Method of manufacturing semiconductor device

Abstract

A method for manufacturing a semiconductor chip laminate, which is a semiconductor device, includes: irradiating ultraviolet rays on at least one of a first insulating resin film of a first semiconductor component and a second insulating resin film of a second semiconductor component; and bonding the first semiconductor member and the second semiconductor member by a hybrid bonding in which the first insulating resin film and the second insulating resin film are bonded. Even at a low temperature of about 200 DEG C, the insulating resin films can be well bonded to each other.

Description

TECHNICAL FIELD

[0001] The present application relates to a method of manufacturing a semiconductor device. BACKGROUND

[0002] As a three-dimensional integration technique of semiconductor chips, a hybrid bonding technique of bonding electrodes to each other and bonding insulating films around the electrodes to each other is sometimes used. The insulating film used for hybrid bonding is mostly a silicon dioxide film, but an insulating resin film formed of a photosensitive resin is also being studied (for example, Patent Literature 1). The insulating resin film is less likely to be affected by foreign matter and the like than the silicon dioxide film, and thus it is expected that the yield of products will be improved by using the insulating resin film.

[0003] PRIOR ART DOCUMENT PATENT LITERATURE Patent Literature 1: Japanese Patent Application Publication No. 2012-069585 SUMMARY

[0004] PROBLEMS TO BE SOLVED BY THE INVENTION The present application relates to a method of bonding insulating resin films to each other by heating at a lower temperature, in the case where a semiconductor device is manufactured by hybrid bonding including a step of bonding the insulating resin films to each other.

[0005] MEANS FOR SOLVING THE PROBLEMS The present application includes the following. [1] A method of manufacturing a semiconductor device, including the steps of: preparing a first semiconductor component having a first semiconductor substrate and a first bonding layer provided on the first semiconductor substrate, the first bonding layer including a first electrode and a first insulating resin film having an opening in which the first electrode is provided; preparing a second semiconductor component having a second semiconductor substrate and a second bonding layer provided on the second semiconductor substrate, the second bonding layer including a second electrode and a second insulating resin film having an opening in which the second electrode is provided; irradiating at least one of the first insulating resin film or the second insulating resin film with ultraviolet rays; and bonding the first semiconductor component and the second semiconductor component by hybrid bonding of the first electrode and the second electrode, and the first insulating resin film and the second insulating resin film. [2] The method according to [1], wherein, The process of bonding the first semiconductor component to the second semiconductor component includes heating the first semiconductor component and the second semiconductor component to a temperature of 180°C or higher and 250°C or lower and pressing them together, thereby bonding the first insulating resin film to the second insulating resin film. [3] According to the method described in [1] or [2], wherein, The first semiconductor substrate is a semiconductor wafer, and the second semiconductor substrate is a semiconductor chip. Multiple second semiconductor components are bonded to one first semiconductor component. The method further includes the step of dividing the first semiconductor component, which is bonded to the second semiconductor component, thereby forming a semiconductor chip stack including the first semiconductor component having the first semiconductor substrate monolithically formed as a semiconductor chip and the second semiconductor component. [4] According to any one of [1] to [3], wherein, The first insulating resin film and the second insulating resin film comprise resins containing imide groups. [5] According to the method described in [4], wherein, The resin containing imide groups is a polyimide resin, a polyamide-imide resin, a bismaleimide resin, or a combination thereof. [6] According to the method described in [4], wherein, The resin containing imide groups is a resin having structural units containing imide groups and polysiloxanes bonded to those structural units. [7] According to any one of [1] to [3], wherein, The first insulating resin film and the second insulating resin film comprise polybenzoxazole resin. [8] According to any one of [1] to [3], wherein, The first insulating resin film and the second insulating resin film contain benzocyclobutene resin.

[0014] Invention Effects In the case of manufacturing a semiconductor device by hybrid bonding, which includes a process of bonding insulating resin films to each other, bonding the insulating resin films to each other can be achieved by heating at a lower temperature. By bonding the insulating resin films to each other at a low temperature, damage to the semiconductor components caused by high heat can be easily avoided. Furthermore, the generation of exhaust gas from the insulating resin films can be suppressed. Attached Figure Description

[0015] Figure 1 This is a process diagram illustrating an example of a method for manufacturing a semiconductor device.

[0016] Figure 2 This is a process diagram illustrating an example of a method for manufacturing a semiconductor device.

