holes 25 formed in the interlayer insulating film 42g. Slits 44 penetrating in the thickness direction of the infrared sensor thin film 42 are formed by etching from one surface side of the silicon substrate 41 at the four corners of the rectangular region serving as the infrared absorbing portion 21. The slit 44 can thermally separate each thermocouple and improve the sensor sensitivity of the thermal infrared detector 40a.

  Furthermore, the infrared array sensor 2a has an n-type compensating polysilicon layer 42d capable of enhancing the uniformity of the stress balance of the infrared sensor thin film 42 and an electrically neutral p on the infrared incident surface side of the infrared absorber 21. A mold compensating polysilicon layer 42f is preferably provided. The n-type compensation polysilicon layer 42d and the p-type compensation polysilicon layer 42f are similar to the n-type polysilicon layer 42c and the p-type polysilicon layer 42e when the n-type polysilicon layer 42c and the p-type polysilicon layer 42e are formed. It can be formed by film formation or the like.

  The thickness of the infrared sensor thin film 42 is sufficiently thin as compared with the thickness of the silicon substrate 41. The thickness of the infrared sensor thin film 42 is not limited to the thickness of the infrared sensor thin film 42 constituted by the above-described infrared absorbing film 22 or the like, and may be, for example, about 0.1 μm to 10 μm. The infrared array sensor 2a can output the detection output to the outside via the individual electrode 24 and the common electrode 26.

  Next, the lid 1d used in the infrared sensor device 10A can be hermetically sealed with the package 1a by surrounding the infrared array sensor 2a mounted on the package 1a. The lid 1b has a through hole 1ba serving as a window for the infrared array sensor 2a mounted on the inner bottom surface 1ab side of the package 1a, and a lens that allows infrared rays to enter the infrared array sensor 2a so as to cover the through hole 1ba. A shaped infrared transmitting member 2c is hermetically joined. Note that the infrared sensor device 10A is not limited to the lid 1b that seals the package 1a, but may be a cap used for a can package or a semiconductor wafer.

  It is preferable that the lid 1b can prevent unnecessary infrared rays that cause noise from entering the infrared array sensor 2a and can be hermetically bonded to the package 1a. When seam welding the lid 1b and the package 1a, the lid 1b preferably has conductivity. For the lid 1b, Kovar, stainless steel, iron, or the like can be used as the material of the lid 1b.

  Further, in the infrared sensor device 10A, when the lid 1b is seam welded to the package 1a, it is preferable to provide a Ni plating layer on the surface of the lid 1b where the lid 1b contacts the package 1a or the seam ring.

  Next, the joining part 3 is comprised from the joining material containing Au. As the bonding material containing Au, for example, AuSn that melts at 278 ° C. or higher, AuGe that melts at 356 ° C. or higher, or Au paste that causes sintering at 300 ° C. or higher can be suitably used as the bonding material containing Au. Note that when the Au paste is used as the bonding material of the bonding portion 3, the bonding portion 3 can use a slurry obtained by mixing submicron-order Au particles, an organic solvent, and a surfactant. The bonding part 3 using Au paste as a bonding material can be melted even at a low temperature of 300 ° C., whereas the melting point of Au is normally 1064 ° C.

  The infrared transmitting member 2c used in the infrared sensor device 10A of the present embodiment is joined so as to seal the through hole 1ba of the lid 1b, and is formed into a plano-convex lens shape as shown in FIG. The infrared transmitting member 2c is not limited to a plano-convex lens shape as the shape of the infrared transmitting member 2c. For example, the infrared transmitting member 2c may have a lens shape such as a concave lens, a cylindrical lens, an elliptical spherical lens, a Fresnel lens, a diffraction lens, or a plate-like flat plate shape. .

  Moreover, as a material of the infrared transmitting member 2c, a semiconductor material such as Si or Ge that can transmit infrared rays is preferably used, but is not limited thereto. The infrared transmitting member 2c can be formed by, for example, a semiconductor lens forming method using an anodizing technique in order to make the infrared transmitting member 2c into a lens shape.

