Temporary joining composition and method for producing joined body

Abstract

Provided is a method for producing a joined body having small positional deviation and high joining reliability. This temporary joining composition is used for producing a joined body in which an anisotropic conductive member and a member to be joined are joined. The temporary joining composition contains a temporary adhesive and a solvent. The temporary adhesive has a boiling point or a decomposition point, the lower of which is 200°C-400°C.

Description

Temporary bonding composition and method for manufacturing a bonded body

[0001] The present invention relates to a temporary bonding composition used in the manufacture of a bonded body in which an anisotropic conductive member and a member to be bonded are joined, and to a method for manufacturing such a bonded body, and more particularly to a temporary bonding composition comprising a temporary adhesive and a solvent, and to a method for manufacturing such a bonded body.

[0002] Currently, various bonding methods are used to obtain electrical connections between electronic components such as semiconductor elements, and between electronic components and circuit boards. Various forms have been proposed for connecting semiconductor elements to each other, and between semiconductor elements and substrates, such as wafer-on-wafer, chip-on-wafer, or chip-on-chip. Anisotropic conductive members, which have conductivity in the thickness direction of an insulating substrate that is an electrically insulating film, are used as electronic connection members for bonding the aforementioned electronic components.

[0003] For example, Patent Document 1 describes a method for manufacturing a multilayer wiring board comprising an anisotropic conductive bonding member and a wiring board having a plurality of electrodes, wherein the anisotropic conductive bonding member has an insulating substrate made of an inorganic material and a plurality of conductive passages made of a conductive material that penetrate the insulating substrate in the thickness direction and are insulated from each other, the plurality of conductive passages have protruding portions that protrude from the surface of the insulating substrate, the height of the plurality of electrodes on the wiring board is 10 μm or less, and the method for manufacturing a multilayer wiring board comprises, in this order, a temporary bonding process in which the anisotropic conductive bonding member and the wiring board are bonded using a non-conductive thermosetting resin, and a final bonding process in which the conductive passages on the anisotropic conductive bonding member and the electrodes on the wiring board are electrically bonded by heating at a temperature below the curing temperature of the thermosetting resin.

[0004] Japanese Patent Publication No. 2018-037509

[0005] When the above-mentioned anisotropic conductive member is used as an electronic connection member, it is preferable that the misalignment is small and the conductivity is good. However, in Patent Document 1, as described above, a temporary bonding process is carried out in which the anisotropic conductive bonding member and the wiring board are bonded using a non-conductive thermosetting resin, followed by the main bonding process. After the main bonding process, the thermosetting resin is cured by heating it to a temperature above its curing temperature, but if the thermosetting resin penetrates the bonding surface, conductivity may be inhibited. Currently, there is a demand for bonding with small misalignment and high reliability. The object of the present invention is to provide a temporary bonding composition and a method for manufacturing a bonded body that have small misalignment and high bonding reliability.

[0006] The above objectives can be achieved by the following configurations. Invention [1] is a temporary bonding composition used in the manufacture of a joint in which an anisotropic conductive member and a member to be joined are joined, comprising a temporary adhesive and a solvent, wherein the temporary adhesive has a boiling point or decomposition point, the lower of which is 200°C or more and 400°C or less. Invention [2] is the temporary bonding composition according to Invention [1], wherein the temporary adhesive has a viscosity of 20 mPa·s or more at a temperature of 25°C. Invention [3] is the temporary bonding composition according to Invention [1] or [2], wherein the temporary adhesive has a polar group. Invention [4] is the temporary bonding composition according to any one of Inventions [1] to [3], wherein the temporary adhesive contains a compound having an isobornyl group. Invention [5] is the temporary bonding composition according to any one of Inventions [1] to [4], wherein the temporary adhesive contains a compound represented by the following formula.

[0007]

[0008] Invention [6] is a temporary bonding composition according to any one of Inventions [1] to [5], wherein the water content is 5% or less. Invention [7] is a temporary bonding composition according to any one of Inventions [1] to [6], wherein the member to be bonded is a power semiconductor element.

[0009] Invention [8] is a method for manufacturing a bonded body, comprising a temporary fixing step of temporarily fixing the anisotropic conductive member and the member to be joined by providing a temporary bonding composition between the anisotropic conductive member and the member to be joined, and a bonding step of joining the anisotropic conductive member and the member to be joined, wherein the temporary bonding composition is removed in or after the bonding step, and the temporary bonding composition comprises a temporary adhesive and a solvent, and the temporary adhesive has a boiling point or decomposition point, the lower of which is 200°C or more and 400°C or less. Invention [9] is a method for manufacturing a bonded body according to Invention [8], wherein the temporary fixing step involves providing the temporary bonding composition at at least two locations on the periphery of the anisotropic conductive member. Invention

[10] is a method for manufacturing a bonded body according to Invention [8] or [9], wherein the bonding step is carried out in a reducing atmosphere. Invention

[11] is a method for manufacturing a bonded body according to any one of Inventions [8] to

[10] , wherein the member to be joined is a power semiconductor element.

[0010] According to the present invention, it is possible to provide a temporary bonding composition and a method for manufacturing a bonded body that exhibits small misalignment and high reliability of bonding.

[0011] This is a schematic diagram showing an example of a joint manufactured by the joint manufacturing method of an embodiment of the present invention. This is a schematic diagram showing one step of the first example of the joint manufacturing method of an embodiment of the present invention. This is a schematic diagram showing one step of the first example of the joint manufacturing method of an embodiment of the present invention. This is a schematic diagram showing one step of the first example of the joint manufacturing method of an embodiment of the present invention. This is a schematic diagram showing one step of the second example of the joint manufacturing method of an embodiment of the present invention. This is a schematic cross-sectional view showing an example of an anisotropic conductive member of a joint according to an embodiment of the present invention. This is a schematic plan view showing an example of an anisotropic conductive member of a joint according to an embodiment of the present invention.

[0012] The temporary bonding composition and method for manufacturing the bonded body of the present invention will be described in detail below based on the preferred embodiments shown in the attached drawings. The figures described below are illustrative for illustrating the present invention, and the present invention is not limited to the figures shown below. In the following, the "~" indicating a numerical range includes the numerical values ​​indicated on both sides. For example, ε is the numerical value ε α ~ numerical value ε β The range of ε is the numerical value ε α and the numerical value ε βThis range includes ε α ≦ε≦ε β The "parallel" range includes the generally accepted tolerance range in the relevant technical field unless otherwise specified. Similarly, the ranges for temperature, pressure, time, boiling point, decomposition point, and viscosity also include the generally accepted tolerance range in the relevant technical field unless otherwise specified. The average value is the simple average (arithmetic mean) unless otherwise specified.

[0013] [Example of a Joined Body] Figure 1 is a schematic diagram showing an example of a joined body manufactured by the method for manufacturing a joined body according to an embodiment of the present invention. The joined body is formed by joining an anisotropic conductive member and a member to be joined. The joined body 10 shown in Figure 1 has, for example, an anisotropic conductive member 12, a first member to be joined 14, and a second member to be joined 16. The joined body 10 has a configuration having two members to be joined. The joined body 10 is configured by stacking the first member to be joined 14, the anisotropic conductive member 12, and the second member to be joined in that order from bottom to top. The direction in which the first member to be joined 14, the anisotropic conductive member 12, and the second member to be joined are stacked is the stacking direction Ds (see Figure 1). It is preferable that the thickness direction Dt of the insulating film 50 of the anisotropic conductive member 12 and the stacking direction Ds are substantially parallel. The surface 12a of the anisotropic conductive member 12 is the surface 50a of the insulating film 50. The back surface 12b of the anisotropic conductive member 12 is the back surface 50b of the insulating film 50. The front surface 12a and the back surface 12b of the anisotropic conductive member 12 are opposing surfaces in the thickness direction Dt of the insulating film 50.

[0014] The anisotropic conductive member 12 will be described in detail later, but it has an insulating film 50 having electrical insulating properties and a plurality of conductors 52 that penetrate the insulating film 50 in the thickness direction Dt. The conductors 52 are columnar bodies and are provided within the insulating film 50 in a state where they are electrically insulated from each other. Each of the plurality of conductors 52 has electrical conductivity and functions as an electrical conduction path. The anisotropic conductive member 12 has anisotropic conductivity and has conductivity in the thickness direction Dt, but its conductivity in the direction parallel to the surface 50a of the insulating film 50 is sufficiently low. Each of the plurality of conductors 52 has, for example, protrusions 52a, 52b that protrude from at least one surface of the insulating film 50. The conductors 52 are physically and electrically joined to the electrodes 22, 23, and 24 of the first member to be joined 14. For this reason, it is preferable that the conductors 52 facing the electrodes 22, 23, and 24 have protrusions 52b. Also, the conductors 52 are physically and electrically joined to the electrodes 32 and 33 of the second member to be joined 16. Therefore, it is preferable that the conductor 52 facing the electrodes 32 and 33 has a protruding portion 52a.

