JP2015002338A - Method for manufacturing semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a semiconductor device, capable of achieving high reliability by reducing a void.SOLUTION: A method for manufacturing a semiconductor device in which semiconductor chips or a semiconductor chip and a substrate are electrically joined with each other, includes the steps of: (1) aligning a first electrode formed in a semiconductor chip with a second electrode formed in another semiconductor chip or a substrate via a thermosetting adhesive therebetween; (2) heating the first electrode, the second electrode and the thermosetting adhesive to join the first electrode with the second electrode and temporarily bond the semiconductor chip with another semiconductor chip or the substrate; (3) starting compression of the temporary bonded body obtained to bring it under pressure atmosphere; (4) heating the temporary bonded body under the pressure atmosphere to keep it at a temperature lower than a curing temperature of the thermosetting adhesive; and (5) heating the temporary bonded body to a temperature equal to or more than the curing temperature of the thermosetting adhesive.

Description

The present invention relates to a method for manufacturing a semiconductor device capable of suppressing voids and realizing high reliability.

In recent years, flip-chip mounting using a semiconductor chip having protruding electrodes (bumps) made of solder or the like is frequently used in order to cope with miniaturization and high integration of a semiconductor device that is increasingly developed.
In flip chip mounting, a method is generally used in which a protruding electrode of a semiconductor chip and an electrode of another semiconductor chip or a substrate are joined, and then an underfill is injected to perform resin sealing. However, in recent years, semiconductor chips have been miniaturized, and the pitch between electrodes has been narrowed. In addition, the gap between semiconductor chips or between a semiconductor chip and a substrate has been narrowed. Therefore, air is trapped when the underfill is injected, and voids are easily generated.

In order to suppress voids, a method of supplying a thermosetting adhesive in advance to a substrate or a semiconductor chip is used instead of injecting an underfill after electrode bonding. However, even in such a method, air may be involved when the electrodes are brought into contact with each other, or voids may be generated due to volatile components from the thermosetting adhesive heated to a high temperature. In the method of supplying the thermosetting adhesive in advance, since the electrode bonding and the thermosetting adhesive are simultaneously cured by heating, it is not easy to achieve both high-accuracy electrode bonding and void suppression. Absent.

Thus, for example, a method has been proposed in which a void is reduced by temporarily bonding a semiconductor chip and another semiconductor chip or substrate and then heating the temporary bonded body in a pressurized atmosphere (for example, Patent Document 1). 2). Also, after bonding the sheet-like thermosetting adhesive to the wafer, pressurize the wafer and the sheet-like thermosetting adhesive to reduce the voids, and then separate the wafer into semiconductor chips. A mounting method has also been proposed (for example, Patent Document 3).

JP 2009-4462 A JP 2008-192725 A JP 2006-245242 A

However, there is a limit to reducing the void by the conventional method, and the void has not been sufficiently suppressed. An object of this invention is to provide the manufacturing method of the semiconductor device which can implement | achieve high reliability by suppressing a void.

The present invention is a method for manufacturing a semiconductor device in which semiconductor chips or semiconductor chips and a substrate are electrically joined to each other. (1) A first electrode formed on a semiconductor chip and another semiconductor chip or substrate. Aligning the formed second electrode with a thermosetting adhesive sandwiched between the first electrode and the second electrode; and (2) the first electrode and the second electrode. Heating the electrode and the thermosetting adhesive to bond the first electrode and the second electrode and temporarily bonding the semiconductor chip and the other semiconductor chip or substrate; A step of starting pressurization of the obtained temporary adhesive body to bring it into a pressurized atmosphere; and (4) heating in the pressurized atmosphere, the temporary adhesive body being cured from the curing temperature of the thermosetting adhesive. A step of maintaining the temperature at a low temperature; and (5) the thermosetting property of the temporary adhesive body. A method of manufacturing a semiconductor device having a step of heating the temperature not lower than the curing temperature of Chakuzai.
The present invention is described in detail below.

The present inventor has (1) a first electrode formed on a semiconductor chip and a second electrode formed on another semiconductor chip or a substrate between the first electrode and the second electrode. (2) heating the first electrode and the second electrode, and the thermosetting adhesive to position the first electrode and the second electrode; A step of bonding the electrode and temporarily bonding the semiconductor chip and the other semiconductor chip or substrate; and (3) a step of starting pressurization of the obtained temporary bonded body to be in a pressurized atmosphere; (4) heating in the pressurized atmosphere and maintaining the temporary adhesive body at a temperature lower than the curing temperature of the thermosetting adhesive; and (5) curing the temporary adhesive body of the thermosetting adhesive. According to the method for manufacturing a semiconductor device having a step of heating to a temperature equal to or higher than the temperature, the void It found that it is possible to realize a high reliability by suppressing, thereby completing the present invention.

