JP6221299B2 - Hermetic sealing body and hermetic sealing method - Google Patents

Description

  The present invention relates to a hermetic sealing body and a hermetic sealing method.

  In the solid-state imaging device, a solid-state imaging device is fixed to the bottom surface of an envelope formed of a ceramic or the like with a conductive adhesive, and further, an optical filter, an optical waveguide, or the like is formed in an opening of the envelope. The filter structure is fixed to the upper edge step of the envelope by an adhesive and a thermosetting adhesive in order through a holding frame, and hermetic sealing is performed.

  Various techniques related to such a background are known (see, for example, Patent Document 1).

  For example, Patent Document 1 describes a solid-state imaging device used for a video camera or the like. More specifically, this solid-state imaging device includes an optical filter structure for the purpose of optical furnace wave or optical waveguide, or a holding frame thereof bonded and fixed to an envelope containing a solid-state image sensor, Alternatively, the holding frame is adhered or in contact with the imaging surface or non-imaging part of the solid-state imaging device. In this way, depending on the solid-state image sensor, the adhesion or contact between the filter structure or the lower end surface of the light-shielding frame forming a part of the holding frame and the surface of the solid-state image sensor may be different between the holding frame and the envelope. Even if the dimensional accuracy of the bonded portion is not high, optimum conditions can be obtained, and a solid-state imaging device that is easy to assemble and inexpensive can be obtained.

  The pyroelectric infrared sensor uses the pyroelectric effect of a pyroelectric substance that receives infrared energy radiated from an object and converts it into an electrical signal. It is used not only for crime prevention but also for civilian use as a human body detection sensor. Are also becoming widely used.

  Various techniques relating to such a background are known (see, for example, Patent Document 2).

  For example, Patent Document 2 discloses a pyroelectric element that receives infrared rays and converts it into an electric signal, a shield case in which a field effect transistor and an optical filter that convert the impedance of the signal are attached, and a signal that is attached to the shield case. A pyroelectric infrared sensor comprising a lead wire for leading to the outside is described. More specifically, this pyroelectric infrared sensor has an L-shape, U-shape, or J-shape so that a lead wire drawn perpendicular to the bottom surface of the shield case can be placed on the surface of the substrate. It is bent in a crab. In this way, this pyroelectric infrared sensor can be surface-mounted like many other chip electronic components.

  In recent years, as microprocessors can be used very easily, automatic control using a combination of this and a sensor has been adopted in many devices and apparatuses.

  Various techniques related to such a background are known (see, for example, Patent Document 3).

  For example, Patent Document 3 describes a method for manufacturing an infrared sensor used in a monitoring device, an infrared image device, or the like that detects the presence of a human body. More specifically, in this infrared sensor manufacturing method, a sensor circuit, a ground terminal extending from the lead frame, and an infrared detection element connection terminal are formed on the lead frame, and an electronic component for the sensor circuit section is mounted on the lead frame. After that, an unnecessary part of the lead frame is cut off, and the resin part is produced in a state where the ground terminal and the infrared detection element connection terminal are projected to manufacture an insulating protective body for the infrared sensor. Thus, depending on the manufacturing method of the infrared sensor, it is possible to prevent deterioration of the electronic component due to adverse effects such as moisture.

  In recent years, the package of resin-encapsulated semiconductor devices has been increasing in size and increasing the number of pins, and this tendency is considered to increase further.

  Various techniques related to such a background are known (see, for example, Patent Document 4).

  For example, Patent Document 4 describes a method for manufacturing a resin-encapsulated semiconductor device in which a semiconductor element is mounted face-down on a substrate. More specifically, this method for manufacturing a resin-encapsulated semiconductor device includes a semiconductor device on a surface of a substrate having a wiring circuit and provided with a through hole, and a face with its main surface facing the substrate. Implement down. In this method for manufacturing a resin-encapsulated semiconductor device, an encapsulating resin is disposed on the lower side of the substrate. In this method for manufacturing a resin-encapsulated semiconductor device, the semiconductor element is sealed in a region defined by the base and the upper mold. In this method of manufacturing a resin-encapsulated semiconductor device, pressure is applied to the sealing resin to inject the resin from below the substrate through the through hole, and the sealing resin is inserted into the gap between the semiconductor element and the substrate. The resin is sealed by being disposed on the side surface of the semiconductor element and the back surface of the semiconductor element. In this way, depending on the method of manufacturing this resin-encapsulated semiconductor device, a resin layer that is not filled or void-free can be easily formed around the semiconductor element mounted face-down on the surface of the substrate. Can do.