[0015] The first member to be joined 14 has a substrate 20 and three electrodes 22, 23, and 24 provided on the surface 20a of the substrate 20. An insulating layer (not shown) having electrical insulation properties may be provided between electrode 22 and electrode 23, and between electrode 23 and electrode 24. The second member to be joined 16 has a substrate 30 and two electrodes 32 and 33 provided on the surface 30a of the substrate 30. An insulating layer (not shown) having electrical insulation properties may be provided between electrode 32 and electrode 33.

[0016] In the joint 10, the three electrodes 22, 23, and 24 of the first member to be joined 14 are electrically connected to the conductor 52 of the anisotropic conductive member 12. The two electrodes 32 and 33 of the second member to be joined 16 are electrically connected to the conductor 52 of the anisotropic conductive member 12. In the joint 10, the first member to be joined 14 and the second member to be joined 16 are physically and electrically joined and conductive through the anisotropic conductive member 12. As a result, electrical signals can be exchanged between the first member to be joined 14 and the second member to be joined 16.

[0017] Here, being physically and electrically joined means that even when the joined body 10 is transported for handling, the anisotropic conductive member 12 and the first joined member 14 and the second joined member 16 do not separate, there is electrical conductivity between the anisotropic conductive member 12 and the first joined member 14 and the second joined member 16, electrical signals can be input to the first joined member 14 and the second joined member 16, and electrical signals can be output from the first joined member 14 and the second joined member 16 to the outside.

[0018] The electrodes 22, 23, 24 of the first member to be joined 14 and the electrodes 32, 33 of the second member to be joined 16 are conductive and are composed of, for example, tungsten, cobalt, copper, aluminum, silicide, or a combination thereof. The electrodes 22, 23, 24 of the first member to be joined 14 and the electrodes 32, 33 of the second member to be joined 16 can also be composed of materials used in the semiconductor device field for terminals or electrode pads. The electrodes 22, 23, 24 of the first member to be joined 14 and the electrodes 32, 33 of the second member to be joined 16 are preferably composed of metals or alloys that are more easily deformed than semiconductors, oxides, and nitrides during joining, and more preferably composed of aluminum or copper or an alloy containing aluminum or copper. The configuration of the joined body 10 shown in Figure 1 is not particularly limited, and it may be a configuration in which three semiconductor elements are stacked and electrically connected via an anisotropic conductive member 12, or a configuration in which four or more semiconductor elements are stacked and electrically connected via anisotropic conductive member 12.

[0019] [First Example of Method for Manufacturing a Joined Body] Figures 2 to 4 are schematic diagrams showing a first example of a method for manufacturing a joined body according to an embodiment of the present invention, in order of steps. In Figures 2 to 4, the same reference numerals are used for components identical to those in the joined body 10 shown in Figure 1, and their detailed descriptions are omitted. The first example of a method for manufacturing a joined body is the method for manufacturing the joined body 10 shown in Figure 1 above. However, the method for manufacturing a joined body is not particularly limited to the joined body 10 shown in Figure 1 as described above, and the number of members to be joined is not limited to two.

[0020] In manufacturing the joint 10 shown in Figure 1, first, the anisotropic conductive member 12, the first member to be joined 14, and the second member to be joined 16 shown in Figure 1 are prepared. For example, the anisotropic conductive member 12 does not have any adhesive layer or other adhesive components.

[0021] As shown in Figure 2, for example, a temporary bonding composition 18 is provided on the electrodes 22 and 23 of the first member to be bonded 14. The temporary bonding composition 18 is provided in a predetermined amount in a predetermined area, for example, by a dispensing method or an inkjet method. Next, with the temporary bonding composition 18 provided on the electrodes 22 and 23 of the first member to be bonded 14, the anisotropic conductive member 12 and the second member to be bonded 16 are placed on the electrodes 22 and 23 of the first member to be bonded 14 in this order. The first member to be bonded 14 and the second member to be bonded 16 are positioned with the three electrodes 22, 23, and 24 of the first member to be bonded 14 and the two electrodes 32, 33 of the second member to be bonded 16 facing each other. As shown in Figure 2, the first member to be bonded 14 and the second member to be bonded 16 are positioned with the anisotropic conductive member 12 in between. The temporary bonding composition 18, which will be described in detail later, comprises a temporary adhesive and a solvent, wherein the boiling point or decomposition point of the temporary adhesive is 200°C or higher and 400°C or lower, whichever is lower.

[0022] As shown in Figure 2, when arranging the first member to be joined 14, the anisotropic conductive member 12, and the second member to be joined 16, the first member to be joined 14 and the second member to be joined 16 are aligned using alignment marks (not shown) provided on each. The alignment using alignment marks is not particularly limited, as long as it is possible to obtain an image or reflected image of the alignment marks and determine the position information of the alignment marks, and known alignment methods using alignment marks can be used as appropriate.

[0023] Next, a predetermined load is applied to the first member to be joined 14 and the second member to be joined 16, so that the first member to be joined 14, the anisotropic conductive member 12, and the second member to be joined 16 are stacked as shown in Figure 3, and then temporarily fixed at a predetermined temperature (temporary fixing step). At this time, the temporary bonding composition 18 wraps around between the first member to be joined 14 and the anisotropic conductive member 12, and between the second member to be joined 16 and the anisotropic conductive member 12, and the anisotropic conductive member 12, the first member to be joined 14, and the second member to be joined 16 are temporarily fixed by the temporary bonding composition 18. Here, the temporary fixing by the temporary bonding composition 18 described above maintains the alignment of the first member to be joined 14 and the second member to be joined 16, but it is not a permanently fixed state.

[0024] The laminate 19 is a state in which the first member to be joined 14, the anisotropic conductive member 12, and the second member to be joined 16 are temporarily fixed together. Next, a joining process is carried out between the first member to be joined 14, the anisotropic conductive member 12, and the second member to be joined 16. Through this joining process, the electrodes 22, 23, and 24 of the first member to be joined 14 and the protruding portion 52b of the conductor 52 of the anisotropic conductive member 12 are physically and electrically joined, and the protruding portion 52a of the conductor 52 of the anisotropic conductive member 12 and the electrodes 32 and 33 of the second member to be joined 16 are physically and electrically joined. As a result, conductivity is ensured between the first member to be joined 14 and the second member to be joined 16, and electrical signals can be exchanged between the first member to be joined 14 and the second member to be joined 16. In this way, the joined body 10 shown in Figure 1 is obtained. In the first example of the method for manufacturing the joined body, the anisotropic conductive member 12 and the members to be joined, namely the first member to be joined 14 and the second member to be joined 16, are temporarily fixed together without using thermosetting resin or the like, and are joined directly without any intervening materials such as thermosetting resin. By performing the joining process without any intervening materials such as thermosetting resin between the anisotropic conductive member 12 and the members to be joined, the reliability of the joining, including physical and electrical connections, can be increased, and therefore the joined body 10 (see Figure 1) has high joining reliability.

[0025] In the joining process, for example, as shown in Figure 4, a preset load is applied to the first member to be joined 14 and the second member to be joined 16, and then the temperature is set to a preset level and held for a preset time. At this time, the temporary joining composition 18 used for temporary fixing volatilizes and is removed from the space between the first member to be joined 14 and the anisotropic conductive member 12, and between the second member to be joined 16 and the anisotropic conductive member 12. Therefore, after joining, the temporary joining composition 18 used for temporary fixing is not present between the first member to be joined 14 and the anisotropic conductive member 12, and between the second member to be joined 16 and the anisotropic conductive member 12, and does not hinder the joining of the conductor 52 to the electrodes of the first member to be joined, and the joining of the conductor 52 to the electrodes of the second member to be joined 16, resulting in a highly reliable joining with low electrical resistance of the joined body.