The method for manufacturing a semiconductor device of the present invention electrically joins semiconductor chips or a semiconductor chip and a substrate.
In the method for manufacturing a semiconductor device of the present invention, first, (1) a first electrode formed on a semiconductor chip and a second electrode formed on another semiconductor chip or a substrate are combined with the first electrode and the first electrode. A process of aligning the thermosetting adhesive with the second electrode is performed.

The semiconductor chip (same for other semiconductor chips) is not particularly limited. For example, a protruding electrode or the like made of a semiconductor such as silicon or gallium arsenide and having a tip made of solder as an electrode (referred to as a first electrode) is formed on the surface. A semiconductor chip that is formed can be mentioned. As long as the protruding electrode having the tip portion made of solder has the tip portion made of solder, only the tip portion may be made of solder or the entire protruding electrode may be made of solder.
The said board | substrate is not specifically limited, For example, the board | substrate with which the electrode (it is called 2nd electrode) formed in the surface generally used for flip chip mounting is mentioned.

The thermosetting adhesive may be in the form of a sheet or a paste, and preferably contains a curable compound and a curing agent.
The said curable compound is not specifically limited, For example, the compound hardened | cured by reaction, such as addition polymerization, polycondensation, polyaddition, addition condensation, ring-opening polymerization, is mentioned. Specific examples of the curable compound include urea resin, melamine resin, phenol resin, resorcinol resin, epoxy resin, acrylic resin, polyester resin, polyamide resin, polybenzimidazole resin, diallyl phthalate resin, xylene resin, alkyl- Examples thereof include thermosetting compounds such as benzene resin, epoxy acrylate resin, silicon resin, and urethane resin. Especially, since it is excellent in the reliability and joining strength of a semiconductor device, an epoxy resin and an acrylic resin are preferable and the epoxy resin which has an imide skeleton is more preferable.

The epoxy resin is not particularly limited. For example, bisphenol type epoxy resins such as bisphenol A type, bisphenol F type, bisphenol AD type and bisphenol S type, novolac type epoxy resins such as phenol novolak type and cresol novolak type, resorcinol type epoxy Resin, aromatic epoxy resin such as trisphenolmethane triglycidyl ether, naphthalene type epoxy resin, fluorene type epoxy resin, dicyclopentadiene type epoxy resin, polyether modified epoxy resin, NBR modified epoxy resin, CTBN modified epoxy resin, and These hydrogenated products can be mentioned. Among them, bisphenol F type epoxy resin, resorcinol type epoxy resin, and polyether-modified epoxy resin are preferable because a thermosetting adhesive having a low viscosity can be obtained.

Among the bisphenol F-type epoxy resins, as commercial products, for example, EXA-830-LVP, EXA-830-CRP (manufactured by DIC) and the like can be mentioned. Moreover, EX-201 (made by Nagase ChemteX Corporation) etc. are mentioned as a commercial item among the said resorcinol type epoxy resins. Moreover, as a commercial item among the said polyether modified epoxy resins, EX-931 (made by Nagase ChemteX), EXA-4850-150 (made by DIC), EP-4005 (made by ADEKA) etc. are mentioned, for example. It is done. Moreover, as a commercial item among the said dicyclopentadiene type epoxy resins, HP-7200HH (made by DIC), EP-4088L (made by Adeka) etc. are mentioned, for example.

The above-mentioned curable compound has a preferable upper limit of moisture absorption of 1.5% and a more preferable upper limit of 1.1%. Examples of the curable compound having such a moisture absorption rate include naphthalene type epoxy resin, fluorene type epoxy resin, dicyclopentadiene type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin and the like.

The said hardening | curing agent is not specifically limited, A conventionally well-known hardening | curing agent can be suitably selected according to the said sclerosing | hardenable compound. When using an epoxy resin as the curable compound, examples of the curing agent include latent heat-curing acid anhydride-based curing agents such as trialkyltetrahydrophthalic anhydride, phenol-based curing agents, amine-based curing agents, and dicyandiamide. For example, a cationic curing agent and a cationic catalyst-type curing agent. These curing agents may be used alone or in combination of two or more.