[0017] Figure 3 This is a process diagram illustrating an example of a method for manufacturing a semiconductor device. Detailed Implementation

[0018] This invention is not limited to the following examples.

[0019] Figure 1 , Figure 2 and Figure 3 This is a process diagram illustrating an example of a method for manufacturing a semiconductor device using the method involved in this invention. Figures 1-3 The method shown includes the following steps: preparing a first semiconductor component 10, the first semiconductor component 10 having a first semiconductor substrate 11 and a first bonding layer 15 disposed on the first semiconductor substrate 11, the first bonding layer 15 including a first electrode 12 and a first insulating resin film 13; preparing a second semiconductor component 20, the second semiconductor component 20 having a second semiconductor substrate 21 and a second bonding layer 25 disposed on the second semiconductor substrate 21, the second bonding layer 25 including a second electrode 22 and a second insulating resin film 23; irradiating at least one of the first insulating resin film 13 or the second insulating resin film 23 with ultraviolet light (UV); and bonding the first semiconductor component 10 and the second semiconductor component 20 by hybrid bonding.

[0020] exist Figures 1-3 In the example shown, a first semiconductor component 10 having a first semiconductor substrate 11 as a semiconductor wafer and a second semiconductor component 20 having a second semiconductor substrate 21 as a semiconductor chip are bonded together by a hybrid bonding process. Multiple second semiconductor components 20 are bonded to one first semiconductor component 10, and then the first semiconductor component 10 bonded to the second semiconductor components 20 is split. As a result, a semiconductor chip stack 30 (semiconductor device) is formed having the first semiconductor component 10 and the second semiconductor component 20 monolithically formed as semiconductor chips. However, the combination of the bonded first semiconductor component and the second semiconductor component is not limited to this and can be appropriately varied.

[0021] The process of preparing the second semiconductor component 20 includes, for example, the following processes: Figure 1 As shown in (a), a plurality of second electrodes 22 are disposed on a main surface of the second semiconductor substrate 21; as Figure 1(b) shown, a second insulating resin film 23 covering the second electrode 22 is provided; as Figure 1 (c) shown, a portion of the second insulating resin film 23 is removed from the side opposite to the second semiconductor substrate 21, thereby forming an opening 23a exposing the second electrode 22; and as Figure 2 (d) shown, the second semiconductor substrate 21 and the second insulating resin film 23 are divided, thereby forming the second semiconductor member 20 having the second semiconductor substrate 21, the second electrode 22, and the second insulating resin film 23 which are singulated as semiconductor chips.

[0022] The second semiconductor substrate 21 before being singulated as semiconductor chips can be a semiconductor wafer. The diameter of the semiconductor wafer (second semiconductor substrate) can be, for example, 150 mm or more and 300 mm or less. The thickness of the semiconductor wafer (second semiconductor substrate) can be, for example, 40 μm or more and 1000 μm or less.

[0023] The second electrode 22 can be, for example, a conductor containing copper. The width (maximum width) of the second electrode 22 can be, for example, 1 μm or more and 13 μm or less. The height of the second electrode 22 can be, for example, 1 μm or more and 90 μm or less. A through electrode which penetrates the second semiconductor substrate 21 can be provided. The second electrode 22 can be formed by a general method using plating or the like.

[0024] The second insulating resin film 23 can be, for example, a film containing an imide group-containing resin, a polybenzoxazole resin, a benzocyclobutene resin, or a combination containing the same. The first insulating resin film 13 can also be a film containing an imide group-containing resin, a polybenzoxazole resin, a benzocyclobutene resin, or a combination containing the same.

[0025] The imide group-containing resin constituting the first insulating resin film 13 and the second insulating resin film 23 can be a polyimide resin, a polyamide-imide resin, or a bismaleimide resin. The polyimide resin can be, for example, a polymer containing a structural unit (imide unit) represented by the following formula (1A). The polyamide-imide resin can be a polymer containing a structural unit (imide unit) represented by the following formula (1B) or (1C). Alternatively, the imide group-containing resin can be a resin having an imide unit represented by formula (1A), (1B), or (1C) and a linear, branched, or cage-like polysiloxane bonded to the imide unit.

[0026] In formulae (1A) to (1C), R 1 represents a 4-valent organic group, R 2 represents a 3-valent organic group, R 10 represents a 2-valent organic group, represents a bond.