  More specifically, in order to form a semiconductor lens to be the infrared transmitting member 2c by applying an anodic oxidation technique, an anode having a pattern designed according to a desired lens shape is provided on one surface of a semiconductor substrate (for example, a silicon substrate). It is formed so as to make ohmic contact with the semiconductor substrate on the side. For example, in order to form a convex lens-shaped infrared transmitting member 2c, a semiconductor substrate is formed by forming a conductive layer serving as a base of an anode on one surface of a semiconductor substrate and then forming a circular opening in the conductive layer. Patterning is performed so that a part of one surface of the provided semiconductor substrate is exposed in a circular shape.

  Next, the entire region where the porous portion is to be formed on the other surface of the semiconductor substrate is immersed in an electrolytic solution capable of etching away oxides of constituent elements of the semiconductor substrate.

  Thereafter, a current is passed between the cathode and the anode arranged opposite to the other surface side of the semiconductor substrate to form a porous portion having a desired shape on the other surface side of the semiconductor substrate by oxidation. Subsequently, by removing the porous portion formed on the semiconductor substrate by etching or the like, the infrared transmitting member 2c having a convex lens shape can be formed.

  In addition, instead of the anode that is designed according to the desired lens shape, an insulating layer that is designed according to the desired lens shape is formed on one surface side of the semiconductor substrate, and the one surface side of the semiconductor substrate having the insulating layer The porous portion to be removed later is formed on the other surface side of the semiconductor substrate by forming a conductive layer on the surface of the semiconductor substrate and disposing the current-carrying electrode opposite to the one surface side of the semiconductor substrate with the electrolytic solution. It can also be formed. Moreover, if an anode having a rectangular planar shape is formed instead of providing a circular opening in the conductive layer, a plano-concave cylindrical lens can be formed as the infrared transmitting member 2c. The infrared transmitting member 2c can be formed by forming a plurality of lens shapes on a wafer level semiconductor substrate and separating them into individual pieces by dicing.

  Next, a method for manufacturing the infrared sensor device 10A of the present embodiment will be described. Prior to joining the infrared array sensor 2a to the package 1a, the manufacturing method of the infrared sensor device 10A is provided with an Au—Sn joining portion 3 on the inner bottom surface 1ab of the package 1a as a joining material containing Au by plating. (See FIG. 1 (a)). Note that the joint 3 may be formed not only by a plating method but also by a sputtering method or a vapor deposition method. Alternatively, the bonding portion 3 may be provided in the package 1a by melting a ribbon-like thin film made of Au—Sn by laser welding. In the infrared sensor device 10A of the present embodiment, the bonding portion 3 is made of Au—Sn as a bonding material containing Au, and the silicon substrate 41 on the bonding portion 3 side of the infrared array sensor 2a constitutes the bonding portion 3 (here Then, it consists of the base material (here Si) comprised other than Au and Sn).

  The manufacturing method of the infrared sensor device 10A is, for example, a temperature at which the bonding portion 3 made of Au—Sn provided in the package 1a is melted in a vacuum chamber (not shown) of a heating furnace having a predetermined vacuum atmosphere inside. (Here, 278 ° C.) or higher. The heating furnace can heat the bonding part 3 together with the package 1a to melt the bonding material to be in a liquid phase state. Subsequently, the manufacturing method of the infrared sensor device 10A performs a contact process in which the silicon substrate 41 in the solid phase state of the infrared array sensor 2a is brought into contact with the bonding material that is in the liquid phase state by melting by heating in the vacuum chamber. . In the contact process, the silicon substrate 41 may be pressed not only on the liquid phase bonding material but also on the liquid phase bonding material. Moreover, the heating which fuse | melts the junction part 3 is not restricted only to the heating furnace. Therefore, the joining part 3 can also be melted in a liquid phase state by irradiating a laser, for example.

  Subsequently, after the contact step, the temperature of the heating furnace is increased, and an alloy (here, Au—Si) of Au and an element (here, Si) constituting the base material of the silicon substrate 41 in the infrared array sensor 2a. A bonding step is performed in which the infrared array sensor 2a is bonded to the package 1a side by heating to a temperature equal to or higher than the melting point (here, 363 ° C.) (see FIG. 1B). Here, in the vicinity of the solid-liquid interface between the infrared array sensor 2a and the joint 3, Si precipitates in AuSn, or Au or Sn precipitates in Si. As a result, the vicinity of the solid-liquid interface between the infrared array sensor 2a and the bonding portion 3 is formed by the bonding reaction portion 3a (eg, Au—Si (—Sn)) schematically illustrated by the broken line in FIG. It is formed.