Although the compounding quantity of the said hardening | curing agent is not specifically limited, When using the hardening | curing agent which reacts equally with the functional group of the said sclerosing | hardenable compound, it is 60-100 equivalent with respect to the functional group amount of the said sclerosing | hardenable compound. preferable. Moreover, when using the hardening | curing agent which functions as a catalyst, as for the compounding quantity of the said hardening | curing agent, a preferable minimum is 1 weight part with respect to 100 weight part of said curable compounds, and a preferable upper limit is 20 weight part.

The thermosetting adhesive may contain a curing accelerator in addition to the curing agent in order to adjust the curing speed, physical properties of the cured product, and the like.
The said hardening accelerator is not specifically limited, For example, an imidazole series hardening accelerator, a tertiary amine type hardening accelerator, etc. are mentioned. Of these, an imidazole curing accelerator is preferred because it is easy to control the reaction system for adjusting the curing speed and the physical properties of the cured product. These hardening accelerators may be used independently and may use 2 or more types together.

The imidazole-based curing accelerator is not particularly limited. For example, 1-cyanoethyl-2-phenylimidazole in which the 1-position of imidazole is protected with a cyanoethyl group, an imidazole-based curing accelerator whose basicity is protected with isocyanuric acid (trade name “ 2MA-OK ", manufactured by Shikoku Kasei Kogyo Co., Ltd.), 2MZ, 2MZ-P, 2PZ, 2PZ-PW, 2P4MZ, C11Z-CNS, 2PZ-CNS, 2PZCNS-PW, 2MZ-A, 2MZA-PW, C11Z-A, 2E4MZ-A, 2MAOK-PW, 2PZ-OK, 2MZ-OK, 2PHZ, 2PHZ-PW, 2P4MHZ, 2P4MHZ-PW, 2E4MZ · BIS, VT, VT-OK, MAVT, MAVT-OK (above, Shikoku Chemical Industries, Ltd.) Manufactured), Fuji Cure 7000 (manufactured by T & K TOKA), and the like. These imidazole type hardening accelerators may be used independently and may use 2 or more types together.

The compounding quantity of the said hardening accelerator is not specifically limited, A preferable minimum is 1 weight part with respect to 100 weight part of said curable compounds, and a preferable upper limit is 10 weight part.

When an epoxy resin is used as the curable compound and the curing agent and the curing accelerator are used in combination, the blending amount of the curing agent used is equivalent to the theoretically required equivalent to the epoxy group in the epoxy resin to be used. The following is preferable. If the blending amount of the curing agent exceeds the theoretically required equivalent, chlorine ions may be easily eluted by moisture from a cured product obtained by curing the thermosetting adhesive. That is, when the curing agent is excessive, for example, when the eluted component is extracted with hot water from the cured product of the resulting thermosetting adhesive, the pH of the extracted water becomes about 4-5, Large amounts of chloride ions may elute. Accordingly, it is preferable that the pH of pure water after immersion of 1 g of the cured product of the resulting thermosetting adhesive with 10 g of pure water at 100 ° C. for 2 hours is 6 to 8, and the pH is 6.5 to 7. 5 is more preferable.

The thermosetting adhesive may contain a diluent in order to reduce the viscosity.
The diluent preferably has an epoxy group, and the preferable lower limit of the number of epoxy groups in one molecule is 2, and the preferable upper limit is 4. If the number of epoxy groups in one molecule is less than 2, sufficient heat resistance may not be exhibited after the thermosetting adhesive is cured. If the number of epoxy groups in one molecule exceeds 4, distortion due to curing may occur, or uncured epoxy groups may remain, which may result in poor bonding strength or poor bonding due to repeated thermal stress. May occur. A more preferable upper limit of the number of epoxy groups in one molecule of the diluent is 3.
The diluent preferably has an aromatic ring and / or a dicyclopentadiene structure.

The preferable upper limit of the weight loss at 120 ° C. and the weight loss at 150 ° C. is 1%. If the weight loss at 120 ° C. and the weight loss at 150 ° C. exceed 1%, the unreacted material will volatilize during or after the thermosetting adhesive is cured, resulting in increased productivity or performance of the semiconductor device. May cause adverse effects.
The diluent preferably has a lower curing start temperature and a higher curing rate than other curable compounds.

The minimum with the preferable compounding quantity of the diluent in the said thermosetting adhesive is 1 weight%, and a preferable upper limit is 20 weight%. When the blending amount of the diluent is outside the above range, the viscosity of the thermosetting adhesive may not be sufficiently reduced.

