JP6102148B2 - Hermetically sealed package and manufacturing method thereof - Google Patents

Description

  The present invention relates to a hermetically sealed package for electronic components that require hermetic sealing and a method for manufacturing the same.

  Some electronic components such as sensors have a hollow structure inside and are used in a state where the hollow structure is hermetically sealed. An example of the electronic component includes an infrared sensor having an infrared sensor element in a hermetically sealed hollow structure inside the electronic component. An electronic component having a hollow structure includes a substrate, a sensor element mounted on the substrate, a metal lid member, and a connection material such as solder or a conductive adhesive that connects the substrate and the lid member. . However, with such a configuration, the air inside the hollow structure expands by heating in a reflow furnace or the like to connect the lid and the substrate, and the solder at the connecting portion between the substrate and the lid blows out. In some cases, pinholes are generated inside the conductive adhesive, and airtightness cannot be ensured.

  An airtight sealed package (ceramic package) having a flow hole communicating with a hollow structure (accommodating space) is disclosed in Patent Document 1. In this hermetic sealing package, a lid member (cap member) provided with a circulation hole in a substrate and a cap member not provided with a circulation hole are bonded with a thermosetting adhesive so that a hollow structure is formed inside. It is configured by bonding. Even if the air in the hollow structure expands when the entire hermetic sealed package is heated to bond the lid and cap member with a thermosetting adhesive, it expands through the flow holes provided in the lid. Air is exhausted. After being heated until the thermosetting adhesive is completely cured, the through holes are sealed with additional adhesive.

  In order to prevent the formation of pinholes due to the phenomenon of breathing in the bonded part, a substrate and a lid (using a thermosetting adhesive that takes longer to start gelation than the breathing time during curing) A method for adhering an electronic component for adhering a cap) is disclosed in Patent Document 2. The breathing phenomenon refers to a phenomenon in which air in an airtight space expands and breaks the adhesive that is being cured to escape to the outside. Since this thermosetting adhesive is liquid when pinholes are formed in the thermosetting adhesive by a breathing phenomenon, it has fluidity and can fill the formed pinholes. Therefore, since the pinhole is not present when the thermosetting adhesive is completely cured, the airtightness of the hollow structure is maintained.

JP 2002-26162 A Japanese Patent No. 3261111

  However, the invention disclosed in Patent Document 1 requires a process in which the adhesive that bonds the lid member and the cap member is completely cured, and then the adhesive is further applied to the flow holes and cured again. The efficiency of forming a hermetically sealed package is poor. Also, if the entire hermetic sealing package is heated to cure the adhesive applied to the flow holes, the air in the hollow structure may expand again and pin holes may be formed in the adhesive applied to the flow holes. . When pin holes are formed in the adhesive applied to the flow holes, there is a problem that the airtightness of the hollow structure cannot be maintained. In addition, since the hermetic sealing package in which the sensor element is packed with the lid member and the cap member is fixed to the substrate, the number of components used is larger than that in the case where the sensor element is directly mounted on the substrate, and the manufacturing cost is reduced. It will increase.

  On the other hand, in the invention disclosed in Patent Document 2, a thermosetting adhesive having a long time until gelation starts is used, but there are few types of adhesives having such characteristics, and adhesion that can be used. The agent will be limited. Further, since these adhesives are very expensive, there is a problem that the manufacturing cost of the hermetic sealing package increases.

  Therefore, an object of the present invention is to solve the above-mentioned problems, and even if a special thermosetting adhesive is not used, a pinhole can be formed in the thermosetting adhesive even if heated to cure the thermosetting adhesive. Another object of the present invention is to provide a hermetically sealed package in which no is formed and a method for manufacturing the same.

In order to achieve the above-described object, the method for manufacturing a hermetic sealed package according to the present invention includes a portion of the first exterior member that forms a gap through which air passes in the contact portion that is in contact with the second exterior member. The step of applying a thermosetting adhesive except the step, the step of mounting the second exterior member on the contact portion of the first exterior member, and the contact of the second exterior member with the first exterior member In a state where it is mounted on the part, when the temperature of the contact part is equal to or higher than the curing temperature of the thermosetting adhesive, the step of heating at least until the temperature of the contact part reaches the curing temperature of the thermosetting adhesive by injecting additional heat curable adhesive on at least the gap, on the adhesive part, thermosetting coated prior to the step of mounting the second exterior member on abutment of the first exterior member And a step of curing all of the adhesive and the additional thermosetting adhesive.