  Thereby, in the manufacturing method of the infrared sensor device 10A, the infrared array sensor 2a can be mounted on the inner bottom surface 1ab of the concave package 1a.

  In addition, 10 A of infrared sensor apparatuses are joined by the solid-liquid reaction which makes the liquid phase joint part 3 and the solid-phase infrared array sensor 2a contact and react. Therefore, in the infrared sensor device 10A, even if the other surface side of the infrared array sensor 2a has irregularities, the bonding portion 3 in the liquid phase can embed the irregularities and join them. Thereby, 10 A of infrared sensor apparatuses can increase a contact area with the junction part 3, even if there exists an unevenness | corrugation in the other surface side of the infrared array sensor 2a. Therefore, the infrared sensor device 10A can increase the bonding strength between the infrared array sensor 2a and the bonding portion 3. In addition, you may share the junction part 3 with the circuit pattern formed in the inner bottom face 1ab of the package 1a electrically connected with the infrared array sensor 2a.

  Subsequently, in the manufacturing method of the infrared sensor device 10A, the individual electrodes 24 and the common electrode 26 of the infrared array sensor 2a and the circuit pattern are wire-bonded and electrically connected by the wire 6.

  In the manufacturing method of the infrared sensor device 10A, the infrared transmitting member 2c is bonded to the lid 1d separately from mounting the infrared array sensor 2a on the package 1a.

  In the manufacturing method of the infrared sensor device 10A of the present embodiment, prior to bonding the infrared transmitting member 2c to the lid 1d side, the bonding portion 3 of Au—Sn as a bonding material containing Au is formed on the lid 1b by plating. (See FIG. 2A). The joint portion 3 is a peripheral portion of the through hole 1ba penetrating the lid 1b, and is provided on the base layer 1bb made of metal formed in the lid 1b. Note that the joint 3 may be formed not only by a plating method but also by a sputtering method or a vapor deposition method. Alternatively, the bonding portion 3 may be provided on the lid 1d by melting a ribbon-like thin film made of Au—Sn by laser welding. In the infrared sensor device 10A of the present embodiment, the bonding portion 3 is made of Au—Sn as a bonding material containing Au, and the infrared transmitting member 2c is formed of elements other than the elements (here, Au and Sn) constituting the bonding portion 3. The base material is made of Si (here, Si). In the infrared transmitting member 2c, a filter 2ca formed by a dielectric multilayer film is formed on the infrared incident surface side of the infrared transmitting member 2c, and formed by a dielectric multilayer film on the infrared emitting surface side of the infrared transmitting member 2c. A filtered filter 2cb is formed. In the infrared transmitting member 2c, the base material is exposed on the side of the joint portion 3 in the side surface 2cc of the infrared transmitting member 2c.

  The manufacturing method of the infrared sensor device 10A is, for example, a temperature at which the bonding portion 3 made of Au—Sn provided on the lid 1d is melted in a vacuum chamber (not shown) of a heating furnace having a predetermined vacuum atmosphere inside. (Here, 278 ° C.) or higher. The heating furnace can heat the bonding part 3 together with the lid 1d to melt the bonding material to be in a liquid phase state. Subsequently, the manufacturing method of the infrared sensor device 10A performs a contact process in which the side surface 2cc of the infrared transmitting member 2c that is in a solid phase is brought into contact with the bonding material that is in a liquid phase state by melting by heating in a vacuum chamber. In addition, the heating which fuse | melts the junction part 3 is not restricted only to the thing by a heating furnace. Therefore, the joining part 3 can also be melted in a liquid phase state by irradiating a laser, for example.

