JPH08250543A - Semiconductor device - Google Patents

Abstract

PURPOSE: To lower the connecting resistance by fixing a semiconductor chip and a circuit board by a bonding agent at a part of a region, wherein the semiconductor chip other than a protruding electrodes, which are contributing to the electric connection of the semiconductor chip and the circuit board, faces the circuit board. CONSTITUTION: Under the state, wherein a semiconductor chip 10 is mounted on a circuit board 12, heating, is performed at 120 deg.C for 30 minutes, and a conductive resin 13 and a bonding agent 15 are hardened at the same time. As a result, the semiconductor chip 10 is temporarily fixed on the circuit board 12, and protruding electrodes 11 of the semiconductor chip 10 and bonding pads 14 of the circuit board 12 can be electrically connected. The conductive resin 13 is formed by mixed kneading with thermosetting epoxy resin so that the weight ratio of contained filler becomes 90-95% in much account of connection resistance. Thus, even the protruding electrodes of the semiconductor chip can obtain the electric connection with the bonding pads of the circuit board.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device using flip-chip mounting as means for connecting a semiconductor chip and a circuit board, and particularly, a conductive resin is used as a connecting member for the purpose of low temperature connection or leadless connection. The present invention relates to a semiconductor device used.

[0002]

2. Description of the Related Art Conventionally, flip-chip mounting using a conductive resin as a connecting member is mainly intended to mount a driving semiconductor chip on a glass circuit board for a liquid crystal panel because low-temperature connection is possible. It has become popular. On the other hand, in flip-chip mounting on a ceramic circuit board or a glass epoxy circuit board that is widely and commonly used, solder containing lead and tin as main components has been used as a typical connecting member.

Solder containing lead and tin as main components is inexpensive, has excellent availability, can reduce connection resistance, and is also excellent in mechanical properties. However, in recent years, as attention has been paid to the harmfulness of lead, a solder component containing no lead and other connecting members have been actively studied.

Next, as a first conventional example, a structure and a manufacturing method of a semiconductor device by flip chip mounting for a liquid crystal panel using a conductive resin as a connecting member will be described with reference to FIGS. 14 to 18. FIG. 14 is a view of the semiconductor chip 40 constituting the semiconductor device as seen from the element formation surface. Semiconductor chip 4
A plurality of protruding electrodes 41 are arranged on the element formation surface of 0. FIG. 15 is a view of the circuit board 42 constituting the semiconductor device as seen from the surface on which the semiconductor chip 40 is mounted. The bonding pad 44 is arranged at a position facing the protruding electrode 41 of the semiconductor chip 40.

FIG. 16 shows the semiconductor chip 40 on the circuit board 4.
2 shows a cross section of the semiconductor chip 40 and the circuit board 42 in a state immediately before mounting on the semiconductor device 2. The semiconductor chip has protruding electrodes 41 as input / output terminals, and the circuit board 42 has bonding pads 44 as input / output terminals on the side of the circuit board 42 at positions facing the protruding electrodes 41 of the semiconductor chip 40. Further, at the tip of the protruding electrode 41, before the semiconductor chip 40 is mounted on the circuit board 42, the conductive resin 4 as a connecting member is attached.
3 is transferred in the required minimum amount so as not to short-circuit the adjacent protruding electrodes 41.

Next, after adjusting the relative positions of the semiconductor chip 40 and the circuit board 42, as shown in FIG.
0 is mounted on the circuit board 42, and is heated and hardened depending on the hardening condition of the conductive resin 43. The protruding electrode 41 facing here
And the bonding pad 44 are connected via the conductive resin 43. That is, the conductive resin 43 is applied to the semiconductor chip 40.
It is necessary to fulfill the functions of both the temporary fixing and the electrical connection between the semiconductor chip 40 and the circuit board 42.

At this stage, it is possible to electrically inspect the connection and operation of the semiconductor chip 40 from the side of the circuit board 42. If the semiconductor chip 40 needs to be repaired at this stage, the adhesive force of the conductive resin 43 is about temporary fixing, so that the semiconductor chip 40 can be easily removed from the circuit board 42.

After the temporary fixing is completed, as shown in FIG.
The sealing resin 45 is filled between the semiconductor chip 40 and the circuit board 42 from the end of the semiconductor chip 40 using a dispenser or the like. The filled sealing resin 45 is cured by irradiation with UV light in some cases when heated. The sealing resin 45 is
The semiconductor chip 40 is firmly fixed to the circuit board 42 by the curing of the sealing resin 45, and the curing shrinkage of the sealing resin 45 reduces the connection resistance between the protruding electrode 41 and the bonding pad 44. To complete a semiconductor device with high reliability.