  The infrared sensor is mounted on a metal package because it can be hermetically sealed and an infrared filter can be formed on the package.

  Various techniques related to such a background are known (see, for example, Patent Document 5).

  For example, in Patent Document 5, an infrared sensing unit that is formed on the surface of a silicon substrate and receives an infrared ray to change its output, a first structure formed of glass so as to surround the sensing unit, and a first structure An infrared sensor is described comprising a second structure formed of silicon located on the top of the body. More specifically, the infrared sensor is formed by anodic bonding between the silicon substrate on which the sensing unit is formed and the first structure and the first structure and the second structure. A space surrounded by the silicon substrate, the first structure body, and the second structure body that are bonded and formed with the sensing portion is in a vacuum. In this way, depending on the infrared sensor, the vacuum structure is reliably formed, so that high sensitivity and low cost can be realized.

  In addition, one of the infrared sensors used in human body detection and security devices is an infrared sensor element in which a light receiving electrode is disposed on a pyroelectric element on a metal base provided with a lead terminal. There is an infrared sensor with a lead terminal in which an infrared sensor element is housed in a cylindrical metal case provided with an optical filter that transmits infrared rays on the upper surface side.

  Various techniques relating to such a background are known (see, for example, Patent Document 6).

  For example, Patent Document 6 discloses an infrared sensor element, a package corresponding to surface mounting in which the infrared sensor element is accommodated, and a package having a box shape with one substantially square surface opened. An optical filter configured to allow infrared rays having a predetermined wavelength to pass therethrough, the planar shape of the package being disposed so as to cover a substantially rectangular opening, and causing the infrared sensor element to receive infrared rays having a predetermined wavelength An infrared sensor including an optical filter that simultaneously performs the function and the function as a lid for sealing the opening is described. More specifically, the infrared sensor includes an optical filter disposed so as to cover the opening at the four corners of the opening having a substantially square shape in the package, and the upper end of the inner peripheral wall of the opening. A support portion is disposed at a position lower than the support portion, and the optical filter is fixed to the package in a state where a part of the surface side facing the support portion of the optical filter enters the opening and is supported by the support portion. The package includes a metal package body and an insulating coating material that covers the main part of the metal package body, and is connected to the optical filter via the conductive adhesive. The metal package body is exposed, and the optical filter and the package body are electrically connected by a conductive adhesive. In this way, with this infrared sensor, the ratio of the area where the field of view is blocked to the entire surface area of the optical filter can be made extremely low, effectively reducing the optical filter without narrowing the infrared light receiving area. Can be attached to the package.

  In small information devices such as hard disk drives, mobile computers, or IC (Integrated Circuit) cards, and mobile communication devices such as mobile phones, automobile phones, and paging systems, piezoelectric vibrators, piezoelectric oscillators, and other piezoelectric devices are used. The device is widely used.

  Various techniques relating to such a background are known (see, for example, Patent Document 7).

  For example, Patent Document 7 describes a method for manufacturing a piezoelectric device. More specifically, in this piezoelectric device manufacturing method, each layer has a size corresponding to a plurality of products of the same number, a base substrate layer constituting the base substrate, and a piezoelectric vibrating piece with a frame. An element layer that forms a lid and a lid layer that constitutes a lid, and a metal layer is formed on each of the sealing portions of the base substrate layer, the element layer, and the lid layer. Next, a plateable layer is formed, then a barrier layer is formed, and then a gold bonding layer formed on the surface side of the barrier layer is formed, and the base substrate layer, the element layer, and the lid layer are formed. Laminate them, fix them with Au-Ge solder, and cut them to the size of each product. Thus, depending on the manufacturing method of this piezoelectric device, the lid is formed of a material that transmits light, i.e., glass other than metal. Processing is possible.