  Subsequently, after the contacting step, the temperature of the heating furnace is raised, and the melting point (here, Au—Si) of an alloy (here, Si—Si) of Au and the element (here, Si) constituting the base material of the infrared transmitting member 2c. Then, the joining process of joining the infrared transmitting member 2c to the lid 1d side by heating to a temperature of 363 ° C. or higher is performed (see FIG. 2B). Here, in the vicinity of the solid-liquid interface between the infrared transmitting member 2 c and the joint portion 3, Si precipitates in AuSn, or Au or Sn precipitates in Si. As a result, in the vicinity of the solid-liquid interface between the infrared transmitting member 2c and the bonding portion 3, the bonding reaction portion 3a (eg, Au—Si (—Sn)) schematically illustrated by the broken line in FIG. It is formed.

  Thereby, in the manufacturing method of the infrared sensor device 10A, the infrared transmitting member 2c can be joined to the lid 1d so as to cover and close the through hole 1ba of the lid 1d.

  Thereafter, the package 1a and the lid 1b provided with the infrared transmitting member 2c are seam-welded so as to form an airtight space 10a inside the infrared sensor device 10A. Specifically, in the manufacturing method of the infrared sensor device 10A, the lid 1b is seam welded in a vacuum atmosphere and hermetically sealed through a seam ring so as to cover the package 1a on which the infrared array sensor 2a and the like are mounted. In the manufacturing method of the infrared sensor device 10A, the infrared sensor device 10A can be formed by an airtight sealing process (see FIG. 3).

  Further, in the manufacturing method of the infrared sensor device 10A of the present embodiment shown in FIG. 1, the silicon substrate 41 on the other surface side of the infrared array sensor 2a is used as a base material that comes into contact with the bonding material in a liquid phase state. However, it is not limited to this.

  Therefore, for example, as shown in FIG. 5, the infrared sensor device 10 </ b> A may be provided with a base material that is bonded to a bonding material in a liquid phase on the package 1 a side of the infrared array sensor 2 a as the reaction layer 2 b.

Examples of the reaction layer 2b include those using Si, Ge, or the like as a base material. The reaction layer 2b can be formed relatively easily on the package 1a side of the infrared array sensor 2a by using various CVD methods. The reaction layer 2b may be provided directly on the other surface side of the infrared array sensor 2a, or may be provided on the other surface side of the infrared array sensor 2a via an insulating layer 2aa such as SiO ₂ or SiN. In the infrared sensor device 10A shown in FIG. 5, the bonding portion 3 is provided on the base layer 1aa made of a refractory metal such as W or Ti provided on the package 1a.

  The manufacturing method of the infrared sensor device 10A of the present embodiment shown in FIGS. 6A and 6B is similar to the joining of the infrared transmitting member 2c and the lid 1b shown in FIGS. 2A and 2B. Alternatively, the side surface 2ac of the infrared array sensor 2a may be brought into contact with a bonding material in a liquid phase state to be bonded.

  Thereby, the manufacturing method of the infrared sensor device 10A can bond the infrared array sensor 2a to the package 1a side without removing the insulating film 2aa provided on the other surface side of the infrared array sensor 2a.

(Embodiment 2)
The infrared sensor device 10A of the present embodiment shown in FIGS. 7 to 9 has substantially the same structure as the infrared sensor device 10A of the first embodiment shown in FIG. In the manufacturing method of the infrared sensor device 10A according to the present embodiment, before the infrared array sensor 2a or the infrared transmitting member 2c comes into contact with the bonding material in the liquid phase state, the bonding surface with the bonding portion 3 is pre-diced or etched. The difference is that it is being processed. In addition, about the component similar to Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted suitably.

  In the manufacturing method of the infrared sensor device 10A of the present embodiment, on the package 1a side, as shown in FIG. 7 (a), the bonding portion 3 made of Au—Sn is mounted so that the infrared array sensor 2a can be mounted on the package 1a side. Is provided in the package 1a through the base layer 1aa.

Here, the infrared array sensor 2a includes an insulating layer 2aa such as SiO ₂ or SiN on the package 1a side of the infrared array sensor 2a. The infrared array sensor 2a includes a groove portion 2ae in which a joint surface with the joint portion 3 side is partially removed together with the insulating layer 2aa by a dicing process using a dicer (not shown) in advance. The infrared array sensor 2a exposes the base material made of Si on the inner peripheral surface of the groove 2ae by dicing.

