JPWO2019123518A1 - Semiconductor devices, manufacturing methods and adhesives for semiconductor devices - Google Patents

Abstract

The first member having a connecting portion and the second member having a connecting portion are separated from the melting point of the connecting portion of the first member and the melting point of the connecting portion of the second member via a thermosetting adhesive. A step of obtaining a temporary crimping body in which the connecting portion of the first member and the connecting portion of the second member are arranged to face each other by crimping at a low temperature, and a pair of temporary crimping bodies arranged to face each other. A process of obtaining a crimped body by sandwiching it between pressing members and pressurizing it while heating it to a temperature equal to or higher than the melting point of at least one of the connecting portion of the first member or the connecting portion of the second member, and crimping. Disclosed is a method of manufacturing a semiconductor device comprising a step of further heating the body under a pressurized atmosphere. The first member is a semiconductor chip or a semiconductor wafer, and the second member is a wiring circuit board, a semiconductor chip or a semiconductor wafer.

Description

The present invention relates to semiconductor devices, methods for manufacturing semiconductor devices, and adhesives.

Conventionally, a wire bonding method using a fine metal wire such as a gold wire has been widely applied when connecting a semiconductor chip and a substrate.

In recent years, in order to meet the demands for high functionality, high integration, high speed, etc. for semiconductor devices, conductive protrusions called bumps are provided as connecting parts on semiconductor chips or wiring circuit boards, and the semiconductor chips and wiring are made by connecting the connecting parts. A flip-chip connection method (FC connection method) that directly connects a circuit board or another semiconductor chip is widely adopted. For example, the COB (Chip On Board) type connection method, which is a connection between a semiconductor chip and a wiring circuit board, is an FC connection method. The FC connection method is also widely used in a CoC (Chip On Chip) type connection method in which bumps or wirings are provided on semiconductor chips as connection portions and the semiconductor chips are connected to each other.

In the FC connection method, in general, from the viewpoint of reliability of the connection portion, the connection portion of solder, tin, gold, silver, copper or the like is often metal-bonded.

Japanese Unexamined Patent Publication No. 2008-294382

In assembling an FC connection type semiconductor device, generally, first, a semiconductor chip is picked up by a collet from a dicing semiconductor wafer and supplied to a pressing device. The semiconductor chip is then crimped to the wiring circuit board or other semiconductor chip with a pressing device. During crimping, the temperature of the pressing device is raised so that the metal at one or both of these connections reaches above the melting point so that a metal bond is formed. Then, after cooling the high temperature pressing device, the semiconductor chip is supplied to the pressing device again. A semiconductor adhesive may be supplied in advance on the semiconductor chip picked up by the collet, and in that case, in order to continuously manufacture the semiconductor device, the pressing device is pressed from a high temperature at which the metal at the connection portion melts to the semiconductor. It is necessary to cool the semiconductor chip to which the adhesive is supplied to a temperature at which it can be supplied.

Therefore, a semiconductor chip is temporarily crimped to a wiring circuit board or another semiconductor chip at a relatively low temperature with one pressing device, and the obtained temporary crimping body is heated at a high temperature using a pressing device different from the temporary crimping device. By adopting a method in which the semiconductor chip is adhered to the wiring circuit board or another semiconductor chip and an electrically connected connector is obtained by pressurizing while applying pressure, it is not necessary to repeatedly raise and cool the pressing device. It is expected that production efficiency will improve.

However, even such a method is not always sufficient in terms of production efficiency. When a large number of semiconductor devices are continuously manufactured, a large number of pressing devices are required, so that there is a limit to the improvement of production efficiency.

According to the study by the present inventors, a step of temporarily crimping a semiconductor chip to a substrate or another semiconductor chip using the first pressing device at a relatively low temperature, and a second step different from the first pressing device. This includes a step of obtaining a crimped body by pressurizing while heating at a temperature equal to or higher than the melting point of the metal of the connection portion of the semiconductor chip or the substrate using the pressing device of the above, and a step of further heating the crimped body in a heating furnace. Depending on the method, the production efficiency can be further improved. However, in the case of manufacturing a semiconductor device having a particularly high density, thinness, and miniaturization by this method, there is a possibility that a connection failure may occur or voids may remain in the adhesive. It became clear by further examination of the people. Voids can cause reduced reliability, so it is desirable to suppress voids.

Therefore, an object of one aspect of the present invention includes adhering a semiconductor chip or a semiconductor wafer having a connecting portion to another member having a connecting portion via an adhesive and electrically connecting the connecting portions to each other. The present invention relates to a method for manufacturing a semiconductor device, which is to make it possible to efficiently manufacture a large number of semiconductor devices while suppressing the generation of voids in an adhesive and ensuring an appropriate electrical connection.

One aspect of the present invention is to attach a first member having a connecting portion and a second member having a connecting portion to the melting point of the connecting portion of the first member and the first member via a thermosetting adhesive. A step of obtaining a temporary crimping body in which the connecting portion of the first member and the connecting portion of the second member are arranged to face each other by crimping at a temperature lower than the melting point of the connecting portion of the second member. By sandwiching the temporary crimping body between a pair of pressing members arranged so as to face each other, while heating to a temperature equal to or higher than the melting point of at least one of the connecting portion of the first member or the connecting portion of the second member. Provided is a method for manufacturing a semiconductor device, comprising a step of obtaining a crimped body by pressurizing and a step of heating the crimped body in a pressurized atmosphere. The first member may be a semiconductor chip or a semiconductor wafer, and the second member may be a wiring circuit board, a semiconductor chip or a semiconductor wafer.

Here, in the present specification, the step of obtaining a temporary crimping body by crimping the first member and the second member with a thermosetting adhesive may be referred to as a "first crimping step". .. The process of obtaining a crimped body by pressurizing the temporary crimping body while heating it to a temperature equal to or higher than the melting point of at least one of the connecting portion of the first member or the connecting portion of the second member is called a "second crimping step". Sometimes. The step of further heating the crimped body under a pressurized atmosphere is sometimes called a "third crimping step". By combining these three crimping steps, it is possible to efficiently manufacture a large number of semiconductor devices while suppressing the generation of voids in the adhesive and ensuring an appropriate electrical connection.

In the second crimping step of obtaining the crimping body by pressurizing the temporary crimping body while heating, the third crimping step of partially curing the thermosetting adhesive and heating the crimping body in a pressurized atmosphere. In, the thermosetting adhesive may be further cured. In this case, in the second crimping step, the thermosetting adhesive may be cured until the curing reaction rate becomes 30% or less. Further, in the third crimping step, the thermosetting adhesive may be further cured until the curing reaction rate becomes 85% or more.

In the third crimping step of heating the crimped body in a pressurized atmosphere, a plurality of crimped bodies may be heated at once. The heating temperature in the third crimping step may be 130 ° C. or higher and 300 ° C. or lower.

The thermosetting adhesive may contain a thermosetting resin having a weight average molecular weight of less than 10,000, a curing agent of the thermosetting resin, and a polymer component having a weight average molecular weight of 10,000 or more.

Another aspect of the invention relates to thermosetting adhesives used in the methods described above. The minimum melt viscosity of this adhesive may be 3000 Pa · s or less. Further, the thermosetting adhesive may be in the form of a film.

Yet another aspect of the present invention comprises a first member having a connecting portion, a second member having a connecting portion, and an adhesive layer interposed between them, and the connecting portion of the first member. Provided is a semiconductor device in which a second member and a connecting portion of a second member are electrically connected by a metal joint. The adhesive layer may consist of a cured product of a thermosetting adhesive, and the minimum melt viscosity of the thermosetting adhesive may be 3000 Pa · s or less. A semiconductor device in which the first member is a semiconductor chip or a semiconductor wafer and the second member is a wiring circuit board, a semiconductor chip or a semiconductor wafer.

One aspect of the present invention is a semiconductor device including adhering a semiconductor chip or semiconductor wafer having a connecting portion to another member having a connecting portion via an adhesive and electrically connecting the connecting portions to each other. With respect to the method of manufacturing the above, it is possible to efficiently manufacture a large number of semiconductor devices while suppressing the generation of voids in the adhesive and ensuring an appropriate electrical connection.