The thermosetting adhesive preferably further contains a thixotropic agent. By containing the thixotropy imparting agent, the thermosetting adhesive can achieve a desired viscosity behavior.
The thixotropy imparting agent is not particularly limited, and examples thereof include fine metal particles, calcium carbonate, fumed silica, inorganic fine particles such as aluminum oxide, boron nitride, aluminum nitride, and aluminum borate. Of these, fumed silica is preferable. Moreover, as the thixotropy-imparting agent, a thixotropy-imparting agent subjected to surface treatment can be used as necessary. In particular, it is preferable to use particles having a hydrophilic group on the surface as the thixotropic agent. Specific examples of the particles having a hydrophilic group on the surface include fumed silica having a hydrophilic group on the surface.

When a particulate thixotropy imparting agent is used as the thixotropy imparting agent, the preferable upper limit of the average particle diameter is 1 μm. When the average particle diameter of the thixotropy-imparting agent exceeds 1 μm, the thermosetting adhesive may not exhibit desired thixotropy.

The blending amount of the thixotropy imparting agent in the thermosetting adhesive is not particularly limited, but a preferred lower limit is 0.5% by weight and a preferred upper limit is 20% by weight. If the amount of the thixotropy-imparting agent is less than 0.5% by weight, sufficient thixotropy may not be imparted to the thermosetting adhesive. When the blending amount of the thixotropy-imparting agent exceeds 20% by weight, the exclusion property of the thermosetting adhesive may be lowered. A more preferable lower limit of the amount of the thixotropy-imparting agent is 3% by weight, and a more preferable upper limit is 10% by weight.

The thermosetting adhesive preferably further contains a polymer compound having a functional group capable of reacting with the curable compound. By including such a polymer compound, the bonding reliability when heat distortion occurs is improved.

In the case of using an epoxy resin as the curable compound as a polymer compound having a functional group capable of reacting with the curable compound, for example, an amino group, a urethane group, an imide group, a hydroxyl group, a carboxyl group, an epoxy group, etc. For example, a polymer compound. Among these, a polymer compound having an epoxy group is preferable. By adding the polymer compound having the epoxy group, the cured product of the thermosetting adhesive exhibits excellent flexibility. That is, the cured product of the thermosetting adhesive is excellent in mechanical strength, heat resistance and moisture resistance derived from the epoxy resin as the curable compound, and excellent in the polymer compound having the epoxy group. Since it combines flexibility, it will be excellent in cold-heat cycle resistance, solder reflow resistance, dimensional stability, etc., and will exhibit high joint reliability or high conduction reliability.

The polymer compound having an epoxy group is not particularly limited as long as it is a polymer compound having an epoxy group at the terminal and / or side chain (pendant position). For example, an epoxy group-containing acrylic rubber, an epoxy group-containing butadiene rubber, Examples thereof include bisphenol type high molecular weight epoxy resin, epoxy group-containing phenoxy resin, epoxy group-containing acrylic resin, epoxy group-containing urethane resin, and epoxy group-containing polyester resin. Among these, an epoxy group-containing acrylic resin is preferable because a polymer compound containing a large amount of epoxy groups can be obtained, and the cured product has better mechanical strength or heat resistance. These polymer compounds having an epoxy group may be used alone or in combination of two or more.

As the polymer compound having a functional group capable of reacting with the curable compound, the polymer compound having the epoxy group, particularly when the epoxy group-containing acrylic resin is used, the weight average molecular weight of the polymer compound having the epoxy group is A preferred lower limit is 10,000. When the weight average molecular weight is less than 10,000, the film forming property of the thermosetting adhesive becomes insufficient, and the flexibility of the cured product may not be sufficiently improved.

As the polymer compound having a functional group capable of reacting with the curable compound, a polymer compound having the epoxy group, particularly when an epoxy group-containing acrylic resin is used, the epoxy equivalent of the polymer compound having the epoxy group is preferable. The lower limit is 200, and the preferred upper limit is 1000. When the epoxy equivalent is less than 200, the flexibility of the cured product of the thermosetting adhesive may not be sufficiently improved. If the epoxy equivalent exceeds 1000, the mechanical strength or heat resistance of the cured product of the thermosetting adhesive may be insufficient.