  In the manufacturing method of the infrared sensor device 10A of the present embodiment, a bonding material (here, Au −) heated to a temperature higher than the melting temperature (here, 278 ° C.) of the bonding portion 3 provided in the package 1a to be in a liquid phase state. Sn) is contacted with an element (here, Si) constituting the solid-phase base material exposed in the groove 2ae of the infrared array sensor 2a. In the contact process, since the joining part 3 is in a liquid phase state by heating, the joining part 3 can enter the groove part 2ae of the infrared array sensor 2a relatively easily (see FIG. 7B).

  After the contact step, the infrared array sensor 2a is heated to the melting point (here, 363 ° C.) or higher of the alloy (Au—Si) of Au and the element constituting the base material (here, Si) to make the infrared array sensor 2a side of the package 1a It is possible to perform a bonding process for bonding to the substrate.

  Further, in the manufacturing method of the infrared sensor device 10A of the present embodiment, on the lid 1b side, as shown in FIG. 8A, the bonding made of Au—Si is performed so that the infrared transmitting member 2c can be bonded to the lid 1b side. The portion 3 is provided on the lid 1b through the base layer 1bb.

Here, the infrared transmitting member 2c has a dielectric multilayer film (for example, a laminated film of metal oxide such as Ta ₂ O ₅ , SiO ₂ , MgF ₂ or fluoride) on the infrared incident surface side of the infrared transmitting member 2c. The filter 2ca formed by is provided. Similarly, the infrared transmitting member 2c has a dielectric multilayer film (for example, a laminated film of metal oxide such as Ta ₂ O ₅ , SiO ₂ , MgF ₂ or fluoride) on the infrared emitting surface side of the infrared transmitting member 2c. The filter 2cb formed by the above is provided. In the infrared transmitting member 2c, a cutout portion 2cd is formed in which the outer peripheral portion on the joint portion 3 side is partially removed together with the filter 2cb by a dicing process.

  In the manufacturing method of the infrared sensor device 10A of the present embodiment, the liquid phase state is obtained by heating to a temperature (in this case, 278 ° C.) or higher at which the joint 3 provided on the lid 1b is melted. The manufacturing method of the infrared sensor device 10A includes a bonding material (here, Au—Sn) in a liquid phase and an element (here, a solid-phase base material exposed at the notch 2cd of the infrared transmitting member 2c). Then, the contact process which contacts Si) is performed. In the contact process, since the joining part 3 is in a liquid phase state by heating, the joining part 3 enters the cutout part 2cd of the infrared transmitting member 2c relatively easily (see FIG. 8B).

  Subsequently, in the manufacturing method of the infrared sensor device 10A according to the present embodiment, after the contact process, heating is performed to a melting point (here, 363 ° C.) or higher of an alloy (Au—Si) of Au and an element constituting the base material. Thus, a joining step for joining the infrared transmitting member 2c to the lid 1b side can be performed.

  Note that the infrared transmitting member 2c is not limited to the infrared transmitting member 2c provided with the cutout portion 2cd as in the infrared transmitting member 2c in FIG. 8, but as shown in FIG. A plurality of grooves 2ce may be formed in advance on the joint 3 side of the transmissive member 2c.

  In the manufacturing method of the infrared sensor device 10A of the present embodiment, the bonding surface between the bonding portion 3 and the bonding portion 3 is previously exposed by dicing or etching, so that the base material is exposed. A wide area can be obtained. Therefore, the manufacturing method of the infrared sensor device 10A of the present embodiment can improve the bonding strength while ensuring airtightness even if the surface of the bonding surface of the infrared array sensor 2a has irregularities.

(Embodiment 3)
The manufacturing method of the acceleration sensor device 10B which is the electronic device 10 of the present embodiment is an acceleration sensor element 2d shown in FIG. 10 instead of manufacturing the infrared sensor device 10A including the infrared array sensor 2a of Embodiment 1 shown in FIG. The point which manufactures the acceleration sensor apparatus 10B provided with is different. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted suitably.

  Hereinafter, the acceleration sensor device 10B and the acceleration sensor element 2d shown in FIG. 10 will be described.

