JP6395292B2 - Penetration electrode substrate manufacturing method and penetration electrode substrate - Google Patents

Description

  The present invention relates to a method for manufacturing a through electrode substrate in which a through electrode is provided on a glass substrate, and the through electrode substrate. The through electrode substrate manufactured according to the present invention is used in a package field such as an interposer and a semiconductor field such as TSV.

As a conventional glass substrate with a through electrode, for example, a configuration in which a tungsten wire or an iron / nickel / cobalt alloy core is used as an electrode material is disclosed (Patent Documents 1 and 2).
Although the glass substrate with a through electrode having the above-described structure is characterized by high airtightness, it must be heated to a high temperature near the melting temperature of the glass serving as a base material because of its manufacturing method. Therefore, the glass substrate may be damaged due to the difference in thermal expansion coefficient between the glass and the electrode material. Therefore, a limited metal such as tungsten having a thermal expansion coefficient close to that of glass is used. That is, when the through electrode is formed by the above manufacturing method, there is a problem that the selection range of the electrode material is narrow.

  Moreover, since the said manufacturing method requires the process heated to the temperature which glass deform | transforms, the flatness of the surface of a glass substrate is easy to be impaired. Therefore, in order to use by bonding to another substrate on which a semiconductor, MEMS, or the like is formed, the glass substrate with a through electrode obtained by the above manufacturing method needs to be polished after the through electrode is formed. It becomes. However, in order to polish the surface of the substrate in which the metal electrode is embedded in the glass, there is a problem that a special polishing technique is required and the process becomes complicated.

As another method for forming a substrate with a through electrode (TSV, TGV), there is a hole filling by plating, but it is difficult to obtain sufficient airtightness in a high aspect and fine hole.
Also, the normal conductive particles larger than the nano-sized particle size, or the ink paste containing them, generally requires a sintering temperature of 500 ° C. or higher, which depends on the difference in thermal expansion coefficient from glass. Problems come out.

  A method of forming an electrode at a low temperature by mixing a binder that remains after baking such as frit glass is also possible, but the resistance value increases because the binder is included. Furthermore, when joining the substrate with a through electrode to another substrate on which a semiconductor, MEMS, or the like is formed, the binder must be processed at a temperature lower than the molding temperature so that the softening of the binder does not start, and the usable range is narrow. turn into. (In general, a process temperature of about 400 ° C. is required for anodic bonding of borosilicate glass and a silicon wafer.)

JP 2011-151414 A JP 2006-60119 A

  The present invention has been made in view of the above circumstances, and it is not necessary to consider the difference in thermal expansion coefficient between the glass substrate and the through electrode, and it is not necessary to polish the glass substrate after the through electrode is formed. An object of the present invention is to provide a through electrode substrate manufacturing method and a through electrode substrate capable of forming a through electrode having a high height.

According to a first aspect of the present invention, there is provided a method for manufacturing a through electrode substrate, comprising: a first step of forming a through hole inside the base with respect to one surface of a base made of flat glass; and the first step. A second step of sealing the through-hole on the other surface side by applying a film-like sealing material to the other surface of the substrate that has undergone, and the penetration from the one surface side of the substrate that has undergone the second step A fluid in which metal or alloy particles are mixed is introduced into the hole, and metal or alloy particles having different melting points are mixed in the through-hole, and at a temperature lower than the heat resistance temperature of the sealing material , by sintering the different metal or alloy particles having a melting point, seen including a third step of forming a through electrode, wherein the third step includes, inside the through hole by the third metal or alloy M5 plating Filling and forming the plated part; and As the fluid, a fluid E consisting of a liquid metal M6 in which a fourth metal or alloy having a melting point lower than that of the third metal or alloy M5 is heated to the melting point or higher to be in a molten state is used. And filling the liquid metal into the pores (micropores) generated in the plated portion of the hole .

According to a second aspect of the present invention, there is provided a method for manufacturing a through electrode substrate comprising: a first step of forming a through hole in the base of one surface of the base made of flat glass; and the first step. A second step of sealing the through-hole on the other surface side by applying a film-like sealing material to the other surface of the substrate that has undergone, and the penetration from the one surface side of the substrate that has undergone the second step A fluid in which metal or alloy particles are mixed is introduced into the hole, and metal or alloy particles having different melting points are mixed in the through-hole, and at a temperature lower than the heat resistance temperature of the sealing material, A third step of forming through electrodes by sintering metal or alloy particles having different melting points, and in the first step, a recess is formed in advance on the other surface of the substrate, Applying a film-like sealant And features.

According to a third aspect of the present invention, there is provided a method for producing a through electrode substrate according to the second aspect , wherein the film-like sealing material is pasted with a laminator.

According to a fourth aspect of the present invention, there is provided the method of manufacturing the through electrode substrate according to the second or third aspect , wherein the third step is performed by using the metal or alloy particles having different melting points as the metal having the lowest melting point. Using In which is lower than the heat resistance temperature of the stopper, the mixing ratio of In and Ag is set to Ag: In = 4: 1 or more so that the melting point of the alloy obtained after sintering is higher than the heat resistance temperature of the through electrode substrate. It is characterized by an Ag ratio.

According to a fifth aspect of the present invention, there is provided the through electrode substrate manufacturing method according to any one of the second to fourth aspects, wherein the third step includes a plurality of metal or alloy particles having different melting points as the fluid. Using the mixed fluid A, and filling the fluid A into the through holes.

According to a sixth aspect of the present invention, in the method of manufacturing a through electrode substrate according to any one of the second to fourth aspects, the third step includes mixing the first metal or alloy particles M3 as the fluid. Using the fluid C, filling the through-hole with the fluid C, and a second metal or alloy having a melting point lower than that of the first metal or alloy particles M3 as the fluid. The step of filling the liquid metal M4 into the pores (micropores) generated in the fluid C in the through hole using the fluid D made of the liquid metal M4 heated to the molten state as described above. It is characterized by including these.

Method for producing a through electrode substrate according to claim 7 of the present invention, Oite to claim 6, the step of filling the liquid metal M4 or the liquid metal M6 forming the fluid is a vacuum pressure It is characterized by using a pressure impregnation method.

