JP2010263200A - Method of manufacturing semiconductor device and pressure container used for the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor device that can obtain excellent solder joint between a bump of a semiconductor chip and a pad of a substrate and improve joint reliability while reducing the cost, and to provide a pressure container used for the method. <P>SOLUTION: The method of manufacturing the semiconductor device in which the semiconductor device is manufactured by mounting a plurality of semiconductor chips 3 having bumps 4 on the substrate 1 in a flip-chip manner includes steps as follows: a step of arranging the plurality of semiconductor chips 3 on the substrate 1 such that the respective bumps 4 are mounted on solder layers 5 on surfaces of respective pads 2 on the substrate 1, a step of putting the work W having the plurality of semiconductor chips 3 arranged on the substrate 1 in the pressure container 8, and a step of raising the atmospheric pressure in the pressure container 8 above the vapor pressure of a solvent contained in an adhesive layer 6 at the highest temperature during heating of the work W and heating the work W by a heater 12 keeping the state as it is to fuse the solder layers 5. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a semiconductor device in which a plurality of semiconductor chips having bumps are flip-chip mounted on a substrate, and the bumps on each semiconductor chip and the pads on the substrate are electrically and mechanically connected. It relates to the pressure vessel used.

Conventionally, as a flip-chip mounting technique, a solder bump is formed on an electrode of a semiconductor device, the bump and an electrode on a substrate are joined, and a gap between the semiconductor device and the substrate is sealed with a resin material. It is known (see, for example, Patent Document 1).
Flip chip mounting technology is advantageous for reducing the size and thickness of packages and modules because a semiconductor chip can be compactly mounted on a substrate. In recent years, it has been widely adopted in various electronic products such as mobile phones. .
FIG. 6D shows a conventional flip chip mounting structure. A circuit pattern pad 102 is formed on the upper surface of the substrate 100. Bumps 104 made of Au, Cu, or high melting point solder project from the external electrodes of the semiconductor chip 103.

  A conventional method for flip-chip mounting the semiconductor chip 103 on the substrate 100 will be described with reference to FIGS. First, as illustrated in FIG. 6A, a solder layer 105 is formed over the pad 102 of the substrate 100. Next, as shown in FIG. 6B, an adhesive layer 106 is formed at least in the region of the substrate 100 on which the semiconductor chip 103 is mounted. Next, as shown in FIG. 6C, the semiconductor chip 103 adsorbed by the bonding tool 107 is pressed so that the bump 104 penetrates the adhesive layer 106 and is grounded on the solder layer 105. At the same time, the semiconductor chip 103 is heated by the bonding tool 107 and the solder layer 105 is melted, so that the solder bonding between the bump 104 and the pad 102 is performed as shown in FIG.

JP 2001-148404 A

However, in the above conventional method, the semiconductor chip 103 is heated and pressure-bonded one by one using the bonding tool 107, so that the flip chip mounting process takes time, and the processing cost and the capital investment cost increase. It was.
On the other hand, a plurality of semiconductor chips 103 are temporarily placed on the substrate 100 (the bumps 104 of the semiconductor chip 103 are placed on the solder layer 105 of the substrate 100 by the bonding tool 107, and solder melting heating is not performed. ), And a method in which a plurality of semiconductor chips 103 are collectively heated and pressed from the back side.

However, in this method, the position of the semiconductor chip 103 is shifted due to the flow of the adhesive layer 106 due to the pressurization when the plurality of semiconductor chips 103 are heated and pressed together, and the bumps 104 of the respective semiconductor chips 103 and Good solder joints with the pads 102 of the substrate 100 cannot be obtained.
If only heating is performed without applying pressure in this manner, the solvent in the adhesive layer 106 bumps and voids are generated. Voids cause breakage at the solder joints in the heat cycle test, and lower the joint reliability.
Further, by increasing the viscosity of the adhesive layer 106, it is possible to reduce the positional deviation of the semiconductor chip 103 at the time of batch pressurization, but the bump 104 cannot penetrate the adhesive layer 106, and the bump 104 and the solder layer 105 The adhesive layer 106 remains between the bumps 104 and the pads 104 and the pads 102 are not soldered.
Further, when the adhesive layer 106 having a high viscosity is heated and pressurized, the molten solder layer 105 flows in a direction where the pressure is low, and a good solder joint with the bump 104 cannot be obtained. Furthermore, there is a problem that the flowed solder short-circuits the circuit patterns on the substrate.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for manufacturing a semiconductor device capable of obtaining a good solder joint between a bump of a semiconductor chip and a pad of a substrate while reducing cost and improving the joint reliability. The object is to provide a pressure vessel for use in the method.