[0026] The temperature conditions in the bonding process are not particularly limited, but are preferably higher than the boiling point or decomposition point of the temporary adhesive, specifically 200°C to 450°C, and more preferably 200°C to 400°C. The pressurization conditions in the bonding process are not particularly limited, but are preferably 30 MPa or less, and more preferably 0.1 MPa to 20 MPa. The bonding time in the bonding process is not particularly limited, but is preferably 1 second to 60 minutes, and more preferably 5 seconds to 10 minutes. As for the equipment used in the bonding process described above, wafer bonding equipment from various companies such as Mitsubishi Heavy Industries Machine Tools Ltd. (Nidek Machine Tools Co., Ltd.), Bondtec Co., Ltd., PMT Co., Ltd., Ayumi Industry Co., Ltd., Tokyo Electron Limited (TEL), EVG, SUSS Microtech Co., Ltd. (SUSS), and Musashino Engineering Co., Ltd. can be used. The atmosphere during the bonding process can be selected from air, an inert atmosphere such as a nitrogen atmosphere, a reduced pressure atmosphere including a vacuum atmosphere, and a reducing atmosphere. A reducing atmosphere is preferred for the bonding process. The reducing atmosphere is, for example, a formic acid gas atmosphere or a hydrogen gas atmosphere. Bonding under a reducing atmosphere facilitates the removal of organic matter and oxide films from the protruding surfaces of anisotropic conductive members, thereby promoting bonding between the conductor and the electrode. In the case of a hydrogen gas atmosphere, the hydrogen concentration is preferably below the explosion limit and at least 1% by volume. The heating temperature in the bonding process is preferably higher than the boiling point or decomposition point of the temporary adhesive, as described above, and can be selected from 200°C to 450°C. The heating rate can also be selected from 10°C / min to 10°C / second depending on the performance of the heating stage or the heating method. The same applies to cooling. It is also possible to heat in steps, dividing the process into several stages and sequentially increasing the heating temperature to perform bonding. The pressure (load) in the bonding process is not particularly limited to those described above, and it is possible to rapidly pressurize or pressurize in steps depending on the physical properties of the objects to be bonded, such as their strength.

[0027] [Second Example of Method for Manufacturing a Joined Body] Figure 5 is a schematic diagram showing one step of a second example of a method for manufacturing a joined body according to an embodiment of the present invention. In Figure 5, the same reference numerals are used for components identical to those in the joined body 10 shown in Figure 1, and their detailed descriptions are omitted. The second example of the method for manufacturing a joined body is the same as the first example of the method for manufacturing a joined body, and is the method for manufacturing the joined body 10 shown in Figure 1 above. The method for manufacturing a joined body is not particularly limited to the joined body 10 shown in Figure 1 above. Furthermore, for steps in the second example of the method for manufacturing a joined body that are the same as those in the first example of the method for manufacturing a joined body above, detailed descriptions are omitted.

[0028] In the second example of the method for manufacturing the joined body, the difference from the first example of the method for manufacturing the joined body is that in the temporary fixing step, the temporary bonding composition 18 is provided at least two locations on the periphery of the anisotropic conductive member 12. The other steps are the same as in the first example of the method for manufacturing the joined body, so a detailed explanation is omitted. In the second example of the method for manufacturing the joined body, as shown in Figure 5, for example, the temporary bonding composition 18 is provided on the electrode 22 of the first member to be joined 14. Furthermore, for example, the temporary bonding composition 18 is provided on the protruding portion 52a of the conductor 52 of the anisotropic conductive member 12 corresponding to the electrode 32 of the second member to be joined 16, so that the temporary bonding composition 18 is provided at two locations on the periphery of the anisotropic conductive member 12. The temporary bonding composition 18 is provided, for example, by a dispensing method or an inkjet method.

[0029] After providing the temporary bonding composition 18 at two locations on the peripheral edge of the anisotropically conductive member 12, as described above, a preset load is applied to the first member to be bonded 14 and the second member to be bonded 16, the first member to be bonded 14, the anisotropically conductive member 12 and the second member to be bonded 16 are brought into a stacked state as shown in FIG. 3, and temporarily fixed at a preset temperature (temporary fixing step). After the temporary fixing step, the above-described bonding step is performed. Thereby, the bonded body 10 shown in FIG. 1 is obtained. When the temporary bonding composition 18 is provided at two locations on the peripheral edge of the anisotropically conductive member 12, the positions where the temporary bonding composition 18 is provided are not particularly limited as long as they are on the peripheral edge of the anisotropically conductive member 12. For example, the temporary bonding composition 18 is provided on the electrode 22 of the first member to be bonded 14. Further, for example, the temporary bonding composition 18 may be provided on the protruding portion 52a of the conductor 52 of the anisotropically conductive member 12 corresponding to the electrode 33 of the second member to be bonded 16. When the outer shape of the anisotropically conductive member 12 is a quadrangle, for example, among the four corners, the temporary bonding composition 18 may be provided at a total of two locations at opposing corners, or the temporary bonding composition 18 may be provided at a total of four locations at each corner.

[0030] <Temporary Fixing Step> The temporary fixing step is a step performed before the bonding step. The temporary fixing in the temporary fixing step refers to a bonding in which the anisotropically conductive member and the member to be bonded are physically fixed, but conduction is not ensured. After temporary fixing, the members are fixed to such an extent that positional displacement does not occur even when conveyed for the bonding step. After temporary fixing, handling such as transfer can be performed while maintaining the fixed state without separation of the anisotropically conductive member and the member to be bonded. In the temporary fixing step, the first member to be bonded 14 and the second member to be bonded 16 are aligned, and stacked and temporarily fixed in the order of the first member to be bonded 14, the anisotropically conductive member 12, and the second member to be bonded 16. In the temporary fixing step, for example, a flip chip bonder or a mounter can be used as the temporary fixing device.

[0031] <Bonding Process> The bonding process is the process of joining an anisotropic conductive member to a member to be bonded, and is performed after the temporary fixing process. Bonding in the bonding process means physically and electrically joining the anisotropic conductive member and the member to be bonded. Through bonding, the anisotropic conductive member and the member to be bonded are physically fixed and electrical conductivity is ensured. In the bonding process, a wafer bonder, for example, can be used as the bonding apparatus.

[0032] <Step to remove temporary bonding composition> The temporary bonding composition is substantially absent at the time the bonded body 10 is manufactured. The temporary bonding composition is removed during or after the bonding process. In the bonding process, the bonded body is heated to a predetermined temperature as described above, and the temporary bonding composition is removed during the process of carrying out the bonding process. Thus, the temporary bonding composition is removed during the bonding process, and the bonding process and the temporary bonding composition removal process are carried out simultaneously. The temporary bonding composition is substantially absent at the time the bonded body 10 is manufactured. In addition, in the bonding process, the temporary bonding composition is removed after being held at a predetermined temperature for a predetermined time as described above. The temporary bonding composition removal process is carried out after the bonding process. As described above, by removing the temporary bonding composition during or after the bonding process, the bonding method can be simplified, the manufacturing equipment can be simplified, and the cycle time can be reduced. The statement that the temporary bonding composition is substantially absent means that the temporary bonding composition is not observed when the bonded body is observed with an infrared microscope.

[0033] <Temporary Bonding Composition> The temporary bonding composition is used in the manufacture of a bonded body in which an anisotropic conductive member and a member to be bonded are joined. It contains a temporary adhesive and a solvent, and the temporary adhesive has a boiling point or decomposition point, the lower of which is 200°C or more and 400°C or less. With this configuration, when joining the anisotropic conductive member and the member to be bonded, the temporary bonding composition suppresses misalignment between the anisotropic conductive member and the member to be bonded during temporary fixing, and is not removed during or after the bonding process, thus not hindering the bonding between the anisotropic conductive member and the member to be bonded. As a result, a bonded body with small misalignment and high bonding reliability can be obtained.

[0034] (Temporary Adhesive) For the temporary adhesive, the lower value between the boiling point and the decomposition point is 200°C or higher and 400°C or lower. If the lower value between the boiling point and the decomposition point of the temporary adhesive is lower than 200°C, sufficient temporary fixing cannot be achieved, leading to increased positional deviation. If the lower value between the boiling point and the decomposition point of the temporary adhesive exceeds 400°C, the temporary bonding composition remains during or after the bonding step, increasing the electrical resistance of the bonded body. Preferably, the lower value between the boiling point and the decomposition point of the temporary adhesive is 220°C to 310°C.

[0035] The boiling point of the temporary adhesive is a value measured when the external pressure is 1013 hPa (1 atm = 760 mmHg). The boiling point of the temporary adhesive is measured in accordance with JIS (Japanese Industrial Standards) K 2254 (corresponding to ISO (International Organization for Standardization) 3405) or JIS K 0066. The decomposition point of the temporary adhesive is measured using a thermogravimetric differential thermal analyzer (TG-DTA). For the measurement of the decomposition point of the temporary adhesive, using a thermogravimetric differential thermal analyzer, the temporary adhesive is heated from 25°C to 600°C at a heating rate of 10°C / min under a nitrogen atmosphere, and the temperature at which the weight of the temporary adhesive decreases by 10% compared to the weight before decomposition is defined as the decomposition point. If there are multiple decomposition points, the lowest temperature is taken as the decomposition point. The above measurement is performed three times for one temporary adhesive, and the average value is taken as the decomposition point of the temporary adhesive.