The through electrode substrate according to claim 8 of the present invention is a through electrode substrate having a through electrode on a base body, and the through electrode is formed of a third metal or alloy particle M5 in the through hole of the base body. And a liquid metal M6 in which a fourth metal or alloy particle having a melting point lower than that of the third metal or alloy particle M5 constituting the plating portion is heated to a melting point or higher to be in a molten state. It is composed of a cooled portion, and the portion where the liquid metal M6 is cooled is arranged in a hole (a fine hole) generated in the plated portion.

  In the present invention, the inside of the through hole provided in the substrate made of glass is in a state in which one opening of the through hole is sealed with a sealing material, and the other opening of the through hole has a metal or alloy A fluid mixed with particles is introduced, and metal or alloy particles having different melting points are mixed in the through hole. Thereafter, the through electrode is formed by sintering at a temperature lower than the heat resistance temperature of the sealing material (the metal or alloy particles having different melting points). At that time, multiple types of metal or alloy particles are melted by heating above the melting point of the metal or alloy particle having the lowest melting point, and alloyed with other metal or alloy particles having a higher melting point. Through electrodes are formed.

  The above alloying process will be described in the case of using a fluid mixed with fine particles in which the ratio of silver (Ag) and indium (In) is 4: 1 or more in atomic ratio (at%). In is melted by heating at a temperature of about 180 ° C. exceeding the melting point of In (156 ° C.). Thereafter, by maintaining the heated state, In diffuses into Ag (melting point: 962 ° C.) and alloying occurs. Once alloyed and solidified, it does not melt at the melting point of In, and if it is completely alloyed, it will not melt until it reaches 693 ° C. (melting point after alloying = solidus) as shown by the Ag-In phase diagram. Does not occur.

The process of “melting, diffusing, and alloying” at such a low temperature is not limited to the combination of silver (Ag) and indium (In), but a solid solution system, a eutectic system, and an intermetallic compound are used. The same can be realized by appropriately selecting a combination in consideration.
Therefore, according to the present invention, by performing “melting, diffusion, and alloying at a low temperature”, it is possible to form a through electrode and a wiring connected thereto, and to remelt the temperature higher than the temperature at which the electrode is formed. It becomes possible to make it high temperature. In other words, the present invention provides a wiring such as a through electrode that can be used up to a high temperature at such a low process temperature. Thereby, the problem of the difference of a thermal expansion coefficient with glass can be solved.

  As described above, according to the present invention, an alloying process can be established at a low temperature of 500 ° C. or lower. Therefore, since the difference in thermal expansion between the glass forming the substrate and the material forming the through electrode can be smaller than in the past, there is no need to consider the difference in the thermal expansion coefficient between the glass substrate and the through electrode, and the method for manufacturing the through electrode substrate Is obtained. Thereby, since the limitation of the elements constituting the plurality of types of metal or alloy particles is relaxed, it is possible to select various materials other than tungsten. Therefore, according to the present invention, it is possible to manufacture a through electrode substrate having a through electrode made of an element that provides desired conductivity.

  In addition, after heat-treating the fluid mixed with metal or alloy particles adhering to one surface of the substrate, performing a heat treatment, forming a through electrode inside the through hole of the substrate, and then removing the film from the substrate, Flatness is naturally secured on the upper and lower surfaces of the through-electrodes exposed on one side and the other side of the substrate. Therefore, this invention contributes to provision of the manufacturing method of a through-electrode board | substrate which does not need the grinding | polishing of a glass substrate after formation of a through-electrode.

  Further, after a plurality of types of metal or alloy particles are mixed in the through hole, the substrate is subjected to a pre-bake treatment and a firing treatment, so that at least one of the metal or alloy particles is in a molten state. After passing through, it is alloyed and a penetration electrode is formed. Therefore, there is no generation of pores that are a problem in sintering, and it is possible to form a through-hole electrode having high airtightness.

The flowchart which shows the manufacturing method of the penetration electrode substrate concerning the present invention. The flowchart (1st embodiment) containing an example of the 3rd process shown in FIG. The schematic cross section which shows the manufacturing method based on FIG. 2 in order of a process. The schematic cross section which shows each process following FIG. 3 in order. The flowchart containing other examples of the 3rd process shown in FIG. 1 (2nd embodiment). The schematic cross section which shows the manufacturing method based on FIG. 5 in order of a process. The schematic cross section which shows each process following FIG. 6 in order. 7 is a flowchart including another example of the third step shown in FIG. 1 (third embodiment). The schematic cross section which shows the manufacturing method based on FIG. 8 in order of a process. The schematic cross section which shows each process following FIG. 9 in order. FIG. 11 is a schematic cross-sectional view sequentially illustrating each step following FIG. 10. The flowchart containing other examples of the 3rd process shown in FIG. 1 (4th embodiment). The schematic cross section which shows the manufacturing method based on FIG. 12 in order of a process. FIG. 14 is a schematic cross-sectional view sequentially illustrating each step following FIG. 13. The schematic cross section which shows each process following FIG. 14 in order. The phase diagram in an example of a high melting metal (alloy) and a low melting metal (alloy).

Below, the manufacturing method of the penetration electrode substrate concerning the present invention is explained based on a drawing.
FIG. 1 is a flowchart showing a method for manufacturing a through electrode substrate according to the present invention, which includes the following five steps.
A first step of forming a through hole from one surface of the substrate toward the other surface.
A second step of sticking a film to the other surface of the substrate and sealing the through hole on the other surface side.
A third step in which a fluid in which metal or alloy particles are mixed is introduced into one surface of the substrate so that a plurality of types of metal or alloy particles are mixed in the through hole.
A fourth step in which the base is placed in a sealed container and fired while the inside of the container is evacuated to form an alloyed through electrode.
A fifth step of removing the substrate from the sealed container, removing the heating means, removing the film, and then cleaning the substrate.
Through the above five steps, the through electrode substrate according to the present invention is obtained.
In the present invention, “a plurality (at least two or more kinds) of metal or alloy particles” which are mixed into the fluid A and are the material of the through electrode (or wiring pattern) by the subsequent heat treatment are referred to as starting materials. Also called.

