JP2000150575A - Packaging method of semiconductor device and semiconductor device assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a packaging method of a semiconductor device and a semiconductor device assembly capable of improving productivity, facilitating the management of a manufacturing process, and realizing high reliability in connection. SOLUTION: An electron-beam cure resin 16 is filled between a semiconductor chip 10 and a wiring substrate 12 and is irradiated with an electron beam. The electron beam passes through the semiconductor chip 10 to cure the electron-beam cure resin 16 under the semiconductor chip 10. Since the electron- beam cure resin 16 does not contain a reaction starting agent or a reaction promoting agent and resists deteriorating, it is easy to manage a manufacturing process. Since the electron-beam cure resin 16 is cured in a short time, it is possible to realize an in-line production. The electron-beam cure resin 16 does not produce a residual stress after it is cured and the resin 16 between the semiconductor chip 10 and the wiring substrate 12 is also cured, that is, so-called underfill resin curing can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for mounting a semiconductor device for directly connecting a semiconductor integrated circuit chip to a wiring substrate via a protruding connection electrode, and a semiconductor device assembly manufactured by such a mounting method. About.

[0002]

2. Description of the Related Art In recent years, flip-chip mounting has been widely adopted as a mounting method for a high-frequency semiconductor device for a microwave band or a millimeter wave band or a high-speed digital LSI (large-scale integrated circuit). In this flip chip mounting method, as shown in FIG.
A pad (not shown) for connecting an external circuit is formed on the surface (semiconductor circuit forming surface) of the substrate No. 00, and a protruding connection electrode (hereinafter, referred to as a bump) 101 is formed on the pad. The formed surface is connected to the wiring board 1
The semiconductor chip 100 and the wiring board 102 are electrically connected by the bumps 101 by directly mounting the wiring pattern 103 on the wiring pattern 103.

According to the flip-chip mounting method, a thinner and smaller mounting form can be realized as compared with a conventional mounting method using wire bonding. Further, since the wiring distance between the semiconductor chip 100 and the wiring board 102 can be reduced, the parasitic inductance component is reduced, and the high frequency characteristics are improved.

Usually, solder 104 is applied to the connection between the bump 101 and the wiring pattern 103 shown in FIG. 18 as shown in FIG. 19, or a conductive paste 105 is applied as shown in FIG. As a result, the electrical connection between the semiconductor chip 100 and the wiring board 102 is ensured. However, in any case, the bonding strength and thus the reliability against the stress generated due to the difference in the coefficient of thermal expansion between the semiconductor chip 100 and the wiring board 102 and the warpage of the board are insufficient, and the practical use as it is poor.

Therefore, as shown in FIG. 21, the gap between the semiconductor chip 100 and the wiring board 102 is filled with an underfill resin 106, and the semiconductor chip 100 and the wiring board 1 are filled.
In this method, the reliability of the connection is ensured by bonding the surface of the substrate 02 to the surface of the substrate and uniformly distributing the stress.
Conventionally, as the underfill resin 106, for example, an epoxy-based thermosetting resin has been used.

[0006]

However, the underfill resin 106 conventionally used is, as described above,
Since it is a thermosetting epoxy resin or the like, it takes a long time of 2 to 8 hours to completely cure, and batch production is required, resulting in low productivity. Further, since the composition is cured in a heated state, if the temperature is returned to room temperature after the completion of the curing, the substrate is warped or residual stress is generated.

On the other hand, when the resin is to be cured at a lower temperature, it is necessary to add a large amount of a catalyst and a reaction initiator, and the storage stability of the resin deteriorates. For this reason, for example, when the work is interrupted and left in the middle of the process, the resin is degraded, and there is a problem that great care must be paid to the work management.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a semiconductor device mounting method and a semiconductor device capable of improving productivity, facilitating management of work steps, and realizing high connection reliability. An object of the present invention is to provide a semiconductor device assembly.

[0009]

SUMMARY OF THE INVENTION A method of mounting a semiconductor device according to the present invention is to electrically connect a semiconductor circuit in the semiconductor device to a wiring board via a protruding connection electrode provided on an outer surface of the semiconductor device. The first step of arranging the semiconductor device on the wiring board so that the protruding connection electrode of the semiconductor device comes into contact with the wiring pattern of the wiring board; and curing by irradiation with an electron beam. The method includes a second step of applying the electron beam-curable resin so that the wiring substrate and the semiconductor device are joined to each other, and a third step of irradiating the electron beam to cure the electron beam-curable resin.