JP 62-262445 A Japanese Utility Model Publication No. 3-72329 JP-A-8-15007 Japanese Patent No. 3455667 JP 2006-138704 A Japanese Patent No. 4702366 Japanese Patent No. 4665768

  As in the hermetic sealing body disclosed in Patent Document 3, the hermetic sealing body using a metal case includes seam welding, solder bonding, and conductive adhesive bonding as methods for connecting the substrate and the case. In the case of seam welding, it is necessary that the substrate is made of a ceramic material and has heat resistance, and the substrate itself is expensive. In addition, special welding equipment is required and batch processing is not possible, resulting in low production capacity and high cost.

  In addition, in the case of solder bonding or conductive resin connection, the gas accumulated in the hollow portion expands due to heating during bonding, and this expansion causes part of the solder or conductive resin to expand, resulting in poor appearance and airtightness such as voids. It becomes a leak point with the part. Furthermore, in this method, the filter is bonded to the center of the cap, but the solder or conductive adhesive used for bonding must be designed to have heat resistance so that it can withstand the heat when bonding the cap to the substrate. There is a cost.

  Furthermore, the hermetic seal disclosed in Patent Documents 3 and 6 has several problems. When the optical filter is bonded to the upper part of the resin frame without using a metal case, solder bonding or conductive resin is used for bonding. In this case, the gas accumulated in the hollow portion expands due to heating during bonding, and the expansion may cause the optical filter to tilt. Further, when there is further expansion of the internal gas, there is a problem that part of the solder or the conductive resin of the joint portion swells and becomes a leak path of an airtight portion due to a bad appearance such as a void or rupture of the void.

  The objective of this invention is providing the airtight sealing body and the airtight sealing method which solve the subject mentioned above.

In order to solve the above-mentioned problem, according to a first embodiment of the present invention, there is provided a hermetically sealed body, a substrate, a sensor element provided on the surface of the substrate, and a frame provided around the sensor element. And a filter provided on the frame, and a resin part for fixing the frame and the filter. The resin part is provided so as to hang on the edge of the upper surface of the filter, and is disposed on the outer peripheral part of the optical surface of the filter. Is formed with a recess for preventing the inflow of resin from the outside to the inside of the filter .

According to a second aspect of the present invention, the hermetic sealing body includes a substrate, a sensor element provided on the surface of the substrate, a filter having a cavity structure, and a resin portion that fixes the filter . The resin portion is provided so as to hang over the edge portion of the upper surface of the filter .

According to a fourth aspect of the present invention, there is provided a hermetic sealing method comprising: mounting a sensor element on a substrate; temporarily fixing a frame around the sensor element; and a filter having an optical surface, A step of temporarily fixing on the frame a filter in which a concave portion that prevents inflow of resin from the outside to the inside of the filter is formed on the outer peripheral portion of the optical surface; and a step of fixing the filter, the frame, and the substrate with resin. The resin is provided so as to be applied to the edge of the upper surface of the filter.

According to a fourth aspect of the present invention, there is provided a hermetic sealing method, the step of mounting a sensor element on a substrate, the step of temporarily fixing a filter with a cavity, and the step of fixing the filter and the substrate with a resin. The resin is provided so as to be applied to the edge of the upper surface of the filter .

  It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. Also, a sub-combination of these feature groups can also be an invention.

  As is apparent from the above description, according to the present invention, it is possible to prevent a void or a leak path from being formed in the connection portion due to the expansion of the gas inside the hollow at the time of manufacture.