[0036] The viscosity of the temporary adhesive at 25°C is preferably 20 mPa·s or more, and the upper limit is, for example, 70000 mPa·s. The viscosity of the temporary adhesive is obtained by measurement using a rotational rheometer at a temperature of 25°C.

[0037] The temporary adhesive contains, for example, a compound having an isobornyl group. The compound having an isobornyl group is, for example, a terpene compound. Further, the temporary adhesive has, for example, a polar group. Examples of compounds having a polar group include a compound having a hydroxyl group, and a compound having an isobornyl group and a hydroxyl group.

[0038] Compounds having a hydroxyl group are, for example, compounds having a hydroxyl group, and terpineol and 1,3-butylene glycol can also be used. Of the terpineols, α-terpineol is preferred. Terpineol and 1,3-butylene glycol can also produce the same effects as isobornylcyclohexanol described above. In addition, for example, diglycerin having a hydroxyl group (boiling point 265-270°C), 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (boiling point 255°C), and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (boiling point 281.5°C) can also be used as temporary binders.

[0039] Compounds containing an isobornyl group and a hydroxyl group include, for example, isobornylcyclohexanol or isobornylphenol. Isobornylcyclohexanol is a terpene derivative formed by bonding a terpene and cyclohexanol, and is sold under the name "Tersolve MTPH". Isobornylcyclohexanol is a compound represented by the following formula.

[0040]

[0041] Isobornylcyclohexanol has a boiling point of 308°C and a viscosity of 65,500 mPa·s at 25°C, but its viscosity decreases at 70°C. Because isobornylcyclohexanol's viscosity decreases at 70°C, it exhibits tackiness during temporary fixing. This suppresses misalignment between the anisotropic conductive member and the member to be joined during temporary fixing. Furthermore, isobornylcyclohexanol volatilizes during or after the bonding process, which is heated to approximately 200°C, thus minimizing residue and not adversely affecting the bonding of the anisotropic conductive member and the member to be joined. Examples of temporary adhesives include polyvinyl acetate (PVAc, decomposition temperature approximately 250-340°C), polylactic acid (PLA, decomposition temperature 200-300°C), and polymethyl vinyl ether (PMVE, decomposition temperature 360-390°C).

[0042] (Solvent) The solvent is preferably one or more selected from the group consisting of, for example, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), cyclohexanone (CHN), ethyl lactate (EL), isopropanol (IPA), 4-methyl-2-pentanol (MIBC), butyl acetate (nBA), propylene glycol monoethyl ether, propylene glycol monopropyl ether, methyl methoxypropionate, cyclopentanone, diisoamyl ether, isoamyl acetate, dimethyl sulfoxide, ethylene glycol, propylene glycol, cycloheptanone, 2-heptanone, butyl butyrate, isobutyl isobutyrate, isoamyl ether, n-hexane, toluene, ethyl acetate, benzoyl chloride, and undecane. Examples of using two or more solvents include the combined use of PGMEA (propylene glycol monomethyl ether acetate, 2-methoxy-1-methylethyl acetate) and PGME, and the combined use of PGMEA and CHN. 2,4-diethyl-1,5-pentanediol can also be used as a solvent. It is preferable that the solvent has a lower boiling point and decomposition point than the temporary adhesive, as this will cause the solvent to evaporate and be removed before the temporary adhesive. Note that water is not used as a solvent.

[0043] (Antioxidant) In addition to the temporary adhesive and solvent, the temporary bonding composition may contain at least one of an antioxidant and a surfactant. Examples of antioxidants include amine-based antioxidants and phenol-based antioxidants. One type of antioxidant may be used alone, or two or more types may be used in combination. When the temporary bonding composition contains an antioxidant, the antioxidant content is preferably 0.0001 to 1% by mass, more preferably 0.0001 to 0.1% by mass, and even more preferably 0.0001 to 0.01% by mass, based on the total mass of the temporary bonding composition. For example, the antioxidant described in Japanese Patent Publication No. 6759174 can be used. Formic acid can also be used as an antioxidant. The content of the antioxidant such as formic acid is preferably 1 to 5% by mass, based on the total mass of the temporary bonding composition, due to its antioxidant effect.

[0044] (Surfactant) The type of surfactant is not particularly limited, and known surfactants can be used. Examples thereof include ionic surfactants (e.g., anionic surfactants, cationic surfactants, amphoteric surfactants), or nonionic surfactants. Examples of the anionic surfactants include higher fatty acid salts (soaps), α-sulfo fatty acid methyl ester salts, linear alkylbenzene sulfonates, alkyl sulfate esters, alkyl ether sulfate esters, (mono)alkyl phosphate esters, α-olefin sulfonates, and alkane sulfonates. Examples of the cationic surfactants include alkyl trimethyl ammonium salts, dialkyl dimethyl ammonium salts, alkyl dimethyl benzyl ammonium salts, and N-methylbishydroxyethylamine fatty acid ester hydrochloride. Examples of the amphoteric surfactants include alkylamino fatty acid salts, alkyl betaines, and alkyl amine oxides. Examples of the nonionic surfactants include sucrose fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene fatty acid esters, fatty acid alkanolamides, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, alkyl glycosides, and polyoxyethylene alkylphenyl ethers. Examples of the fluorine-based surfactants include perfluorooctane sulfonic acid (PFOS, CF ３ (CF ２ ) ｎ SO ３ H), perfluorooctanoic acid (PFOA, CF ３ (CF ２ ) ｎ COOH), and fluorotelomer alcohols (FTOHs, F(CF ２ ) ｎ CH ２ CH ２ OH) are exemplified. The content of the surfactant is, for example, 1 to 5% by mass relative to the total mass of the temporary bonding composition.

[0045] (Moisture Content) The moisture content of the temporary bonding composition is preferably 5% by mass or less. A moisture content of 5% by mass or less is preferable because it reduces the likelihood of insulation defects such as rust occurring in the bonded body, thus lowering the electrical resistance of the bonded body. The moisture content of the temporary bonding composition is more preferably 3% by mass or less, even more preferably 1% by mass or less, and particularly preferably 0% by mass. A moisture content of 0% by mass means that no water is added as an additive to the temporary bonding composition. The moisture content of the temporary bonding composition is measured by conditioned the object to be measured for 24 hours in an environment of 25°C and 50% humidity, and then measured by the Karl Fischer method (150°C, vaporization method). Note that "Karl Fischer method (150°C, vaporization method)" means that the amount of moisture was measured by the moisture vaporization method at a vaporization temperature of 150°C using a Karl Fischer moisture meter, in accordance with the description in JIS (Japanese Industrial Standards) K0113:2005.

[0046] The temporary bonding composition, for example, contains 30 to 60% by mass of temporary adhesive and 40 to 70% by mass of solvent. In this case, the ratio of temporary adhesive to solvent is 30:70 to 60:40 by mass.

[0047] The configuration of the anisotropic conductive member will be described in more detail below. [Configuration of the Anisotropic Conductive Member] (Anisotropic Conductive Member) The anisotropic conductive member will be described using Figures 6 and 7. Figure 6 is a schematic cross-sectional view showing an example of an anisotropic conductive member of a joint according to an embodiment of the present invention, and Figure 7 is a schematic plan view showing an example of an anisotropic conductive member of a joint according to an embodiment of the present invention. Figure 7 is a plan view of the insulating film in Figure 6 as seen from the surface side. The anisotropic conductive member 12 shown in Figure 6 has an insulating film 50 that has electrical insulating properties and a plurality of conductors 52 that penetrate through the thickness direction Dt of the insulating film 50. The conductors 52 are provided in a state in which they are electrically insulated from each other within the insulating film 50. In the joint 10 described above (see Figure 1), the anisotropic conductive member 12 is laminated with members to be joined, such as the first member to be joined 14 and the second member to be joined 16, with the thickness direction Dt of the insulating film 50 and the lamination direction Ds of the joint 10 being substantially parallel.

[0048] Multiple conductors 52 are provided in the insulating film 50 in a state where they are electrically insulated from each other. In this case, the insulating film 50 has multiple pores 51 that penetrate in the thickness direction Dt. Conductors 52 are provided in the multiple pores 51. Therefore, the shape of the conductor 52 will correspond to the internal shape of the pores 51. If the pores 51 are cylindrical, the conductor 52 will be a cylindrical columnar body. The conductor 52 is not particularly limited to being cylindrical. In an anisotropic conductive member, the conductor 52 may have a protrusion that protrudes from at least one surface of the insulating film 50, and it is sufficient to have either a protrusion 52a or a protrusion 52b, but as described above, it is preferable that the anisotropic conductive member 12 has a protrusion on the surface facing the electrode. The insulating film 50 is composed of, for example, an anodic oxide film. The anodic oxide film is formed by anodizing a valve metal, for example, and an aluminum anodic oxide film is an example. The surface 50a and the back surface 50b of the insulating film 50 are opposing surfaces in the thickness direction Dt of the insulating film 50.