It is a process drawing which shows one Embodiment of the process of crimping a 1st member and a 2nd member, and obtaining a temporary crimping body. It is a process drawing which shows one Embodiment of the process of heating and pressurizing a temporary crimping body to obtain a crimping body. It is a process drawing which shows one Embodiment of the process of heating a pressure-bonded body in a pressurized atmosphere. It is a schematic cross-sectional view which shows the other embodiment of the semiconductor device. It is a schematic cross-sectional view which shows the other embodiment of the semiconductor device. It is a schematic cross-sectional view which shows the other embodiment of the semiconductor device. It is a schematic cross-sectional view which shows the other embodiment of the semiconductor device.

Hereinafter, some embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

(Manufacturing method of semiconductor device)
1, FIG. 2 and FIG. 3 are process diagrams showing an embodiment of a method for manufacturing a semiconductor device. In the method according to the present embodiment, the first member having a connecting portion and the second member having a connecting portion are connected to each other via a thermosetting adhesive to obtain the melting point of the connecting portion of the first member and the second member. By crimping at a temperature lower than the melting point of the connecting portion of the first member, the first crimping step of obtaining a temporary crimping body in which the connecting portion of the first member and the connecting portion of the second member are arranged to face each other. By sandwiching the temporary crimping body between a pair of pressing members arranged so as to face each other, the temporary crimping body is heated to a temperature equal to or higher than the melting point of at least one of the connecting portion of the first member and the connecting portion of the second member. It includes a second crimping step of obtaining a crimping body by pressing and a third crimping step of heating the crimping body in a pressurized atmosphere.

FIG. 1 shows a first crimping step of crimping a semiconductor chip 1 (first member) and a wiring circuit board 2 (second member) to obtain a temporary crimping body 4. First, as shown in FIG. 1A, a semiconductor chip main body 10 and a semiconductor chip 1 having a bump 30 as a connecting portion are connected to a substrate main body 20 and a wiring circuit board 2 having a wiring 16 as a connecting portion. A thermosetting adhesive layer 40 is placed between them and superposed to form a laminated body 3. After the semiconductor chip 1 is formed by dicing the semiconductor wafer, it is picked up and conveyed onto the wiring circuit board 2, and is aligned so that the bump 30 as a connecting portion and the wiring 16 are arranged so as to face each other. The laminate 3 is formed on the stage 42 of the pressing device 43 having the crimping head 41 and the stage 42 as a pair of temporarily crimping pressing members arranged so as to face each other. The bump 30 is provided on the wiring 15 provided on the semiconductor chip main body 10. The wiring 16 of the wiring circuit board 2 is provided at a predetermined position on the board main body 20. The bump 30 and the wiring 16 each have a surface formed of a metal material.

The thermosetting adhesive layer 40 may be a layer formed by attaching a film-like adhesive prepared in advance to the wiring circuit board 2. The film-like adhesive can be attached by heat pressing, roll laminating, vacuum laminating or the like. The supply area and thickness of the adhesive layer are appropriately set according to the size of the semiconductor chip 1 or the wiring circuit board 2, the height of the connecting portion, and the like. A film-like adhesive may be attached to the semiconductor chip 1. The semiconductor chip 1 to which the film-like adhesive is attached may be produced by attaching the film-like adhesive to the semiconductor wafer and then dicing the semiconductor wafer to separate the semiconductor wafer.

Subsequently, as shown in FIG. 1B, the laminate 3 is heated and pressurized by being sandwiched between the stage 42 as the temporary crimping pressing member and the crimping head 41, whereby the semiconductor chip 1 is heated and pressed. The wiring circuit board 2 is temporarily crimped to obtain a temporary crimping body 4. In the case of the embodiment of FIG. 1, the crimping head 41 is arranged on the semiconductor chip 1 side, and the stage 42 is arranged on the wiring circuit board 2 side. As a temporary crimping pressing device having a stage and a crimping head, a flip chip bonder or the like can be used.

When at least one of the stage 42 and the crimping head 41 heats and pressurizes the laminate 3 for temporary crimping, it serves as the melting point of the bump 30 as the connecting portion of the semiconductor chip 1 and the connecting portion of the wiring circuit board 2. It is heated to a temperature lower than the melting point of the wiring 16. In the present specification, the "melting point of the connecting portion" means the melting point of the metal material forming the surface of the connecting portion.

In the step of obtaining the temporary crimping body, the temporary crimping pressing member is set to a low temperature so that heat is not transferred to the semiconductor chip or the like when the semiconductor chip or the like as the first member is picked up. While heating and pressurizing the laminate for temporary crimping, the temporary crimping pressing member may be heated to a certain high temperature in order to increase the fluidity of the adhesive layer to the extent that the entrained voids can be eliminated. In order to shorten the cooling time, the difference between the temperature of the pressing member when picking up the semiconductor chip or the like and the temperature of the pressing member when heating and pressurizing the laminate to obtain the temporary pressure-bonded body may be small. This temperature difference may be 100 ° C. or lower, or 60 ° C. or lower. This temperature difference may be constant. When the temperature difference is 100 ° C. or lower or 60 ° C. or lower, the time required for cooling the temporary crimping pressing member can be shortened.

The temperature of the temporary crimping pressing member when heating and pressurizing the laminate to obtain the temporary crimping body may be lower than the reaction start temperature of the adhesive layer. The reaction start temperature is obtained when measured using a DSC (DSC-Pyrs1 manufactured by PerkinElmer) under the conditions of an adhesive sample amount of 10 mg, a heating rate of 10 ° C./min, and a measurement atmosphere: air or nitrogen. It refers to the On-set temperature in the DSC thermogram to be measured.

From the above viewpoint, the temperature of the stage 42 and / or the crimping head 41 when heating and pressurizing the laminate to obtain the temporary crimping body is such that the adhesive adheres to the wiring circuit board, the semiconductor wafer, or the like, and the adhesive is used. The temperature can be set so that the curing reaction does not proceed. From this point of view, the temperature of the stage 42 and / or the crimping head 41 when heating and pressurizing the laminate to obtain the temporary crimping body may be 140 ° C. or lower, 110 ° C. or lower, or 80 ° C. or lower. It may be 25 ° C. or higher. Even if the first crimping step is performed at a low temperature in this way, it is possible to obtain a semiconductor device sufficient in terms of void suppression and connection by going through the subsequent second crimping step and the third crimping step. it can.

The pressing load for pressurizing the laminated body 3 to obtain the temporary crimping body 4 is appropriately set in consideration of the number of bumps, absorption of bump height variation, and control of the bump deformation amount. In the temporary crimping body 4, the connecting portion (bump 30) of the semiconductor chip 1 and the connecting portion (wiring 16) of the wiring circuit board 2 may be in contact with each other. As a result, metal bonds are likely to be formed in the subsequent steps, and the adhesive tends to be less bitten. From the viewpoint of sufficiently contacting the connecting portions, the pressing load for pressurizing the laminated body 3 in order to obtain the temporary crimping body 4 is, for example, 0.009 to 0. Per bump 30 of the semiconductor chip 1. It may be 2N.

From the viewpoint of improving productivity, the time for pressurizing the laminated body 3 to obtain the temporary pressure-bonded body 4 may be 5 seconds or less, 3 seconds or less, or 1 second or less, and 0.5 seconds or more. May be good.

FIG. 2 shows a second crimping step of obtaining the crimping body 6 by pressurizing the temporary crimping body 4 while heating. As shown in FIGS. 2A and 2B, a pressing device 46 having a stage 45 and a crimping head 44 arranged to face each other as the main crimping pressing member prepared separately from the pressing device 43 is used. The temporary crimping body 4 is heated and pressurized. The temporary crimping body 4 is heated and pressurized by sandwiching it between the stage 45 and the crimping head 44. In the case of the embodiment of FIG. 2, the crimping head 44 is arranged on the semiconductor chip 1 side of the temporary crimping body 4, and the stage 45 is arranged on the wiring circuit board 2 side of the temporary crimping body 4.