  According to a first aspect of the present invention, there is provided a method for manufacturing a semiconductor device comprising: forming an adhesive layer on a substrate having a plurality of semiconductor chips each having a bump; and a solder layer provided on a surface of the pad. A semiconductor device manufacturing method for manufacturing a semiconductor device by flip-chip mounting, wherein: (a) the plurality of semiconductor chips are placed on the solder layer on the surface of each pad corresponding to each bump; Pressing and placing on the substrate; (b) placing a work in which the plurality of semiconductor chips are placed on the substrate into a pressure vessel; and (c) air pressure in the pressure vessel, By raising the vapor pressure of the solvent contained in the adhesive layer at the highest temperature when heating the workpiece, and heating the workpiece and melting the solder layer in this state, the bump and the pad are heated. Characterized in that it comprises the the steps of obtaining a solder joint with.

  According to this configuration, in the step of obtaining the solder joint between the bump of the semiconductor chip and the pad of the substrate, the adhesive layer is not mechanically pressurized, so that the positional deviation of the semiconductor chip due to the flow of the adhesive layer is suppressed. The Therefore, the viscosity of the adhesive layer can be lowered to such an extent that the bump penetrates and the molten solder gets wet on the bump. For these reasons, the solder layer melted by heating does not flow due to the pressure bias and does not short-circuit between the patterns. Moreover, since the atmospheric pressure in the pressure vessel at the time of heating is higher than the vapor pressure of the solvent contained in the adhesive layer at the highest temperature when the workpiece is heated, generation of voids due to bumping of the solvent can be prevented. This improves the bonding reliability between the bumps of the semiconductor chip and the pads of the substrate. In addition, since a plurality of semiconductor chips are heated together in a pressure vessel and the solder layer is melted to obtain a solder joint between the bump and the pad, the processing cost and the capital investment cost can be reduced. .

According to a second aspect of the present invention, there is provided a method for manufacturing a semiconductor device, wherein the plurality of semiconductor chips are arranged on the substrate in the method for manufacturing a semiconductor device according to the first aspect of the present invention. a) is performed by positioning the semiconductor chip such that a gap is formed between the surface of the semiconductor chip and the surface of the adhesive layer material, and pressing the semiconductor chip under reduced pressure. To do.
According to this configuration, the plurality of semiconductor chips are positioned so that a gap is generated between the surface of the semiconductor chip and the surface of the adhesive layer, and then the semiconductor chip is pressed under reduced pressure, whereby the substrate and the semiconductor chip In particular, it is possible to reduce the problem that air enters the periphery of the bumps and the like to form gaps. As a result, peeling of the semiconductor chip from the substrate and increase in circuit resistance due to bump oxidation can be reduced.

According to a third aspect of the present invention, there is provided a method for manufacturing a semiconductor device, wherein the plurality of semiconductor chips of the method for manufacturing a semiconductor device according to the first or second aspect of the present invention are arranged on the substrate. In the step (a), the pressure to press the semiconductor chip is such that the tip of each bump of the plurality of semiconductor chips penetrates the adhesive layer and reaches the solder layer, and the surface of the semiconductor chip is deformed. The size of the adhesive layer is in close contact with the adhesive layer.
According to this configuration, the flow of the adhesive layer due to pressurization in the above-described method in which a plurality of semiconductor chips are heated and pressed together is suppressed, and the semiconductor chip misalignment due to the flow is suppressed. A good solder joint between the bump and the substrate pad can be obtained.

A method for manufacturing a semiconductor device according to a fourth aspect of the present invention is the method for manufacturing a semiconductor device according to any one of the first to third aspects of the present invention. When the point at which the adhesive layer changes from the softening tendency to the hardening tendency is the inflection point of the melt viscosity of the adhesive layer, the step (c) is performed when the adhesive layer reaches the inflection point. The internal atmospheric pressure is equal to or higher than the vapor pressure of the solvent, and the temperature in the vicinity of the solder layer is equal to or higher than the melting temperature of the solder layer by heating the workpiece.
Here, the temperature in the vicinity of the solder layer is the temperature in the vicinity of the solder layer of the pad of the substrate and the bump of the semiconductor chip to be joined by solder bonding.