In the present invention, among the above five steps, the third step is a characteristic part. Depending on the difference in the third step, there are four types of embodiments described below. Here, for simplification, description will be made using “two types” of metal or alloy particles instead of “plurality” of metal or alloy particles.
First embodiment: When using a fluid in which two kinds of metal or alloy particles are mixed before filling the through holes (applied to a flat substrate).
Second embodiment: When the manufacturing method of the first embodiment is applied to a substrate having a recess.
Third Embodiment: After filling a fluid containing a mixture of first metal or alloy particles into a through-hole, a fluid made of a liquid metal obtained by heating and melting the second metal or alloy particles to the melting point or higher. When filling (applicable to flat substrate).
Fourth embodiment: After a material made of a third metal or alloy is filled into a through hole by a plating method, a flow made of a liquid metal in which the fourth metal or alloy is heated to its melting point or higher to be in a molten state When filling the body (applies to flat substrate).
Below, 1st embodiment-4th embodiment are described in order.

<First embodiment>
2 to 4 are drawings according to the first embodiment, FIG. 2 is a flow chart, FIG. 3 is a schematic cross-sectional view showing an example of the manufacturing method based on FIG. 2, and FIG. It is a schematic cross section which shows a process in order.

  As shown in FIG. 1, the manufacturing method of the first embodiment includes the following seven steps, and particularly SA3 to SA5 correspond to the third step. The feature of the first embodiment is that the fluid A containing a plurality of metal or alloy particles is “prepared in advance (meaning that it is prepared as a starting material before filling the through holes)” and penetrates the fluid A. The point is to fill the inside of the hole. Below, in order to simplify description, the case where the fluid A contains two types of metal particles M1 and M2 will be described.

The through-hole 12 is formed from one surface of the substrate 10 toward the other surface [SA1 (first step): FIG. 3A].
At that time, a film 11 is provided in advance on one surface of the substrate 10 as necessary.
-The film 13 is stuck on the other surface of the substrate 10, and the through hole 12 is sealed on the other surface side [SA2 (second step): FIG. 3 (b)].
A fluid A containing two types of metal particles M1 and M2 is applied to one surface of the substrate 10, and the fluid A is filled into the through holes 12 [SA3 (third step): FIG. 3 (c)].
The substrate 10 is rotated to shake off the fluid A attached on one surface of the substrate [SA4 (third process): FIG. 3 (d)].

The substrate 10 is pre-baked using the heating means 16a [SA5 (third step): FIG. 4 (e)].
The substrate 10 is placed in the sealed container C1, and baked using the heating means 16b while the inside of the container is evacuated (PA) to form the alloyed through electrode MA [SA6 (fourth step): FIG. f)].
The substrate 10 is taken out from the sealed container C1, the heating means 16b is removed, the films 11 and 13 are removed, and then the substrate 10 is washed [SA7 (fifth step): FIG. 4 (g)].
Through the above steps, the through electrode substrate SA including the through electrode 14A (MA) is obtained.

  In the first step (SA1), a substrate made of glass is prepared as the base 10 and, for example, sandblasting (hereinafter referred to as blasting) is performed from one surface (upper surface in FIG. 3) to the other surface (lower surface in FIG. 3). Through holes 12 are also formed. At that time, a masking dry film 11 having an opening at a position corresponding to the through hole is frequently used on one surface of the substrate. Further, the dry film used for blasting masking can be left without peeling and used as a protective film or masking film in post-processing. Furthermore, when used for a protective film / masking film, it is effective to use polyimide having high heat resistance.

  As the substrate 10 made of the glass, a substrate having a flat and clean surface was previously polished. In addition, various kinds of glass such as soda lime glass, non-alkali glass, white plate, and quartz can be used as the glass. In the present embodiment, the case where the substrate is a substrate made of glass will be described in detail. However, even if a substrate other than glass, for example, a substrate such as silicon, SiC, or ceramics, is used as the substrate, the manufacturing method of the present invention is applicable. Is possible.

  The through hole processing method is not limited to the blast processing described above, and, for example, a dry etching method, laser processing, machining, or the like can be appropriately employed. Depending on the processing method, it is not necessary to provide the dry film 11 used in the blasting method. Moreover, the design of the size and pitch of the through holes is also free. In laser processing, a through hole having a diameter of up to about 0.02 mm is possible, which is desirable when a finer through electrode is required. When a finer through electrode is required, a dry etching method can be used. At this time, it is desirable to protect the surface in advance with a film of a heat resistant material such as polyimide or a coating solution.

  In the second step (SA2), a polyimide film 13 is formed on the other surface of the glass substrate 10 in which the through hole 12 has been processed in the previous step (SA1) (the lower surface in FIG. Apply using a laminator.

The third step includes the following three steps (SA3 to SA5).
In the first step (SA3), first, Ag (M1) and In (M2) are provided as two types of metal particles M1 and M2 on one surface of the substrate 10 on which the film 13 is provided on the other surface in the previous step (SA2). By applying the fluid A14 containing, the fluid A14 is filled into the through-holes 12. At that time, the fluid A <b> 14 is dispensed in a paddle shape on one surface of the substrate 10. At that time, the fluid A14 includes a high melting point metal (alloy) [Ag (M1) in this example] and a low melting point metal (alloy) [In (M2) in this example] in an individual state. It is important to be included.
The filling method of the fluid A14 is not limited to the dispensing method, and the fluid A14 may be filled into the through holes by other methods such as a printing method and a suction method.

  In the second step (SA4), the substrate 10 on which the fluid A14 is applied from the one surface side of the substrate 10 in the previous step (SA3) is rotated to shake off the excess fluid A14 adhering to the one surface of the substrate 10. Thereby, the fluid A14 which makes the upper surface of the through-hole 12 exposed to the one surface side of the base | substrate 10 is planarized. However, instead of the “rotating and shaking method”, a method of removing excess ink (fluid A14) using a squeegee and flattening the ink (fluid A14) forming the upper surface of the through hole 12 is used. May be.