In the method of mounting a semiconductor device according to the present invention,
The electron beam curable resin applied in the second step is
The semiconductor device is cured by the irradiation of the electron beam in the step, and the semiconductor device is fixed to the wiring substrate. Thereby, the electrical connection between the protruding connection electrode of the semiconductor device and the wiring pattern of the wiring board is ensured.

In the method of mounting a semiconductor device according to the present invention, in the second step, the electron beam curable resin is applied so as to be interposed between the semiconductor device and the wiring board, and the third step is performed. In the step, the irradiation of the electron beam may be controlled so that the electron beam passes through the semiconductor device and reaches an electron beam cured resin interposed between the semiconductor device and the wiring substrate.

In the method for mounting a semiconductor device according to the present invention, the second step can be performed before the first step.

A semiconductor device assembly according to the present invention is a semiconductor device assembly in which a semiconductor circuit in a semiconductor device and a wiring board are electrically connected via a protruding connection electrode provided on an outer surface of the semiconductor device. The semiconductor device is arranged on the wiring board so that the protruding connection electrodes of the semiconductor device come into contact with the wiring pattern of the wiring board, and the semiconductor device is wired by an electron beam cured resin cured by irradiation with an electron beam. It is configured to be joined to a substrate.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 to 5 show a method of mounting a semiconductor device according to an embodiment of the present invention. Each of these figures shows a cross section in each step. The semiconductor device assembly according to one embodiment of the present invention is embodied by the semiconductor device mounting method according to the present embodiment, and will be described below.

In the present embodiment, first, the back surface (the surface opposite to the bump forming surface) of the semiconductor chip 10 as a flip chip having the bumps 11 is polished by a back grinding method or the like so that the thickness of the semiconductor chip 10 is reduced. The thickness is set to a predetermined value. Here, the thickness of the semiconductor chip 10 is, for example, about 200 to 400 μm, as described later.

Next, as shown in FIG.
Wiring pattern 13 formed of a conductor such as copper formed thereon
The solder 14 is coated thereon.

Next, as shown in FIG. 2, the semiconductor chip 10 is mounted on the wiring board 12 with the bump surface facing down. At this time, positioning is performed so that the bumps 11 coincide with the wiring patterns 13.

Next, as shown in FIG. 3, reflow heating is performed to electrically connect between the bump 11 and the wiring pattern 13.

Next, as shown in FIG.
In the gap between the semiconductor chip 10 and the electron beam hardening resin 16
Fill. At this time, as the electron beam curing resin 16,
For example, a material that cures with energy of 10 to 30 × 10 ⁶ rad (rad) is used. Here, 1 rad means that an energy of 100 erg (erg) per 1 g of the electron beam curable resin is changed from the electron beam 17 to the electron beam curable resin 16.
Is the absorbed dose given to Electron beam curable resin 1
Examples of the compound 6 include a compound having a main chain of polyether, polyester, polyurethane or the like and having an acryloyl group at a terminal or a part thereof, a compound containing an acryloyl group such as urethane acrylate, or an unsaturated polyester, polybutadiene, or the like. Compounds containing a carbon double bond ('-C = C-' double bond) such as triallyl isocyanate are exemplified. The filling of the electron beam curable resin 16 is performed using, for example, a microdispenser or the like.

Next, as shown in FIG. 5, an electron beam 17 is irradiated from above the semiconductor chip 10. Here, when the acceleration voltage of the electron beam 17 is set to be, for example, 200 to 300 keV, the electron beam curing resin 16 is cured by irradiation of the electron beam for about 5 seconds. Thus, the step of mounting the semiconductor chip 10 on the wiring board 12 is completed.

Next, the mechanism of curing the electron beam curing resin 16 by the electron beam irradiation shown in FIG. 5 will be described.

Prior to this, first, a chemical reaction in a resin caused by a general electron beam will be described with reference to FIGS. As shown in FIG. 6, this type of chemical reaction includes a polymerization reaction in which a monomer M is polymerized by irradiation with an electron beam to form a polymer P.
As shown in FIG. 7, there is a crosslinking reaction in which a bridge is bridged between a plurality of polymers P by irradiation with an electron beam to form a three-dimensional network structure N. Further, as shown in FIG. 8, the decomposition reaction in which the polymer P is decomposed into the monomer M by the irradiation of the electron beam, and the radical R is generated from the polymer P by the irradiation of the electron beam as shown in FIG. Further, a graft polymerization in which a graft polymer G is formed by attaching the monomer M thereto, and an electron beam curing reaction in which a three-dimensional network structure N is formed from the polymer P and the monomer M as shown in FIG. There is.