It is a figure which shows an example of the cross section of the airtight sealing body which concerns on 1st Embodiment. It is a figure which shows an example of the cross section of the airtight sealing body which concerns on 2nd Embodiment. It is a figure which shows an example of the cross section of the airtight sealing body which concerns on 3rd Embodiment. It is a figure which shows an example of the cross section of the airtight sealing body which concerns on 4th Embodiment. It is a figure which shows an example of the cross section of the airtight sealing body which concerns on 5th Embodiment. It is a figure which shows an example of the cross section of the airtight sealing body which concerns on 6th Embodiment. It is sectional drawing which shows the manufacturing method of the airtight sealing body which concerns on 1st Embodiment. It is sectional drawing which shows the manufacturing method of the airtight sealing body which concerns on 1st Embodiment. It is sectional drawing which shows the manufacturing method of the airtight sealing body which concerns on 2nd Embodiment.

  Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the claimed invention, and all combinations of features described in the embodiments are described below. However, this is not always essential for the solution of the invention.

  FIG. 1 shows an example of a cross section of the hermetic sealer according to the first embodiment. The sensor element 1 is mounted on the substrate 2 and is electrically connected. The sensor element 1 is surrounded by a frame 3, the filter 4 is disposed on the frame 3, and the filter 4 and the frame 3 are fixed by a resin 5. The resin 5 is arranged so as to hang over the outer periphery of the filter 4, and the frame 3 and the filter 4 are fixed together by the resin 5.

  By connecting the frame 3 and the filter 4 to the ground via the substrate 2, the influence on noise can be suppressed. The frame 3 is made of a metal material, and is mounted on the substrate 2 simultaneously with the sensor element 1 by a conductive adhesive or solder, and the filter 4 has a conductive film on the surface. Can be obtained. In order to enhance electrical connectivity, a conductive adhesive for temporarily fixing, a conductive sheet, or the like may be supplied to the interface between the frame 3 and the filter 4.

  Next, the hermetic sealing method according to the first embodiment will be described with reference to FIG. The sensor element 1 and the frame 3 are mounted on the substrate 2 with a conductive adhesive or solder. Next, the substrate 2 and the sensor element 1 are electrically connected by wire bonding, and the filter 4 is mounted on the frame 3. In this state, it is set on the lower mold 11, the upper mold 10 is lowered, and the upper mold 10 is abutted against a predetermined surface of the substrate 2 and the filter 4 and clamped. Next, the mold 5 that has been clamped is filled with the resin 5 at a predetermined pressure, and is held for a predetermined time until the resin 5 is cured after the filling is completed. When the curing of the resin 5 is completed, the upper mold 10 is raised and the hermetic seal is taken out. According to the above steps, the frame 3 and the filter 4 can be collectively fixed to the substrate 2 by the resin 5, and the filter 4 can be inclined by filling the resin while pressing the filter 4 with the upper mold 10. Does not occur. Since the resin 5 is held at a predetermined pressure by the mold when it is heated, there is no occurrence of a leak path due to expansion of the gas inside the hollow.

  The above steps are performed under atmospheric pressure, but it is also possible to depressurize the hollow portion with a vacuum pump after the mold is clamped. In addition, by introducing an inert gas such as nitrogen or argon after the pressure is reduced once, the hollow interior can be filled with a predetermined gas.

  In order to depressurize the inside of the mold and introduce an inert gas, an O-ring is provided on the outer periphery of the product in the mold, and after performing mold clamping, the pressure is reduced by a vacuum pump from a predetermined path of the mold. Inert gas is introduced from the route.

  In addition, as shown in FIG. 8, by providing a protrusion 13 on the upper mold 10, the area where the upper mold 10 and the filter 4 come into contact with each other during mold clamping may be reduced.

  FIG. 2 shows an example of a cross section of the hermetic sealing body according to the second embodiment. The sensor element 1 is mounted on the substrate 2 and is electrically connected. The sensor element 1 is surrounded by a frame 3, the filter 4 is disposed on the frame 3, and the filter 4 and the frame 3 are fixed by a resin 5. A groove 6 a is formed on the outer periphery of the filter 4, and the resin 5 is disposed so as to hang over the outer periphery of the filter 4, and the frame 3 and the filter 4 are fixed together by the resin 5. The groove 6a may be an example of the “concave portion” in the present invention.