[0027] R 1 may be a group containing an aromatic group, for example, R 1 may be a group obtained by removing 4 hydrogen atoms from a compound represented by the following formula (11), (12), or (13). R 2 may be a group containing an aromatic group, for example, R 2 may be a group obtained by removing 3 hydrogen atoms from a compound represented by the following formula (11), (12), or (13). In formula (13), X represents a direct bond, methylene, propane-2,2-diyl, 1,1,1,3,3,3-hexafluoropropane-2,2-diyl, carbonyl, sulfonyl, sulfido, carbonyloxy, oxy, fluorene-9,9-diyl, or amido.

[0028] R 10 may be a group containing an aromatic group, for example, R

[0029] The insulating resin film containing a resin containing an imide group can be formed, for example, by a method including: applying a resin varnish containing a resin precursor on the first semiconductor substrate or the second semiconductor substrate; and forming the insulating resin film containing a resin containing an imide group by heating the coated film. In the case of forming the insulating resin film containing a polymer containing an imide unit (polyimide resin or polyamide-imide resin), the resin precursor can be a polyamic acid having a structural unit corresponding to the imide unit. By heating the coated film, a curing reaction including an imidization reaction is performed, whereby the insulating resin film containing a polyimide resin or a polyamide-imide resin is formed. In the case of forming the insulating resin film containing a resin containing a polysiloxane bonded to an imide unit, the resin precursor can contain a combination of a polycarboxylic acid compound corresponding to the imide unit and a polysiloxane substituted with a substituent having an amino group. The polycarboxylic acid compound can contain an acid anhydride or a carboxylic acid ester. By the reaction of the amino group of the substituent bonded to the polysiloxane with the polycarboxylic acid compound and the curing reaction including the imidization reaction, the insulating resin film containing a resin having an imide group is formed.

[0030] The insulating resin film containing the polybenzoxazole resin can be formed, for example, by a method including: applying a resin varnish containing a resin precursor onto the first semiconductor substrate or the second semiconductor substrate; and performing a curing reaction including a reaction for forming a benzoxazole group by heating the coated film, whereby the insulating resin film containing the polybenzoxazole resin is formed.

[0031] A portion of the second insulating resin film 23 formed so as to cover the entire second electrode 22 is removed to expose the second electrode 22. Thus, the second bonding layer 25 containing the second insulating resin film 23 having a plurality of openings 23a and the second electrode 22 disposed in each of the openings 23a is formed. For example, a portion of the second insulating resin film 23 is removed by chemical mechanical polishing (CMP). The surface of the second bonding layer 25 on the opposite side of the second semiconductor substrate 21, that is, the second bonding surface S2 can be a flat surface, and a convex portion or a concave portion can be formed at the position of the second electrode 22.

[0032] After the second insulating resin film 23 is formed, as shown in Figure 2 (d), the second semiconductor substrate 21 is fixed to the dicing tape 42, and in this state, the second semiconductor substrate 21 is divided together with the second insulating resin film 23 by cutting. By the division, the second semiconductor component 20 having the second semiconductor substrate 21 as a semiconductor chip is formed on the dicing tape 42.

[0033] As shown in Figure 2 (e), before the bonding based on the hybrid bonding is performed, the second insulating resin film 23 is irradiated with ultraviolet rays UV. The insulating resin film irradiated with the ultraviolet rays can be well bonded to other insulating resin films at a relatively low temperature. It is considered that the formation of a polar group on the surface of the second insulating resin film 23 by the irradiation with the ultraviolet rays contributes to the improvement of the bondability at a low temperature.

[0034] The cumulative light amount of the ultraviolet rays irradiated on the second insulating resin film 23 can be adjusted in consideration of conditions such as the heating temperature for adopting the hybrid bonding to obtain appropriate bonding. For example, the cumulative light amount of the ultraviolet rays irradiated on the second insulating resin film 23 can be 500 mJ / cm 2 or more and 20000 mJ / cm 2 or less. The cumulative light amount of the ultraviolet rays irradiated on the second insulating resin film 23 can be 600 mJ / cm 2 or more, 700 mJ / cm 2 or more, 800 mJ / cm 2 or more, 900 mJ / cm 2 or more, 1000 mJ / cm 2 or more, 1100 mJ / cm 2 or more, 1200 mJ / cm2 Above, 1300mL / cm 2 Above, 1400mL / cm 2 Above, 1500mL / cm 2 Above, 1600mL / cm 2 Above, 1700mL / cm 2 Above or 1800mL / cm 2 The above could also be 19000 mJ / cm 2 Below, 18000mJ / cm 2 Below, 17000mJ / cm 2 Below, 16000mJ / cm 2 Below, 15000mJ / cm 2 Below, 14000mJ / cm 2 Below, 13000mJ / cm 2 Below, 12000mJ / cm 2 Below, 11000mJ / cm 2 Below, 10000mJ / cm 2 Below or 9000mJ / cm 2 the following.