The electron beam curable resin 16 in the present embodiment
The curing mechanism is that the above-mentioned chemical reactions are combined, and as a result, as shown in FIGS. 11 to 13, curing is mainly performed by polymerization of radicals generated by cutting of double bonds. it is conceivable that. That is, by irradiating the electron beam 17 as shown in FIG.
The double bond in the polymer P constituting the electron beam curable resin is broken, and a radical R is generated as shown in FIG. 12, and further, the radical R is polymerized.
As shown in FIG. 13, the three-dimensional network structure N is formed, and the electron beam curing resin 16 is cured.

Next, the advantages of using the electron beam curable resin 16, which is the most significant feature of the present invention, will be listed and described.

The electron beam-curable resin 16 is, for example, a benzoin ether-based or acetophenone-based reaction initiator or accelerator contained in an ultraviolet-curable resin cured by ultraviolet irradiation, or a peroxide-based reaction initiator contained in a thermosetting resin. Contains no agents. Therefore, even if the electron beam-curable resin 16 is stored at room temperature for a long time, or is left unattended after work, it is not deteriorated like the ultraviolet-curable resin, and the design of the production process is large.

The time required for curing the electron beam curable resin 16 is only about several seconds as described above. For this reason, the temperature of the semiconductor chip 10 and the wiring substrate 12 does not rise, and the resin can be cured at room temperature. Therefore, the use of the electron beam curable resin 16 enables in-line production, which was impossible with a thermosetting resin that does not cure unless a temperature of about 150 ° C. is maintained for a long time of 2 to 8 hours. Can be dramatically improved.

In the case of the thermosetting resin, when the curing is completed and the temperature returns to room temperature, the wiring board 12 warps or remains due to the difference in the respective thermal expansion coefficients of the semiconductor chip 10, the wiring board 12 and the electron beam curing resin 16. Although the stress is generated, the electron beam curing resin 16 does not have such a problem, and a highly reliable connection is possible.

In the case of an ultraviolet curable resin, although the peripheral portion of the semiconductor chip 10 can be cured, the ultraviolet rays do not reach the lower side of the semiconductor chip 10, so that the resin in the gap between the semiconductor chip 10 and the wiring board 12 is cured. do not do. On the other hand, in the case of the electron beam curing resin 16, since the electron beam can pass through the semiconductor chip 10 and reach the resin below the semiconductor chip 10, the electron beam curing resin 16 includes a gap between the semiconductor chip 10 and the wiring board 12. Curing of the resin in all areas is possible.

Next, the relationship between the energy of the electron beam and the penetrable thickness will be described with reference to FIG. In this figure, the horizontal axis indicates the thickness of the semiconductor chip 10, and the vertical axis indicates the transmittance of electron energy. Assuming that 90% of the irradiation energy is transmitted, as shown in FIG. 14, the thickness of the semiconductor chip 10 is 110 μm or less at an electron beam energy of 200 keV, 220 μm or less at 250 keV, and 350 μm or less at 300 keV. It is necessary to be.

Generally, the semiconductor chip 10 has a thickness of 400 μm or less.
Although it is often formed to a thickness of about 650 μm, FIG.
Furthermore, if an irradiation source of, for example, 300 keV is used, even if the thickness of the semiconductor chip 10 is 400 μm, an energy transmittance close to 80% can be obtained, so that electrons in the gap between the semiconductor chip 10 and the wiring board 12 can be obtained. The line-curable resin 16 can be cured in a relatively short time, and is sufficiently practical. Furthermore, if the back surface of the semiconductor chip 10 is polished by a back grinding method or the like to make it thinner to a thickness of about 200 μm, a high energy transmittance of 95% can be obtained even with an electron beam having a smaller energy of 250 keV. And can be cured for a short time. Note that the semiconductor circuit in the semiconductor chip 10 is formed on a very surface portion of the bump surface.
Even if the thickness is reduced to about 00 μm, there is no problem such as strength.

As described above, according to the method of mounting a semiconductor device according to the present embodiment, the electron beam curable resin 16 is used for joining the semiconductor chip 10 and the wiring board 12, so that the work and the process Since the control is easy, the degree of freedom in designing the production process is large, and the curing is completed in a short time, in-line production becomes possible, and the productivity is dramatically improved. In addition, since there is no residual stress after curing, and so-called underfill resin curing, which cures the resin between the semiconductor chip 10 and the wiring board 12, the reliability of the connection of the semiconductor chip 10 to the wiring board 12 is improved. Can be increased.

[Second Embodiment] Next, a second embodiment of the present invention will be described.
A method of mounting the semiconductor device according to the embodiment will be described.