[0049] As shown in Figure 7, the anisotropic conductive member 12 has, for example, a rectangular shape in plan view, with all interior angles being 90°. The external shape and size of the anisotropic conductive member 12 are determined as appropriate according to the application, etc. The external shape of the anisotropic conductive member 12 may also be circular. The anisotropic conductive member has, for example, the same configuration as the structure described in International Publication No. 2022 / 163260, and can be manufactured in the same manner as the above-described structure.

[0050] <Insulating Film> The insulating film 50 is made of a conductive material and electrically insulates a plurality of conductors 52 from each other. As described above, the insulating film 50 has electrical insulating properties. The insulating film 50 also has a plurality of pores 51 in which the conductors 52 are formed. The composition of the insulating film 50 will be described later. The length of the insulating film 50 in the thickness direction Dt, that is, the thickness ht of the insulating film 50, is preferably in the range of 1 to 1000 μm, more preferably in the range of 5 to 500 μm, and even more preferably in the range of 10 to 300 μm. When the thickness ht of the insulating film 50 is in this range, the handling of the insulating film 50 is good.

[0051] The thickness of the insulating film can be measured by cutting the insulating film 50 in the thickness direction Dt using a focused ion beam (FIB), and acquiring an image of the cross-section at a magnification of 50,000x using a scanning electron microscope (SEM). In the acquired image, the length of 10 points corresponding to the thickness of the insulating film is measured, and the average of the measured lengths of these 10 points is calculated. This average value is taken as the thickness of the insulating film.

[0052] <Average diameter of pores> The average diameter of the pores 51 is preferably 1 μm or less, more preferably 5 to 500 nm, even more preferably 20 to 400 nm, even more preferably 40 to 200 nm, and most preferably 50 to 100 nm. When the average diameter d of the pores 51 is 1 μm or less and within the above range, a conductor 52 having the above average diameter can be obtained. The average diameter of the pores 51 can be measured by taking a picture of the surface of the insulating film 50 from directly above at a magnification of 100 to 10000 using a scanning electron microscope and obtaining the captured image. In the captured image, at least 20 pores that are connected in an annular shape around the periphery are extracted, their diameters are measured and defined as the aperture diameter, and the average value of these aperture diameters is calculated as the average diameter of the pores. The magnification can be appropriately selected within the above range so as to obtain a captured image in which 20 or more pores can be extracted. The aperture diameter is determined by measuring the maximum distance between the ends of the pore portions. In other words, the shape of the pore opening is not limited to a roughly circular shape. If the shape of the opening is not circular, the maximum distance between the ends of the pore portion is taken as the opening diameter. Therefore, for example, even in the case of a pore that is formed by the integration of two or more pores, it is considered as a single pore, and the maximum distance between the ends of the pore portion is taken as the opening diameter.

[0053] <Conductors> The plurality of conductors 52 are columnar bodies as described above and are provided in an insulating film 50, for example, an anodic oxide film, in a state where they are electrically insulated from one another. Each of the plurality of conductors 52 has electrical conductivity and functions as an electrical conduction path as described above. The conductors are made of a conductive material. The conductive material is not particularly limited, but metals can be cited. Specific examples of metals that are preferably exemplified are gold (Au), silver (Ag), copper (Cu), aluminum (Al), magnesium (Mg), nickel (Ni), zinc (Zn), and cobalt (Co). From the viewpoint of electrical conductivity, copper, gold, aluminum, nickel, and cobalt are preferred, copper and gold are more preferred, and copper is the most preferred. Metals have superior ductility and are easily deformable compared to oxide conductors, and are also easily deformed by compression during joining, so it is preferable that the conductors be made of metal.

[0054] <<Shape of the Conductor>> As described above, the shape of the conductor 52 corresponds to the internal shape of the pore 51. If the pore 51 is cylindrical, the conductor 52 will be a cylindrical columnar body. The average diameter of the pore 51 is approximately equal to the average diameter d of the conductor 52. The average diameter d of the conductor 52 is preferably 1 μm or less, more preferably 5 to 500 nm, even more preferably 20 to 400 nm, even more preferably 40 to 200 nm, and most preferably 50 to 100 nm. The density of the conductor 52 is 20,000 particles / mm 2 Preferably, the density is 2 million pieces / mm². 2 It is more preferable that the number be greater than or equal to 10 million pieces / mm². 2 It is even more preferable that the number be 50 million / mm² or higher. 2 It is particularly preferable that the value be 100 million pieces / mm². 2 The above is most preferable. Furthermore, the distance p between the centers of adjacent conductors 52 is preferably 20 nm to 500 nm, more preferably 40 nm to 200 nm, and even more preferably 50 nm to 140 nm.

[0055] The average diameter of the conductor is determined by taking an image of the insulating film surface from directly above using a scanning electron microscope at a magnification of 100 to 10,000 times. In the image, at least 20 conductors with a ring-shaped perimeter are extracted, their diameters are measured and defined as the aperture diameter, and the average of these aperture diameters is calculated as the average diameter of the conductor. The magnification can be appropriately selected within the above range to obtain an image in which 20 or more conductors can be extracted. If the shape of the opening is not circular, the maximum distance between the ends of the conductor portion is defined as the aperture diameter. Therefore, even in the case of a conductor with a shape in which two or more conductors are integrated, for example, it is considered as a single conductor, and the maximum distance between the ends of the conductor portion is defined as the aperture diameter. The average diameter d of the conductor 52 is the same as the average diameter of the protruding portion. The distance p between the centers of adjacent conductors 52 is determined by further identifying the center position (not shown) of the identified conductor in the image of the insulating film 50 obtained as described above. The distance between the center positions of adjacent conductors was determined at 10 locations. The average value of these distances was defined as the distance p between the centers of adjacent conductors 52. The center position is the center position of the region corresponding to conductor 52 in the captured image described above. A known image analysis method is used to calculate the center position of the region in the captured image. Furthermore, as described above, the average diameter of the pores 51 is approximately equal to the average diameter d of conductor 52. Therefore, if high precision is not required, the average diameter of the pores 51 may be used as the average diameter d of conductor 52.

[0056] <<Protruding parts>> The protruding parts are part of the conductor and are columnar in shape. The protruding parts are preferably cylindrical in shape so as to increase the contact area with the object to be joined. The average protrusion length ha of the protruding part 52a from the surface 50a of the insulating film 50 and the average protrusion length hb of the protruding part 52b from the back surface 50b of the insulating film 50 are preferably 300 nm to 5 μm, and more preferably 300 nm to 3 μm. If the above-mentioned average protrusion lengths ha and hb are 300 nm to 5 μm, the bonding with the member to be joined will be good. The above-mentioned average protrusion lengths ha and hb are measured as described above. With respect to the conductor 52, the spacing between adjacent protruding parts is preferably 20 nm to 200 nm, and more preferably 40 nm to 100 nm. If the spacing between adjacent protruding parts is within the above range, the spacing of the conductors 52 can be maintained on the surface 50a or back surface 50b of the insulating film 50 of the conductor 52. This suppresses short circuits in the conductor 52 when connecting to a target such as a semiconductor device, further increasing reliability during connection.

[0057] <Member to be bonded> The member to be bonded is, for example, a power semiconductor device. Examples of power semiconductor devices include IGBTs (Insulated Gate Bipolar Transistors), SiC-MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), and GaN-HEMTs (High Electron Mobility Transistors). When the member to be bonded is a power semiconductor device, the electrodes are, for example, a source electrode, a drain electrode, or a gate electrode.

[0058] Furthermore, the member to be joined has, for example, an electrode and an insulating layer as described above. Examples of members to be joined include electronic components having electrodes such as electrodes, terminals or wiring and an insulating layer, printed wiring boards, printed circuit boards, and TSVs (Through Silicon Vias). Examples of electronic components include semiconductor elements other than the power semiconductor elements described above.

[0059] The insulating layer is not particularly limited in its composition as long as it can prevent conductivity between electrodes, and can be made of known insulating layers used in semiconductor devices. For example, the insulating layer is a silicon oxide film (SiO ２ ), silicon nitride film (Si ３ N ４ The insulating layer is composed of a PSG (Phospho Silicate Glass) film, a BPSG (Boron Phospho Silicate Glass) film, or an SOG (Spin On Glass) film. The insulating layer may also be a resin layer with the following composition. The composition of the resin layer will be described below. For example, the resin layer contains a polymer material and may also contain an antioxidant material. Specific examples of resin materials constituting the resin layer include thermoplastic resins such as ethylene copolymers, polyamide resins, polyester resins, polyurethane resins, polyolefin resins, acrylic resins, acrylonitrile resins, and cellulose resins. Polyacrylonitrile can also be used as a resin material constituting the resin layer. In addition to the above, the resin layer may contain, for example, a main composition containing an acrylic polymer, an acrylic monomer, and a maleimide compound as described in International Publication No. 2022 / 163260.