If the adhesive layer is hardened when the temperature in the vicinity of the solder layer reaches the melting temperature of the solder layer, the flow of the molten solder may be hindered by the adhesive layer, and good solder bonding may not be possible. However, according to this configuration, when the temperature in the vicinity of the solder layer reaches the melting temperature of the solder layer, the adhesive layer is in a softened state before the inflection point, thereby preventing the flow of solder from being inhibited by the adhesive layer. In addition, good solder bonding can be performed.
Further, when the atmospheric pressure in the pressure vessel is higher than the vapor pressure of the solvent at the boiling point of the solvent contained in the adhesive layer, generation of voids due to bumping of the solvent can be prevented. This improves the bonding reliability between the bumps of the semiconductor chip and the pads of the substrate.

A pressure vessel according to a first aspect of the present invention is a pressure vessel used in the method for manufacturing a semiconductor device according to any one of the first to fourth aspects of the present invention, and has an opening at an upper portion thereof. A container main body capable of accommodating a work in which a plurality of semiconductor chips each having a bump and a substrate having a pad and a solder layer provided on the surface of the pad are disposed via an adhesive layer, and the opening And high pressure air is introduced into the container body so that the pressure in the pressure vessel and the pressure in the pressure vessel are higher than the vapor pressure of the solvent contained in the adhesive layer at the highest temperature when heating the workpiece. A heater that is attached to the inner surface of the lid, and that heats the work housed in the container body so that the solder layer can be melted and the bumps and the pads can be soldered together. Having And features.
According to this configuration, high-pressure air is introduced into the pressure vessel from the introduction portion, and the atmospheric pressure in the pressure vessel can be adjusted, and the workpiece can be heated by the heater.

The pressure vessel according to the second aspect of the present invention is characterized in that the heater of the pressure vessel according to the first aspect of the present invention is a pulse heater.
According to this configuration, by controlling the temperature profile according to the type of adhesive constituting the adhesive layer, the workpiece can be rapidly heated without promoting the softening / curing of the adhesive layer. Therefore, the solder can be melted in a state where the adhesive layer is softened before the inflection point, and good solder bonding can be performed.

  According to the present invention, it is possible to obtain a good solder joint between the bump of the semiconductor chip and the pad of the substrate while reducing the cost, and to improve the joint reliability.

(A) is a figure for demonstrating the process (2) of the manufacturing method of the semiconductor device which concerns on one Embodiment of this invention, (B) is the process of the manufacturing method of the semiconductor device which concerns on one Embodiment of this invention. It is a figure for demonstrating (3). 2A is a view for explaining a step (4) of the method for manufacturing a semiconductor device according to the embodiment, and FIG. 2B is an enlarged view of a portion X in FIG. 2A. 3A is a view for explaining steps (5) and (6) of the method for manufacturing a semiconductor device according to the embodiment, and FIG. 3B is an enlarged view of a Y portion in FIG. 3A. It is. The heating point temperature (T) with respect to the heating time (t), the atmospheric pressure (P) in the pressure vessel 8 and the melt viscosity (η) of the adhesive constituting the adhesive layer 6 are used to explain the problems during soldering. FIG. The heating point temperature (T) with respect to the heating time (t), the atmospheric pressure (P) in the pressure vessel 8 and the melt viscosity (η) of the adhesive constituting the adhesive layer 6 are shown for explaining good solder bonding. It is a figure. (A)-(D) are the figures for demonstrating the process of a prior art.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
A method for manufacturing a semiconductor device according to an embodiment of the present invention will be described with reference to FIGS.
In this semiconductor device manufacturing method, as shown in FIGS. 3A and 3B, a plurality of semiconductor chips 3 each having a bump 4 are flip-chip mounted on a substrate 1, and each bump of the plurality of semiconductor chips 3 is mounted. 4 and corresponding pads 2 on the substrate 1 are electrically and mechanically connected.

This semiconductor device manufacturing method includes the following steps.
<Step (1)>
In step (1), bumps 4 of semiconductor chip 3 are formed.
First, a semiconductor wafer (not shown) is cut in units of semiconductor chips to prepare a plurality of semiconductor chips 3, and bumps 4 are formed on external electrodes (not shown) of each semiconductor chip 3. As the bump 4, an Au stud bump having a height of 50 to 70 μm may be formed on the external electrode of the semiconductor chip 3.
The Au stud bump is formed by, for example, discharging and melting the tip of a gold wire to form a ball, joining the ball to an external electrode of the semiconductor chip 3 by ultrasonic waves, and cutting the gold wire. The bumps 4 may be stud bumps made of Cu or high melting point solder.