As a second conventional example, a structure and a manufacturing method of a semiconductor device which is flip-chip mounted on a ceramic circuit board or a glass epoxy circuit board using a conductive resin as a connecting member will be described with reference to FIGS. 19 to 22. explain. FIG. 19 is a view of the semiconductor chip 50 forming the semiconductor device as seen from the element formation surface. On the element formation surface of the semiconductor chip 50,
A plurality of protruding electrodes 41 are arranged as in the semiconductor chip 40 of FIG. 14 shown as the first conventional example, but the protruding electrode 41 of the semiconductor chip 40 is also arranged in the central portion of the semiconductor chip 40. On the other hand, basically the protruding electrode 5
The location of 1 is limited to the peripheral portion of the semiconductor chip 50.

FIG. 20 shows a circuit board 5 which constitutes a semiconductor device.
FIG. 2 is a view of No. 2 viewed from the surface on which the semiconductor chip 50 is mounted. The bonding pad 54 is arranged at a position facing the protruding electrode 51 of the semiconductor chip 50. Further, the sealing resin 55 is provided between the bonding pads 54 on the circuit board 52 and at a position facing substantially the center of the semiconductor chip 50.
Is applied in advance so as not to cover the bonding pad 54.

FIG. 21 shows the semiconductor chip 50 on the circuit board 5.
2 shows a cross section of the semiconductor chip 50 and the circuit board 52 in a state immediately before being mounted on the semiconductor device 2. The semiconductor chip has protruding electrodes 51 as input / output terminals, and the circuit board 52 has bonding pads 54 as input / output terminals on the side of the circuit board 52 at positions facing the protruding electrodes 51 of the semiconductor chip 50. In addition, at the tip of the protruding electrode 51, before the semiconductor chip 50 is mounted on the circuit board 52, the conductive resin 5 as a connecting member is attached.
3 is transferred in a necessary minimum amount so as not to short-circuit adjacent protruding electrodes 51.

Next, after adjusting the relative positions of the semiconductor chip 50 and the circuit board 52, as shown in FIG.
When 0 is mounted on the circuit board 52, the sealing resin 55 compressed between the semiconductor chip 50 and the circuit board 52 spreads and is filled between the semiconductor chip 50 and the circuit board 52.
At this time, in order to prevent the conductive filler of the conductive resin 53 transferred to the tip of the protruding electrode 51 from flowing out by the sealing resin 55, a method of preliminarily curing the semiconductor chip 50 on the circuit board 52 is also possible. Proposed.

In this way, the semiconductor chip 50 is mounted on the circuit board 5
Since the filling of the sealing resin 55 is completed at the same time when the semiconductor chip 50 is mounted on the circuit board 2, the semiconductor chip 50 is fixed to the circuit board 52 by heating and curing the sealing resin 55, and each protruding electrode 51 is connected via the conductive resin 53. And the bonding pad 54 are electrically connected to complete the semiconductor device.

[0014]

The conductive resin generally used as the connecting member is an epoxy resin containing metal powder as a conductive filler for obtaining conductivity. As the metal powder to be contained, scaly silver or silver palladium is often used.

In the first conventional example, the conductive resin 43 is used for two purposes of temporarily fixing the semiconductor chip 40 and electrically connecting the semiconductor chip 40 and the circuit board 42. In order to fill the sealing resin 45 after the semiconductor chip 40 is temporarily fixed with the conductive resin 43, sufficient temporary fixing strength is required. Therefore, the amount of the resin component contained in the conductive resin 43 inevitably increases.

On the other hand, the higher the content of the conductive filler contained in the conductive resin 43 is, the more the effect of lowering the connection resistance is obtained. However, considering the strength of temporary fixing described above, the conductive resin 43 in the conductive resin 43 has The content of the conductive filler is limited to about 80% by weight when the metal powder of the conductive filler is silver or silver palladium. When it is contained more than this, the resin component ratio in the conductive resin 43 is too small, and the adhesive strength of the conductive resin 43 is lowered, so that the sealing resin 45 is temporarily fixed before or during the filling. There is a high possibility that the existing semiconductor chip 40 will fall off the circuit board 42 or an open will occur at any of the connection points, resulting in a decrease in yield and extremely poor workability.

The first conventional example has been put into practical use mainly for mounting a driving semiconductor chip of a liquid crystal panel on a glass circuit board. Since the circuit pattern formed on the glass circuit board used in this liquid crystal panel is made of a transparent electrode material having a high resistance, such as ITO, the connection resistance value of the driving semiconductor chip has not been a big problem. It was However, in order to adapt flip-chip mounting that uses conductive resin as a connecting member for applications other than liquid crystal panels, the connection resistance value during mounting must be kept low from the viewpoint of circuit speed and low power consumption. Is required. When the conductive resin having the above-mentioned conductive filler content is actually used for the connecting member, the connection resistance value at one connection terminal is several hundred mΩ to
It will be in the order of 1Ω.