Although the compounding quantity of the high molecular compound which has a functional group which can react with the said curable compound is not specifically limited, A preferable minimum is 1 weight part and a preferable upper limit is 150 weight part with respect to 100 weight part of said curable compounds. When the blending amount of the polymer compound having a functional group capable of reacting with the curable compound is less than 1 part by weight, the thermosetting adhesive may not have sufficient reliability against thermal strain. When the compounding quantity of the high molecular compound which has a functional group which can react with the said sclerosing | hardenable compound exceeds 150 weight part, the heat resistance of a thermosetting adhesive agent may fall.

The thermosetting adhesive preferably further contains a surface-treated silica filler. Although the said surface-treated silica filler is not specifically limited, The silica filler surface-treated with the phenylsilane coupling agent is preferable.
The amount of the surface-treated silica filler is not particularly limited, but a preferable lower limit is 30 parts by weight and a preferable upper limit is 400 parts by weight with respect to 100 parts by weight of the curable compound. When the amount of the surface-treated silica filler is less than 30 parts by weight, the thermosetting adhesive may not be able to maintain sufficient reliability. When the compounding amount of the surface-treated silica filler exceeds 400 parts by weight, the viscosity of the thermosetting adhesive becomes too high, and the coating stability may be lowered.

The thermosetting adhesive may further contain an additive having a flux action.
The additive having the flux action is not particularly limited, and examples thereof include aliphatic monocarboxylic acids such as valeric acid, lauric acid, and stearic acid, fats such as succinic acid, adipic acid, sebacic acid, and 1,10-dodecanedicarboxylic acid. Aromatic carboxylic acids such as aromatic dicarboxylic acid, benzoic acid, phthalic acid, 1,2,4-trimellitic acid and pimelic acid, and rosin derivatives.

The said thermosetting adhesive may contain a solvent as needed. The solvent is not particularly limited, and examples thereof include aromatic hydrocarbons, chlorinated aromatic hydrocarbons, chlorinated aliphatic hydrocarbons, alcohols, esters, ethers, ketones, glycol ethers (cellosolves), and fats. Examples thereof include cyclic hydrocarbons and aliphatic hydrocarbons.
The thermosetting adhesive may contain an inorganic ion exchanger as necessary. Among the inorganic ion exchangers, examples of commercially available products include IXE series (manufactured by Toagosei Co., Ltd.). The preferable upper limit of the blending amount of the inorganic ion exchanger in the thermosetting adhesive is 10% by weight, and the preferable lower limit is 1% by weight.
The said thermosetting adhesive may contain other additives, such as adhesive imparting agents, such as a bleed inhibitor and an imidazole silane coupling agent, as needed.

The said thermosetting adhesive has a preferable lower limit of the curing temperature of 100 ° C and a preferable upper limit of 220 ° C. When the curing temperature is less than 100 ° C., the thermosetting adhesive is cured on the stage of the mounting apparatus in the step (2) described later, and proper electrode bonding and temporary bonding may not be performed. When the curing temperature exceeds 220 ° C., even if the solder is heated to a temperature higher than the melting temperature of the solder in step (2) described later, the solder is not melted and proper electrode bonding and temporary bonding may not be performed. A more preferable lower limit of the curing temperature is 120 ° C., and a more preferable upper limit is 200 ° C.
The curing temperature of the thermosetting adhesive means a lower limit temperature at the start of a peak in an exothermic peak measured at 10 ° C./min using differential scanning calorimetry (DSC), and is also referred to as a DSC start temperature (Table 1 (corresponding to “curing temperature of thermosetting adhesive (DSC start temperature)”).

The above-mentioned thermosetting adhesive has a preferable lower limit of 0.1 Pa · s and a preferable upper limit of 10 ⁴ Pa · s in the minimum melt viscosity in the temperature range from room temperature to the solder melting point. If the minimum melt viscosity is less than 0.1 Pa · s, the fillet may protrude too much and contaminate other devices. If the minimum melt viscosity exceeds 10 ⁴ Pa · s, voids may not be sufficiently suppressed.
The minimum melt viscosity in the temperature range from room temperature to the solder melting point can be measured using a rheometer.

The method for producing the thermosetting adhesive is not particularly limited. For example, the curable compound and the curing agent may include a curing accelerator, a polymer compound having a functional group capable of reacting with the curable compound, if necessary, and thixotropy. A method of producing a paste-like thermosetting adhesive by mixing a predetermined amount of an additive, other additives, and the like, and applying a resin composition obtained by mixing in the same manner onto a release film And a method of producing a sheet-like thermosetting adhesive by drying. The mixing method is not particularly limited, and examples thereof include a method using a homodisper, a universal mixer, a Banbury mixer, a kneader and the like.