<Step (2)>
Next, in step (2), a solder layer 5 is formed on the surface of each pad 2. FIG. 1A is a view for explaining step (2) of the method for manufacturing a semiconductor device according to the embodiment of the present invention.
As shown in FIG. 1A, a plurality of circuit patterns (unit circuit patterns) respectively corresponding to a plurality of semiconductor chips 3 are formed on the upper surface of the substrate 1, and a plurality of pads 2 are formed on each circuit pattern. It is formed (see FIG. 1A).
As the solder layer 5, for example, a solder layer having a thickness of 3 to 10 μm may be formed on the surface of the pad 2 by electrolytic plating. As a solder layer, Sn alloy and Sn alloy such as Sn37Pb, Sn3.5Ag, Sn3.0Ag0.5Cu are used. The Sn3.5Ag solder layer has a composition in which a small amount of Ag (0 wt% <Ag ≦ 3.5 wt%) is added to Sn.

<Step (3)>
Next, in the step (3), an adhesive layer 6 is formed in a region on the substrate 1 where at least a plurality of semiconductor chips 3 are mounted. FIG. 1B is a view for explaining step (3) of the method for manufacturing a semiconductor device according to the embodiment of the present invention.
For the adhesive layer 6, for example, a semi-cured epoxy adhesive film having a thickness of 20 to 50 μm may be laminated on the substrate 1. The adhesive layer 6 is not limited to an epoxy resin, and for example, a thermoplastic resin such as a phenol resin, an unsaturated polyester resin, a polyimide resin, a general-purpose engineering plastic, or a super engineering plastic can be used. Further, two or more kinds of materials may be mixed (polymer blend) by a chemical method or a mechanical method during the production process. As a method for forming the adhesive layer 6, in addition to lamination, a method of screen printing a liquid resin can be used.

<Process (4)>
Next, in the step (4), the bumps 4 are pressed so as to be placed on the solder layer 5 on the surface of the pad 2 and arranged on the substrate 1. 2A and 2B are views for explaining step (4) of the method for manufacturing a semiconductor device according to the embodiment of the present invention.
As shown in FIG. 2A, the plurality of semiconductor chips 3 are arranged on the solder layer 5 on the surface of each pad 2 corresponding to each bump 4 (see FIG. 2B) of the plurality of semiconductor chips 3. To be placed on the substrate 1.
For example, the semiconductor chips 3 are sucked one by one using the flip chip bonder 20, and the sucked semiconductor chips 3 are aligned and arranged so that the pads 2 on the substrate 1 and the bumps 4 of the semiconductor chip 3 are aligned.

  At this time, as shown in FIG. 2B, the pressure for pressing the semiconductor chip 3 against the substrate 1 is such that the tips of the bumps 4 that are Au stud bumps penetrate the adhesive layer 6 that is an epoxy adhesive film. The solder layer 5 is preferably deformed and the surface of the semiconductor chip 3 is preferably sized so as to be in close contact with the adhesive layer 6. At this time, the adhesive layer 6 has a thickness smaller than the height of the bump 4. Thus, when the semiconductor chip 3 is disposed so that the surface of the semiconductor chip 3 is in close contact with the adhesive layer 6, the tip of the bump 4 penetrates the adhesive layer 6 and reaches the solder layer 5 to be deformed. The bump 4 and the solder layer 5 are connected to each other.

  As described above, the semiconductor chip 3 may be arranged on the substrate 1 under normal pressure (atmospheric pressure), but the semiconductor chip 3 is placed between the surface of the semiconductor chip 3 and the surface of the adhesive layer 6. Then, the semiconductor chip 3 may be pressed under a reduced pressure, preferably in an atmosphere of 50 hPa or less with a vacuum pump or the like. Thereby, it is possible to reduce the problem that air enters between the substrate 1 and the semiconductor chip 3, particularly in the vicinity of the unevenness of the bumps 4 and a gap is formed. As a result, peeling of the semiconductor chip 3 from the substrate 1 and increase in circuit resistance due to oxidation of the bumps 4 can be reduced. The semiconductor chip 3 is positioned such that the tip of the bump 4 enters the adhesive layer 6, and desirably at least a part of the bump 4 is in contact with the pad 2. By positioning in this way, when the substrate 1 and the semiconductor chip 3 are moved after positioning, it is possible to prevent the position from being shifted from the predetermined position.