[0035] Before the first semiconductor component 10 and the second semiconductor component 20 are bonded, the second insulating resin film 23 is irradiated with ultraviolet light. Alternatively, the second insulating resin film 23 may be irradiated with ultraviolet light before it has been split by cutting.

[0036] Figure 2 The first semiconductor component 10 shown in (f) can also be prepared by the same method as the method described above for preparing the second semiconductor component 20. The first semiconductor component 10 has a first bonding layer 15, which includes a first insulating resin film 13 having a plurality of openings 13a and a first electrode 12 disposed in each of the respective openings 13a.

[0037] The diameter of the semiconductor wafer used as the first semiconductor substrate 11 can be, for example, 150 mm or more and 300 mm or less. The thickness of the semiconductor wafer used as the first semiconductor substrate 11 can be, for example, 40 μm or more and 1000 μm or less.

[0038] The first electrode 12 can be, for example, a conductor including copper. The width (maximum width) of the first electrode 12 can be, for example, 1 μm or more and 13 μm or less. The height of the first electrode 12 can be, for example, 1 μm or more and 90 μm or less. A through electrode that penetrates the first semiconductor substrate 11 can be provided. The surface of the first bonding layer 15 on the opposite side of the first semiconductor substrate 11, that is, the first bonding surface S1 can be a flat surface, and a convex portion or a concave portion can be formed at the position of the first electrode 12.

[0039] Before the first semiconductor member 10 and the second semiconductor member 20 are bonded, the first insulating resin film 13 can be irradiated with ultraviolet rays. The first insulating resin film 13 and the second insulating resin film 23 can be irradiated with ultraviolet rays, or only one of the first insulating resin film 13 and the second insulating resin film 23 can be irradiated with ultraviolet rays.

[0040] In the case of Figure 2 and Figure 3 In the example, a plurality of second semiconductor members 20 picked up from the dicing tape 42 are bonded by hybrid bonding with respect to one first semiconductor member 10 fixed to the dicing tape 41. The second semiconductor members 20 are disposed at positions on the second bonding surface S2 on which the first electrodes 12 and the second electrodes 22 are disposed in opposition to each other, in a direction in which the first bonding surface S1 and the second bonding surface S2 are in contact with each other. In this state, the first semiconductor member 10 and the second semiconductor members 20 are heated to a predetermined heating temperature and are subjected to press bonding, whereby the first semiconductor member 10 and the second semiconductor members 20 are bonded (bonding step S3). Figure 3 (g).

[0041] The step of bonding the first semiconductor member 10 and the second semiconductor member 20 can include a pre-bonding step of heating the first semiconductor member 10 and the second semiconductor member 20 and subjecting them to press bonding, whereby the first insulating resin film 13 and the second insulating resin film 23 are bonded, and an annealing step of heating and pressurizing the entire laminate having the first semiconductor member 10 and the plurality of second semiconductor members 20, whereby the first electrode 12 and the second electrode 22 are bonded. In the case of the method including the pre-bonding step and the annealing step, the first insulating resin film 13 and the second insulating resin film 23 are mainly bonded at the pre-bonding step, and the first electrode 12 and the second electrode 22 are mainly bonded at the annealing step. However, at the pre-bonding step, the first electrode 12 and the second electrode 22 can be bonded to some extent. Also, at the annealing step, the first insulating resin film 13 and the second insulating resin film 23 can be further strongly bonded.

[0042] If the first insulating resin film 13, the second insulating resin film 23, or both are subjected to ultraviolet irradiation before the mixed joining, the insulating resin films can be joined to each other well even if the heating temperature is low. The heating temperature for the pre-joining can be the same as the temperature of the annealing process for the joining of the electrodes to each other, or can be lower than the temperature of the annealing process for the joining of the electrodes to each other. The heating temperature for the joining (pre-joining) of the first insulating resin film 13 and the second insulating resin film 23 can be, for example, 180°C or higher and 250°C or lower. The heating temperature can be 240°C or lower, 230°C or lower, or 220°C or lower, or can be 190°C or higher or 200°C or higher. The pressure for the pre-joining can be, for example, 0.5 MPa or higher and 10 MPa or lower. The time for the heating and the pressurization for the pre-joining can be, for example, 3 seconds or longer and 120 minutes or shorter.