The second conventional example is an attempt to reduce the connection resistance because the first conventional example has a high connection resistance and is not suitable for applications other than liquid crystal panels. That is, the purpose of the conductive resin 53 is to abandon the function of temporarily fixing the semiconductor chip 50 to the circuit board 52, and to make electrical connection between the protruding electrodes 51 and the bonding pads 54 through the conductive resin 53. Is limited.

As a result, the conductive resin 53 contained in the conductive resin 53 may contain a small amount of resin component to such an extent that the conductive filler adheres to the protruding electrode 51 by transfer and does not damage the shape after transfer. Specifically, when the metal powder of the conductive filler contained in the conductive resin 53 is silver or silver palladium, the weight ratio is 90.
If adjusted to ˜95%, the connection resistance value at one connection terminal can be set to 10 to 50 mΩ.

However, the semiconductor chip 5 is not attached to the conductive resin 53.
Since the adhesive strength for temporarily fixing 0 to the circuit board 52 cannot be expected at all, the sealing resin 55 is previously supplied onto the circuit board 52 for fixing the semiconductor chip 50, as described above. The semiconductor chip 50 is mounted on the circuit board 52, and at the same time, the sealing resin 55 is placed on the semiconductor chip 50 and the circuit board 52.
Need to fill in between.

The sealing resin 55 spreads when the semiconductor chip 50 and the circuit board 52 are shortened when the semiconductor chip 50 is mounted.
It is necessary to prevent the encapsulation resin 55 from penetrating between the conductive resin 53 transferred to the tip of the and the bonding pad 54 and causing the conduction failure. Moreover, it is necessary to adjust the amount so that the expanded sealing resin 55 forms a good fillet with respect to the outer shape of the semiconductor chip 50. Very delicate control is required to ensure the reliability of the completed semiconductor device.

In addition, as shown in FIGS. 20 and 21, in order to previously supply the sealing resin 55 on the circuit board 52 in an amount sufficient to sufficiently fill the gap between the semiconductor chip 50 and the circuit board 52, As shown in FIG. 14 of the first conventional example, it is impossible to dispose the protruding electrode 51 also in the central portion of the semiconductor chip 50. That is, in the second conventional example, there is a large restriction on the arrangement of the protruding electrodes 51 of the semiconductor chip 50, and the flip-chip mounting can also arrange the protruding electrodes at the central portion of the semiconductor chip, which makes it possible to cope with the increase in the number of pins of the semiconductor chip. You cannot take advantage of the advantage of being there.

Furthermore, the electrical inspection of the connection and operation of the semiconductor chip 50 must be performed after the sealing resin 55 has been cured, and when the semiconductor chip 50 is determined to be defective, the semiconductor chip 50 can be removed from the entire surface of the semiconductor chip 50. Is fixed by the sealing resin 55, which is more difficult than the first conventional example. After removing at least the semiconductor chip 50,
The sealing resin 55 and the like left on the circuit board 52 must be removed cleanly.

That is, in the first conventional example, it is difficult to balance the strength of temporary fixing before sealing and the connection resistance value, and the main application is limited to mounting a semiconductor chip on a glass circuit board for a liquid crystal panel. On the other hand, in the second conventional example, although the restriction of the circuit board is eliminated, the control of the sealing resin is difficult, the projection electrode arrangement is restricted, and the defective semiconductor chip requiring repair is restricted. This makes it difficult to popularize flip chip mounting using a conductive resin as a connecting member.

The object of the present invention is to maintain the temporary fixing strength of the semiconductor chip before filling the encapsulating resin, to lower the connection resistance, to reduce the restrictions on the arrangement of the protruding electrodes, and to facilitate the repair, and to improve the conductivity. It is intended to provide a configuration of a semiconductor device by flip mounting using a resin as a connecting member.

[0026]

In order to achieve the above object, the semiconductor device of the present invention adopts the structure described below.

In the semiconductor device of the present invention, the metal powder of the conductive filler is used as a connecting member between the protruding electrode formed on the semiconductor chip and the bonding pad of the circuit board in a weight ratio of 9%.
A semiconductor device in which the semiconductor chip is flip-chip mounted on the circuit board using a conductive resin containing 0 to 95%, wherein the semiconductor chip and the circuit other than the projecting electrodes contribute to the electrical connection between the semiconductor chip and the circuit board. The semiconductor chip and the circuit board are fixed by an adhesive in a part of a region where the boards face each other, and a gap between the semiconductor chip and the circuit board is filled with a sealing resin.