[0060] Semiconductor devices include, for example, logic LSIs (Large Scale Integration), ASICs (Application Specific Integrated Circuits), FPGAs (Field Programmable Gate Arrays), and ASSPs (Application Specific Standard Products). Other examples include microprocessors such as CPUs (Central Processing Units) and GPUs (Graphics Processing Units). Furthermore, there are memory types such as DRAM (Dynamic Random Access Memory), SRAM (Static Random Access Memory), HMCs (Hybrid Memory Cubes), MRAMs (Magnetic RAM), PCMs (Phase-Change Memory), ReRAMs (Resistive RAM), FeRAMs (Ferroelectric RAM), and flash memory. Other examples include LEDs (Light Emitting Diodes), MEMS (Micro Electro Mechanical Systems), GPS (Global Positioning System), FM (Frequency Modulation), NFC (Nearfield Communication), RFEM (RF Expansion Module), MMIC (Monolithic Microwave Integrated Circuit), WLAN (Wireless Local Area Network), discrete components, BSI (Back Side Illumination), CIS (Contact Image Sensor), camera modules, passive devices, SAW (Surface Acoustic Wave) filters, RF (Radio Frequency) filters, RFIPD (Radio Frequency Integrated Passive Devices), etc. Examples of MEMS include sensors, actuators, and antennas.The sensors include, for example, various sensors such as acceleration, sound, pressure, and light sensors, as well as gyroscopes. The bonded member may be a semiconductor device in which multiple semiconductor elements described above are stacked and electrically connected. A semiconductor device is a collection of multiple semiconductor elements that perform a specific function, but it also includes those that only transmit electrical signals. A semiconductor device may be, for example, a logic device with a two-dimensional (2D), 2.5-dimensional (2.5D), or three-dimensional (3D) architecture. Furthermore, a semiconductor device may be, for example, a DRAM stack made by stacking multiple DRAMs, or a configuration in which a DRAM stack and a logic LSI are stacked.

[0061] The present invention is basically configured as described above. Although the temporary bonding composition and the method for manufacturing the bonded body of the present invention have been described in detail above, the present invention is not limited to the embodiments described above, and various improvements or modifications may be made without departing from the spirit of the present invention.

[0062] The features of the present invention will be further described in detail below with reference to examples. The materials, reagents, amounts and proportions of substances, and procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following examples. In these examples, the temporary bonding compositions of Examples 1 to 13 and the temporary bonding compositions of Comparative Examples 1 to 5 were evaluated for supply, misalignment, volatilization, and electrical resistance, respectively. The evaluation results for supply, misalignment, volatilization, and electrical resistance are shown in Table 1 below. Next, each evaluation item will be explained.

[0063] (Supply) For supply, the temporary bonding composition was evaluated by attempting to make it fly using a dispenser. It was also evaluated by attempting to make it fly using an inkjet printer. The attempts to make the temporary bonding composition fly were evaluated according to the following evaluation criteria. The evaluation results are shown in the "Supply" column of Table 1 below. Evaluation Criteria A: Flying is possible with both the dispenser and the inkjet printer. B: Flying is possible with either the dispenser or the inkjet printer. C: Flying is not possible with either the dispenser or the inkjet printer. For the dispenser, a SuperJET2 manufactured by Musashi Engineering Co., Ltd. was used. For the inkjet printer, a LaboJet-Bio inkjet micro-dispenser manufactured by Microjet Co., Ltd. was used.

[0064] (Misalignment) An anisotropic conductive member, a first chip having a vernier scale pattern, and a second chip having a vernier scale pattern were prepared. The first chip corresponds to the first member to be joined, and the second chip corresponds to the second member to be joined. The first chip has a vernier scale pattern in the configuration of the first member to be joined shown in Figure 1, and its size is 8 mm × 6 mm. The second chip has a vernier scale pattern in the configuration of the second member to be joined shown in Figure 1, and its size is 6 mm × 4.2 mm. The anisotropic conductive member has the configuration of the anisotropic conductive member shown in Figures 1 and 6, and its size is 5.2 mm × 4 mm. The configuration of the anisotropic conductive member will be explained later.

[0065] After placing an anisotropic conductive member on top of the first chip, 1 μl (microliter) of temporary bonding composition was dropped onto the boundary between the first chip and the anisotropic conductive member. The first chip and the second chip were then aligned using a flip-chip bonder, and the first chip, anisotropic conductive member, and second chip were temporarily fixed by holding the aligned state at a temperature of 70°C for 30 seconds. The misalignment of the first chip and the second chip in the temporarily fixed state was measured using an infrared microscope. The misalignment was measured using the vernier scale pattern described above. Next, after measuring the misalignment in the temporarily fixed state, a bonding process was carried out to bond the first chip, anisotropic conductive member, and the second chip to obtain a bonded body. The bonding process was carried out in a nitrogen gas atmosphere containing 5 volume% hydrogen, under conditions of a load of 30 MPa, a temperature of 250°C, and a time of 30 minutes. The misalignment of the first chip and the second chip of the bonded body was measured using an infrared microscope. The misalignment was measured using the vernier scale pattern described above. The difference between the misalignment in the temporarily fixed state and the misalignment of the joined body was determined. The difference in misalignment was evaluated according to the evaluation criteria shown below. The evaluation results of the difference in misalignment are shown in the "Misalignment" column of Table 1 below. Evaluation Criteria A: No delamination of the first and second chips, and the difference in misalignment is 1 μm or less B: No delamination of the first and second chips, and the difference in misalignment is greater than 1 μm and less than or equal to 10 μm C: No delamination of the first and second chips, and the difference in misalignment is greater than 10 μm and less than or equal to 100 μm D: No delamination of the first and second chips, and the difference in misalignment is greater than 100 μm E: At least one of the first and second chips has delaminated An infrared microscope, the Olympus Corporation semiconductor / FPD inspection microscope MX61 (product name), was used. For the lens, the Olympus Corporation objective lens LMRLN5XIR (product name) for near-infrared region (700 nm to 1300 nm) observation was used. Furthermore, a Merzhäuser automated XY stage for upright microscopes was used as the stage.

[0066] (Volatility) In the same manner as the evaluation of "misalignment" described above, a temporary bonding composition was applied to the first chip, and the first chip, anisotropic conductive member, and second chip were stacked in that order and temporarily fixed. An infrared microscope was used to examine the presence or absence of the temporary bonding composition in the first and second chips in the temporarily fixed state. Next, after examining the presence or absence of the temporary bonding composition in the temporarily fixed state, the bonding process was carried out in the same manner as the evaluation of "misalignment" described above, and the first chip, anisotropic conductive member, and second chip were bonded to obtain a bonded body. An infrared microscope was used to examine the presence or absence of the temporary bonding composition in the first and second chips of the bonded body. Based on the presence or absence of the temporary bonding composition in the temporarily fixed state and the presence or absence of the temporary bonding composition in the bonded body, the evaluation was performed according to the evaluation criteria shown below. The evaluation results regarding the presence or absence of the temporary bonding composition are shown in the Volatilization column of Table 1 below. Evaluation Criteria A: Temporary bonding composition is present in the temporarily fixed state, but not in the bonded body. B: Temporary bonding composition is present in the temporarily fixed state, and the bonded body also contains the temporary bonding composition, or temporary bonding composition is absent in the temporarily fixed state. The same infrared microscope used for evaluating "positional misalignment" as described above was used.

