JP3300525B2 - Semiconductor device and method of manufacturing semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device in which a semiconductor element and a die pad or an internal lead are fixed by a fixing member, and a method of manufacturing the semiconductor device.

[0002]

2. Description of the Related Art FIG. 7 is a sectional view showing the structure of a conventional semiconductor device. In the figure, reference numeral 1 denotes a semiconductor element made of, for example, silicon. Reference numeral 2 denotes a die pad on which the semiconductor element 1 is mounted, which is made of, for example, 42 alloy or copper alloy.
Reference numeral 3 denotes a die bonding material as a fixing member for fixing the semiconductor element 1 and the die pad 2, and is made of, for example, an epoxy resin as a main component and a mixture of silver powder as a filler. Note that, depending on the integrated circuit (not shown) of the semiconductor element 1, it may be necessary to ground the die pad 2. In such a case, it is necessary to electrically connect the semiconductor element 1 and the die pad 2. In addition, the die bonding material 3 is made of an epoxy resin mixed with about 80 wt% of silver powder to have conductivity.

[0003] Reference numeral 4 denotes a wire connecting the semiconductor element 1 to a lead terminal described later, which is made of, for example, gold or aluminum. Reference numeral 10 denotes an electrode for connecting the wire 4 on the semiconductor element 1, and 5 denotes a lead terminal for transmitting an electric signal of the semiconductor element 1 to the outside via the wire 4, and is made of, for example, 42 alloy or copper alloy. . Reference numeral 6 denotes a molding resin as a sealing member for enclosing a part of the semiconductor element 1, the die pad 2, the die bonding material 3, the wire 4, and the lead terminal 5 and protecting it from external conditions.
Consists of 70% silica. FIG. 9 shows the respective values of the linear expansion coefficient and the longitudinal elastic coefficient of a general material used for the semiconductor device formed as described above.

Next, a method of manufacturing the semiconductor device having the above structure will be described with reference to FIGS.
First, the die bonding material 3a is die-patched from the nozzle 7a at the tip of the syringe 7 using, for example, a dispensing method (there are other methods such as stamping and screen printing).
The fixed amount is discharged upward (FIG. 8A). Next, the semiconductor element 1
Is placed at a predetermined position on the die bonding material 3a of the die pad 2, and the semiconductor element 1 is
The die pad 2 and the semiconductor element 1 are fixed with the die bonding material 3 while pressing at about m ² (FIG. 8B).

Next, the wire 4 is connected to the electrode 1 by the capillary 9.
0 and the lead terminals 5 respectively (FIG. 8
(C)). Next, as shown in FIG. 7, a part of the semiconductor element 1, the die pad 2, the wire 4, and the lead terminal 5 is sealed with a mold resin 6 to form a desired shape, and for example, soldering to a printed board or the like is performed. Implement by The operation of the semiconductor device formed as described above is such that an electric signal is externally applied to the lead terminal 5 and the semiconductor element 1 is connected via the wire 4.
This electrical signal is transmitted to the upper integrated circuit (not shown). After a predetermined operation (operation or the like) is performed in the integrated circuit, an electric signal is taken out from the lead terminal 5 to the outside again via the wire 4.

Next, a semiconductor device different from the conventional example will be described. FIG. 10 is a sectional view showing a configuration of a conventional semiconductor device. In the figure, the same parts as those in the conventional case are denoted by the same reference numerals, and the description is omitted. 5a is an internal lead of the lead terminal 5 sealed with the molding resin 6, 5b is an external lead not sealed with the molding resin 6 of the lead terminal 5, and 11 is the semiconductor element 1 and the internal lead 5.
The adhesive tape is, for example, a double-sided tape as a fixing member for fixing the adhesive tape a.

Next, a method of manufacturing the semiconductor device configured as described above will be described with reference to FIGS. First, the semiconductor element 1 is placed on the tray 12, and the adhesive tape 1 is placed at a desired position on the semiconductor element 1 in consideration of the arrangement of the electrodes 10 and the internal leads 5a of the semiconductor element 1.
1 (FIGS. 11 and 12 (a)). Next, the internal leads 5a are placed at predetermined positions on the adhesive tape 11 (FIG. 12B), and the semiconductor element 1 and the internal leads 5a are held down with the adhesive tape 11 by holding down the internal leads 5a with the tool 13. Is fixed (FIG. 12C).