  In the third step (SA5), the substrate 10 on which the fluid A14 that forms the upper surface of the through hole 12 in the previous step (SA4) is flattened is pre-baked using the heating means 16a. At that time, the surface of the substrate 10 on which the fluid A14 is flattened is an upper surface, and the other surface of the substrate 10 (the surface to which the film 13 is attached) is the lower surface. A heating means 16 a is provided so that heat is conducted to the base 10. Thereby, the prebaking process of the base | substrate 10 is performed using the heating means 16a.

Such a pre-baking process is performed using the heating means 16a which consists of a hot plate, for example. The purpose of the pre-baking process is to volatilize the solvent contained in the fluid A14, and is performed, for example, under conditions of 70 ° C. and 30 minutes.
If the fluid A14 is not sufficiently filled in the through-hole 12, the third step from filling to pre-baking [(first step (SA3), second step (SA4), third step (SA5)] May be repeated a plurality of times.

  3 to 4 show examples in which each process is performed while leaving the dry film 11 provided on one surface (upper surface) of the substrate 10 as masking during blasting. The dry film 11 is heat resistant. In the case of a film having low properties, the film 11 is peeled off at this point (before the pre-bake treatment: between SA4 and SA5). When the file 11 is a film having high heat resistance, the state can be left as it is (the process proceeds to SA5 and subsequent steps without removing the film 11).

  The fluid A includes a plurality (at least two or more types) of metal or alloy particles serving as a material for the through electrode (or wiring pattern), and is heated above the melting point of the metal or alloy having the lowest melting point. And then alloyed with other metals or alloys having a higher melting point. Examples of the fluid A include silver (Ag) and indium (In), in which fine particles of each are mixed at an atomic ratio of 4: 1.

  As a work procedure, first, a fluid A is used to form a through electrode or other wiring pattern on a substrate such as glass, ceramic, or silicon. Next, by heating at a temperature exceeding the melting point (156 ° C.) of In (preferably 180 ° C. or higher), In particles having a low melting point are melted. Thereafter, by maintaining the heated state, In having a low melting point diffuses into Ag particles having a high melting point, and alloying is performed. The alloy produced by this method does not melt at the melting point of In once it is alloyed and solidified, and it does not melt unless it is alloyed at 693 ° C. or higher as shown in the Ag-In phase diagram. I have.

The process of “melting, diffusing, and alloying” at such a low temperature is not limited to the combination of silver (Ag) and indium (In), but a solid solution system, a eutectic system, and an intermetallic compound are used. The same can be realized by appropriately selecting a combination in consideration.
Therefore, according to the present invention, by performing “melting, diffusion, and alloying at a low temperature”, it is possible to form a through electrode or a wiring connected thereto, and the remelting temperature is higher than the temperature at which the electrode is formed. It is possible to make the temperature higher. In other words, the present invention provides a wiring such as a through electrode that can be used at such a low process temperature up to a high temperature. Thereby, the problem of the difference of a thermal expansion coefficient with glass can be solved.

  In addition, the kind and mixing ratio of the metal and alloy used as the starting material according to the present invention can be arbitrarily selected according to the intended process and use conditions. As a starting material, in the case of a binary system, for example, Ag—Sn, Ag—Zn, Au—Bi, Au—In, Au—Sn, Au—Pb, Au—Zn, Cu—In, Cu—Sn, Cu -Pb, Cu-Zn, Ni-Bi, Ni-In, Ni-Sn, Ni-Zn, Pb-Sn, Sn- (Pb-Sn) and the like. There are combinations of ternary and higher, and there are infinite combinations.

  In the fourth step (SA6), the base body 11 in which the solvent is volatilized from the fluid A14 filled in the through hole in the previous step (SA5) is contained in the sealed container C1, and the inside of the sealed container C1 is exhausted ( PA) and firing treatment using heating means 16b in vacuum in order to prevent oxidation of the material metal, thereby forming the through electrode MA. By this firing treatment, the low melting point metal (alloy) [In (M2) in this example] is melted and diffused with the high melting point metal (alloy) [Ag (M1) in this example] to be alloyed.

Such a baking process is performed using the heating means 16b which consists of a hotplate, for example. The purpose of the firing (alloying) treatment is to solidify the fluid A14 filled in the through-holes, for example, under conditions of 300 ° C. and 1 hour lower than the heat resistance temperature of the polyimide forming the films 11 and 13. .
The method for preventing the oxidation of the metal material is not limited to the vacuum described above, but in an inert gas (nitrogen, argon, etc.) or a reducing gas (formic acid, hydrogen, carbon monoxide, The calcination treatment may be performed in hydrogen sulfide, sulfur dioxide or the like.

  Therefore, it is possible to select the sealing material, the type and mixing ratio of the starting metal and alloy so that the firing (alloying) processing temperature is lower than the heat resistance temperature of the sealing material. Is a key point. That is, in the third step described above, among the metal or alloy particles having different melting points, as the metal or alloy particles having the lowest melting point, the one having a temperature lower than the heat-resistant temperature of the sealing material is used. It becomes possible.

  In the third step, the melting point of the alloy obtained after sintering is higher than the melting point of the metal or alloy particle having the lowest melting point among the metal or alloy particles having different melting points. It is preferable to set the mixing ratio (mixing ratio) of the metal or alloy particles. Among these, a mixing ratio that provides a melting point (solid phase line) higher than the heat resistant temperature required for the through electrode is more preferable.

Taking the high melting point metal (alloy) [Ag (M1)] and the low melting point metal (alloy) [In (M2)] contained in the fluid A14 used in the present embodiment as an example, the above-described book in these state diagrams. FIG. 16 is a graph in which points of the invention are added.
As shown in FIG. 16, the four conditions [Ag melting point (962 ° C.), melting point after alloying (693 ° C.), heat resistance temperature of sealing material, In melting point (156 ° C.)] “A range of alloying process (composition / temperature): region surrounded by dotted line” suitable for the invention is appropriately selected. FIG. 16 shows that an Ag ratio of Ag: In = 4: 1 or more is preferable in terms of atomic ratio (atm%) of Ag particles and In particles.