[0043] In the annealing process, the laminate having the first semiconductor member 10 and the plurality of second semiconductor members 20 is subjected to heating and pressurization, for example, in a press oven. The heating temperature of the annealing process is adjusted to form the metal joint, and can be, for example, 190°C or higher and 400°C or lower. The heating temperature of the annealing process can be 200°C or higher, 210°C or higher, 220°C or higher, 230°C or higher, 240°C or higher, 250°C or higher, or 260°C or higher, or can be 390°C or lower, 380°C or lower, 370°C or lower, 360°C or lower, or 350°C or lower. The pressure in the annealing process can be, for example, 0.1 MPa or higher and 5 MPa or lower. The time for the heating and the pressurization for the annealing process can be, for example, 10 minutes or longer and 120 minutes or shorter.

[0044] In the case where the first electrode 12 and the second electrode 22 are metal-joined at a relatively low temperature, the first electrode 12 and the second electrode 22 can be sufficiently joined at the temperature of the pre-joining. In this case, the first insulating resin film 13 and the second insulating resin film 23 can be joined, and the first electrode 12 and the second electrode 22 can be joined by one-stage press bonding.

[0045] After the first semiconductor member 10 and the second semiconductor member 20 are joined, as shown in Figure 3 (h), the first semiconductor member 10 joined to the second semiconductor member 20 is divided by dicing. As a result, the semiconductor chip laminate 30 including the first semiconductor member 10 having the first semiconductor substrate singulated into a semiconductor chip and the second semiconductor member 20 is formed on the dicing tape 41. Thereafter, as shown in Figure 3 (i), the semiconductor chip laminate 30 (semiconductor device) is picked up from the dicing tape 41.

[0046] Example The present application is not limited to the following test examples.

[0047] (Test 1) By the following steps, a test semiconductor chip stack in which the lower semiconductor component and the upper semiconductor component were joined was produced, and the shear peel strength of the joining surface was measured.

[0048] First, on a silicon wafer for the upper semiconductor component, a plurality of copper pillars (electrodes) of 10 μm square and 4 μm in height were formed. On the silicon wafer on which the copper pillars were provided, a resin varnish containing polyamic acid was applied, and the coating film was cured by heating at 250°C, thereby forming an insulating resin film containing polyimide resin (PI) and covering the copper pillars. By polishing the insulating resin film with a CMP method, a joining layer of the upper semiconductor component having the copper pillars exposed and the insulating resin film (thickness: 3.9 μm) filling the periphery thereof was formed. The upper semiconductor component was fixed to a dicing tape, and then, by dicing using a blade dicer, the upper semiconductor component having semiconductor chips and the joining layer singulated was formed. The semiconductor chips singulated had a size of 4 mm x 4 mm. The entire surface of the insulating resin film on the semiconductor chips was irradiated with ultraviolet rays. The cumulative light quantity of the ultraviolet rays was adjusted by the exposure time.

[0049] On a silicon wafer for the lower semiconductor component, an insulating resin film filling the copper pillars and the periphery thereof was formed in the same manner as the lower semiconductor component, thereby obtaining the lower semiconductor component having the silicon wafer and the joining layer. The upper semiconductor component after the ultraviolet rays were irradiated on the insulating resin film was picked up from the dicing tape, and after the copper pillars of the upper semiconductor component and the copper pillars of the lower semiconductor component were positionally aligned, the upper semiconductor component was press-bonded to the lower semiconductor component with the copper pillars in contact with each other, thereby pre-joining the lower semiconductor component and the upper semiconductor component. During this pre-joining, the lower semiconductor component and the upper semiconductor component were heated to 210°C. After the pre-joining, the pre-joined body thus formed was subjected to an annealing treatment by heating at a prescribed annealing treatment temperature (210 to 300°C) for 120 minutes in a pressurized oven in a nitrogen atmosphere, and the copper pillars were metal-bonded to each other.