FIGS. 15 to 17 show a method of mounting a semiconductor device according to a second embodiment of the present invention. These figures show a cross section of the device. In these figures, the same elements as those in the first embodiment (FIGS. 1 to 5) are denoted by the same reference numerals. The method for mounting a semiconductor device according to the present embodiment is based on a pressure welding process.

In the present embodiment, as shown in FIG. 15, an electron beam curable resin 16 is applied in advance to a region where a semiconductor chip is to be mounted on the wiring substrate 12 by a printing method or a dispensing method.

Next, as shown in FIG. 16, the semiconductor chip 10 is mounted on the wiring board 12 with the wiring pattern 13 and the bumps 11 positioned so as to coincide with each other.

Next, the electron beam 17 is irradiated from above the semiconductor chip 10 to cure the electron beam curing resin 16. At this time, the electron beam curing resin 16 in the gap between the semiconductor chip 10 and the wiring board 12 is also cured. Due to the shrinkage of the electron beam curable resin 16 during curing, the wiring pattern 13 of the wiring board 12 and the bumps 11 are brought into pressure contact with each other, and conduction is secured.

In this embodiment, parameters such as the type of the electron beam curing resin 16, the energy of the electron beam, and the thickness of the semiconductor chip 10 are the same as those in the first embodiment. Can be set to

As described above, according to the method of mounting a semiconductor device according to the present embodiment, the electron beam curable resin 16 is applied before the semiconductor chip 10 is mounted on the wiring board 12. The application of the electron beam curable resin 16 is easier than in the case of filling the electron beam curable resin 16 later as in the case of the first embodiment. In particular, the gap between the wiring board 12 and the semiconductor chip 10 is
It is easier to fill without gaps.

As described above, the present invention has been described with reference to some embodiments. However, the present invention is not limited to these embodiments, and various modifications are possible. For example, the combination of the thickness of the semiconductor chip 10 and the magnitude of the energy of the electron beam, and the type of the electron beam curable resin 16 are not limited to the above examples, and can be changed as appropriate.

[0041]

As described above, according to the method for mounting a semiconductor device according to any one of claims 1 to 9 or the semiconductor device assembly according to claim 10, the protruding connection electrode of the semiconductor device is provided. The semiconductor device is disposed on the wiring board so that the semiconductor device comes into contact with the wiring pattern of the wiring board. Since the electron beam curing resin is applied and cured by irradiating an electron beam, the effect due to the warpage and residual stress of the wiring board after curing is small, and there is an effect that mounting with high connection reliability can be realized. In addition, curing can be performed in an extremely short time as compared with the conventional thermosetting process, and productivity is greatly improved, so that continuous production can be performed instead of batch processing. Furthermore, the electron beam curable resin does not require a reaction initiator or an accelerator, and the reaction does not proceed in a standing state, so that storage at room temperature and management during work can be simplified, and storage and management costs can be reduced. It works.

In particular, according to the semiconductor device mounting method of the present invention, the electron beam curing resin is applied so as to be interposed between the semiconductor device and the wiring board, and the electron beam is applied to the semiconductor device. Since the irradiation of the electron beam is controlled so as to penetrate and reach the electron beam cured resin interposed between the semiconductor device and the wiring board, so-called underfill filling is possible while retaining each of the above effects. It has the effect of becoming.

Further, according to the method of mounting a semiconductor device according to the third aspect of the present invention, furthermore, after the protruding connection electrodes of the semiconductor device arranged on the wiring board and the wiring pattern of the wiring board are connected by soldering, Since the application step of the electron beam curing resin is performed, an effect is obtained that the electrical connection between the semiconductor circuit in the semiconductor device and the wiring pattern on the wiring board becomes more reliable.

According to the semiconductor device mounting method of the present invention, since the electron beam curable resin is applied before the semiconductor device is arranged on the wiring board, the operation of applying the electron beam curable resin can be performed. This has the effect of being easier.

According to the semiconductor device mounting method of the present invention, the surface of the semiconductor device opposite to the surface on which the semiconductor circuit is formed is polished, so that the semiconductor device has a predetermined thickness. As described above, it is possible to sufficiently cure the electron beam cured resin in the gap between the semiconductor device and the wiring board even when using an electron beam with weak energy. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing one step in a method for mounting a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a sectional view following FIG. 1;

FIG. 3 is a sectional view following FIG. 2;

FIG. 4 is a sectional view following FIG. 3;

FIG. 5 is a sectional view following FIG. 4;

FIG. 6 is a diagram showing an example of a chemical reaction in an electron beam curing resin.