[0067] (Electrical Resistance) A first chip and a second chip were prepared, each having an anisotropic conductive member and electrodes that enable evaluation of a daisy chain for a total of 1000 cycles. The anisotropic conductive member was the same one used in the evaluation of "misalignment" described above, and its size was set to 5.2 mm × 4 mm. The configuration of the anisotropic conductive member will be described later. After the anisotropic conductive member was placed on top of the first chip, 1 μl (microliter) of a temporary bonding composition was dropped onto the boundary between the first chip and the anisotropic conductive member, and the first chip, anisotropic conductive member, and second chip were aligned. In the aligned state, they were temporarily fixed by holding at a temperature of 70°C for 30 seconds. Next, after temporary fixing, a bonding process was carried out to bond the first chip, anisotropic conductive member, and second chip to obtain a bonded body. The bonding process was carried out in a nitrogen gas atmosphere containing 5 volume% hydrogen, under conditions of a load of 30 MPa, a temperature of 250°C, and a time of 30 minutes. Ten of the above-described joints were prepared using the temporary bonding compositions of Examples 1 to 13 and the temporary bonding compositions of Comparative Examples 1 to 5. The connection resistance of each joint was measured. The connection resistance was measured in air by contacting a probe with the pad of the lead wiring of the daisy chain and using a measuring device. A Keithley source meter was used as the measuring device. Based on the connection resistance, the joints were evaluated according to the evaluation criteria shown below. The evaluation results of the connection resistance are shown in the electrical resistance column of Table 1 below. Evaluation Criteria A: All 10 joints have a connection resistance of less than 10 mΩ B: Of the 10 joints, one to three have a connection resistance of 10 mΩ or more C: Of the 10 joints, four to nine have a connection resistance of 10 mΩ or more D: All 10 joints have a connection resistance of 10 mΩ or more

[0068] Next, the anisotropic conductive member will be described. An anodized aluminum film was used as the insulating film. [Anisotropic conductive member] <Preparation of aluminum substrate> An aluminum alloy containing Si: 0.06 mass%, Fe: 0.30 mass%, Cu: 0.005 mass%, Mn: 0.001 mass%, Mg: 0.001 mass%, Zn: 0.001 mass%, and Ti: 0.03 mass%, with the remainder being Al and unavoidable impurities, was used to prepare a molten metal. After molten metal treatment and filtration, an ingot with a thickness of 500 mm and a width of 1200 mm was produced by the DC (Direct Chill) casting method. Next, the surface was milled to an average thickness of 10 mm using a surface mill, and then it was heated to 550°C for about 5 hours. When the temperature dropped to 400°C, it was rolled into a 2.7 mm thick sheet using a hot rolling mill. Furthermore, after heat treatment at 500°C using a continuous annealing machine, the material was cold-rolled to a thickness of 1.0 mm to obtain an aluminum substrate conforming to JIS (Japanese Industrial Standards) 1050. After widening this aluminum substrate to 1030 mm, the following treatments were performed.

[0069] <Electrolytic Polishing Treatment> The above-mentioned aluminum substrate was subjected to electrolytic polishing treatment using an electrolytic polishing solution with the following composition under the conditions of a voltage of 25V, a liquid temperature of 65°C, and a liquid flow rate of 3.0 m / min. A carbon electrode was used as the cathode, and a GP0110-30R (manufactured by Takasago Seisakusho Co., Ltd.) was used as the power supply. The flow rate of the electrolyte was measured using a vortex-type flow monitor FLM22-10PCW (manufactured by AS ONE Corporation).

[0070] (Electrolytic polishing solution composition) • 85% by mass phosphoric acid (reagent manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 660 mL • Pure water 160 mL • Sulfuric acid 150 mL • Ethylene glycol 30 mL

[0071] <Anodizing Process> Next, the aluminum substrate after electropolishing was subjected to anodizing by a self-regulating method according to the procedure described in Japanese Patent Publication No. 2007-204802. The aluminum substrate after electropolishing was subjected to a pre-anodizing treatment for 5 hours with an electrolyte of 0.50 mol / L oxalic acid under the conditions of a voltage of 40 V, a liquid temperature of 16 °C, and a liquid flow rate of 3.0 m / min. After that, the aluminum substrate after pre-anodizing was subjected to a defilm removal treatment by immersing it in a mixed aqueous solution of 0.2 mol / L anhydrous chromic acid and 0.6 mol / L phosphoric acid (liquid temperature: 50 °C) for 12 hours. After that, a re-anodizing treatment was performed for 3 hours and 45 minutes with an electrolyte of 0.50 mol / L oxalic acid under the conditions of a voltage of 40 V, a liquid temperature of 16 °C, and a liquid flow rate of 3.0 m / min to obtain an anodic oxide film with a thickness of 30 μm. For both the pre-anodic oxidation and re-anodic oxidation processes, a stainless steel electrode was used as the cathode, and a GP0110-30R power supply (manufactured by Takasago Seisakusho Co., Ltd.) was used. A NeoCool BD36 (manufactured by Yamato Scientific Co., Ltd.) was used as the cooling device, and a Pair Stirrer PS-100 (manufactured by EYELA Tokyo Rikakikai Co., Ltd.) was used as the stirring and heating device. Furthermore, the electrolyte flow rate was measured using a vortex flow monitor FLM22-10PCW (manufactured by AS ONE Corporation).

[0072] <Barrier Layer Removal Process> Next, after the anodic oxidation process, an etching treatment was performed by immersing the substrate in an alkaline aqueous solution prepared by dissolving zinc oxide in a sodium hydroxide aqueous solution (50 g / l) at a concentration of 2000 ppm at 30°C for 150 seconds. This removed the barrier layer at the bottom of the micropores of the anodic oxide film and simultaneously deposited zinc on the surface of the exposed aluminum substrate. The average thickness of the anodic oxide film after the barrier layer removal process was 30 μm.

[0073] <Metal Filling Process> Next, electroplating was performed using an aluminum substrate as the cathode and platinum as the cathode. Specifically, a copper plating solution with the following composition was used, and constant current electrolysis was performed to create a metal-filled microstructure in which nickel was filled inside the micropores. Here, constant current electrolysis was performed using a plating device manufactured by Yamamoto Plating Testing Equipment Co., Ltd., with a power supply (HZ-3000) manufactured by Hokuto Denko Co., Ltd., and after confirming the deposition potential by performing cyclic voltammetry in the plating solution, the process was carried out under the following conditions. (Copper plating solution composition and conditions) ・Copper sulfate 100 g / L ・Sulfuric acid 50 g / L ・Hydrochloric acid 15 g / L ・Temperature 25℃ ・Current density 10 A / dm ２

[0074] The surface of the anodic oxide film after filling micropores with metal was observed using a scanning electron microscope, and the presence or absence of metal sealing in 1000 micropores was observed. The sealing rate (number of sealed micropores / 1000 micropores) was calculated to be 98%. Furthermore, the anodic oxide film after filling micropores with metal was machined in the thickness direction using a focused ion beam (FIB), and surface photographs (magnification 50,000x) of the cross-section were taken using a scanning electron microscope to examine the inside of the micropores. It was found that the inside of the sealed micropores was completely filled with metal.

[0075] <Substrate Removal Process> Next, the aluminum substrate was dissolved and removed by immersion in a mixed solution of copper chloride / hydrochloric acid to fabricate a metal-filled microstructure with an average thickness of 30 μm. The diameter of the conductors in the fabricated metal-filled microstructure was 60 nm, the pitch between conductors was 100 nm, and the density of conductors was 57.7 million conductors / mm². ２ That was the case.

[0076] <Protrusion Process> After the substrate removal process, the metal-filled microstructure was immersed in an aqueous potassium hydroxide (KOH) solution (concentration: 0.01 mol / L), and the immersion time was adjusted so that the height of the protrusions was 300 nm, selectively dissolving the surface of the aluminum anodic oxide film. Then, it was washed with water and dried to protrude the copper cylinders that act as conductors. Similarly, copper cylinders that act as conductors were protruded from the back surface of the aluminum anodic oxide film so that the height of the protrusions was 300 nm. Next, the metal-filled microstructure was processed to a size of 5.2 mm x 4 mm to produce an anisotropic conductive member with a size of 5.2 mm x 4 mm.

[0077] The following describes the temporary bonding compositions of Examples 1 to 13 and Comparative Examples 1 to 5. (Example 1) Example 1 consisted only of a temporary adhesive and a solvent. Example 1 used isobornylcyclohexanol as the temporary adhesive and propylene glycol monomethyl ether acetate (PGMEA, boiling point 146°C) as the solvent. For the isobornylcyclohexanol, MTPH (boiling point 308°C, viscosity 65500 mPa·s (temperature 25°C)) manufactured by Nippon Terpene Chemical Co., Ltd. was used. In Example 1, the mass percentage ratio of the temporary adhesive to the solvent was temporary adhesive:solvent = 50:50. (Example 2) Example 2 consisted only of a temporary adhesive and a solvent. Example 2 used pine oil as the temporary adhesive and PGMEA (boiling point 146°C) as the solvent. For the pine oil, α-terpineol (boiling point 220°C, viscosity 67 mPa·s (at 25°C)) manufactured by Nippon Terpene Chemical Co., Ltd. is used. In Example 2, the ratio of the temporary adhesive to the solvent is 60:40 by mass. (Example 3) Example 3 has the same configuration as Example 1, except that isopropanol (IPA, boiling point 82.3°C) is used as the solvent.