When at least one of the stage 45 or the crimping head 44 heats and pressurizes the temporary crimping body 4, the melting point of the bump 30 as the connecting portion of the semiconductor chip 1 or the wiring 16 as the connecting portion of the wiring circuit board 2 It is heated to a temperature equal to or higher than the melting point of at least one of the melting points.

The oxide film on the surface of the connection portion may be usually removed by the second crimping step. Therefore, the temperature of the stage 45 and / or the crimping head 44 (that is, the heating temperature in the second crimping step) can be set to a temperature higher than the temperature at which the oxide film on the surface of the connecting portion is efficiently removed. From this point of view, the heating temperature in the second crimping step may be 220 ° C. or higher and 330 ° C. or lower. When the metal material of the connecting portion contains solder, if the heating temperature in the second crimping step is 220 ° C. or higher, the solder of the connecting portion is likely to melt and a sufficient metal bond is easily formed. When the temperature is 330 ° C. or lower, voids are less likely to occur and solder is less likely to scatter. The heating temperature of the second crimping step may be 220 ° C. or higher even when the metal material of the connecting portion contains Sn / Ag having a melting point of about 220 ° C.

The pressing load in the second crimping step is appropriately set in consideration of removal of the oxide film on the surface of the connecting portion, the number of bumps, absorption of bump height variation, control of the bump deformation amount, and the like. When the pressing load is large, the oxide film tends to be easily removed. The pressing load may be, for example, 0.009 to 0.2 N per connection portion (bump) of the semiconductor chip. When this pressing load is 0.009 N or more, the oxide film formed on the connecting portion is easily removed, and the adhesive is less likely to be trapped on the connecting portion. Further, when the pressing load is 0.2 N or less, problems such as bumps containing solder and the like being crushed or scattered are unlikely to occur.

The adhesive may be partially cured by the second crimping step to the extent that it has some fluidity in the third crimping step of heating the crimping body in a pressurized atmosphere. By allowing the adhesive to flow in contact with the adhesive in the third crimping step, the residual voids in the adhesive layer can be further suppressed. Further, by limiting the heat history applied to the adhesive in the second crimping step to such that the curing reaction rate remains small, the fillet around the connection portion can be suppressed. From these viewpoints, the curing reaction rate of the adhesive after the second crimping step may be 50% or less, 30% or less, 27% or less, or 25% or less.

The curing reaction rate of the adhesive after the second crimping step is determined based on the change in calorific value due to the curing reaction, which is measured by differential scanning calorimetry. The calorific value ΔH (J / g) due to the curing reaction of the adhesive before the first crimping step is set to “ΔH0”, and the calorific value ΔH (J / g) due to the curing reaction after the second crimping step is set to “ΔH2”. , The curing reaction rate after the second crimping step can be calculated by the following formula. Here, the curing reaction rate of the adhesive used in the first crimping step is regarded as 0%.
Curing reaction rate (%) after the second crimping step = (ΔH0-ΔH2) / ΔH0 × 100
The differential scanning calorimetry for measuring the calorific value due to the curing reaction can be performed at a heating rate of 20 ° C./min and in a temperature range of 30 to 300 ° C. Instead of the actual crimping process, a hot plate, an oven, or the like is used, and the curing reaction rate is measured using an adhesive after applying a thermal history under the same conditions as the first crimping step and the first crimping step. Therefore, the curing reaction rate after the second crimping step can be estimated.

The curing reaction rate after the second crimping step can be adjusted mainly based on the heating and pressurizing times. For example, if the heating and pressurizing time in the second crimping step is 3 seconds or less, or 1 second or less, the curing reaction rate becomes, for example, 50% or less, 30% or less, 27% or less, or 25% or less. The adhesive can be cured up to.

The temporary crimping pressing member and the crimping pressing member may be installed in two or more separate devices, respectively, or both may be installed in one device.

Subsequently, as shown in FIG. 3, the semiconductor device 100 is obtained through a third crimping step in which the crimping body 6 is heated in a pressurized atmosphere in the heating furnace 60. A plurality of pressure-bonded bodies 6 can be collectively heated in one heating furnace 60. When a plurality of crimped bodies are collectively pressurized by using a pressing member, it is difficult to uniformly heat the plurality of crimped bodies. On the other hand, in the heating furnace, a large number of pressure-bonded bodies can be easily and uniformly heated, which improves productivity. As the heating furnace, a reflow furnace, a pressurized oven, or the like can be used.

When the pressure-bonded body is heated in a pressurized atmosphere, the fillet tends to be suppressed as compared with the case where the pressure-bonded body is heated and pressurized using the pressing member. Fillet suppression is particularly important in the manufacture of miniaturized and high density semiconductor devices. Here, the fillet suppression means that the fillet width is suppressed to be small, and the fillet width is the length of the adhesive protruding from the outer peripheral portion of the semiconductor device. The fillet width can be measured, for example, by taking an external image of a semiconductor device with a digital microscope (manufactured by KEYENCE, VHX-5000) and measuring the obtained image. The length (fillet width) of the adhesive layer protruding from the four peripheral sides of the semiconductor chip is measured, and the average value thereof is obtained as the fillet value. The fillet value may be 150 μm or less from the viewpoint of mounting many semiconductor chips or the like on a semiconductor wafer or a wiring circuit board or the like.

The pressure-bonded body is heated in a state where the inside of the heating furnace 60 is in a pressurized atmosphere. In the present specification, "pressurized atmosphere" means a gaseous atmosphere having a pressure equal to or higher than atmospheric pressure. The air pressure in the heating furnace 60 may be 0.1 MPa or more and 0.8 MPa or less, or 0.2 MPa or more and 0.5 MPa or less. When the air pressure is 0.1 MPa or more, the voids disappear particularly effectively. When the atmospheric pressure is 0.8 MPa or less, problems such as a large warp of the semiconductor device are unlikely to occur.

The heating temperature (atmospheric temperature in the heating furnace 60) in the third crimping step may be a temperature at which the adhesive melts or a temperature equal to or higher than the glass transition temperature (Tg) of the adhesive, and the adhesive is cured. It may be the temperature at which The ambient temperature in the heating furnace 60 may be, for example, 130 ° C. or higher and 300 ° C. or lower, or 140 ° C. or higher and 270 ° C. or lower. When this temperature is 130 ° C. or higher, the adhesive tends to be appropriately cured while having some fluidity, and voids tend to be suppressed particularly effectively by pressurization. When the temperature is 300 ° C. or lower, voids are particularly suppressed and the semiconductor device is less likely to warp. When raising the temperature of the atmosphere in the heating furnace 60 as described later, the maximum temperature reached may be within the above range.

The heating and pressurizing times in the third crimping step are set so that the curing of the adhesive proceeds sufficiently. For example, the time during which the ambient temperature in the heating furnace 60 is 130 ° C. or higher and 300 ° C. or lower may be 1 minute or longer and 120 minutes or shorter, or 5 minutes or longer and 60 minutes or shorter.

The atmosphere in the heating furnace 60 may be heated during the third crimping step. In that case, the heating rate is not particularly limited, but may be 5 ° C./min or more and 300 ° C./min or less, or 10 ° C./min or more and 250 ° C./min or less. When the heating rate is 5 ° C./min or higher, the productivity is improved and the voids tend to disappear particularly effectively. When the rate of temperature rise is 300 ° C./min or less, problems such as void generation due to rapid temperature rise are unlikely to occur.

A connector in which the adhesive is further cured by the third crimping step, and the semiconductor chip 1 (first member) and the wiring circuit board 2 (second member) are firmly adhered by the cured adhesive layer 40. (Semiconductor device 100) can be formed. The curing reaction rate of the adhesive after the third crimping step may be 80% or more, 85% or more, or 90% or more. When the curing reaction rate of the adhesive after the third crimping step is 80% or more, the generation of voids due to springback or the like can be more effectively suppressed.