Next, the wire 4 is connected to the electrode 10 and the inner lead 5.
a (FIG. 12D). Next, as shown in FIG. 10, the semiconductor element 1, the wires 4, and the internal leads 5a are sealed with a mold resin 6 to form a desired shape, and are mounted on, for example, a printed board by soldering or the like.

[0009]

As described above, in the conventional semiconductor device, as shown in FIG. 9, the semiconductor element 1 and the die pad 2 are fixed by the die bonding material 3 different from the molding resin 6 as shown in FIG. Or the semiconductor element 1 and the internal leads 5a are fixed with an adhesive tape 11, so that the heat generated when the semiconductor device at the time of mounting is attached to a printed circuit board by soldering is used to form a die bond with the mold resin 6. A thermal stress is generated between the material 3 and the adhesive tape 11, and the die-bonding material 3 and the adhesive tape 11 absorb a large amount of water vapor that enters from the outside of the semiconductor device at the time of mounting, and the die-bonding material 3 and the adhesive Tape 11
Are peeled off, and the cracks are generated in the mold resin 6 along with these, and the wires 4 are cut, so that the reliability of the semiconductor device is reduced.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-described problems, and provides a semiconductor device and a method of manufacturing a semiconductor device, in which cracks in a sealing member are prevented and reliability is improved. With the goal.

[0011]

According to a first aspect of the present invention, in a semiconductor device, a linear expansion coefficient of a fixing member for fixing a semiconductor element and an internal lead is 0.7 times a linear expansion coefficient of a sealing member.
.About.1.5 times.

[0012] Further, the semiconductor device according to claim 2 of the present invention resides in that in Claim 1, the securing member silica was filled 70～80Wt% epoxy resin, a linear expansion coefficient of 10.5
30 × 10 ⁻⁶ 1 / ° C.

According to a third aspect of the present invention, in the method of manufacturing a semiconductor device, a sheet-shaped fixing member having a desired thickness is inserted into a predetermined portion between the internal lead and the semiconductor element, and the fixing member is heated. Then, the inner lead and the semiconductor element are sealed with a sealing member.

[0014]

According to the first aspect of the present invention, the fixing member of the semiconductor device reduces thermal stress with the sealing member.

Further, the fixing member of the semiconductor device according to the second aspect of the present invention can easily obtain a sealing member capable of reducing moisture absorption and reducing thermal stress.

According to a third aspect of the present invention, in the method of manufacturing a semiconductor device, a sheet-like fixing member having a desired thickness is inserted into a predetermined portion between the internal lead and the semiconductor element, and the fixing member is heated and heated. Since the internal leads and the semiconductor element are sealed with a sealing member by applying pressure and cured, the thermal stress between the fixing member and the sealing member is reduced.

[0017]

[Embodiment 1] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing a configuration of a semiconductor device according to Embodiment 1 of the present invention. In the figure, the same parts as those in the conventional case are denoted by the same reference numerals, and description thereof will be omitted. Reference numeral 14 denotes a die bonding material as a fixing member for fixing the semiconductor element 1 and the die pad 2, for example, 70 to 80 wt% of silica in epoxy resin.
High filling, linear expansion coefficient 10.5-30 × 10 ^-6 1
/ ° C.

Next, a method of manufacturing the semiconductor device configured as described above will be described with reference to FIGS.
First, for example, a bulk die bond material 14a is
(FIG. 2 (a)), and the die bonding material 14a is melted by pressing and heating using the plunger 16, and at this time, the die bonding material 14a is formed through a vacuum hole 15a provided at the bottom of the die 15. Degas the air inside, for example, 50
It is formed into a sheet-like die bond material 14b having a thickness of not more than μm (FIG. 2B). At this time, the die bonding material 14b is
The reason why it is formed to a thickness of 0 μm or less is to make it easy to form a thickness of 20 μm or less, which is a finished thickness described later. Next, the die bond material 14b is processed into a desired shape using, for example, a mechanical or chemical treatment.

The reason why the die bond material 14b having a desired shape in the form of a sheet is formed through such a process is that the viscosity of the die bond material 14 is compared with the viscosity of the die bond material 3 in the conventional case. This is because it is extremely high and the fluidity is poor, so that it is not possible to use processes such as a dispensing method, stamping, and screen printing which have been conventionally used.