As a method of aligning the first electrode and the second electrode in a state where the thermosetting adhesive is sandwiched between the first electrode and the second electrode, for example, the thermosetting adhesive is used. There is a method of aligning the first electrode and the second electrode using a mounting device such as a flip chip bonder after the semiconductor chip is supplied to the semiconductor chip or the other semiconductor chip or substrate.
The method for supplying the thermosetting adhesive to the substrate is not particularly limited. For example, the thermosetting adhesive is applied onto the substrate using a combination of a syringe equipped with a precision nozzle and a dispenser. And the like.

In the semiconductor device manufacturing method of the present invention, next, (2) the first electrode and the second electrode, and the thermosetting adhesive are heated to join the first electrode and the second electrode. In addition, a step of temporarily bonding the semiconductor chip and the other semiconductor chip or substrate is performed.

The method for heating the first electrode, the second electrode, and the thermosetting adhesive is not particularly limited. For example, using a mounting device such as a flip chip bonder, a contact temperature of about 120 to 220 ° C. Examples include a method of heating for about 0.1 to 60 seconds at (the temperature at which the electrodes are brought into contact), and then heating for about 0.1 to 60 seconds at a bonding temperature of about 230 to 300 ° C. (temperature for bonding the electrodes). For example, when the first electrode is solder, the contact temperature may be a temperature equal to or lower than the solder melting temperature, and the bonding temperature may be equal to or higher than the solder melting temperature.
At this time, by controlling the contact temperature, the bonding temperature, the heating time, etc., the semiconductor chip and the other semiconductor chip or substrate are bonded together while favorably bonding the first electrode and the second electrode. Good temporary adhesion can be achieved.

When heating the first electrode, the second electrode, and the thermosetting adhesive, the semiconductor chip is pressed, the first electrode and the second electrode are joined, and the thermosetting is performed. It is preferable to fill the sealing region with the adhesive.
Although the pressure at the time of the said press is not specifically limited, 1-100N is preferable. Further, the pressure per electrode is preferably 0.1 to 10N. If the pressure per electrode is less than 0.1 N, the electrodes may not contact each other. If the pressure per one electrode exceeds 10 N, the protruding electrode may be crushed too much and contact with the adjacent protruding electrode, resulting in a short circuit.

In the temporary bonded body obtained in the step (2), the preferable upper limit of the curing rate of the thermosetting adhesive is 40%. When the said hardening rate exceeds 40%, the effect which presses the said temporary bonded body in the process (3) and (4) mentioned later cannot fully be acquired, and a void may not fully be suppressed. A more preferable upper limit of the curing rate of the thermosetting adhesive is 20%.
The curing rate (%) of the thermosetting adhesive means a value obtained by the following formula (1), and is adjusted by controlling, for example, the above-described contact temperature, bonding temperature, heating time, and the like. The
Curing rate of thermosetting adhesive (%) = (1−Dh / Di) × 100 (1)
In formula (1), Di represents the heat generation amount of the initial state of the thermosetting adhesive calculated by differential scanning calorimetry (DSC), and Dh is the thermosetting adhesive calculated by the differential scanning calorimeter. Represents the calorific value after the heat treatment.

Next, in the method for manufacturing a semiconductor device of the present invention, (3) a step of starting pressurization of the obtained temporary bonded body to bring it into a pressurized atmosphere.
In this step, pressurization of the temporary adhesive body is started to be in a pressurized atmosphere, and in the step (4) described later, the temporary adhesive body is left in the pressurized atmosphere and the curing temperature of the thermosetting adhesive is maintained. By continuing to heat to maintain a lower temperature and flowing the thermosetting adhesive, even if air is caught in the thermosetting adhesive, the voids can be crushed and removed, In addition, the occurrence of voids in the thermosetting adhesive itself can be suppressed.

The method of starting pressurization of the temporary adhesive body and bringing it into a pressurized atmosphere is not particularly limited. For example, the temporary adhesive body is placed in a pressure resistant container at about room temperature (for example, 20 to 40 ° C.), and then And a method of increasing the internal pressure of the pressure-resistant container to be higher than the atmospheric pressure (normal pressure) by introducing a pressurized fluid.