In the fifth step (SA7), the base body 10 in a state in which the fluid A14 filled in the through hole in the previous step (SA6) is solidified to form the through electrode 14A (MA) is transferred from the sealed container C1 to the outside. After removing the heating means 16b and removing the films 11 and 13 from the substrate 10, the substrate 10 is washed.
The operation of removing (peeling) the films 11 and 13 from the substrate 10 is performed after the substrate 10 is cooled to a desired temperature or lower. The cleaning process of the substrate 10 is performed using, for example, a glass substrate detergent / pure water. Thereafter, it is preferable to perform IPA vapor drying.

In 1st embodiment, penetration electrode substrate SA was produced by passing through SA1-SA7 mentioned above. Therefore, the through electrode substrate SA according to the first embodiment is a through electrode substrate in which a base is provided with a through electrode, and the through electrode is a plurality of metals or alloys having different melting points in the through hole of the base. Consists of particles.
The airtightness of the through electrode 14A (MA) constituting the manufactured through electrode substrate SA was evaluated by using a helium spraying method. As a result, the airtightness of the through electrode 14A was 1 × 10 ⁻⁹ [Pa · m ³ / sec] or less, and it was confirmed that the through electrode 14A has a good airtightness.

<Second embodiment>
5 to 7 are drawings according to the second embodiment, FIG. 5 is a flowchart, FIG. 6 is a schematic cross-sectional view showing an example of the manufacturing method based on FIG. 5, and FIG. It is a schematic cross section which shows a process in order.
The manufacturing method of 2nd embodiment is a case where the manufacturing method of 1st embodiment is applied with respect to the base | substrate which processed the recessed part, as shown in FIGS.

As shown in FIGS. 5 to 7, the manufacturing method of the second embodiment includes the following steps.
A recess 20C is formed on the other surface of the substrate 20 [SB1 (previous process): FIG. 5A].
The through hole 22 is formed from one surface of the base 20 toward the other surface [SB2 (first step): FIG. 5B]. At that time, if necessary, a film 21 is provided in advance on one surface of the substrate 20.
-The film 23 is stuck on the other surface of the base body 20, and the through hole 22 is sealed on the other surface side [SB3 (second step): FIG. 5 (c)].
A fluid B24 containing two kinds of metal particles M1 and M2 is applied to one surface of the substrate 20, and the fluid B24 is filled in the through holes 12 [SB4 (third step): FIG. 6 (d)].

The substrate 20 is rotated to shake off the fluid B24 attached on one surface of the substrate [SB5 (third step): FIG. 7 (e)].
-The base 20 is pre-baked using the heating means 26a [SB6 (third step): FIG. 7 (f)].
The base body 20 is placed in the sealed container C2, and baked using the heating means 26b while exhausting (PB) the inside of the container to form an alloyed through electrode MA [SB7 (fourth step): FIG. g)].
The substrate 20 is taken out from the sealed container C2, the heating means 26b is removed, the films 21 and 23 are removed, and then the substrate 20 is washed [SB8 (fifth step): FIG. 7 (h)].
Through the above steps, the through electrode substrate SB including the through electrode 24A (MA) is obtained.

  In the previous step (SB1), a substrate made of glass is prepared as the base 20, and a recess 20C having a desired depth is formed from the other surface (lower surface in FIG. 6) to one surface (upper surface in FIG. 6). To do. As a method for forming the recess 20C, for example, a method disclosed in JP2013-022534A can be cited.

  As the substrate 20 made of the above glass, a substrate that had been polished in advance and had a flat and clean surface was used. In addition, various kinds of glass such as soda lime glass, non-alkali glass, white plate, and quartz can be used as the glass. In the present embodiment, the case where the substrate is a substrate made of glass will be described in detail. However, even if a substrate other than glass, for example, a substrate such as silicon, SiC, or ceramics, is used as the substrate, the manufacturing method of the present invention is applicable. Is possible.

  In the first step (SB2), for example, sandblasting (hereinafter referred to as blasting) is performed from one surface (upper surface in FIG. 6) to the other surface (lower surface in FIG. 6) from one surface (upper surface in FIG. 6) on which the recess 20C is formed in the previous step (SB1). Through holes 22 are formed by a process). At that time, a masking dry film 21 having an opening at a position corresponding to the through hole is frequently used on one surface of the substrate. Further, the dry film used for blasting masking can be left without peeling and used as a protective film or masking film in post-processing. Furthermore, when used for a protective film / masking film, it is effective to use polyimide having high heat resistance.

  The second step (SB3), the third step (SB4, SB5, SB6), the fourth step (SB7), and the fifth step (SB8) are respectively the second step (SA2) and the third step in the first embodiment described above. The same processing as in the steps (SA3, SA4, SA5), the fourth step (SA6), and the seventh step (SA7) was performed. The second embodiment is different from the first embodiment only in that the glass substrate 20 has a recess 20C, and the other points are the same as the first embodiment.

In the second embodiment, the through electrode substrate SB was manufactured through the above-described steps (SB1 to SB8). Therefore, the through electrode substrate SB according to the second embodiment is a through electrode substrate having a through electrode on the base, like the through electrode substrate SA described above, and the through electrode is in the through hole of the base. In FIG. 4, the particles are composed of a plurality of metal or alloy particles having different melting points. The through electrode substrate SB differs from the through electrode substrate SA only in that the through electrode substrate SB includes a recess 20C.
The airtightness of the through electrode 24A constituting the produced through electrode substrate SB was evaluated using a helium spraying method. As a result, the airtightness of the through electrode 24A (MA) was 1 × 10 ⁻⁹ [Pa · m ³ / sec] or less, and it was confirmed that the airtightness was good.

<Third embodiment>
8 to 10 are drawings according to the third embodiment, FIG. 8 is a flowchart, FIG. 9 is a schematic cross-sectional view showing an example of the manufacturing method based on FIG. 8 in the order of steps, and FIG. FIG. 11 is a schematic cross-sectional view sequentially showing the steps following FIG. 10.