  Providing the groove 6a serves as a positioning function when the encapsulating mold abuts the surface of the filter 4 and clamps the mold. In addition, when the resin 5 has high fluidity and enters the optical surface of the filter 4, the resin 5 can ooze out in the groove 6 a, and optical deterioration can be prevented.

  In addition, the formation of the groove 6a has an effect that the distortion generated in the filter peripheral portion due to the pressure stress caused by the resin is alleviated and does not affect the filter central portion.

  FIG. 9 is a sectional view for explaining a manufacturing process when the groove 6a is applied. In accordance with the groove 6 a, a protrusion 13 that abuts against the upper mold 10 at the time of mold clamping is pushed in so that the resin 5 does not flow out into the surface of the filter 4.

  In addition, by designing the groove 6a to be filled with resin, there is an effect that the joining portion is lengthened and the formation of a leak path due to peeling due to shrinkage of the resin due to the resin biting is prevented.

  FIG. 3 shows an example of a cross section of the hermetic sealer according to the third embodiment. The sensor element 1 is mounted on the substrate 2 and is electrically connected. The sensor element 1 is surrounded by a frame 3, the filter 4 is disposed on the frame 3, and the filter 4 and the frame 3 are fixed by a resin 5. Grooves 6 b are formed on the outer periphery of the filter 4, and the resin 5 is disposed so as to hang over the outer periphery of the filter 4, and the frame 3 and the filter 4 are fixed together by the resin 5. The groove 6b may be an example of the “concave portion” in the present invention.

  The groove 6b serves as a pool for the seepage of the resin 5, the seepage of the adhesive for temporarily fixing the filter 4 and the frame 3, or the conductive adhesive for electrical connection, and prevents optical deterioration. Can do.

  FIG. 4 shows an example of a cross section of the hermetic sealer according to the fourth embodiment. 2 and 3, both of the grooves 6 a and 6 b described in the embodiment are provided, and in particular, the grooves 6 a and 6 b are not in the same position on the upper and lower surfaces. Damage due to mold clamping can be minimized.

  FIG. 5 shows an example of a cross section of the hermetic sealer according to the fifth embodiment. A cap 7 to which a filter 4 is bonded in advance is temporarily fixed on a substrate 2 on which the sensor element 1 is mounted and electrically connected, and is covered from the flange of the cap 7 so that the resin 5 does not cover the outer peripheral region of the filter 4. Stick. Since the encapsulating mold is designed to escape the filter 4, there is no optical deterioration due to exudation of the resin 5, no leak path is formed due to gas expansion inside the cap 7, and a highly airtight structure is obtained. be able to.

  FIG. 6 shows an example of a cross section of the hermetic sealer according to the sixth embodiment. The filter 8 with the cavity is temporarily fixed on the substrate 2 on which the sensor element 1 is mounted and electrically connected, the resin 5 is applied to the outer periphery of the filter 4, and the filter 8 with the substrate 2 cavity is fixed together. Considering the mold clamping by the enclosed mold, the mold is abutted in a range not exceeding the side wall forming the cavity of the filter 4, and it is possible to produce with high yield by designing the mold to be clamped. According to this structure, steps such as temporary fixing and joining of the filter can be omitted as in the frame 3 or the filter 8 with the cavity shown in FIGS. When the sensor element 1 is mounted, there is nothing in the periphery, the wire bonding process can be performed without considering the influence of the frame 3, the yield is high, and there is no waste such as enlargement of the PKG due to the installation range limitation of the frame 3. Further, special equipment corresponding to the frame 3 and having a large vertical stroke is not required.

  The hermetic sealing body of the present invention includes a substrate, a sensor element, a filter, a frame disposed around the sensor element, and a resin. The filter is disposed on the frame, and the filter and the frame are collectively made of the resin. Can be fixed. At this time, the resin is cured by covering with a metal mold or the like so as to protect the use surface of the filter, thereby preventing the formation of a leak path to the outside due to the expansion of the gas inside the hollow or the inclination of the filter.

  In addition, by forming a groove on the outer periphery of the upper surface to prevent the resin from flowing out to the filter, the resin flows on the optical surface of the filter even if the resin is pressed out by the injection pressure. A safe reservoir can be provided.