The curing reaction rate of the adhesive after the third crimping step is also determined based on the change in calorific value due to the curing reaction, which is measured by differential scanning calorimetry. The calorific value ΔH (J / g) due to the curing reaction of the adhesive before the first crimping step is set to “ΔH0”, and the calorific value ΔH (J / g) due to the curing reaction after the third crimping step is set to “ΔH3”. , The curing reaction rate after the second crimping step can be calculated by the following formula.
Curing reaction rate (%) after the third crimping step = (ΔH0-ΔH3) / ΔH0 × 100
The conditions for measuring the differential scanning calorimetry are the same as the method for determining the curing reaction rate after the second crimping step.

The atmosphere in the heating furnace 60 is not particularly limited, but may be air, nitrogen, formic acid, or the like.

From the viewpoint of improving productivity, a semiconductor wafer may be used as at least one of the first member and the second member. Examples thereof include CoW (Chip On Wafer) in which a semiconductor chip is connected to a semiconductor wafer and then individualized, and WoW (Wafer On Wafer) in which semiconductor wafers are crimped and then individualized.

(Semiconductor device)
4, FIG. 5, FIG. 6 and FIG. 7 are cross-sectional views showing another embodiment of the semiconductor device that can be manufactured by the method according to the above-described embodiment, respectively.

In the semiconductor device 200 shown in FIG. 4, the semiconductor chip 1 (first member) having the semiconductor chip body 10 and the wiring circuit board 2 (second member) having the substrate body 20 are bonded to each other. The agent layer 40 is provided. In the case of the semiconductor device 200, the semiconductor chip has bumps 32 arranged on the surface of the semiconductor chip on the wiring circuit board 2 side as a connecting portion. The wiring circuit board 2 has bumps 33 arranged on the surface of the board body 20 on the semiconductor chip side as connecting portions. The bump 32 of the semiconductor chip 1 and the bump 33 of the wiring circuit board 2 are electrically connected by metal bonding. That is, the semiconductor chip 1 and the wiring circuit board 2 are flip-chip connected by bumps 32 and 33. The bumps 32 and 33 are shielded from the external environment by being sealed by the adhesive layer 40.

5 and 6 show a CoC type semiconductor device which is a connector in which semiconductor chips are connected to each other. The configuration of the semiconductor device 300 shown in FIG. 5 is the same as that of the semiconductor device 100, except that the two semiconductor chips are flip-chip-connected as the first member and the second member via the wiring 15 and the bump 30. Is. The configuration of the semiconductor device 400 shown in FIG. 6 is the same as that of the semiconductor device 200, except that the two semiconductor chips 1 are flip-chip connected via the bumps 32.

In the semiconductor devices 100, 200, 300, and 400 shown in FIGS. 3 to 6, the connection portion of the wiring 15, bump 32, etc. may be a metal film (for example, gold-plated) called a pad, and is a post electrode. It may be (for example, a copper pillar). For example, in FIG. 2B, even if one semiconductor chip has a copper pillar and a connection bump (solder: tin-silver) as a connection portion and the other semiconductor chip has gold plating as a connection portion. Good. In this case, the temperature of the connecting portion may reach a temperature equal to or higher than the melting point of the solder having the lowest melting point among the metal materials forming the surface of the connecting portion.

The semiconductor chip main body 10 is not particularly limited, and various semiconductors such as elemental semiconductors composed of elements of the same type such as silicon and germanium, and compound semiconductors such as gallium arsenide and indium phosphorus can be used.

The wiring circuit board 2 is not particularly limited, and has an insulating substrate mainly composed of glass epoxy, polyimide, polyester, ceramic, epoxy, bismaleimide triazine, etc. as the substrate main body, and a metal layer formed on the surface thereof. Circuit board on which wiring (wiring pattern) is formed by removing unnecessary parts by etching, circuit board on which wiring (wiring pattern) is formed by metal plating or the like on the surface of the insulating substrate, conductivity on the surface of the insulating substrate A circuit board or the like on which a material is printed and wiring (wiring pattern) is formed can be used.

The main components of the connecting parts of the wirings 15 and 16, bumps 30, bumps 32 and 33, etc. are gold, silver, copper and solder (main components are, for example, tin-silver, tin-lead, tin-bismuth). , Tin-copper, tin-silver-copper), tin, nickel and the like are used. The connecting portion may be composed of only a single component, or may be composed of a plurality of components. The connecting portion may have a structure in which these metals are laminated. Of the metal materials, copper and solder are relatively inexpensive. From the viewpoint of improving connection reliability and suppressing warpage, the connection portion may contain solder.

Pad materials include gold, silver, copper, solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper, tin-silver-copper), tin, and nickel. Etc. are used. The pad may be composed of only a single component, or may be composed of a plurality of components. The pad may have a structure in which these metals are laminated. From the viewpoint of connection reliability, the pad may contain gold or solder.

The surfaces of wirings 15 and 16 (wiring patterns) are mainly composed of gold, silver, copper, solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper), tin, nickel, etc. A metal layer as a component may be formed. This metal layer may be composed of only a single component, or may be composed of a plurality of components. The metal layer may have a structure in which a plurality of metal layers are laminated. The metal layer may contain relatively inexpensive copper or solder. From the viewpoint of improving connection reliability and suppressing warpage, the metal layer may contain solder.

Semiconductor devices (packages) such as semiconductor devices 100, 200, 300, 400 are laminated to form gold, silver, copper, and solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, tin- Copper, tin-silver-copper), tin, nickel, etc. may be electrically connected. The metal for connection may be relatively inexpensive copper or solder. For example, as seen in TSV technology, an adhesive layer may be flip-chip connected or laminated between semiconductor chips to form holes penetrating the semiconductor chips and connected to electrodes on a patterned surface.

FIG. 7 is a cross-sectional view showing another embodiment of the semiconductor device. The semiconductor device 500 shown in FIG. 7 has a TSV structure in which a plurality of semiconductor chips are laminated. In the semiconductor device 500 shown in FIG. 7, the wiring 15 formed on the interposer main body 50 as a wiring circuit board is connected to the bump 30 of the semiconductor chip 1, so that the semiconductor chip 1 and the interposer 5 are flip-chips. It is connected. An adhesive layer 40 is interposed between the semiconductor chip 1 and the interposer 5. The semiconductor chip 1 is repeatedly laminated on the surface of the semiconductor chip 1 opposite to the interposer 5 via the wiring 15, the bump 30, and the adhesive layer 40. The wiring 15 on the pattern surface on the front and back of the semiconductor chip 1 is connected to each other by a through electrode 34 filled in a hole penetrating the inside of the semiconductor chip main body 10. As the material of the through electrode 34, copper, aluminum, or the like can be used.

According to the semiconductor device having a TSV (Through-Silicon Via) structure as illustrated in FIG. 7, a signal can be acquired from the back surface of a semiconductor chip that is not normally used. Further, since the through electrode 34 is passed vertically through the semiconductor chip 1, the distance between the opposing semiconductor chips 1 and between the semiconductor chip 1 and the interposer 5 can be shortened, and flexible connection is possible.

In the case of the semiconductor device 500 of FIG. 7, a plurality of semiconductor chips 1 are stacked one by one and temporarily crimped in sequence, then a crimped body is obtained by a second crimping step, and finally, a plurality of semiconductor chips are collectively pressed. It may be heated in an atmosphere.

As another example of a semiconductor device having a multi-layer semiconductor chip, there is also a chip stack type package, POP (Package On Package), which can also be manufactured by the same method as TSV.

These are also effective in reducing the mounting area, increasing functionality, reducing noise, and saving power by further reducing the size and thickness of the semiconductor device.

(adhesive)
Hereinafter, an adhesive (thermosetting adhesive) that can be used in the above-mentioned method for manufacturing a semiconductor device will be described.

The adhesive according to one embodiment contains a thermosetting resin and a curing agent thereof. The adhesive may further contain a polymer component having a weight average molecular weight of 10,000 or more.

<Thermosetting resin>
The weight average molecular weight of the thermosetting resin may be less than 10,000. When a thermosetting resin having a weight average molecular weight of less than 10,000 reacts with a curing agent, the curability of the adhesive is improved. It is also advantageous in terms of suppressing voids and heat resistance.

Examples of the thermosetting resin include an epoxy resin and an acrylic resin.