  As shown in FIG. 10, the acceleration sensor element 2d includes a base substrate including a support portion 2da and a cantilever portion 2db that is swingably supported by the support portion 2da, and a cantilever portion 2db on one surface side of the base substrate. And a strain detection sensor portion 2dd whose resistance value changes according to the bending of the cantilever portion 2db. Although not shown, the strain detection sensor unit 2dd is formed with two piezoresistors as strain detection elements, and is connected to form a bridge circuit. The base substrate includes a weight portion 2dc on the side facing the support portion 2da via the cantilever portion 2db.

  When an external force (that is, acceleration) is applied to the acceleration sensor element 2d, the positions of the support portion 2da and the weight portion 2dc are relatively displaced, and the cantilever portion 2db is bent, whereby the piezoresistor in the strain detection sensor portion 2dd. The resistance value of changes. The acceleration sensor element 2d can detect acceleration by detecting a change in the resistance value of the piezoresistor.

  Here, the base substrate of the acceleration sensor element 2d is formed using, for example, an SOI substrate or a single crystal silicon substrate. Therefore, instead of joining the infrared array sensor 2a of Embodiment 1 shown in FIG. 1 to the package 1a side, the acceleration sensor element 2d shown in FIG. 10 can be joined to the package 1a side.

  Specifically, in the manufacturing method of the acceleration sensor device 10B of the present embodiment, the bonding portion 3 made of Au—Sn provided on the inner bottom surface 1ab of the package 1a is heated to a temperature equal to or higher than the melting temperature (here, 278 ° C.). . Subsequently, the manufacturing method of the acceleration sensor device 10B performs a contact process in which the bonding material heated to be in a liquid phase state is brought into contact with the base substrate in the solid phase state of the acceleration sensor element 2d.

  Subsequently, after the contact step, the melting point (here, 363 ° C.) of the alloy (here, Au—Si) of Au and the element (here, Si) constituting the base material of the base substrate in the acceleration sensor element 2d. A bonding step is performed in which the acceleration sensor element 2d is bonded to the package 1a side by heating to a temperature equal to or higher than the above temperature. Thereby, 10 A of acceleration sensor apparatuses can mount the acceleration sensor element 2d in the package 1a. Since the acceleration sensor device 10B does not need to transmit infrared rays unlike the infrared sensor device 10A, the flat plate-like lid 1b made of metal is seam welded to the package 1a.

  The acceleration sensor device 10B manufactured according to the present embodiment is compared with a device in which the acceleration sensor element 2d is mounted on the package 1a with a die-bonding material such as epoxy resin or silicone resin in an airtight space 10a between the package 1a and the lid 1b. Thus, no outgas is released from the die bond material. Therefore, in the acceleration sensor device 10B, the released outgas does not become an obstruction factor for increasing the vacuum of the internal airtight space 10a, and the performance deterioration of the acceleration sensor element 2d is also suppressed.

  In addition, the acceleration sensor device 10B manufactured by the method of manufacturing the acceleration sensor device 10B of the present embodiment is generally compared with a device in which the acceleration sensor element 2d is mounted using a glass frit that requires heating at 400 ° C. or higher. Thus, the acceleration sensor element 2d can be mounted at a lower temperature of less than 400 ° C.

  The manufacturing method of the electronic device 10 of the present embodiment is not limited to the acceleration sensor device 10B and the infrared sensor device 10A described in the first embodiment, but also a gyro sensor device, a pressure sensor device, a vibration power generator, and a MEMS optical scanner. Needless to say, the present invention can also be applied to manufacturing methods such as these.

(Embodiment 4)
The electronic device 10 of the present embodiment is an infrared sensor in which an infrared array sensor 2a is mounted by a joint 3 in an airtight space 10a between a lid 1b having the infrared transmitting member 2c of the first embodiment shown in FIG. Instead of the device 10A, as shown in FIG. 11, an infrared sensor device 10C in which the semiconductor cover 2e provided with the recess 2ee and the infrared array sensor 1c are joined to make the inside of the recess 2ee an airtight space 10a is formed. Is different. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted suitably.