In the third embodiment, the above-mentioned “third process” uses the fluid C mixed with the first metal or alloy particles as the fluid, and the fluid C is filled in the through holes. And using the fluid D made of a liquid metal in which the second metal or alloy having a melting point lower than that of the first metal or alloy particles is heated to the melting point or higher to be in a molten state as the fluid, Filling the fluid D into the pores (micropores) generated in the fluid C in the through holes.
Hereinafter, the first metal or alloy particle M3 contained in the fluid C is a liquid metal in which the second metal or alloy particle contained in the fluid D is heated to a melting point or higher to be in a molten state. The description will be made assuming that “melting point is higher” than M4.

As shown in FIGS. 8 to 11, the manufacturing method according to the third embodiment includes the following steps.
A through hole 32 is formed from one surface of the substrate 30 to the other surface [SC1 (first step): FIG. 9A]. At that time, a film 31 is provided in advance on one surface of the substrate 30 as necessary.
A film 33 is stuck on the other surface of the substrate 30, and the through hole 32 is sealed on the other surface side [SC2 (second step): FIG. 9B].
The fluid C34a containing the metal particles M3 having a high melting point is applied to one surface of the substrate 30, and the fluid C34a (M3) is filled in the through holes 32 [SC3 (third step): FIG. 9 (c) ].
The substrate 30 is rotated to shake off the fluid C34a (M3) adhering to one surface of the substrate [SC4 (third step): FIG. 9 (d)]. Thereby, the upper surface (opening side of the through hole) of the filled fluid C34a (M3) is flattened.

The substrate 30 is pre-baked using the heating means 36a [SC5 (third step): FIG. 10 (e)]. As a result, voids (fine holes) P are generated inside the fluid C34a (M3) filled in the through holes 32.
The substrate 30 filled with the fluid C34a in the through hole 32 is placed in the sealed container C3, and the inside of the sealed container is evacuated (PC1) [SC6 (third step): FIG. 10 (f)]. Thereby, the inside of the micropore (hole P) existing in the fluid C34a (M3) is degassed.

-While exhausting (PC2) the inside of the sealed container C3 containing the substrate 30 that has passed through the SC6, the liquid metal M4 described above is introduced (PC3) into the sealed container, and the substrate 30 is in a liquid state. [SC7 (third step): FIG. 10 (g)].
At this time, as the liquid metal M4, a metal or alloy having a melting point lower than that of the metal or alloy particles M3 contained in the fluid C34a is heated to the melting point or higher to be in a molten state.

A pressure (PC4) is applied to the substrate 30 that has undergone the SC7 through the liquid metal M4 [SC8 (third step): FIG. 11 (h)]. As a result, the liquid metal M4 is injected (filled) into the pores P in the fluid C34a (M3) filled in the through holes. Thereby, the void | hole (micropore) P of the state by which the liquid metal M4 was inject | poured is obtained.
The above-mentioned SC6 to SC8 are “liquid metal M4 in which the second metal or alloy particle having a melting point lower than that of the first metal or alloy particle M3 is heated to the melting point or higher as the fluid. This corresponds to the step of filling the liquid metal M4 into the pores (fine holes) generated in the fluid C in the through hole using the fluid D consisting of
In the third embodiment, the “vacuum pressure impregnation method” shown in SC6 to SC8 described above is used. However, the present invention is not limited to this method. For example, an IMA (Injection Molded Solder) method may be used. The IMA method is a method of forming solder bumps by injecting molten metal.

The substrate 30 having undergone the SC8 is taken out from the sealed container C3, and the liquid metal M4 adhering to the outer surface of the substrate 30 is removed [SC9 (third step): FIG. 11 (i)]. As a result, the liquid metal M4 remaining on the outer surface of the substrate 30, particularly the upper surface of the fluid C34a (M3) is removed.

The base electrode 30 is placed in the sealed container C4, the inside of the container is evacuated (PC5), and then subjected to a firing treatment in a vacuum using the heating means 36b to prevent oxidation of the metal material, and an alloyed through electrode 34A (MA) is formed [SC10 (fourth step): FIG. 11 (j)]. Thereby, the structure by which the site | part with which the said liquid metal M4 was cooled was distribute | arranged inside the micropore (hole P) which exists in the fluid C34a (M3) is obtained.
The method for preventing the oxidation of the metal material is not limited to the vacuum described above, but in an inert gas (nitrogen, argon, etc.) or a reducing gas (formic acid, hydrogen, carbon monoxide, The calcination treatment may be performed in hydrogen sulfide, sulfur dioxide or the like.

The substrate 30 is taken out from the sealed container C4, the heating means 36b is removed, the films 31 and 33 are removed, and then the substrate 30 is washed [SC11 (fifth step): FIG. 11 (k)].
Through the above steps, the through electrode substrate SC including the through electrode 34A (MA) is obtained.

  In the third embodiment, the through electrode substrate SC was manufactured through the above-described SC1 to SC11. Therefore, the through electrode substrate SC according to the third embodiment is a through electrode substrate in which a base is provided with a through electrode, and the through electrode has a plurality of first metals or alloys in the through hole of the base. And a portion where a plurality of second metal or alloy particles having a melting point lower than that of the first metal or alloy particles are heated to a melting point or higher to cool the liquid metal. The portion where the liquid metal is cooled is configured to be arranged in pores (micropores) formed between the first metal or alloy particles.

The airtightness of the through electrode 34A (MA) constituting the produced through electrode substrate SC was evaluated using a helium spraying method. As a result, the airtightness of the through electrode 34A was 1 × 10 ⁻⁹ [Pa · m ³ / sec] or less, and it was confirmed that the through electrode 34A had good airtightness.

  In the case of the third embodiment described above, for example, M3 is Ag particles and M4 is In molten metal. First, the through hole is filled with M3 (Ag particles) with the fluid C34a. Thereafter, M4 (In) in a molten state is filled into vacancies (fine holes) generated in the through holes filled with M3. At that time, the porosity may be adjusted so that the ratio of Ag and In is 4: 1 or more in atomic ratio (at%).

<Fourth embodiment>
12 to 15 are drawings according to the fourth embodiment, FIG. 12 is a flowchart, FIG. 13 is a schematic cross-sectional view illustrating an example of the manufacturing method based on FIG. 12, and FIG. FIG. 15 is a schematic cross-sectional view sequentially showing each step following FIG. 14.
The fourth embodiment solves the problem that it is difficult to completely fill a through hole without leaving a hole (micro hole) inside a through electrode (plated portion) formed by a plating method. It provides a method for this. That is, the fourth embodiment increases the airtightness of the through electrode by filling the hole (micropore) remaining in the through electrode (plated portion) with molten metal and alloying. With the goal.