Next, the die pad 2 is placed on the heating table 17, and the die bonding material 1 is placed at a predetermined position on the die pad 2.
4b is placed (FIG. 3A), and the semiconductor element 1 is placed at a predetermined position thereon (FIG. 3B). Next, the heating temperature is applied to the die bonding material 14b via the die pad 2 on the heating table 17, for example, the melting temperature of the die bonding material 14b, for example, 1
It is generally used by applying a heat of 50 to 200 ° C. and applying a pressure of, for example, about 30 kg / mm ² which does not affect the semiconductor element 1 or the like via the semiconductor element 1 by the tool 18. The die bond material 14 having a thickness of, for example, 20 μm or less is fixed (FIG. 3C). (still,
At this time, the tool 18 may be provided with a heating mechanism so that the tool 18 applies heat to the die bonding material 14b via the semiconductor element 1. )

Hereinafter, as in the conventional case, the capillary 9
The wire 4 is crimped to the electrode 10 and the lead terminal 5 respectively (FIG. 3D). Next, as shown in FIG. 1, a part of the semiconductor element 1, the die pad 2, the wire 4, and the lead terminal 5 are sealed with a mold resin 6 and formed into a desired shape.
For example, it is mounted on a printed circuit board or the like by soldering or the like.

The semiconductor device of the first embodiment configured as described above, a semiconductor device using a die bond material having a higher linear expansion coefficient than the die bond material 14, and a die bond material having a lower linear expansion coefficient than the die bond material 14 were used. An experiment was conducted to compare the incidence of cracks in semiconductor devices. As the experimental conditions, the temperature was 85 ° C., the temperature was 85% RH,
Each of the semiconductor devices is stored for 24 hours to 72 hours, and then reflowed (for example, a hot air or a thermal infrared ray of 230 hours).
C.) The cracking rates were compared.
From the above experimental results, it was found that when the coefficient of linear expansion of the die bond material 14 was within the range of 0.7 to 1.5 times the coefficient of linear expansion of the mold resin 6, the crack generation rate was particularly low.

Embodiment 2 FIG. In the first embodiment, the case where the semiconductor element 1 and the die pad 2 are not electrically connected is described. In the second embodiment, the case where the semiconductor element 1 and the die pad 2 are electrically connected is described. First, FIG.
Sheet-like die bonding material 14b as shown in (b)
Is formed, the surface of the die bonding material 14b is covered with a metal thin film of, for example, silver, copper, aluminum, or the like by a method such as plating, vapor deposition, or sputtering, so that the die bonding material 14b has conductivity. Thereafter, a semiconductor device is formed through the same steps as in the first embodiment. By doing so, the semiconductor element 1 and the die pad 2
Can be electrically conducted, and the semiconductor element 1 can be grounded by the die pad 2.

Embodiment 3 FIG. FIG. 4 is a sectional view showing the configuration of the third embodiment of the present invention.
In the figure, the same parts as those in the conventional case are denoted by the same reference numerals, and the description is omitted. Reference numeral 19 denotes a die bonding material as a fixing member for fixing the semiconductor element 1 and the internal lead 5a, for example, 70 to 80 wt% of silica in epoxy resin.
High filling, linear expansion coefficient 10.5-30 × 10 ^-6 1
/ ° C.

Next, a method of manufacturing the semiconductor device configured as described above will be described with reference to FIGS.
First, the die bonding material 19a is formed into a sheet having a size of, for example, 50 μm or less through the same process as that of the first embodiment.
The die bond material 19a is processed into a desired shape using, for example, a mechanical or chemical treatment. Then, similarly to the conventional case, the semiconductor element 1 is placed on the tray 12, and the processed die bonding material 19a is placed at a predetermined position on the semiconductor element 1 (FIGS. 5 and 6A).

Next, the internal lead 5a is placed at a predetermined position on the die bonding material 19a (FIG. 6B), and the tool 20 having a heating means is applied to the die bonding material 19a via the internal lead 5a. Generally, heat of, for example, 150 to 200 ° C., which is the melting temperature of the die bonding material 19 a, is applied, and does not affect the semiconductor element 1 or the like, for example, 30 kg / mm.
A pressure of about ² is applied to melt and fix to a generally used die bond material 19 having a thickness of, for example, 20 μm or less (FIG. 6C).

Subsequently, the wire 4 is connected to the electrode 10 and the internal lead 5a as in the conventional case (FIG. 6 (d)).
Next, as shown in FIG. 4, the semiconductor element 1, the wires 4 and the internal leads 5a are sealed with a mold resin 6 to form a desired shape, and are mounted on a printed circuit board or the like by soldering or the like.

Since the semiconductor device of the fourth embodiment configured as described above is formed using the same die bonding material 19 as that of the first embodiment, it goes without saying that the same effect as that of the first embodiment can be obtained. No.