The increase in pressure may be performed in one stage or in multiple stages. Although the said pressurized fluid is not specifically limited, Gases, such as nitrogen gas, argon gas, and air, are preferable and air is especially preferable from the convenience. Moreover, a liquid can also be used as the pressurized fluid.
It is preferable that the pressure (internal pressure of the pressure vessel) exceeds 0.1 MPa, and the preferable upper limit is 10 MPa. If the pressure exceeds 0.1 MPa, even if air is involved in the thermosetting adhesive, the void can be crushed and removed, and voids are generated in the thermosetting adhesive. This can also be suppressed. When the pressure is 10 MPa or less, the pressure vessel is not enlarged or complicated. The more preferable lower limit of the pressure is 0.5 MPa, and the more preferable upper limit is 5 MPa.
In addition, the pressure (internal pressure of a pressure-resistant container) when it is set as a pressurized atmosphere is a pressure when atmospheric pressure shall be 0.1 MPa.

In the method for manufacturing a semiconductor device of the present invention, next, (4) a step of heating in the pressurized atmosphere to keep the temporary adhesive body at a temperature lower than the curing temperature of the thermosetting adhesive is performed.
In this step, the temporary adhesive body is kept heated at a temperature lower than the curing temperature of the thermosetting adhesive while maintaining the pressurized atmosphere, and the thermosetting adhesive is flowed to temporarily heat the temporary adhesive body. Even when air is entrained in the curable adhesive, the voids can be crushed and removed, and the occurrence of voids in the thermosetting adhesive itself can be suppressed.
On the other hand, when the temperature at which the temporary adhesive body is heated is equal to or higher than the curing temperature of the thermosetting adhesive, the thermosetting adhesive is insufficiently flowed and voids cannot be sufficiently suppressed.

This step may be performed after starting the pressurization of the temporary adhesive body in the above-described step (3) and putting it in a pressurized atmosphere. However, the temporary adhesive body is kept in the pressurized atmosphere for a predetermined time ( For example, after pressurizing for 5 to 30 minutes, it is preferable to heat the thermosetting adhesive by heating it to a temperature lower than the curing temperature of the thermosetting adhesive.
More specifically, the preferable lower limit of the time from the pressurization start time to the heating start time is 5 minutes, and the preferable upper limit is 30 minutes. If the time from the pressurization start time to the heating start time is less than 5 minutes, the void may not be sufficiently suppressed. If the time from the pressurization start time to the heating start time exceeds 30 minutes, the production efficiency may be reduced. The more preferable lower limit of the time from the pressurization start time to the heating start time is 10 minutes, and the more preferable upper limit is 20 minutes.

There is no particular limitation on the method of heating in the pressurized atmosphere and maintaining the temporary adhesive body at a temperature lower than the curing temperature of the thermosetting adhesive. For example, by introducing a pressurized fluid, the internal pressure is reduced to atmospheric pressure ( Examples thereof include a method of heating the temporary adhesive body to a temperature lower than the curing temperature of the thermosetting adhesive with a heater or the like in a pressure-resistant container that is higher than normal pressure.
The temperature for heating the temporary adhesive body to a temperature lower than the curing temperature of the thermosetting adhesive is appropriately selected according to the thermosetting adhesive, but is usually 200 ° C. or lower, preferably 150 ° C. or lower. . The time for heating the temporary adhesive body to a temperature lower than the curing temperature of the thermosetting adhesive is usually 10 minutes to 2 hours, preferably 20 minutes to 1 hour.
The curing temperature of the thermosetting adhesive means a lower limit temperature at the start of a peak in an exothermic peak measured at 10 ° C./min using differential scanning calorimetry (DSC), and is also referred to as a DSC start temperature (Table 1 (corresponding to “curing temperature of thermosetting adhesive (DSC start temperature)”).

In the method for manufacturing a semiconductor device of the present invention, next, (5) a step of heating the temporary adhesive body to a temperature equal to or higher than the curing temperature of the thermosetting adhesive is performed.
That is, in the method for manufacturing a semiconductor device of the present invention, the thermosetting adhesive is cured also in the step (4), but in the step (4), it is not completely cured but is cured to an intermediate stage, Thereafter, a two-step temperature profile is performed to raise the temperature and completely cure the thermosetting adhesive. Note that the step (5) may be performed with or without applying pressure.