The fourth embodiment includes a step of filling the inside of the through hole with a third metal or alloy M5 by plating, and a fourth metal or alloy having a melting point lower than that of the third metal or alloy M5 as the fluid. Using the fluid E made of the liquid metal M6 heated to the melting point or higher to be melted, the liquid metal M6 is filled in the voids (micropores) formed in the plated portion of the through hole. Steps.
Hereinafter, the third metal or alloy M5 filled by the plating method is more liquid than the liquid metal M6 in which the fourth metal or alloy contained in the fluid E is heated to the melting point or higher to be in a molten state. Will be described on the assumption that the melting point is high.

As shown in FIGS. 12 to 15, the manufacturing method according to the fourth embodiment includes the following steps.
The through hole 42 is formed from one surface of the base body 40 toward the other surface [SD1 (first step): FIG. 13A]. At that time, a film 41 is provided in advance on one surface of the substrate 40 as necessary.
-The film 43 is stuck on the other surface of the base body 40, and the through hole 42 is sealed on the other surface side [SD2 (second step): FIG. 13 (b)].

A third metal or alloy M3 is filled by a plating method to form a plated portion 44a (M5) [SD3 (third process): FIG. 14 (c)]. Thereby, voids (fine holes) P are generated inside the plated portion C44a (M5) filled in the through holes 42.

The substrate 30 having the plated portion C44a (M5) filled in the through hole 42 is put in the sealed container D3, and the inside of the sealed container is evacuated (PD1) [SD4 (third step): FIG. 14 (d) ]. Thereby, the inside of the fine hole (hole P) existing in the plating part C44a (M5) is deaerated.

The above-mentioned liquid metal M6 is introduced into the inside of the airtight container (PD3) while the inside of the airtight container D3 containing the base body 40 having undergone the SD4 is exhausted (PD2). It is set as the state immersed in the metal M6 of [SD5 (3rd process): FIG.14 (e)].
At this time, as the liquid metal M6, a metal or alloy having a melting point lower than that of the third metal or alloy M5 contained in the plated portion C44a (M5) is heated to the melting point or higher to be in a molten state. Used.

A pressure (PD4) is applied to the substrate 40 that has undergone the SD5 through the liquid metal M6 [SD6 (third step): FIG. 15 (f)]. As a result, the liquid metal M6 is injected (filled) into the inside of the hole P existing in the plated portion C44a (M5) filled in the through hole. Thereby, the void | hole (micropore) P of the state in which the liquid metal M6 was inject | poured is obtained.

The above-mentioned SD4 to SD6 indicate that “a liquid obtained by heating a fourth metal or alloy having a melting point lower than that of the third metal or alloy M5 filled in the through-hole using a plating method to a melting state or higher. This corresponds to the step of “filling the liquid metal M6 into the pores (fine holes) generated in the plated portion of the through-hole using the fluid E made of the metal M6”.
In the fourth embodiment, the “vacuum pressure impregnation method” shown in SD4 to SD6 described above is used. However, the present invention is not limited to this method, and for example, an IMA (Injection Molded Solder) method may be used. The IMA method is a method of forming solder bumps by injecting molten metal.

The substrate 40 having undergone the SD6 is taken out from the sealed container D3, and the liquid metal M6 adhering to the outer surface of the substrate 40 is removed [SD7 (third step): FIG. 15 (g)]. As a result, the liquid metal M6 remaining on the outer surface of the substrate 40, in particular, the upper surface of the plated portion C44a (M5) is removed.

The base electrode 40 is put in the sealed container D4, and the inside of the container is evacuated (PD5). Then, in order to prevent oxidation of the metal as a material, it is fired using a heating means 46b in a vacuum to form an alloyed through electrode 44A (MA) is formed [SD8 (fourth step): FIG. 15 (h)]. Thereby, the structure by which the site | part in which the said liquid metal M6 was cooled was distribute | arranged inside the micro hole (hole P) which exists in plating part C44a (M5) is obtained.
The method for preventing the oxidation of the metal material is not limited to the vacuum described above, but in an inert gas (nitrogen, argon, etc.) or a reducing gas (formic acid, hydrogen, carbon monoxide, The calcination treatment may be performed in hydrogen sulfide, sulfur dioxide or the like.

The substrate 40 is taken out from the sealed container D4, the heating means 46b is removed, the films 41 and 43 are removed, and then the substrate 40 is washed [SD9 (fifth step): FIG. 15 (i)].
Through the above steps, the through electrode substrate SD including the through electrode 44A (MA) is obtained.

  In the fourth embodiment, the through electrode substrate SD is manufactured through the above-described SD1 to SD9. Therefore, the through electrode substrate SD according to the fourth embodiment is a through electrode substrate having a through electrode on a base, and the through electrode is formed from a third metal or alloy M5 in the through hole of the base. And the liquid metal M6 in which the fourth metal or alloy having a melting point lower than that of the third metal or alloy M5 constituting the plated portion is heated to the melting point or higher to be in a molten state is cooled. The portion where the liquid metal M6 is cooled is configured to be arranged in a hole (microhole) generated in the plated portion.

The airtightness of the through electrode 44A (MA) constituting the manufactured through electrode substrate SD was evaluated using a helium spraying method. As a result, the airtightness of the through electrode 44A was 1 × 10 ⁻⁹ [Pa · m ³ / sec] or less, and it was confirmed that the through electrode 44A has a good airtightness.

  In the case of the fourth embodiment described above, for example, M5 is Ag and M6 is In. First, Ag is deposited on the inner wall of the through hole by plating, and the through hole is buried in Ag. In is filled into holes (fine holes) formed in the through holes after plating. At that time, the porosity generated in Ag embedded in the through hole may be adjusted so that the ratio of Ag and In is 4: 1 or more in atomic ratio (at%).

