US-12623962-B2 - Bonded body manufacturing method and bonded body

Abstract

A method of manufacturing a bonded body includes: a preparation step of interposing a sealing material ( 6 ) containing glass between a highly thermal conductive substrate ( 2 ) and a glass substrate ( 3 ); and a bonding step of forming a sealing layer ( 4 ) by irradiating the sealing material ( 6 ) with laser light (L). The bonding step includes: a first heating step of preheating the sealing material ( 6 ) at a temperature lower than a softening point of the sealing material ( 6 ) or a temperature at which the sealing material ( 6 ) is prevented from softening and flowing by irradiation with the laser light (L); and a second heating step of heating, after the second heating step, the sealing material ( 6 ) at a temperature equal to or higher than the softening point of the sealing material ( 6 ) or a temperature at which the sealing material ( 6 ) softens and flows by irradiation with the laser light (L).

Inventors

• Toru Shiragami

Assignees

• NIPPON ELECTRIC GLASS CO., LTD.

Dates

Publication Date

20260512

Application Date

20241101

Priority Date

20200331

Claims (7)

1. 1 . A method of manufacturing a bonded body comprising a highly thermal conductive substrate, a glass substrate, and a sealing layer configured to bond the highly thermal conductive substrate and the glass substrate to each other, the method comprising: a preparation step of interposing a sealing material containing glass between the highly thermal conductive substrate and the glass substrate; and a bonding step of forming the sealing layer by irradiating the sealing material with laser light, wherein the bonding step comprises: a first heating step of preheating the sealing material by irradiation with the laser light; and a second heating step of heating, after the first heating step, the sealing material by irradiation with the laser light, and wherein an output of the laser light in the first heating step is smaller than an output of the laser light in the second heating step.
2. 2 . The method of manufacturing a bonded body according to claim 1 , wherein, in the preparation step, the sealing material is formed into a closed curve shape, and wherein, in the first heating step, the laser light is scanned so as to orbit a plurality of times along a circumferential direction of the sealing material.
3. 3 . The method of manufacturing a bonded body according to claim 1 , wherein, in the second heating step, the laser light having an output larger than an output of the laser light in the first heating step is radiated to the sealing material.
4. 4 . The method of manufacturing a bonded body according to claim 1 , wherein the highly thermal conductive substrate is a silicon substrate.
5. 5 . The method of manufacturing a bonded body according to claim 1 , wherein the laser light is a semiconductor laser.
6. 6 . The method of manufacturing a bonded body according to claim 1 , wherein the bonded body further comprises an element between the highly thermal conductive substrate and the glass substrate.
7. 7 . The method of manufacturing a bonded body according to claim 1 , further comprising, before the preparation step, a step of forming a silicon oxide film or a silicon nitride film on a surface of the highly thermal conductive substrate, to thereby interpose the silicon oxide film or the silicon nitride film between the highly thermal conductive substrate and the sealing layer.

Description

TECHNICAL FIELD The present invention relates to a method of manufacturing a bonded body by bonding a highly thermal conductive substrate and a glass substrate to each other, and to a bonded body. BACKGROUND ART As is well known, LED elements and other electronic elements are each housed in a hermetic package in order to prevent deterioration. The hermetic package is formed as, for example, a bonded body obtained by bonding a glass substrate to a base substrate. As a method of bonding the base substrate and the glass substrate to each other, there has been known, for example, a method involving heating a sealing material containing glass powder by irradiation with laser light under a state in which the sealing material is interposed between the base substrate and the glass substrate (see, for example, Patent Literature 1). The sealing material softens and flows by heating with laser light, and the base substrate (container) and the glass substrate (glass cover) adhere to each other. When the sealing material that has softened and flowed is firmly fixed by cooling, a sealing layer is formed, and the base substrate and the glass substrate are hermetically bonded to each other. As described above, a hermetic package can be obtained without applying a thermal load to the element by irradiating the sealing material with laser light (laser sealing). CITATION LIST Patent Literature 1: JP 2017-212251 A SUMMARY OF INVENTION Technical Problem The base substrate may be formed of a material having high thermal conductivity (hereinafter referred to as “highly thermal conductive substrate”) in order to prevent the deterioration of the element by heat generation. When the highly thermal conductive substrate and the glass substrate are bonded to each other via the sealing material, there is a risk in that the sealing material and the glass substrate having been heated may be rapidly cooled due to the rapid progress of heat conduction from the sealing material to the highly thermal conductive substrate. In particular, in the case of laser sealing, unlike a sealing method using a general firing furnace, only the sealing material and the periphery thereof are locally heated, and hence the above-mentioned risk is increased. When the sealing material and the glass substrate are rapidly cooled, cracks occur at the interface between the sealing layer and the glass substrate, in the sealing layer itself, and in the glass substrate itself, which causes bonding failure. Herein, the “highly thermal conductive substrate” refers to a substrate having a thermal conductivity of 10 W/m·K or more at 20° C. The present invention has been made in view of the above-mentioned circumstances, and a technical object of the present invention is to reduce the occurrence of bonding failure between a highly thermal conductive substrate and a glass substrate. Solution to Problem In order to achieve the above-mentioned object, according to one embodiment of the present invention, there is provided a method of manufacturing a bonded body comprising a highly thermal conductive substrate, a glass substrate, and a sealing layer configured to bond the highly thermal conductive substrate and the glass substrate to each other, the method comprising: a preparation step of interposing a sealing material containing glass between the highly thermal conductive substrate and the glass substrate; and a bonding step of forming the sealing layer by irradiating the sealing material with laser light, wherein the bonding step comprises: a first heating step of preheating the sealing material at a temperature lower than a softening point of the sealing material by irradiation with the laser light; and a second heating step of heating, after the first heating step, the sealing material at a temperature equal to or higher than the softening point of the sealing material by irradiation with the laser light. According to this configuration, when the sealing material is preheated at a temperature lower than the softening point thereof by irradiation with the laser light in the first heating step of the bonding step, the highly thermal conductive substrate can be heated via the sealing material. When the sealing material is heated at a temperature equal to or higher than the softening point thereof by irradiation with the laser light in the second heating step after the first heating step, the sealing layer with which the highly thermal conductive substrate and the glass substrate are hermetically bonded to each other can be formed while the rapid cooling of the sealing material and the glass substrate due to heat conduction from the sealing material to the highly thermal conductive substrate is reduced. As a result, the occurrence of bonding failure between the highly thermal conductive substrate and the glass substrate can be reduced. In order to achieve the above-mentioned object, according to one embodiment of the present invention, there is also provided a method of manufa