Embodiment 4 FIG. In each of the above embodiments, the linear expansion coefficient of the mold resin 6 is 15 to
In the case of 20 × 10 ⁻⁶ 1 / ° C., as an example of the die bonding materials 14 and 19, 70 to 80 w
t% high filling, linear expansion coefficient 10.5-30 × 10
^{Although an} example in which the temperature is set to ⁻⁶ 1 / ° C. has been described, the present invention is not limited to this.
The use of a 1.5-fold die-bonding material can reduce the moisture absorption of the die-bonding material and the thermal stress between the die-bonding material and the molding resin. .

[0030]

As described above, according to the first aspect of the present invention, the linear expansion coefficient of the fixing member for fixing the semiconductor element and the internal lead is 0.7 to 1.0 of the linear expansion coefficient of the sealing member. Since the ratio is made five times, it is possible to provide a semiconductor device in which cracking of the sealing member is prevented and reliability is improved.

According to the second aspect of the present invention,
1 , the fixing member is made of epoxy resin with silica of 70 to
80 wt% filling, linear expansion coefficient 10.5-30 × 10
A semiconductor device capable of easily obtaining a sealing member capable of reducing the hygroscopicity of the fixing member and reducing thermal stress with the fixing member because the temperature is set to ⁻⁶ 1 / ° C. can do.

Further, according to claim 3 of the present invention, claim
In 1 or claim 2, the desired sandwiching a sheet-like fixing member having a thickness in a predetermined position between the inner leads and the semiconductor element, and curing the fixing member heated and pressurized, the internal lead and the semiconductor element Is sealed with a sealing member, so that it is possible to provide a method of manufacturing a semiconductor device in which cracking of the sealing member is prevented and reliability is improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing one step of a method of manufacturing the semiconductor device shown in FIG.

FIG. 3 is a cross-sectional view showing a step of the method for manufacturing the semiconductor device shown in FIG.

FIG. 4 is a sectional view illustrating a configuration of a semiconductor device according to a third embodiment of the present invention;

5 is a cross-sectional view showing a step of the method for manufacturing the semiconductor device shown in FIG.

6 is a cross-sectional view showing a step of the method for manufacturing the semiconductor device shown in FIG.

FIG. 7 is a cross-sectional view illustrating a configuration of a conventional semiconductor device.

8 is a cross-sectional view showing a step of the method for manufacturing the semiconductor device shown in FIG.

9 is a view illustrating physical properties of materials of the semiconductor device illustrated in FIG. 7;

FIG. 10 is a cross-sectional view showing a configuration of another conventional semiconductor device.

11 is a cross-sectional view showing a step of the method of manufacturing the semiconductor device shown in FIG.

12 is a cross-sectional view showing a step of the method for manufacturing the semiconductor device shown in FIG.

[Explanation of symbols]

1 semiconductor device, 2 die pad, 5 lead terminal, 5
a internal lead, 5b external lead, 6 sealing resin, 1
4, 14a, 14b, 19, 19a Die bond material, 1
5 die, 15a vacuum hole, 16 plunger, 17
Heating table, 18 tools, 20 tools.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-5-235063 (JP, A) JP-A-1-293640 (JP, A) JP-A-1-166530 (JP, A) JP-A-2- 168635 (JP, A) JP-A-59-181628 (JP, A) JP-A-7-288262 (JP, A) JP-A 55-130134 (JP, A) JP-A-6-236899 (JP, A) JP-A-63-104455 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/52 H01L 21/58 H01L 23/28-23/31

Claims (3)

(57) [Claims] 1. A semiconductor device, an internal lead, and the semiconductor
On the surface on which the electrodes of the
In a semiconductor device comprising a fixing member for fixing the semiconductor element and the internal lead in the vicinity, and a sealing member for sealing the semiconductor element and the internal lead, the linear expansion coefficient of the fixing member is 0.7 to the linear expansion coefficient of the stop member
A semiconductor device comprising 1.5 times. 2. The fixing member is made of epoxy resin containing 70% silica.
~ 80wt% filling, linear expansion coefficient 10.5-30x
2. The semiconductor device according to claim 1 , wherein the temperature is 10 ⁻⁶ 1 / ° C. 3. A step of inserting a sheet-shaped fixing member having a desired thickness into a predetermined position between the internal lead and the semiconductor element, a step of heating and pressurizing the fixing member, and a step of curing the internal lead. And sealing the semiconductor element with a sealing member.
The method for manufacturing a semiconductor device according to claim 1.