[0078] (Example 4) Example 4 has the same configuration as Example 1, except that the mass percentage ratio of the temporary adhesive to the solvent is 33:67. (Example 5) Example 5 has the same configuration as Example 1, except that the mass percentage ratio of the temporary adhesive to the solvent is 20:80. (Example 6) Example 6 has a configuration consisting only of a temporary adhesive and a solvent. Example 6 uses 1,3-butylene glycol (boiling point 208°C, viscosity 95 mPa·s (temperature 25°C)) as the temporary adhesive and IPA (isopropanol) from Example 3 as the solvent. Example 6 has a mass percentage ratio of temporary adhesive to solvent of 50:50.

[0079] (Example 7) Example 7 has a configuration consisting only of a temporary binder, a solvent, and an antioxidant. Example 7 uses isobornylcyclohexanol from Example 1 as the temporary binder. 2,4-diethyl-1,5-pentanediol (boiling point 150°C, viscosity 2100 mPa·s (temperature 25°C)) is used as the solvent. Formic acid is used as the antioxidant. In Example 7, the mass percentage ratio of the temporary binder, solvent, and antioxidant is 45:50:5. (Example 8) Example 8 has a configuration consisting only of a temporary binder, a solvent, and a surfactant. In Example 8, isobornylcyclohexanol from Example 1 is used as the temporary binder. IPA from Example 3 is used as the solvent. Fluorotelomer alcohol is used as the surfactant. In Example 8, the mass percentage ratio of the temporary binder, solvent, and surfactant is 49:50:1.

[0080] (Example 9) Example 9 has a configuration consisting only of a temporary adhesive, a solvent, and water. Example 9 uses isobornylcyclohexanol from Example 1 as the temporary adhesive. IPA from Example 3 is used as the solvent. DIW (De-Ionized Water) is used as the water. In Example 9, the mass percentage ratio of the temporary adhesive, solvent, and water is temporary adhesive:solvent:water = 44:50:6. (Example 10) Example 10 has a configuration consisting only of a temporary adhesive and a solvent. In Example 10, diglycerin (boiling point 265-270°C) is used as the temporary adhesive. PGMEA (boiling point 146°C) is used as the solvent. In Example 10, the mass percentage ratio of the temporary adhesive and solvent is temporary adhesive:solvent = 50:50.

[0081] (Example 11) Example 11 has a configuration consisting only of a temporary adhesive and a solvent. In Example 11, polyvinyl acetate (PVAc, with a thermal decomposition temperature of approximately 250 to 340°C) is used as the temporary adhesive. IPA from Example 3 is used as the solvent. In Example 11, the mass percentage ratio of the temporary adhesive to the solvent is temporary adhesive:solvent = 30:70. (Example 12) Example 12 has a configuration consisting only of a temporary adhesive and a solvent. In Example 12, polylactic acid (with a decomposition temperature of 200 to 300°C) is used as the temporary adhesive. Ethyl acetate (with a boiling point of 77.1°C) is used as the solvent. In Example 12, the mass percentage ratio of the temporary adhesive to the solvent is temporary adhesive:solvent = 30:70. (Example 13) Example 13 has a configuration consisting only of a temporary adhesive and a solvent. Example 13 uses polymethyl vinyl ether (PMVE, with a decomposition temperature of 360-390°C) as a temporary adhesive. The IPA from Example 3 is used as the solvent.

[0082] (Comparative Example 1) Comparative Example 1 has a configuration that consists only of a temporary adhesive. Comparative Example 1 uses isobornylcyclohexanol from Example 1 as the temporary adhesive. Since Comparative Example 1 cannot be flown by a dispenser or inkjet printer, displacement, volatilization, and electrical resistance evaluations were not performed. For this reason, "-" is written in the columns for displacement, volatilization, and electrical resistance in Table 1. (Comparative Example 2) Comparative Example 2 has a configuration that consists only of a solvent. Comparative Example 2 uses IPA from Example 3 as the solvent. Since at least one of the first and second chips peels off when evaluating displacement in Comparative Example 2, volatilization and electrical resistance evaluations were not performed. For this reason, "-" is written in the columns for volatilization and electrical resistance in Table 1. (Comparative Example 3) Comparative Example 3 has a configuration that consists only of a temporary adhesive. Comparative Example 3 uses ethylene glycol (boiling point 198°C, viscosity 16 mPa·s (temperature 25°C)) as the temporary adhesive. In Comparative Example 3, although there was no delamination between the first and second chips during the misalignment evaluation, the difference in misalignment was greater than 100 μm, so volatilization and electrical resistance evaluations were not performed. Therefore, "-" is indicated in the volatilization and electrical resistance columns of Table 1.

[0083] (Comparative Example 4) Comparative Example 4 has a configuration that consists only of a temporary adhesive. Comparative Example 4 uses propylene glycol phenyl ether (PPH, boiling point 243°C, viscosity 23 mPa·s (temperature 25°C)) as the temporary adhesive. In Comparative Example 4, there is no peeling of the first and second chips when evaluating misalignment, but since the difference in misalignment is more than 10 μm and less than or equal to 100 μm, volatilization and electrical resistance evaluations were not performed. For this reason, "-" is written in the Volatilization and Electrical Resistance column of Table 1. (Comparative Example 5) Comparative Example 5 has a configuration that consists only of a temporary adhesive, water, and methanol. Comparative Example 5 uses polyvinyl alcohol (PVA, boiling point 220°C) as the temporary adhesive. DIW (De-Ionized Water) is used for the water. In Comparative Example 5, the mass percentage ratio of the temporary adhesive, water, and methanol is temporary adhesive:water:methanol = 10:85:5.

[0084]

[0085] As shown in Table 1, Example 1 achieved a bond with smaller misalignment and higher reliability compared to Comparative Examples 1 to 5. Examples 2 to 13 also achieved a bond with smaller misalignment and higher reliability compared to Comparative Examples 1 to 5, similar to Example 1. In Example 1, the temporary bonding composition consisted of isobornylcyclohexanol as the temporary adhesive, PGMEA (propylene glycol monomethyl ether acetate, boiling point 146°C) as the solvent, and a mass% ratio of temporary adhesive:solvent = 50:50. Anisotropic conductive members and TEG chips (Test Element Group chips) capable of evaluating daisy chains were temporarily fixed and then bonded. The TEG chips have electrodes that enable evaluation of 1000 daisy chains. As a result of the bonding, it was confirmed that all 1000 daisy chains were connected and that the connection resistance was low.

[0086] 10 Joint 12 Anisotropic conductive members 12a, 20a, 50a Front surface 12b, 50b Back surface 14 First member to be joined 16 Second member to be joined 18 Temporary joining composition 19 Laminate 20, 30 Substrate 22, 23, 24, 32, 33 Electrode 30 Substrate 50 Insulating film 51 Pore 52 Conductor 52a, 52b Protrusion Ds Lamination direction Dt Thickness direction d Average diameter ht Thickness p Distance between centers

Claims

1. A temporary bonding composition used in the manufacture of a joint in which an anisotropic conductive member and a member to be joined are joined, comprising a temporary adhesive and a solvent, wherein the temporary adhesive has a boiling point or decomposition point, the lower of which is 200°C or more and 400°C or less.

2. The temporary bonding composition according to claim 1, wherein the temporary adhesive has a viscosity of 20 mPa·s or more at a temperature of 25°C.

3. The temporary bonding composition according to claim 1 or 2, wherein the temporary bonding agent has a polar group.

4. The temporary bonding composition according to claim 1 or 2, wherein the temporary bonding agent comprises a compound having an isobornyl group.

5. The temporary bonding composition according to claim 1 or 2, wherein the temporary adhesive comprises a compound represented by the following formula.

6. The temporary bonding composition according to claim 1 or 2, wherein the water content is 5% or less.

7. The temporary bonding composition according to claim 1 or 2, wherein the member to be bonded is a power semiconductor element.

8. A method for manufacturing a joined body, comprising: a temporary fixing step of providing a temporary bonding composition between an anisotropic conductive member and a member to be joined, and temporarily fixing the anisotropic conductive member and the member to be joined; and a joining step of joining the anisotropic conductive member and the member to be joined, wherein the temporary bonding composition is removed in the joining step or after the joining step, and the temporary bonding composition comprises a temporary adhesive and a solvent, wherein the temporary adhesive has a boiling point or decomposition point, the lower of which is 200°C or more and 400°C or less.

9. The method for manufacturing a joined body according to claim 8, wherein the temporary fixing step involves providing the temporary bonding composition at at least two locations on the periphery of the anisotropic conductive member.

10. The method for manufacturing a bonded body according to claim 8 or 9, wherein the bonding step is carried out in a reducing atmosphere.

11. The method for manufacturing a bonded body according to claim 8 or 9, wherein the member to be bonded is a power semiconductor element.

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