  According to the present invention, the thermosetting adhesive is applied so as to leave a gap through which air passes, and the first exterior member and the second exterior member are bonded to each other. By using a structure that escapes from the formed gap to the outside air, the generation of pinholes is suppressed. In addition, since the expansion of air in the hollow structure is confined, and the gap through which the air passes in a state where the temperature is raised to the temperature at which the thermosetting adhesive is cured is filled with the additional thermosetting adhesive, the thermosetting that fills the gap The step of heating again to cure the adhesive is omitted.

(A)-(d) is sectional drawing which shows the process of forming the electronic component containing the airtight sealing package of the 1st Embodiment of this invention. (A)-(c) is a top view of the electronic component shown in FIG.1 (c), (d) is a top view of the electronic component shown in FIG.2 (d). (A)-(d) is sectional drawing which shows the process of forming the electronic component containing the airtight sealing package of 2nd Embodiment. (A)-(d) is sectional drawing which shows the process of forming the electronic component containing the airtight sealing package of 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIGS. 1A to 1D are cross-sectional views illustrating steps for manufacturing an electronic component including an airtight sealed package according to the first embodiment of the present invention.

  The electronic component includes a sensor element 1, a substrate 3 that is a first exterior member, and a lid member 4 that is a second exterior member. The sensor element 1 is an element such as an infrared sensor element. The board | substrate 3 and the cover material 4 are adhere | attached with the conductive adhesive 5 which is a thermosetting adhesive, and forms the airtight sealing package. The substrate 3 has a recess, and the lid member 4 is bonded to a position that closes the recess. The lid 4 is bonded to the contact portion 8 of the substrate 3 to cover the concave portion, so that the hollow structure 2 is formed. The sensor element 1 is mounted on the hollow structure 2 (concave portion) of the substrate 3. The lid member 4 has a plate shape and is made of a metal material such as 42Ni, phosphor bronze, brass, iron foil, iron, or the like, or a material having infrared transparency such as germanium, silicon, or sapphire. Alternatively, the lid member 4 may be made of glass, a ceramic material, or a resin material depending on the type of the sensor element 1 mounted on the substrate 3. The conductive adhesive 5 is composed of a mixture of metal particles such as Ag and Cu and an epoxy resin as a conductive material. On the substrate 3, in addition to the sensor element 1, a spacer member for insertion between the sensor element 1 and the substrate 3 and other elements necessary for constituting the sensor are mounted as necessary. Also good. The portion to which the conductive adhesive 5 is bonded is composed of a portion applied before the lid 4 is mounted on the substrate 3 and a portion injected after the lid 4 is mounted on the substrate 3. ing.

  A method for manufacturing an electronic component including the hermetically sealed package having the above-described configuration will be described.

  As shown in FIG. 1A, the sensor element 1 is mounted in the concave portion of the substrate 3. As a mounting method, a connection method that can achieve electrical continuity such as adhesion using solder or a conductive adhesive or mechanical connection using a wire is used. At this time, a spacer member, an additional element, or the like is appropriately selected according to the type of the sensor element 1 and mounted on the substrate 3 together with the sensor element 1.

  Next, as shown in FIG. 1B, the conductive adhesive 5 is applied to the contact portion 8 of the substrate 3. The conductive adhesive 5 is applied so as to form a gap 8a through which air passes so that the air in the hollow structure 2 formed when the substrate 3 is bonded to the lid member 4 communicates with the outside air. (Refer FIG. 2 (a)-(c)). The plurality of gaps 8a existing in the contact part 8 may be wider or narrower than the range where the conductive adhesive 5 is applied, but the total length of the gaps 8a in the contact part is 0.5 mm or more. Preferably it is. That is, the sum of the lengths L1 + L2 + L3 + L4 of the gaps 8a should be 0.5 mm or more (see FIGS. 2A and 2B, referring to L1 + L2 in the configuration of FIG. 2C). When the lid member 4 is mounted on the portion where the conductive adhesive 5 is applied, the lid member 4 is applied to two opposite sides of the contact portion 8 so that the lid member 4 is not inclined due to the surface tension of the conductive adhesive 5. The application shape of the conductive adhesive 5 is preferably the same. In this embodiment, the conductive adhesive 5 that is cured by heating at 125 ° C. for 5 minutes is used.

  As shown in FIG. 1C, the lid member 4 is mounted on the portion of the contact portion 8 where the conductive adhesive 5 is applied. At this time, the lid 4 needs to be mounted on the conductive adhesive 5 applied to the contact portion 8 of the substrate 3 so that a space of 5 μm or more is formed between the substrate 3 and the lid 4. is there. In order to mount the lid 4 on the substrate 3 with an interval of 5 μm or more, there is a method in which the interval is formed by controlling the load of the lid 4 itself, and between the substrate 3 and the lid 4. There is a method in which the interval is formed by controlling the size of the metal particles contained in the conductive adhesive 5.