The epoxy resin is not particularly limited as long as it has two or more epoxy groups in the molecule. As the epoxy resin, bisphenol A type, bisphenol F type, naphthalene type, phenol novolac type, cresol novolac type, phenol aralkyl type, biphenyl type, triphenylmethane type, dicyclopentadiene type, various polyfunctional epoxy resins and the like should be used. Can be done. These can be used alone or as a mixture of two or more kinds.

The acrylic resin is not particularly limited as long as it has one or more (meth) acrylic groups in the molecule. Acrylic resins include, for example, bisphenol A type, bisphenol F type, naphthalene type, phenol novolac type, cresol novolac type, phenol aralkyl type, biphenyl type, triphenylmethane type, dicyclopentadiene type, fluorene type, adamantan type, and many others. A functional acrylic resin or the like can be used. These can be used alone or as a mixture of two or more kinds. In the present specification, "(meth) acrylic group" is used as a term meaning either an acrylic group or a methacrylic group.

The acrylic resin may be solid at room temperature (25 ° C.). Solids are less likely to generate voids than liquids, and the viscosity (tack) of the B-stage adhesive before curing tends to be small, making it easier to handle.

The number of (meth) acrylic groups contained in the acrylic resin may be 3 or less per molecule. When the number of (meth) acrylic groups is 3 or less, curing tends to proceed sufficiently in a short time until the remaining unreacted groups are reduced.

The content of the thermosetting resin in the adhesive is, for example, 10 to 50 parts by mass with respect to 100 parts by mass of the total mass (mass of components other than the solvent) of the adhesive. When the content of the thermosetting resin is 10 parts by mass or more, the flow of the adhesive after curing tends to be easily controlled. When the content of the thermosetting resin is 50 parts by mass or less, the warp of the semiconductor device tends to be suppressed.

<Hardener>
The curing agent can be a compound that reacts with the thermosetting resin, a compound that functions as a catalyst for the curing reaction of the thermosetting resin, or a combination thereof. Examples of the curing agent include phenol resin-based curing agents, acid anhydride-based curing agents, amine-based curing agents, imidazole-based curing agents, phosphine-based curing agents, azo compounds, and organic peroxides. Among these, an imidazole-based curing agent may be used.

The phenolic resin-based curing agent is not particularly limited as long as it has two or more phenolic hydroxyl groups in the molecule. Examples thereof include phenol novolac, cresol novolac, phenol aralkyl resin, and cresolnaphthol formaldehyde polycondensate. Examples thereof include triphenylmethane type polyfunctional phenol and various polyfunctional phenol resins. These can be used alone or as a mixture of two or more.

The equivalent ratio (phenolic hydroxyl group / epoxy group, molar ratio) of the phenolic resin-based curing agent to the thermosetting resin is 0.3 to 1.5, 0 from the viewpoint of good curability, adhesiveness and storage stability. .4 to 1.0, or 0.5 to 1.0. When the equivalent ratio is 0.3 or more, the curability tends to be improved and the adhesive strength tends to be improved, and when it is 1.5 or less, unreacted phenolic hydroxyl groups do not remain excessively and the water absorption rate is high. It is kept low and tends to improve insulation reliability.

Examples of the acid anhydride-based curing agent include methylcyclohexanetetracarboxylic acid dianhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic acid dianhydride, and ethylene glycol bisamhydrotrimellitic acid. These can be used alone or as a mixture of two or more.

The equivalent ratio (acid anhydride group / epoxy group, molar ratio) of the acid anhydride-based curing agent to the thermosetting resin is 0.3 to 1.5 from the viewpoint of good curability, adhesiveness and storage stability. , 0.4 to 1.0, or 0.5 to 1.0. When the equivalent ratio is 0.3 or more, the curability tends to be improved and the adhesive strength tends to be improved, and when it is 1.5 or less, unreacted acid anhydride does not remain excessively and the water absorption rate is high. It is kept low and tends to improve insulation reliability.

As the amine-based curing agent, for example, dicyandiamide can be used.

The equivalent ratio (amine / epoxy group, molar ratio) of the amine-based curing agent to the thermosetting resin is 0.3 to 1.5, 0.4 to 1 from the viewpoint of good curability, adhesiveness and storage stability. It may be 0.0 or 0.5 to 1.0. When the equivalent ratio is 0.3 or more, the curability tends to be improved and the adhesive strength tends to be improved, and when it is 1.5 or less, unreacted amine does not remain excessively and the insulation reliability is improved. Tend to do.

Examples of the imidazole-based curing agent include 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole. , 1-Cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimerite, 1-cyanoethyl-2-phenylimidazolium trimerite, 2,4-diamino-6- [2'-methylimidazolyl -(1')]-Ethyl-s-triazine, 2,4-diamino-6- [2'-undecylimidazolyl- (1')]-ethyl-s-triazine, 2,4-diamino-6- [ 2'-Ethyl-4'-methylimidazolyl- (1')] -ethyl-s-triazine, 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s-triazine isocyanul Acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and adducts of epoxy resin and imidazoles Can be mentioned. From the viewpoint of excellent curability, storage stability and connection reliability, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1- Cyanoethyl-2-phenylimidazolium trimeritate, 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s-triazine, 2,4-diamino-6- [2'- Ethyl-4'-methylimidazolyl- (1')] -ethyl-s-triazine, 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s-triazine isocyanuric acid adduct , 2-Phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole and 2-phenyl-4-methyl-5-hydroxymethylimidazole may be selected from imidazole-based curing agents. These can be used alone or in combination of two or more. Microcapsules containing these can also be used as a latent curing agent.

The content of the imidazole-based curing agent may be 0.1 to 20 parts by mass or 0.1 to 10 parts by mass with respect to 100 parts by mass of the thermosetting resin. When the content of the imidazole-based curing agent is 0.1 parts by mass or more, the curability tends to be improved, and when it is 20 parts by mass or less, the adhesive does not cure before the metal bond is formed. Poor connection tends to be less likely to occur.

Examples of the phosphine-based curing agent include triphenylphosphine, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra (4-methylphenyl) borate and tetraphenylphosphonium (4-fluorophenyl) borate.

The content of the phosphine-based curing agent may be 0.1 to 10 parts by mass or 0.1 to 5 parts by mass with respect to 100 parts by mass of the thermosetting resin. When the content of the phosphine-based curing agent is 0.1 parts by mass or more, the curability tends to be improved, and when it is 10 parts by mass or less, the adhesive does not cure before the metal bond is formed. Poor connection tends to be less likely to occur.

The phenolic resin-based curing agent, the acid anhydride-based curing agent, and the amine-based curing agent can be used alone or as a mixture of two or more. The imidazole-based curing agent and the phosphine-based curing agent may be used alone, or may be used together with a phenol resin-based curing agent, an acid anhydride-based curing agent, or an amine-based curing agent.

Examples of the organic peroxide include ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxydicarbonates, peroxyesters and the like. From the viewpoint of storage stability, hydroperoxide, dialkyl peroxide, or peroxy ester may be selected. Further, from the viewpoint of heat resistance, hydroperoxide or dialkyl peroxide may be selected. These can be used alone or as a mixture of two or more kinds.

The content of the organic peroxide may be 0.5 to 10% by mass or 1 to 5% by mass with respect to the acrylic resin. When the content of the organic peroxide is 0.5% by mass or more, the curing tends to proceed sufficiently. When the content of the organic peroxide is 10% by mass or less, there is a tendency that the decrease in reliability due to the shortening of the molecular chain after curing and the remaining unreacted groups can be suppressed.

The curing agent combined with the epoxy resin or the acrylic resin is not particularly limited as long as the curing progresses. The curing agent combined with the epoxy resin is a combination of a phenol resin-based curing agent and an imidazole-based curing agent, a combination of an acid anhydride-based curing agent and an imidazole-based curing agent, and an amine from the viewpoints of handleability, storage stability, and curability. The combination of the system curing agent and the imidazole system curing agent, or the imidazole system curing agent alone may be used. Since productivity is improved when the connection is made in a short time, an imidazole-based curing agent having excellent quick curing property may be used alone. Since volatile components such as low molecular weight components can be suppressed by curing in a short time, it is possible to suppress the generation of voids. The curing agent combined with the acrylic resin may be an organic peroxide from the viewpoint of handleability and storage stability.