  In each of the above-described embodiments, in a case where Ag and In are melted and alloyed by a heating means including a hot plate while evacuating (evacuating as necessary) the inside of the container in which the substrate is incorporated, By performing heat treatment at 300 ° C. (preferably 180 ° C. or higher) higher than the melting point (156 ° C.) for 1 hour, a homogeneous alloy can be obtained by diffusing In into Ag.

  In addition, in order not to oxidize the metal as a material, in addition to the above-described vacuum, in inert gas (nitrogen, argon, etc.) or reducing gas (formic acid, hydrogen, carbon monoxide, hydrogen sulfide, sulfur dioxide) Etc.) may be performed.

According to the present invention, the electrodes and wirings can be formed at a low temperature of 500 ° C. or lower (it can be further reduced depending on the combination of the starting metal and alloy), so the following actions and effects can be obtained. It is done.
(1) Since the difference in thermal expansion between the substrate made of glass and the through electrode material formed inside the substrate is small, various materials other than tungsten can be selected.
(2) Electrodes and wirings can be formed while protecting and masking the glass substrate surface with a heat resistant resin such as polyimide. This has an effect that a flat and clean surface can be obtained without polishing the through electrode formation.

(3) By using this method for a glass substrate with a step, there is an effect that a complicated process of obtaining a through electrode glass substrate with a step by joining the glass at the step portion after forming the through electrode can be largely omitted. .
(4) A wiring such as a through electrode can be formed even on a substrate on which a semiconductor element or a MEMS element is formed and a high temperature process cannot be adopted.

Further, according to the present invention, it is possible to raise the use temperature above the melting point of the starting material or the heat resistant temperature during the process by alloying the electrode / wiring material in the firing / diffusion process. (By alloying, it is possible to select an alloy composition having a higher melting point than a material having the lowest melting point among the starting materials.)
Furthermore, according to the present invention, since no binder remains in the formed electrode / wiring and there is no void, an electrode / wiring having a small specific resistance can be manufactured.

  The present invention is widely applicable to a method for manufacturing a through electrode substrate. Such a through electrode substrate is suitably used in the package field such as an interposer, the semiconductor field such as TSV, and the like.

  M3 first metal or alloy [high melting point metal (alloy)], M4 second metal or alloy [low melting point metal (alloy)], M5 third metal or alloy [high melting point metal (alloy)], M6 first Four metals or alloys [low melting point metal (alloy)], SA, SB, SC, SD Penetration electrode substrate, P pores (micropores) 10, 20, 30, 40 Base, 11, 21, 31, 41 Film , 12, 22, 32, 42 Through hole, 13, 23, 33, 43 Film, 14A, 24A, 34A, 44A (MA) Through electrode.

Claims (8)

A first step of forming a through hole in the inside of the base with respect to one surface of the base made of flat glass; and
A second step of sealing the through hole on the other surface side by affixing a film-like sealing material to the other surface of the substrate that has undergone the first step;
Introducing a fluid mixed with metal or alloy particles into the through hole from one side of the substrate after the second step, and in a state where metal or alloy particles having different melting points are mixed in the through hole, wherein at a temperature lower than the heat resistant temperature of the sealing material, by sintering the different metal or alloy particles of said melting point, seen including a third step of forming a through electrode,
The third step includes a step of filling the through hole with a third metal or alloy M5 by a plating method to form a plated portion, and a fluid having a melting point lower than that of the third metal or alloy M5. Using the fluid E made of the liquid metal M6 in which the four metals or alloys are heated to the melting point or higher to form a molten state, the liquid is contained in the pores (micropores) formed in the plated portion of the through hole. Filling a metal of the through-electrode substrate. A first step of forming a through hole in the inside of the base with respect to one surface of the base made of flat glass; and
A second step of sealing the through hole on the other surface side by affixing a film-like sealing material to the other surface of the substrate that has undergone the first step;
Introducing a fluid mixed with metal or alloy particles into the through hole from one side of the substrate after the second step, and in a state where metal or alloy particles having different melting points are mixed in the through hole, A third step of forming a through electrode by sintering metal or alloy particles having different melting points at a temperature lower than the heat resistance temperature of the sealing material,
In the first step, a recess is formed in advance on the other surface of the base body,
A method of manufacturing a through electrode substrate, comprising attaching a film-like sealing material to the recess. The method for producing a through electrode substrate according to claim 2, wherein the film-like sealing material is pasted with a laminator. The third step, among the different metal or alloy particles of said melting point, and the lowest melting point metals, using lower than the heat resistant temperature of the sealing material In,
The mixing ratio of In and Ag is set to an Ag ratio of Ag: In = 4: 1 or more so that a melting point of an alloy obtained after sintering is higher than a heat resistant temperature of the through electrode substrate. A method for producing a through electrode substrate according to 2 or 3 . The third step includes the step of filling the fluid A with the fluid A in which a plurality of metal or alloy particles having different melting points are mixed as the fluid. The manufacturing method of the penetration electrode substrate as described in any one of Claims 2 thru | or 4. In the third step, the fluid C mixed with the first metal or alloy particles M3 is used as the fluid, and the fluid C is filled in the through holes. Using a fluid D consisting of a liquid metal M4 in which a second metal or alloy having a melting point lower than that of one metal or alloy particle M3 is heated to the melting point or higher to be in a molten state, 5. The method of manufacturing a through electrode substrate according to claim 2 , further comprising: filling the liquid metal M < b > 4 into holes (fine holes) generated in C. 6. Oite to claim 6, the step of filling the liquid metal M4 or the liquid metal M6 forming the fluid The method for producing a through electrode substrate, which comprises using a vacuum pressure impregnation. A through electrode substrate comprising a through electrode on a substrate,
The through electrode includes a plated portion made of a third metal or alloy particle M5 and a fourth metal having a lower melting point than the third metal or alloy particle M5 constituting the plated portion in the through hole of the base. Alternatively, it is composed of a portion where the liquid metal M6 in which the alloy particles are heated to the melting point or higher to be in a molten state is cooled, and the portion where the liquid metal M6 is cooled is generated in the plated portion. A through electrode substrate, wherein the through electrode substrate is arranged in a hole (fine hole).

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