  After the substrate 3 and the lid member 4 are bonded to each other with an interval of 5 μm or more, at least a portion where the conductive adhesive 5 is applied is heated so that the curing temperature of the conductive adhesive 5 is 125 ° C. To do. In addition to the portion where the conductive adhesive 5 is applied, the entire substrate including the substrate 3 and the lid member 4 may be heated. Moreover, if it is the temperature more than the curing temperature of the conductive adhesive 5, it may not be 125 degreeC. When heated at 125 ° C. for 5 minutes, the conductive adhesive 5 is cured, and the lid 4 is bonded to the substrate 3 with a gap 8a through which air passes. If heating is continued for 5 minutes, the air in the hollow structure 2 expands and flows to the outside air through the gap 8a through which the air passes. Therefore, since the conductive adhesive 5 is not subjected to the load of the air of the hollow structure 2, pinholes due to a respiration phenomenon are not formed.

  Finally, as shown in FIG. 1 (d) and FIG. 2 (d), in the gap 8a through which air passes between the substrate 3 and the lid member 4 while being heated to 125 ° C., is additionally provided. A conductive adhesive 5 is injected and filled. At this time, since the substrate 3 and the lid member 4 are bonded by the conductive adhesive 5 applied first after curing, the lid member 4 is not easily moved from the substrate 3. Therefore, when the additional conductive adhesive 5 is injected into the gap 8a through which air passes, the position of the lid member 4 is not shifted even if a slight force is applied, and the conductive adhesive 5 is easily injected. The additional conductive adhesive 5 may be applied not only to the gap 8a through which air passes but also to the entire contact portion 8. Since the additionally injected conductive adhesive 5 is injected in an environment of 125 ° C., it hardens immediately in 5 minutes from the injection, and as a result, the gap 8a through which air passes is filled and the contact adhesive 5 is The conductive adhesive 5 is completely cured, resulting in a space in which the hollow structure 2 is sealed. The additional conductive adhesive 5 is cured by injecting and curing the additional conductive adhesive 5 while maintaining the temperature (125 ° C. in this embodiment) for curing the conductive adhesive 5 applied first. The additional process for making it unnecessary becomes unnecessary.

  As described above, in order to mount an element used in a hermetically sealed state such as a sensor, the substrate 3 and the lid material 4 are bonded to each other by providing a gap 8a through which air passes between the substrate 3 and the lid material 4. The air inside the hollow structure 2 formed between the two communicates with the outside air. Even if expansion occurs because the air inside the hollow structure 2 communicates with the outside air, the conductive adhesive 5 between the substrate 3 and the lid 4 is not loaded, and a pinhole is formed due to a respiration phenomenon. Not. Further, since the gap 8a through which air passes with the air inside the hollow structure 2 fully expanded is filled with the additional conductive adhesive 5, no pinholes are formed in the additional conductive adhesive 5. The airtightness of structure 2 is maintained. Furthermore, since the additional conductive adhesive 5 is injected at a temperature at which the conductive adhesive 5 is cured, it is heated again to cure the conductive adhesive 5 as compared with the case where it is injected at room temperature. Since no process is required, the manufacturing cost can be reduced.

(Second Embodiment)
FIGS. 3A to 3D are cross-sectional views showing respective steps for manufacturing an electronic component including an airtight sealed package according to the second embodiment of the present invention.

  The electronic component includes a sensor element 1, a substrate 3 that is a first exterior member, a frame member 6, and a lid member 4 that is a second exterior member. The substrate 3 and the lid member 4 have a plate shape. The frame member 6 has a shape of a hollow rectangular parallelepiped, and is made of a metal material such as 42Ni, phosphor bronze, brass, western foil, iron, or the like, or a material having infrared transparency such as germanium, silicon, or sapphire. . Alternatively, the frame member 6 may be made of glass, a ceramic material, or a resin material depending on the type of the sensor element 1 mounted on the substrate 3. The frame member 6 is bonded by solder, a conductive adhesive 5 or the like so that the surface of the substrate 3 faces one end of the hollow opening, and the sensor element 1 is attached to the frame member 6 on the substrate 3. It is bonded to a position surrounded by the inner peripheral surface. The lid member 4 is bonded to the contact portion 8 at the end of the frame member 6 so as to close the other end of the hollow opening of the frame member 6 bonded to the substrate 3. The lid member 4 is bonded to the contact portion 8 of the frame member 6 to form an airtight sealed package, and the hollow structure 2 is configured. Other configurations are the same as those in the first embodiment, and are omitted.