<Step (5)>
Next, in step (5), the workpiece W is put into the pressure vessel 8. FIGS. 3A and 3B are views for explaining the step (5) and the next step (6) of the method for manufacturing a semiconductor device according to the embodiment of the present invention.
As shown in FIG. 3A, a work W (see FIG. 2A) on which a plurality of semiconductor chips 3 are placed on a substrate 1 is placed in a pressure vessel 8. The pressure vessel 8 will be described as an example of a pressure vessel according to an embodiment of the present invention.
The pressure vessel 8 has an opening 13 at the top, a container body 9 that can accommodate a work W in which a plurality of semiconductor chips 3 are arranged on the substrate 1, a lid 10 that closes the opening 13, a container A high-pressure air introduction pipe 11 that is fixed to the side wall of the main body 9 so as to penetrate the side wall and that introduces high-pressure air into the container main body 9, and a heater 12 that is attached to the inner surface of the lid 10. . The lid 10 is removed and the workpiece W is put into the pressure vessel 8 through the opening 13.

<Step (6)>
Next, in step (6), each bump 4 and each pad 2 are soldered together.
As shown in FIGS. 3A and 3B, high-pressure air is introduced into the pressure vessel 8 from the high-pressure air introduction pipe 11 so that the atmospheric pressure in the pressure vessel 8 is at the highest temperature when the workpiece W is heated. The vapor pressure of the solvent contained in the adhesive layer 6 is set higher, and in this state, the workpiece W is heated by the heater 12 and the solder layer 5 is melted to obtain a solder joint between each bump 4 and each pad 2. .

  In step (6), when the adhesive layer 6 reaches the inflection point of the melt viscosity, (1) the atmospheric pressure in the pressure vessel 8 is equal to or higher than the vapor pressure of the solvent contained in the adhesive layer 6; (2) It is desirable that the above two conditions that the temperature in the vicinity of the solder layer 5 is equal to or higher than the melting temperature of the solder layer 5 by heating the workpiece W are satisfied. Here, the inflection point is a point at which the state (melt viscosity) of the adhesive layer 6 changes from a softening tendency to a hardening tendency as a result of heating. The temperature in the vicinity of the solder layer 5 is the temperature in the vicinity of the solder layer 5 of the pad 2 of the substrate 1 and the bump 4 of the semiconductor chip 3 to be joined by solder bonding.

  For example, as shown in FIG. 4, when the temperature in the vicinity of the solder layer 5 (heating point temperature) reaches the melting temperature (T2) of the solder layer 5, the adhesive layer 6 is cured, i.e., changes. When the heating time has passed from the local point (A), the flow of the melted solder is hindered by the adhesive layer 6 in a cured state, and there may be a problem that good solder bonding cannot be performed. is there. FIG. 4 shows the heating point temperature (T) with respect to the heating time (t), the atmospheric pressure (P) in the pressure vessel 8, and the melt viscosity of the adhesive that constitutes the adhesive layer 6 for the purpose of explaining problems during solder joining. It is the figure which showed ((eta)). Here, the horizontal axis indicates the heating time (t), and the vertical axis indicates the heating point temperature (T), the atmospheric pressure (P) in the pressure vessel 8, and the melt viscosity (η) of the adhesive constituting the adhesive layer 6. Indicated. Further, the atmospheric pressure (P) in the pressure vessel 8 rises after the lid 10 of the pressure vessel 8 is closed.

  In order to prevent the above-described problem of solder joining, as shown in FIG. 5, when the adhesive layer 6 reaches the inflection point (A), the temperature in the vicinity of the solder layer 5 is increased by the heating of the workpiece W. By satisfying the condition (2) that causes the melting temperature (T2) of the layer 5 to be higher than the melting temperature (T2), the adhesive bonding of the adhesive layer 6 can be performed in a softened state before the inflection point (A). That is, it is possible to prevent the solder flow from being hindered by the adhesive layer 6 and perform good solder bonding. FIG. 5 shows the heating point temperature (T) with respect to the heating time (t), the atmospheric pressure (P) in the pressure vessel 8 and the melt viscosity of the adhesive constituting the adhesive layer 6 for explaining good solder bonding (FIG. It is the figure which showed (eta). Here, the horizontal axis indicates the heating time (t), and the vertical axis indicates the heating point temperature (T), the atmospheric pressure (P) in the pressure vessel 8, and the melt viscosity (η) of the adhesive constituting the adhesive layer 6. Indicated. Further, the atmospheric pressure (P) in the pressure vessel 8 rises after the lid 10 of the pressure vessel 8 is closed.