<Polymer component with a weight average molecular weight of 10,000 or more>
The polymer component having a weight average molecular weight of 10,000 or more can be a thermosetting resin, a thermoplastic resin, or a combination thereof. Examples of polymer components include epoxy resin, phenoxy resin, polyimide resin, polyamide resin, polycarbodiimide resin, cyanate ester resin, acrylic resin, polyester resin, polyethylene resin, polyether sulfone resin, polyetherimide resin, and polyvinyl acetal resin. , Urethane resin, acrylic rubber and the like. Epoxy resin, phenoxy resin, polyimide resin, acrylic resin, acrylic rubber, cyanate ester resin, or polycarbodiimide resin having excellent heat resistance and film forming property may be selected. Epoxy resin, phenoxy resin, polyimide resin, acrylic resin, or acrylic rubber having excellent heat resistance and film forming property may be selected. These polymer components can also be used alone or as a mixture of two or more kinds or a copolymer. The polymer component having a weight average molecular weight of 10,000 or more may be a thermosetting resin that reacts with a curing agent.

The mass ratio of the polymer component to the epoxy resin as the thermosetting resin described above is not particularly limited. The mass ratio of the epoxy resin to the polymer component may be 0.01-5, 0.05-4, or 0.1-3 in order for the adhesive to retain its film-like form. When this mass ratio is 0.01 or more, the curability tends to be improved and the adhesive strength tends to be further improved. When this mass ratio is 5 or less, good film formability can be easily obtained.

The mass ratio of the polymer component to the acrylic resin as the thermosetting resin described above is not particularly limited. The mass ratio of the acrylic resin to the polymer component may be 0.01 to 10, 0.05 to 5, or 0.1 to 5. When this mass ratio is 0.01 or more, the curability tends to be improved and the adhesive strength tends to be further improved. When this mass ratio is 10 or less, good film formability can be easily obtained.

The glass transition temperature (Tg) of the polymer component may be 50 ° C. or higher and 200 ° C. or lower from the viewpoint of excellent adhesion of the adhesive to the wiring circuit board or the semiconductor chip. When the Tg of the polymer component is 50 ° C. or higher, the tack (viscous) force of the adhesive tends to be moderately weakened. When the Tg of the polymer component is 200 ° C. or lower, the adhesive easily embeds irregularities such as bumps of semiconductor chips, electrodes formed on the wiring circuit board, and wiring patterns, and the effect of suppressing voids tends to be relatively large. There is. The Tg here is measured using a DSC (manufactured by PerkinElmer Co., Ltd., DSC-7 type) under the conditions of a sample amount of 10 mg, a heating rate of 10 ° C./min, and an air atmosphere.

The weight average molecular weight of the polymer component is 10,000 or more. In order to exhibit good film forming property by itself, the weight average molecular weight of the polymer component may be 30,000 or more, 40,000 or more, or 50,000 or more, or 500,000 or less. As used herein, the weight average molecular weight means a standard polystyrene-equivalent value measured by gel permeation chromatography (GPC).

The adhesive can contain a flux activator, which is a compound exhibiting flux activity (activity to remove oxides and impurities). Examples of the flux activator include nitrogen-containing compounds having an unshared electron pair such as imidazoles and amines, carboxylic acids, phenols and alcohols. Organic acids express flux activity more strongly than alcohols and the like, and improve connectivity.

The organic acid that can be used as the flux activator may be a carboxylic acid because the acid does not easily remain in the adhesive by reacting with an epoxy resin or the like. The carboxylic acid may be solid from the viewpoint of heat resistance. The melting point of the carboxylic acid may be 70 ° C. or higher and 150 ° C. or lower from the viewpoint of stability and handleability.

Even if the adhesive contains a filler in order to control the viscosity and physical properties of the cured product, and to suppress the generation of voids and the moisture absorption rate when the semiconductor chips are connected to each other or the semiconductor chips are connected to the wiring circuit board. Good. The filler may be an insulating inorganic filler, and examples thereof include glass, silica, alumina, titanium oxide, carbon black, mica, and boron nitride. Among these, a filler selected from silica, alumina, titanium oxide, and boron nitride, or silica, alumina, and boron nitride may be used. The filler may be a whisker, and examples thereof include aluminum borate, aluminum titanate, zinc oxide, calcium silicate, magnesium sulfate, and boron nitride. The filler may be a resin filler, and examples thereof include polyurethane, polyimide, methyl methacrylate resin, and methyl methacrylate-butadiene-styrene copolymer resin (MBS). These fillers can also be used alone or in combination of two or more. The shape, particle size, and content of the filler are not particularly limited.

Compared with the inorganic filler, the resin filler can impart flexibility at a high temperature such as 260 ° C., and is therefore suitable for improving the reflow resistance. The resin filler is also advantageous in terms of improving film formability.

From the viewpoint of insulation reliability, the filler may be insulating. The adhesive may not substantially contain a conductive metal filler such as a silver filler or a solder filler.

From the viewpoint of improving dispersibility and adhesive strength, the filler may be surface-treated. The filler is surface-treated with, for example, a glycidyl-based (epoxy-based), amine-based, phenyl-based, phenylamino-based, (meth) acrylic-based, or vinyl-based surface treatment agent. From the viewpoint of dispersibility, fluidity, and adhesive strength, the filler may be surface-treated with a glycidyl-based, phenylamino-based, or (meth) acrylic-based surface treatment agent. From the viewpoint of storage stability, the surface treatment agent may be phenyl-based, acrylic-based, or (meth) acrylic-based. From the viewpoint of ease of surface treatment, the surface treatment agent may be a silane compound such as an epoxy silane type, an amino silane type, or an acrylic silane type.

The average particle size of the filler may be 1.5 μm or less from the viewpoint of preventing biting when the flip chip is connected, and may be 1.0 μm or less from the viewpoint of visibility and transparency.

The content of the filler may be 30 to 90% by mass or 40 to 80% by mass based on the solid content mass (mass of the component other than the solvent) of the adhesive. When the content of the filler is 30% by mass or more, the heat dissipation property is high, and the void generation and the hygroscopicity tend to be small. When the content of the filler is 90% by mass or less, the adhesive has an appropriate fluidity and tends to suppress a decrease in connection reliability due to trapping of the filler in the connecting portion.

The adhesive may further contain other components such as ion trappers, antioxidants, silane coupling agents, titanium coupling agents, and leveling agents. These may be used individually by 1 type, and may be used in combination of 2 or more type. The blending amount of these may be appropriately adjusted so that the effect of each additive is exhibited.

The minimum melt viscosity of the adhesive may be 3000 Pa · s or less, 2700 Pa · s or less, or 300 Pa · s or more from the viewpoint of suppressing voids. The minimum melt viscosity of the adhesive is the viscosity (complex viscosity) obtained when the viscoelasticity of the adhesive is measured in the temperature range of 30 to 300 ° C. under the conditions of a heating rate of 10 ° C./min, a frequency of 10 Hz, and a rotation mode. ) And the temperature, which is the lowest viscosity value. As a test piece for measuring viscoelasticity, for example, a laminate obtained by laminating a plurality of film-shaped adhesives so as to have a thickness of 300 to 450 μm may be used. As the viscosity measuring device, for example, ARES G2 manufactured by TA can be used.

The adhesive may be in the form of a film from the viewpoint of improving the production efficiency of the semiconductor device. The film-like adhesive can be produced by applying a resin varnish containing a thermosetting resin, a curing agent, and if necessary, other components to the equipment film, and drying the coating film.

The resin varnish is prepared by mixing a thermosetting resin curing agent and, if necessary, other components with an organic solvent, and dissolving or dispersing them by stirring or kneading. The resin varnish is applied onto the release-treated base film using, for example, a knife coater, a roll coater, an applicator, a die coater, or a comma coater. Then, the organic solvent is reduced from the coating film of the resin varnish by heating, that is, the coating film is dried to form a film-like adhesive on the base film. A film of resin varnish may be formed on a semiconductor wafer or the like by a method such as spin coating, and then a film-like adhesive may be formed on the semiconductor wafer by a method of drying the coating film.