Although the temperature which heats the said temporary adhesive body to the temperature more than the curing temperature of the said thermosetting adhesive is suitably selected according to the said thermosetting adhesive, it is 140-220 degreeC normally, Preferably it is 160-220 degreeC It is. The time for heating the temporary adhesive body at a temperature equal to or higher than the curing temperature of the thermosetting adhesive is usually 10 to 90 minutes, preferably 20 to 60 minutes.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the semiconductor device which can suppress a void and can implement | achieve high reliability can be provided.

Examples of the present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

(Examples 1-2 and Comparative Examples 1-3)
(1) Production of thermosetting adhesive According to the composition described in Table 1, the materials shown below were stirred and mixed to produce a thermosetting adhesive. Moreover, the curing temperature (DSC start temperature) of the obtained thermosetting adhesive was measured using DSC.
1. Epoxy resin Aniline type epoxy resin (EP-39000S, manufactured by Adeka)
2. Curing agent and curing accelerator acid anhydride (YH-307, manufactured by Mitsubishi Chemical Corporation)
Thiol (TMMP, SC Organic Chemicals)
Inclusion imidazole (TEP-2E4MZ, manufactured by Nippon Soda Co., Ltd.)
3. Silica filler spherical silica (SE-2050-SMJ, manufactured by Admatechs, average particle size 0.5 μm)

(2) Manufacture of semiconductor chip mounting body A 10 mL syringe (manufactured by Iwashita Engineering Co., Ltd.) is filled with a thermosetting adhesive, and a precision nozzle (manufactured by Iwashita Engineering Co., Ltd., nozzle tip diameter 0.3 mm) is attached to the syringe tip. (SHOT MASTER300, manufactured by Musashi Engineering Co., Ltd.), applied onto a substrate (WALTS-KIT MB50-0101JY, manufactured by Waltz) at a discharge pressure of 0.4 MPa, a substrate-needle gap of 200 μm, and a coating amount of 3.3 μL. did.
Using a flip chip bonder (FC3000S, manufactured by Toray Engineering Co., Ltd.), the protruding electrode of the semiconductor chip (WALTS-TEG MB50-0101JY, solder melting temperature 235 ° C., manufactured by Waltz) and the substrate electrode were applied and cured. (Step (1)), pressing at 140 ° C. and 20 N for 1 second to bring the protruding electrode of the semiconductor chip into contact with the electrode of the substrate, and then 260 ° C. and 1 N The substrate was heated for 3 seconds to bond the protruding electrode of the semiconductor chip and the electrode of the substrate and to temporarily bond the semiconductor chip and the substrate (step (2)).
The obtained temporary adhesive body was placed in a pressure resistant container (VFS-60A-JP, manufactured by Able Print Technology) at room temperature, and the internal pressure of the pressure resistant container was set to the pressure shown in Table 1 by introducing air (process) (3)). Next, the temporary adhesive body was heated at the heating temperature and heating time described in Table 1 (step (4)), and further heated at 170 ° C. for 30 minutes while being pressurized to completely cure the thermosetting adhesive. (Step (5)) A semiconductor device was obtained. The pressurization start time in step (3) is shown in Table 1 as a value when the heating start time in step (4) is 0 minutes.

(Evaluation)
About the obtained semiconductor device, the presence or absence of void generation was evaluated as follows. The results are shown in Table 1.
The voids of the semiconductor device before and after the step (3) and after the step (4) were observed using an ultrasonic exploration imaging device (C-SAM D9500, manufactured by Nihon Burns) and evaluated according to the following criteria.
○ Little void was observed.
Δ: Slight voids were observed.
X Conspicuous peeling due to voids was observed.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the semiconductor device which can suppress a void and can implement | achieve high reliability can be provided.

Claims (1)

A method of manufacturing a semiconductor device in which semiconductor chips or semiconductor chips and a substrate are electrically joined,
(1) A thermosetting adhesive between the first electrode and the second electrode, the first electrode formed on the semiconductor chip and the second electrode formed on another semiconductor chip or substrate. A process of aligning with the sandwiched,
(2) The first electrode and the second electrode, and the thermosetting adhesive are heated to join the first electrode and the second electrode, and the semiconductor chip and the other semiconductor chip or A step of temporarily bonding the substrate;
(3) starting the pressurization of the obtained temporary adhesive body and bringing it into a pressurized atmosphere;
(4) heating in the pressurized atmosphere and maintaining the temporary adhesive body at a temperature lower than the curing temperature of the thermosetting adhesive;
(5) A method of manufacturing a semiconductor device, comprising: heating the temporary adhesive body to a temperature equal to or higher than a curing temperature of the thermosetting adhesive.