FIG. 7 is a view showing another example of the chemical reaction in the electron beam curing resin.

FIG. 8 is a view showing still another example of the chemical reaction in the electron beam curing resin.

FIG. 9 is a view showing still another example of the chemical reaction in the electron beam curing resin.

FIG. 10 is a view showing still another example of the chemical reaction in the electron beam curing resin.

FIG. 11 is a diagram for explaining a part of a curing mechanism of an electron beam curing resin by electron beam irradiation.

FIG. 12 is a view following FIG. 11;

FIG. 13 is a view following FIG. 12;

FIG. 14 is a diagram showing the relationship between the energy of an electron beam and the penetrable thickness of a semiconductor chip.

FIG. 15 is a sectional view showing one step in a method of mounting a semiconductor device according to a second embodiment of the present invention.

FIG. 16 is a sectional view following FIG. 15;

FIG. 17 is a sectional view following FIG. 16;

FIG. 18 is a cross-sectional view for explaining a general flip-chip mounting method.

FIG. 19 is an enlarged sectional view showing an example of a main part in FIG. 18 in an enlarged manner.

20 is an enlarged sectional view showing another example of the main part in FIG. 18 in an enlarged manner.

FIG. 21 is a cross-sectional view for explaining a conventional flip chip mounting method.

[Explanation of symbols]

10: semiconductor chip, 11: bump, 12: wiring board,
13: wiring pattern, 14: solder, 16: electron beam curing resin, 17: electron beam, P: polymer, M: monomer, R
... radical, N: three-dimensional network structure.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05K 3/32 H05K 3/32 Z 5F061 F term (Reference) 4J011 QA03 QA09 QA12 QA22 QB03 QB05 QB07 QB08 QB12 QB14 QB17 QB18 QB20 QB22 QB23 QB24 QB25 UA03 VA01 WA01 5E319 AA03 AB05 AC15 BB20 CC33 GG11 GG15 5E336 AA04 CC32 CC58 EE03 EE07 GG16 5F044 KK01 KK14 LL01 LL11 RR17 RR19 5F047 AA17 BA06 BA06 BA06 BA06 BA06 BA06

Claims (10)

[Claims] 1. A method for electrically connecting a semiconductor circuit in a semiconductor device to a wiring board via a protruding connection electrode provided on an outer surface of a semiconductor device, wherein the protruding connection electrode of the semiconductor device is provided. A first step of arranging the semiconductor device on the wiring board so as to come into contact with the wiring pattern of the wiring board; A second step of coating so as to be joined, and a third step of irradiating an electron beam to cure the electron beam-curable resin.
And a method of mounting a semiconductor device. 2. The method according to claim 1, wherein the second step is performed so that the electron beam curable resin is interposed between the semiconductor device and the wiring board. 2. The semiconductor device according to claim 1, wherein the irradiation of the electron beam is controlled so that the wire passes through the semiconductor device and reaches an electron beam cured resin interposed between the semiconductor device and the wiring board. Implementation method. 3. The method according to claim 1, further comprising: connecting a protruding connection electrode of the semiconductor device disposed on the wiring board to the wiring pattern of the wiring board by soldering. 2. The method according to claim 1, wherein the second step is performed. 4. The method according to claim 1, wherein the second step is performed before the first step. 5. A fifth step of polishing a surface of the semiconductor device opposite to the surface on which the semiconductor circuit is formed to control the thickness of the semiconductor device to a predetermined thickness. The method for mounting a semiconductor device according to claim 1, wherein: 6. The method according to claim 5, wherein the predetermined thickness is a thickness through which 90% of the energy of the electron beam can pass. 7. When the energy of the electron beam is 250 keV to 300 keV, the predetermined thickness is set to 200 μm to 40 μm corresponding to each energy.
7. The method according to claim 6, wherein the distance is set to 0 micron.
A mounting method of the semiconductor device described in the above. 8. The method according to claim 1, wherein the electron beam curing resin is a compound containing an acryloy group. 9. The method according to claim 1, wherein the electron beam curing resin is a compound containing a carbon double bond. 10. A semiconductor device assembly in which a semiconductor circuit and a wiring board in the semiconductor device are electrically connected via a protruding connection electrode provided on an outer surface of the semiconductor device, wherein the semiconductor device comprises: The semiconductor device is joined to the wiring substrate by an electron beam cured resin cured by irradiation with an electron beam, and the projection-shaped connection electrode is arranged on the wiring substrate so as to come into contact with the wiring pattern of the wiring substrate. A semiconductor device assembly.