The base film is not particularly limited as long as it has heat resistance that can withstand the heating conditions when the organic solvent is volatilized, and is a polyester film, polypropylene film, polyethylene terephthalate film, polyimide film, polyetherimide film, poly. Examples thereof include ether naphthalate film and methylpentene film. The base film is not limited to a single-layer film made of these films, and may be a multilayer film made of two or more kinds of materials.

Specifically, the conditions for volatilizing the organic solvent from the resin varnish after coating may be heating at 50 to 200 ° C. for 0.1 to 90 minutes. The organic solvent may be removed until the residual amount is 1.5% by mass or less as long as it does not substantially affect the void and viscosity preparation after mounting.

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

Examination 1
(1-1) Film-shaped Adhesive A film-shaped adhesive (thickness 0.045 mm) having the composition shown in Table 1 was prepared using the materials shown below.
(I) Thermosetting resin (epoxy resin) with a weight average molecular weight of less than 10,000
-Triphenol methane skeleton-containing polyfunctional solid epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name: EP1032H60, weight average molecular weight: 800 to 2000)
-Bisphenol F type liquid epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name: YL983U, weight average molecular weight: about 336)
-Flexible semi-solid epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name: YL7175-1000, weight average molecular weight: 1000 to 5000)
(Ii) Hardener, 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s-trichloroisocyanuric acid adduct (manufactured by Shikoku Chemicals Corporation, product name: 2MAOK-PW) )
(Iii) Polymer component / phenoxy resin having a weight average molecular weight of 10,000 or more (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., product name: ZX1356-2, Tg: about 71 ° C., weight average molecular weight: about 63000, hereinafter referred to as "ZX1356")
(Iv) Flux agent (carboxylic acid)
-2-Methylglutaric acid (manufactured by Sigma-Aldrich, melting point about 77 ° C)
(V) Phila (inorganic filler)
・ Silica filler (manufactured by Admatex Co., Ltd., product name: SE2050, average particle size 0.5 μm)
-Finyl surface-treated nanosilica filler (manufactured by Admatex Co., Ltd., product name: YA050C-SP (hereinafter referred to as "SP nanosilica"), average particle size of about 50 nm)
(Resin filler)
-Organic filler (manufactured by Dow Chemical Japan Co., Ltd., product name: EXL-2655, core-shell type organic fine particles)

(1-2) Fabrication of Semiconductor Device (Example 1)
First Crimping Step The produced film-like adhesive was cut out, and a film-like adhesive having a size of 8 mm × 8 mm × thickness 0.045 mm was prepared. This was attached to a semiconductor chip (10 mm, thickness 0.1 mm, connection metal: Au, product name: WALTS-TEG IP80, manufactured by WALTS). There, a semiconductor chip with solder bumps (chip size: 7.3 mm x 7.3 mm x thickness 0.05 mm, solder bump melting point: about 220 ° C, bump height: total of about 45 μm of copper pillar and solder, number of bumps 1048 Pins, pitch 80um, product name: WALTS-TEG CC80, manufactured by WALTS) were attached to obtain a laminate. The laminate is installed on the stage of a flip-chip bonder (FCB3, manufactured by Panasonic Corporation) having a stage and a crimping head, and the laminate is pressed with a load of 25 N for 1 second by a heat press sandwiched between the stage and the crimping head. While heating to 80 ° C., a temporary crimped body was obtained.

Second crimping step The obtained temporary crimping body is moved onto the stage of another flip-chip bonder (FCB3, manufactured by Panasonic Corporation) and sandwiched between the stage and the crimping head to pressurize with a load of 25N. A crimped body was obtained by hot pressing, which was heated at ° C. for 1 second.

Third crimping step The crimping body was installed in the oven of a pressure reflow device (manufactured by Shinapex, product name: VSU28). The pressure in the oven was set to 0.4 MPa, and the temperature was raised from room temperature to 175 ° C. at a heating rate of 20 ° C./min. Next, the pressure-bonded body was heated for 10 minutes in a pressurized atmosphere while maintaining the pressure and temperature to obtain a semiconductor device sample for evaluation.

(Example 2)
A semiconductor device sample for evaluation was obtained in the same manner as in Example 1 except that the heating temperature when the crimped body was heated in the oven of the pressure reflow device was changed from 175 ° C. to 260 ° C.

(Comparative Example 1)
A temporary pressure-bonded body was obtained in the same manner as in Example 1. The obtained temporary pressure-bonded body was heated in an oven device (manufactured by Yamato Scientific Co., Ltd., product name: DKN402) at 175 ° C. for 10 minutes under atmospheric pressure to obtain a semiconductor device sample for evaluation.

(Comparative Example 2)
A semiconductor device sample for evaluation was obtained in the same manner as in Comparative Example 1 except that the heating temperature when heating the temporary pressure-bonded body under atmospheric pressure was changed from 175 ° C. to 260 ° C.

(Comparative Example 3)
A crimped body was obtained under the same conditions as in Example 1. The obtained crimped body was heated in an oven device (manufactured by Yamato Scientific Co., Ltd., product name: DKN402) at 175 ° C. for 10 minutes under atmospheric pressure to obtain a semiconductor device sample for evaluation.

(Comparative Example 4)
A semiconductor device sample for evaluation was obtained in the same manner as in Comparative Example 3 except that the heating temperature when heating the crimped body using the oven device was changed from 175 ° C. to 260 ° C.

(1-3) Connection Evaluation A multimeter (manufactured by ADVANTEST, product name: R6781E) was used to measure the possibility of initial continuity of the sample. The connectivity was judged according to the following criteria. The results are shown in Table 2.
A: The initial connection resistance value of the peripheral part is 30Ω or more and 35Ω or less B: The initial connection resistance value is less than 30Ω, exceeds 35Ω, or is not connected.

(1-4) Void evaluation An external image of a sample was taken with an ultrasonic image diagnostic device (product name: Insight-300, manufactured by Insight). From the obtained image, a portion of the adhesive layer on the chip was captured by a scanner (product name: GT-9300UF, manufactured by Seiko Epson Corporation). Using the image processing software Adobe Photoshop, the void portion was identified by color tone correction and bigradation, and the area occupied by the void portion (void generation rate) was calculated from the histogram with the area of the adhesive layer as 100%. The state of void generation was evaluated according to the following criteria. The results are shown in Table 2.
A: Void occurrence rate is 5% or less B: Void occurrence rate is more than 5%

Both Examples 1 and 2 showed good results in terms of void suppression and connection securing. That is, it was confirmed that according to the method of the present invention, it is possible to suppress voids and secure connections at the same time.

Examination 2
(2-1) Film-shaped Adhesive A film-shaped adhesive having the composition shown in Table 3 (thickness 0.040 to 0.045 mm) using the same material as the material used for producing the film-shaped adhesive in Study 1. ) Was prepared.

(2-2) Fabrication of Semiconductor Device and Evaluation thereof A semiconductor device sample for evaluation was obtained under the same conditions as in Example 1. The connections and voids of the obtained samples were evaluated in the same manner as in Study 1. The results are shown in Table 4.

(2-3) Minimum melt viscosity The overall thickness of the film-like adhesive becomes 300 to 450 μm while being heated to 60 ° C. using a roll laminator (HOT DOG Leon 13DX manufactured by Rummy Corporation). Multiple sheets were laminated as described above. Using the obtained laminate as a test piece, using a rotary rheometer (ARES G2 manufactured by TA), a temperature range of 20 ° C. to 300 ° C. under the conditions of a heating rate of 10 ° C./min, a frequency of 10 Hz, and a rotation mode. The change in viscosity (complex viscosity) was measured. The minimum value of the viscosity in the measured viscosity change was defined as the minimum melt viscosity.