  Furthermore, it is also possible to prevent the resin from flowing into the hollow interior by forming a groove in the outer periphery of the back surface of the filter.

  This effect can be exhibited simultaneously by forming grooves in the outer peripheral portions of the upper and lower surfaces of the filter. At this time, the rigidity when pressed by the mold can be increased by disposing the grooves formed in the upper surface outer peripheral portion and the rear surface outer peripheral portion so as not to be at the same position.

  The groove on the upper surface formed here can also be used for positioning when fixing from the upper surface with a mold.

  Moreover, the groove | channel formed in the lower surface has the effect | action that it can utilize for the positioning at the time of temporary fixing with a frame.

  In addition, a cap in which the filter is bonded to the frame in advance can be used. Since the cap is fixed with resin, there is no formation of voids or leak paths due to expansion of the gas inside the hollow. In this structure, a structure in which the resin does not directly contact the filter is possible, and the optical surface can be easily protected.

  In addition, a structure including a substrate, a sensor element, a filter having a cavity structure, and a resin, covering the sensor element mounted on the surface of the substrate with the filter cavity, and fixing the filter with the cavity by the resin, A filter mounting step is not required, and since the filter with the cavity is fixed with resin in a temporarily fixed state, there is no generation of voids or leak paths due to expansion of gas inside the hollow.

  In any of the above-described hermetic sealing bodies, the frame and the filter are grounded through the substrate by applying conductivity or treatment having conductivity on the surface, and therefore have high noise resistance.

  In the above-described embodiment, the example in which the grooves 6a and 6b are formed has been described. In another embodiment, a plurality of recesses may be formed instead of the grooves 6a and 6b.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Sensor element 2 Board | substrate 3 Frame 4 Filter 5 Resin 6a Groove 6b Groove 7 Cap 8 Filter with cavity 10 Upper die 11 Lower die 13 Protrusion

Claims (10)

A substrate,
A sensor element provided on the surface of the substrate;
A frame provided around the sensor element;
A filter provided on the frame;
A resin part for fixing the frame and the filter;
The resin part is provided so as to hang over the edge of the upper surface of the filter ,
An airtight sealing body , wherein a concave portion for preventing inflow of resin from the outside to the inside of the filter is formed on an outer peripheral portion of the optical surface of the filter . The recess is hermetically sealed body according to claim 1, characterized in that it is made form the outer peripheral portion of the upper surface of the filter. The recess is hermetically sealed body according to claim 1, characterized in that it is made form the outer periphery of the lower surface of the filter. 2. The hermetic seal according to claim 1, wherein the concave portion is formed in each of an outer peripheral portion on an upper surface and an outer peripheral portion on a lower surface of the filter. A concave portion and the lower surface of the concave portion of the upper surface of the filter is hermetically sealed body according to claim 4, characterized in that it is formed at a position not facing each other. The filter is hermetically sealed body according to any one of claims 1 to 5, characterized in that Ru Tei joined to the frame. A substrate,
A sensor element provided on the surface of the substrate;
A filter having a cavity structure;
A resin portion for fixing the filter,
The said resin part is provided so that it may be applied to the edge of the upper surface of the said filter. The airtight sealing body characterized by the above-mentioned. The hermetic sealing body according to any one of claims 1 to 7, wherein the filter has conductivity and is grounded through the substrate. Mounting the sensor element on the substrate; and
Temporarily fixing a frame around the sensor element;
A step of temporarily fixing a filter having an optical surface, in which a concave portion for preventing inflow of resin from the outside to the inside of the filter is formed on the outer periphery of the optical surface , on the frame;
Fixing the filter, the frame and the substrate with a resin,
Resin is provided so that it may cover the edge of the upper surface of the said filter. The airtight sealing method characterized by the above-mentioned. Mounting the sensor element on the substrate; and
Temporarily fixing a filter with a cavity;
Fixing the filter and the substrate with a resin,
Resin is provided so that it may cover the edge of the upper surface of the said filter. The airtight sealing method characterized by the above-mentioned.

Images