  A method for manufacturing an electronic component including the hermetically sealed package having the above-described configuration will be described.

  As shown in FIG. 3A, the sensor element 1 and the frame material 6 are mounted on the surface of the substrate 3. The sensor element 1 is bonded to a position surrounded by the inner peripheral surface of the frame member 6. In the frame member 6, the end of one hollow opening of the frame member 6 is soldered or conductive with the end of the frame member 6 facing the surface of the substrate 3. It adheres to the substrate 3 with the adhesive 5. Thereafter, as shown in FIG. 1B, the conductive adhesive 5 is applied to the contact portion 8 at the end of the other hollow opening of the frame member 6 bonded to the substrate 3. The other manufacturing methods are the same as those in the first embodiment, and are therefore omitted.

  As described above, by incorporating the frame material 6 into the electronic component, in addition to the effects obtained in the first embodiment, it is not necessary to form a recess for mounting the sensor element 1 on the substrate 3. The cost for manufacturing the substrate 3 can be reduced.

(Third embodiment)
FIGS. 4A to 4D are cross-sectional views showing respective steps for manufacturing an electronic component including an airtight sealed package according to the third embodiment of the present invention.

  The electronic component includes a sensor element 1, a substrate 3 that is a first exterior member, and a cap 7 that is a second exterior member. The board | substrate 3 and the cap 7 are adhere | attached with the electroconductive adhesive 5 which is a thermosetting adhesive, and forms the airtight sealing package. The cap 7 has a recess, and is bonded to the substrate 3 so that the recess and the substrate 3 face each other. The hollow structure 2 is formed by bonding the cap 7 to the contact portion 8 of the substrate 3. The sensor element 1 is mounted on a hollow structure 2 formed by a substrate 3 and a cap 7. The cap 7 is made of a metal material such as 42Ni, phosphor bronze, brass, Western foil, iron, or the like, or a material having infrared transparency such as germanium, silicon, or sapphire. Alternatively, the cap 7 may be made of glass, a ceramic material, or a resin material depending on the type of the sensor element 1 mounted on the substrate 3.

  A method for manufacturing an electronic component including the hermetically sealed package having the above-described configuration will be described.

  As shown in FIG. 4A, the sensor element 1 is mounted on the surface of the substrate 3. As a mounting method, a connection method that can achieve electrical continuity such as adhesion using solder or a conductive adhesive or mechanical connection using a wire is used. Next, as shown in FIG. 4B, the conductive adhesive 5 is applied to the contact portion 8 of the substrate 3. The contact portion 8 is formed on the surface of the substrate 3 so as to surround the bonded sensor element 1. The other manufacturing methods are the same as those in the first embodiment, and are therefore omitted.

  As described above, by forming the recess in the cap 7 that is the second exterior member, in addition to the effect obtained in the first embodiment, it is not necessary to form the recess for mounting the sensor element 1 on the substrate 3. Therefore, the cost for manufacturing the substrate 3 can be reduced.

DESCRIPTION OF SYMBOLS 1 Sensor element 2 Hollow structure 3 Substrate 4 Lid material 5 Conductive adhesive 6 Frame material 7 Cap 8 Contact part

Claims (4)

A step of applying a thermosetting adhesive to a contact portion of the first exterior member that is in contact with the second exterior member, except for a portion that becomes a gap through which air passes;
Mounting the second exterior member on the contact portion of the first exterior member;
Heating the second exterior member in a state where the second exterior member is mounted on the contact portion of the first exterior member until at least the temperature of the contact portion reaches the curing temperature of the thermosetting adhesive; ,
When the temperature of the contact portion is equal to or higher than the curing temperature of the thermosetting adhesive, an additional thermosetting adhesive is injected into at least the gap, and the second exterior member on the contact portion A step of curing all of the thermosetting adhesive applied before the step of mounting on the contact portion of the first exterior member, and the additional thermosetting adhesive,
The manufacturing method of the airtight sealing package characterized by including.   The method of manufacturing an airtight sealed package according to claim 1, wherein the thermosetting adhesive is a conductive adhesive.   In the step of applying the thermosetting adhesive to the contact portion except the gap, a total length of the gaps existing in the contact portion is 0.5 mm or more. The manufacturing method of the airtight sealing package of Claim 1 or 2. Mounting the element on the first exterior member;
Each method of the manufacturing method of the airtight sealing package of any one of Claim 1 to 3, The manufacturing method of an electronic component containing this.

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