(2-6) Curing reaction rate after the third crimping step A 10 mg sample was taken from the film-like adhesive before being used in the first crimping step, and a DSC (DSC-7 type manufactured by PerkinElmer) was used. Then, the differential scanning calorimetry in the temperature range of 30 to 300 ° C. was performed at a heating rate of 20 ° C./min. From the obtained DSC thermogram, the calorific value ΔH0 (J / g) due to the initial curing reaction was determined.
Using a hot plate and an oven, the film-like adhesive was subjected to a thermal history corresponding to the first, second and third crimping steps similar to those in Example 1. Then, the differential scanning calorimetry under the same conditions as above using a sample collected from the film-like adhesive was used to determine the calorific value ΔH3 (J / g) due to the curing reaction of the corresponding adhesive after the third crimping step. .. From the obtained ΔH0 and ΔH3, the curing reaction rate after the third crimping step was calculated by the following formula.
Curing reaction rate (%) after the third crimping step: (ΔH0−ΔH3) / ΔH0 × 100

All of Examples 3 and 4 showed good evaluation results in terms of void suppression and connection securing.

Examination 3
(3-1) Film-shaped Adhesive A film-shaped adhesive (thickness 0.045 mm) having the composition shown in Table 5 was prepared using the same material as that used in the production of the film-shaped adhesive in Study 1. ..

(3-2) Fabrication of Semiconductor Device (Example 5)
A semiconductor device sample for evaluation was obtained in the same manner as in Example 1 except that the time for heating and pressurizing the laminate in the first crimping step was changed to 3 seconds.

(Example 6)
Evaluation was carried out in the same manner as in Example 1 except that the time for heating and pressurizing the laminate was changed to 3 seconds in the first crimping step and the pressure in the oven was changed to 0.8 MPa in the third crimping step. A semiconductor device sample for use was obtained.

(Comparative Example 5)
The film-like adhesive was cut out to prepare a film-like adhesive having a size of 8 mm × 8 mm × thickness 0.045 mm. This was affixed onto a semiconductor chip (10 mm, thickness 0.1 mm, connection metal: Au, product name: WALTS-TEG IP80, manufactured by WALTS). There, a semiconductor chip with solder bumps (chip size: 7.3 mm x 7.3 mm x thickness 0.05 mm, bump melting point: about 220 ° C, bump height: total of about 45 μm of copper pillar and solder, number of bumps 1048 pins , Pitch 80um, product name: WALTS-TEG CC80, manufactured by WALTS) was attached to obtain a laminate. The laminate was installed on the stage of a flip chip bonder (FCB3, manufactured by Panasonic Corporation) having a stage and a crimping head. A temporary crimped body was obtained by sandwiching it between a stage and a crimping head and heating it at a temperature of 80 ° C. while pressurizing it with a load of 25 N for 3 seconds. The obtained temporary crimping body was moved onto the stage of another flip chip bonder (FCB3, manufactured by Panasonic Corporation). By sandwiching the temporary crimping body between the stage and the crimping head, it was heated at a temperature of 260 ° C. while pressurizing with a load of 25 N for 5 seconds to obtain a semiconductor device sample for evaluation.

(3-3) Evaluation The connections and voids of the obtained semiconductor device samples were evaluated by the same method as in Study 1. The results are shown in Table 6.

(3-4) Curing reaction rate after the second crimping step A 10 mg sample was taken from the film-like adhesive before being used in the first crimping step, and a DSC (DSC-7 type manufactured by PerkinElmer) was used. Then, the differential scanning calorimetry in the temperature range of 30 to 300 ° C. was performed at a heating rate of 20 ° C./min. From the obtained DSC thermogram, the calorific value ΔH0 (J / g) due to the initial curing reaction was determined.
The film-like adhesive was subjected to thermal history corresponding to the first and second crimping steps similar to Examples 5 and 6 using a hot plate and an oven. Then, the differential scanning calorimetry under the same conditions as above using a sample collected from the film-like adhesive was used to determine the calorific value ΔH2 (J / g) due to the curing reaction of the corresponding adhesive after the second crimping step. .. From the obtained ΔH0 and ΔH2, the curing reaction rate after the second crimping step was calculated by the following formula.
Curing reaction rate (%) after the second crimping step: (ΔH0-ΔH2) / ΔH0 × 100

(3-5) Fillet Evaluation An external image of a semiconductor device sample was taken with a digital microscope (manufactured by KEYENCE, VHX-5000). From the obtained image, the length of the adhesive layer protruding from each of the four sides around the semiconductor chip (the length in the direction parallel to the main surface of the semiconductor chip) is measured, and the average value of the measured values is recorded as a fillet value. did.

Both Examples 1 and 2 showed good evaluation results in terms of void suppression and connection securing.

1 ... Semiconductor chip, 2 ... Wiring circuit board, 3 ... Laminated body, 4 ... Temporary crimping body, 5 ... Interposer, 6 ... Crimping body, 10 ... Semiconductor chip body, 15, 16 ... Wiring, 20 ... Board body, 30 , 32, 33 ... Bump, 34 ... Through electrode, 40 ... Adhesive layer, 41, 44 ... Crimping head, 42, 45 ... Stage, 43, 46 ... Pressing device, 50 ... Interposer body, 60 ... Heating furnace, 100 , 200, 300, 400, 500 ... Semiconductor device.

Claims (11)

The first member having a connecting portion and the second member having a connecting portion are connected to each other via a thermosetting adhesive to the melting point of the connecting portion of the first member and the connecting portion of the second member. A step of obtaining a temporary crimping body in which the connecting portion of the first member and the connecting portion of the second member are arranged to face each other by crimping at a temperature lower than the melting point.
By sandwiching the temporary crimping body between a pair of pressing members arranged so as to face each other, the temporary crimping body is heated to a temperature equal to or higher than the melting point of at least one of the connecting portion of the first member or the connecting portion of the second member. The process of obtaining a crimped body by pressurizing while
A step of further heating the pressure-bonded body under a pressurized atmosphere and
With
A method for manufacturing a semiconductor device, wherein the first member is a semiconductor chip or a semiconductor wafer, and the second member is a wiring circuit board, a semiconductor chip, or a semiconductor wafer. In the step of obtaining the crimped body by pressurizing the temporary crimped body while heating, the thermosetting adhesive is partially cured.
The method according to claim 1, wherein in the step of heating the pressure-bonded body in a pressurized atmosphere, the thermosetting adhesive is further cured. The method according to claim 2, wherein in the step of obtaining the pressure-bonded body by pressurizing the temporary pressure-bonded body while heating, the thermosetting adhesive is cured until the curing reaction rate becomes 30% or less. .. The method according to claim 2 or 3, wherein in the step of heating the pressure-bonded body in a pressurized atmosphere, the thermosetting adhesive is further cured until the curing reaction rate becomes 85% or more. The method according to any one of claims 1 to 4, wherein in the step of heating the crimped body in a pressurized atmosphere, a plurality of the crimped bodies are collectively heated. The method according to any one of claims 1 to 5, wherein the heating temperature in the step of heating the pressure-bonded body in a pressurized atmosphere is 130 ° C. or higher and 300 ° C. or lower. Claims 1 to 1, wherein the thermosetting adhesive contains a thermosetting resin having a weight average molecular weight of less than 10,000, a curing agent of the thermosetting resin, and a polymer component having a weight average molecular weight of 10,000 or more. The method according to any one of 6. The method according to any one of claims 1 to 7, wherein the minimum melt viscosity of the thermosetting adhesive is 3000 Pa · s or less. A thermosetting adhesive for use in the method according to any one of claims 1 to 7.
A thermosetting adhesive having a minimum melt viscosity of 3000 Pa · s or less. The thermosetting adhesive according to claim 9, which is in the form of a film. A first member having a connecting portion, a second member having a connecting portion, and an adhesive layer interposed between them are provided, and the connecting portion of the first member and the connecting portion of the second member are provided. Is a semiconductor device that is electrically connected by metal bonding.
The adhesive layer comprises a cured product of a thermosetting adhesive.
The minimum melt viscosity of the thermosetting adhesive is 3000 Pa · s or less.
A semiconductor device in which the first member is a semiconductor chip or a semiconductor wafer, and the second member is a wiring circuit board, a semiconductor chip, or a semiconductor wafer.

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