  Moreover, when the atmospheric pressure in the pressure vessel 8 is higher than the vapor pressure (P1) of the solvent at the boiling point of the solvent contained in the adhesive layer 6 (T1 region: near 100 to 150 ° C.), it is due to bumping of the solvent. Generation of voids can be prevented. Thereby, the bonding reliability between the bumps 4 of the semiconductor chip 3 and the pads 2 of the substrate 1 is improved.

  As described above, a pulse heater is desirably used as the heater 12 in order to satisfy the above two conditions when the adhesive layer 6 reaches the inflection point (A) of the melt viscosity. The pulse heater is easy to control the temperature profile. By controlling the temperature profile according to the type of adhesive constituting the adhesive layer 6, as shown in FIG. Since the workpiece W can be heated rapidly without promoting softening / curing, the adhesive layer 6 can melt the solder in a softened state before the inflection point (A). Solder bonding can be performed.

Next, examples of the present invention will be described, but the present invention is not limited to these examples.
100 semiconductor chips 3 of 6.3 mm × 6.3 mm were prepared, and Au stud bumps having a height of 50 μm or more were formed as bumps 4 on the external electrodes of the respective semiconductor chips 3. A 3 to 5 μm Sn3.5Ag solder layer is formed as the solder layer 5 on the pad 2 formed on the substrate 1, and a 30 μm thick semi-cured epoxy adhesive film is laminated thereon as the adhesive layer 6. did. The solvent contained in the epoxy adhesive film is dimethylformamide.

  The flip chip bonder 20 is used to press the semiconductor chip 3 onto the substrate 1 so that the Au stud bump (bump 4) tip penetrates the epoxy adhesive film (adhesive layer 6) and reaches the solder layer 5. Arranged. The pressing force at this time was 0.84 MPa. At this time, the surface of the semiconductor chip 3 on the Au stud bump (bump 4) side was in close contact with the epoxy adhesive film (adhesive layer 6).

  The workpiece W on which the semiconductor chip 3 is placed on the substrate 1 is put in the pressure vessel 8 and the pressure in the pressure vessel 8 is increased to 0.7 MPa so that the melting point of Sn3.5Ag solder exceeds 221 ° C. W was heated to 230 ° C. and left for 45 seconds. Note that the vapor pressure of dimethylformamide at 230 ° C. is 0.54 MPa.

  After the workpiece W was cooled, it was taken out from the pressure vessel 8, and the presence or absence of voids in the epoxy adhesive film (adhesive layer 6) was observed using a SAT (ultrasonic imaging device) to confirm that there were no voids. Further, as a result of cross-sectional observation of the solder joint state between the Au stud bump (bump 4) of each semiconductor chip 3 and each pad 2 of the substrate 1, a good joint state between each Au stud bump (bump 4) and each pad 2 is obtained. I was able to confirm.

According to the method of manufacturing a semiconductor device according to the above-described embodiment, the following operational effects can be obtained.
(1) In the step (6) for obtaining the solder joint between the bumps 4 of the semiconductor chip 3 and the pads 2 of the substrate 1, the adhesive layer 6 is not mechanically pressed. 3 is suppressed. Therefore, the viscosity of the adhesive layer 6 can be lowered to such an extent that the bumps 4 penetrate and the molten solder gets wet on the bumps 4. For these reasons, the solder layer 5 melted by heating does not flow due to an uneven pressure, and the circuit patterns of the substrate 1 are not short-circuited.

  (2) Since the atmospheric pressure in the pressure vessel 8 at the time of heating is higher than the vapor pressure of the solvent contained in the adhesive layer 6 at the maximum temperature when the workpiece W is heated, generation of voids due to bumping of the solvent is prevented. I can do it. Thereby, the bonding reliability between the bumps 4 of the semiconductor chip 3 and the pads 2 of the substrate 1 is improved.

  (3) Since a plurality of semiconductor chips 3 are collectively heated in the pressure vessel 8 and the solder layer 5 is melted to obtain solder bonding between the bumps 4 and the pads 2, processing costs and capital investment costs Can be reduced.