  The infrared sensor device 10C, which is the electronic device 10 shown in FIGS. 11A and 11B, uses a cover wafer 2f that is the basis of the semiconductor cover 2e and a semiconductor element wafer 1f that is the basis of the infrared array sensor 1c. Forming. As the cover wafer 2f, a silicon wafer having a recess 2ee for protecting the infrared sensor thin film 42 may be used. Further, as the semiconductor element wafer 1f, for example, a wafer before the infrared array sensor 2a described in the first embodiment is formed by singulation may be used. Here, the cover wafer 2f and the semiconductor element wafer 1f are bonded by the bonding portion 3 using Au—Sn as a bonding material. Further, the bonding portion 3 is provided on the semiconductor element wafer 1f via the insulating layer 1ac (see FIG. 11A).

  In the manufacturing method of the infrared sensor device 10C of the present embodiment, first, the bonding portion 3 made of Au—Sn provided on the semiconductor element wafer 1f is heated to a melting temperature (here, 278 ° C.) or higher. Subsequently, the manufacturing method of the infrared sensor device 10C performs a contact process in which the bonding material heated to be in a liquid phase state is brought into contact with the cover wafer 2f in a solid phase state.

  Subsequently, after the contact step, the temperature is higher than the temperature of the melting point (here, 363 ° C.) of the alloy (here, Au—Si) of Au and the element (here, Si) constituting the base material of the cover wafer 2f. A bonding process is performed to heat and bond the cover wafer 2f to the semiconductor element wafer 1f side. Thus, the infrared sensor device 10C can join the cover wafer 2f and the semiconductor element wafer 1f. The manufacturing method of the infrared sensor device 10C is performed at the wafer level until the bonding process for bonding the cover wafer 2f and the semiconductor element wafer 1f is completed. Finally, in the manufacturing method of the infrared sensor device 10C, the separated infrared sensor device 10C can be formed by performing a dicing process in which the cover wafer 2f and the semiconductor element wafer 1f are joined together. it can. In the dicing process, the cover wafer 2f and the semiconductor element wafer 1f bonded together may be diced along a dicing lane (broken line illustrated in FIG. 11B).

  In the manufacturing method of the infrared sensor device 10C of the present embodiment, as shown in FIG. 12, the cover wafer 2f and the semiconductor element wafer 1f are joined by the joining portion 3 without providing the insulating layer 1ac. In the manufacturing method of the infrared sensor device 10C shown in FIG. 12, the bonding reaction part 3a (for example, Au—Si (—Sn)) can be formed on both the cover wafer 2f and the semiconductor element wafer 1f.

  Thereby, the manufacturing method of the infrared sensor device 10C according to the present embodiment can increase the bonding strength between the members constituting the infrared sensor device 10C by a relatively simple method.

DESCRIPTION OF SYMBOLS 1 Base | substrate 2 Semiconductor base | substrate 3 Junction part 10 Electronic device 10a Airtight space

Claims (4)

An electronic device in which a part of the bonding portion is exposed in an airtight space inside the electronic device including a semiconductor substrate, a substrate on which the semiconductor substrate is mounted, and a bonding portion for bonding the semiconductor substrate to the substrate side. A manufacturing method comprising:
The bonding portion is made of a bonding material containing Au, and the bonding portion side of the semiconductor substrate is made of a base material composed of elements other than the elements constituting the bonding material,
A contact step in which the bonding material heated to a temperature higher than a temperature at which the bonding portion provided on the base body is melted and brought into a liquid phase state and the base material in a solid phase state are brought into contact;
An electronic device comprising, after the contacting step, a bonding step of heating the semiconductor substrate to the substrate side by heating to a temperature equal to or higher than a melting point of an alloy of Au and the element constituting the base material. Manufacturing method.   The method for manufacturing an electronic device according to claim 1, wherein a side surface of the semiconductor substrate is bonded to the bonding portion on the substrate.   2. The electron according to claim 1, wherein the base material of the semiconductor substrate is exposed by dicing or etching in advance when the semiconductor substrate contacts the joint. Device manufacturing method.   The method for manufacturing an electronic device according to any one of claims 1 to 3, wherein the bonding material is Au-Sn, and the base material is Si.

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