[0050] After the annealing treatment, the silicon wafer of the lower semiconductor component was singulated into semiconductor chips on the dicing tape by dicing using a blade dicer. The semiconductor chips singulated had a size of 8 mm x 8 mm, and one upper semiconductor component was joined to one lower semiconductor component by mixed joining. The test semiconductor chip stack composed of the lower semiconductor component and the upper semiconductor component was picked up from the dicing tape.

[0051] The test semiconductor chip laminate was fixed on a stage at 260°C, and a jig pressed against the side surface of the upper semiconductor member was moved at a speed of 20 μm / min, thereby applying a shear stress to the upper semiconductor member. The shear strength of the bonding surface based on hybrid bonding was calculated from the stress at the time of peeling of the upper semiconductor member from the lower semiconductor member.

[0052] The production conditions and shear strength of the test semiconductor chip laminates are shown in Table 1. #1 to #3 are examples of test semiconductor chip laminates produced without exposing the insulating resin film before pre-bonding. The test semiconductor chip laminates of #4 to #7, in which the insulating resin film was irradiated with ultraviolet rays before pre-bonding, showed higher shear strength than the semiconductor chip laminate of #1, which was not irradiated with ultraviolet rays, and also showed higher shear strength than the semiconductor chip laminate of #3, which was not irradiated with ultraviolet rays and was subjected to annealing treatment at a high temperature of 300°C.

[0053] [Table 1]

[0054] (Test 2) A test semiconductor chip laminate was produced in the same manner as in Test 1, except that an insulating resin film containing polybenzoxazole resin (PBO) was formed instead of an insulating resin film containing polyimide resin, and the shear strength thereof was measured. The production conditions and shear strength of the semiconductor chip laminate are shown in Table 2. It was confirmed that in the case of the insulating resin film containing polybenzoxazole resin, the shear strength was increased by ultraviolet irradiation before pre-bonding even at a low pre-bonding temperature.

[0055] [Table 2]

[0056] Explanation of Symbols 10 - first semiconductor member, 11 - first semiconductor substrate, 12 - first electrode, 13 - first insulating resin film, 13a - opening, 20 - second semiconductor member, 21 - second semiconductor substrate, 22 - second electrode, 23 - second insulating resin film, 23a - opening, 30 - semiconductor chip laminate (semiconductor device), UV - ultraviolet rays.

Claims

1. A method for manufacturing a semiconductor device, comprising the following steps: Prepare a first semiconductor component, the first semiconductor component having a first semiconductor substrate and a first bonding layer disposed on the first semiconductor substrate, the first bonding layer including a first electrode and a first insulating resin film, the first insulating resin film having an opening, and the first electrode being disposed in the opening; Prepare a second semiconductor component, the second semiconductor component having a second semiconductor substrate and a second bonding layer disposed on the second semiconductor substrate, the second bonding layer including a second electrode and a second insulating resin film, the second insulating resin film having an opening in which the second electrode is disposed; At least one of the first insulating resin film or the second insulating resin film is irradiated with ultraviolet light; and The first semiconductor component is bonded to the second semiconductor component through a hybrid bonding process involving bonding the first electrode to the second electrode and bonding the first insulating resin film to the second insulating resin film.

2. The method according to claim 1, wherein, The process of bonding the first semiconductor component to the second semiconductor component includes heating the first semiconductor component and the second semiconductor component to a temperature of 180°C or higher and 250°C or lower and pressing them together, thereby bonding the first insulating resin film to the second insulating resin film.

3. The method according to claim 1, wherein, The first semiconductor substrate is a semiconductor wafer, and the second semiconductor substrate is a semiconductor chip. Multiple second semiconductor components are bonded to one first semiconductor component. The method further includes the step of dividing the first semiconductor component, which is bonded to the second semiconductor component, thereby forming a semiconductor chip stack including the first semiconductor component having the first semiconductor substrate monolithically formed as a semiconductor chip and the second semiconductor component.

4. The method according to claim 1, wherein, The first insulating resin film and the second insulating resin film comprise resins containing imide groups.

5. The method according to claim 4, wherein, The resin containing imide groups is a polyimide resin, a polyamide-imide resin, a bismaleimide resin, or a combination thereof.

6. The method according to claim 4, wherein, The resin containing imide groups is a resin having structural units containing imide groups and polysiloxanes bonded to those structural units.

7. The method according to claim 1, wherein, The first insulating resin film and the second insulating resin film comprise polybenzoxazole resin.

8. The method according to claim 1, wherein, The first insulating resin film and the second insulating resin film contain benzocyclobutene resin.

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