  (4) In the above step (4), the pressure when mounting the plurality of semiconductor chips 3 on the substrate 1 is such that the tip of each bump 4 of the plurality of semiconductor chips 3 penetrates the adhesive layer 6 and the solder layer The size reaches 5 and deforms, and the surface of the semiconductor chip 3 is in close contact with the adhesive layer 6. Thus, when the plurality of semiconductor chips 3 are heated and bonded together, good solder bonding between the bumps 4 of the semiconductor chip 3 and the pads 2 of the substrate 1 can be obtained without applying pressure.

  (5) In the step (6), when the adhesive layer 6 reaches the inflection point of the melt viscosity, the atmospheric pressure in the pressure vessel 8 is equal to or higher than the vapor pressure of the solvent contained in the adhesive layer 6. In addition, by satisfying the above two conditions that the temperature in the vicinity of the solder layer 5 is equal to or higher than the melting temperature of the solder layer 5 by heating the workpiece W, the adhesive layer 6 is softened before the inflection point. Solder bonding can be performed. That is, it is possible to prevent the solder flow from being hindered by the adhesive layer 6 and perform good solder bonding.

  (6) By using a pulse heater as the heater 12 of the pressure vessel 8, the workpiece W can be rapidly heated without promoting the softening / curing of the adhesive layer 6, and therefore the adhesive layer 6 However, the solder can be melted in a softened state before the inflection point, and good solder bonding can be performed.

1: Substrate 2: Pad 3: Semiconductor chip 4: Bump 5: Solder layer 6: Adhesive layer 8: Pressure vessel 9: Container body 10: Lid 11: High-pressure air introduction pipe 12: Heater W: Workpiece

Claims (6)

Manufacturing a semiconductor device by flip-chip mounting a plurality of semiconductor chips each having a bump on a substrate having a pad and a solder layer provided on the surface of the pad via an adhesive layer. A method,
(A) placing the plurality of semiconductor chips on the substrate by pressing the plurality of semiconductor chips so as to be placed on the solder layer on the surface of the pads corresponding to the bumps;
(B) placing the work in which the plurality of semiconductor chips are arranged on the substrate into a pressure vessel;
(C) The atmospheric pressure in the pressure vessel is made higher than the vapor pressure of the solvent contained in the adhesive layer at the highest temperature when heating the workpiece, and in this state, the workpiece is heated, and the solder layer Obtaining a solder joint between the bump and the pad by melting
A method for manufacturing a semiconductor device, comprising: The step (a) of disposing the plurality of semiconductor chips on the substrate includes:
2. The semiconductor chip is formed by positioning the semiconductor chip so that a gap is formed between the surface of the semiconductor chip and the surface of the adhesive layer material, and pressing the semiconductor chip under reduced pressure. The manufacturing method of the semiconductor device as described in any one of.   In the step (a) of disposing the plurality of semiconductor chips on the substrate, the pressure for pressing the semiconductor chip is such that the tip of each bump of the plurality of semiconductor chips penetrates the adhesive layer and the solder layer 3. The method of manufacturing a semiconductor device according to claim 1, wherein the surface of the semiconductor chip is sized so that the surface of the semiconductor chip is in close contact with the adhesive layer. When the point at which the state of the adhesive layer changes from a softening tendency to a hardening tendency as a result of heating is the inflection point of the melt viscosity of the adhesive layer,
In the step (c), when the adhesive layer reaches the inflection point, the pressure in the pressure vessel is equal to or higher than the vapor pressure of the solvent, and the temperature in the vicinity of the solder layer by heating the workpiece. 4. The method of manufacturing a semiconductor device according to claim 1, wherein the temperature is equal to or higher than a melting temperature of the solder layer. 5. A pressure vessel used in the method of manufacturing a semiconductor device according to any one of claims 1 to 4,
A plurality of semiconductor chips each having an opening at the top and each having a bump, and a substrate having a pad and a solder layer provided on the surface of the pad, can accommodate a workpiece disposed via an adhesive layer. A container body,
A lid that closes the opening;
An introduction part for introducing high-pressure air into the container body such that the atmospheric pressure in the pressure container is higher than the vapor pressure of the solvent contained in the adhesive layer at the highest temperature when heating the workpiece; ,
A heater that is attached to the inner surface of the lid and that heats the work housed in the container body so that the solder layer can be melted and the bumps and the pads can be soldered together. To pressure vessel. The pressure vessel according to claim 5, wherein the heater is a pulse heater.

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