Further, in the above semiconductor device, the adhesive is the same resin component as the resin component other than the conductive filler component in the conductive resin, and the adhesive does not contain the conductive filler. To do.

Further, in the semiconductor device of the present invention, the semiconductor chip is provided with the protruding electrode that contributes to the electrical connection between the semiconductor chip and the circuit board and the dummy protruding electrode that does not contribute to the electrical connection. Another feature is that the circuit boards are fixed with an adhesive.

[0030]

In the present invention, the metal powder of the conductive filler is used as a connecting member between the protruding electrode formed on the semiconductor chip and the bonding pad of the circuit board in a weight ratio of 90 to 95.
% Of the conductive resin is used, the electrical connection between the protruding electrode of the semiconductor chip and the bonding pad of the circuit board can be made with a low connection resistance value.

Further, the semiconductor chip and the circuit board are formed in the conductive resin in a part of a region where the semiconductor chip and the circuit board are opposed to each other except for the protruding electrodes that contribute to the electrical connection between the semiconductor chip and the circuit board. It is the same resin as the resin component excluding the conductive filler component, and since the adhesive is fixed by the adhesive that does not contain the conductive filler, the adhesive strength of the temporary fixing of the semiconductor chip before sealing resin filling is Sufficiently obtained, the probability that the semiconductor chip will drop out during the process or open at any connection point will be low, the yield can be secured and the workability is excellent, and it will be possible in a part of the area excluding the protruding electrodes of the semiconductor chip. Since it may be fixed, the arrangement of the protruding electrodes on the semiconductor chip is not significantly restricted.

Since the protruding electrodes of the semiconductor chip and the bonding pads of the circuit board are already connected by the conductive resin, the semiconductor chip is electrically connected and operated electrically from the circuit board side before the sealing resin is filled. Inspection is possible. Here, even if a defect is found and the semiconductor chip is to be removed for repair, it is not adhesively fixed in the entire gap between the semiconductor chip and the circuit board by the sealing resin, but in the area where the semiconductor chip and the circuit board face each other. Since the adhesive is partially fixed, the semiconductor chip can be easily removed. Further, the adhesives left on the circuit board are very small, and it is easy to remove them.

Next, if the adhesive is the same resin component as the resin component excluding the conductive filler component in the conductive resin,
Since the curing conditions for the adhesive and the conductive resin are the same,
By curing both at the same time, the number of steps can be reduced.

Further, in the semiconductor device of the present invention, the semiconductor chip is provided with the bump electrode that contributes to the electrical connection between the semiconductor chip and the circuit board and the dummy bump electrode that does not contribute to the electrical connection. By fixing the circuit boards with an adhesive, the amount of adhesive applied can be minimized and the spread of the adhesive can be avoided. It can be further reduced.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a semiconductor device according to a first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a view of a semiconductor chip 10 constituting a semiconductor device as seen from an element formation surface. Further, FIG. 2 shows a circuit board 12 constituting a semiconductor device.
FIG. 3 is a view of the semiconductor device viewed from the surface on which the semiconductor chip 10 is mounted.
FIG. 3 shows a cross section of the semiconductor chip 10 and the circuit board 12 immediately before the semiconductor chip 10 is mounted on the circuit board 12.

A plurality of protruding electrodes 11 are formed on the semiconductor chip 10 on the element forming surface of the semiconductor chip 10. The semiconductor chip 10 is a square having a side of 5.4 mm and a thickness of 0.
As shown in FIG. 1, 148 protruding electrodes 11 each having a size of 625 mm and having an interval of 200 μm were arranged.

The details of the bump electrode 11 are shown in FIG. A protective film 18 formed of a nitride film or the like on the semiconductor chip 10.
Is open at the Al input / output terminal 17 portion. A barrier layer 19 is formed on the openings of the input / output terminals 17 and on the protective film 18 by means such as sputtering or vapor deposition for the purpose of preventing metal diffusion into the semiconductor and enhancing the adhesion of the protruding electrodes 11. As the barrier layer 19, Ti, Cr, Ni or the like is used.

On the barrier layer 19, a resist layer (not shown) is further applied, and after the projection electrode forming portion of the resist layer is opened by photolithography, the barrier layer 19 is used as a cathode electrode film. The protruding electrode 11 is formed in the opening of the resist layer by electroplating. Although Au, Cu, or the like is used as the protruding electrode 11, considering the contact resistance of the conductive resin 13 with the conductive filler, it is desirable that at least the surface of the protruding electrode 11 is made of a material such as Au that is not easily oxidized.

After forming the bump electrodes 11, the resist layer is peeled off by a dedicated peeling liquid, and the exposed barrier layer 19 is removed by etching using the bump electrodes 11 as a mask, as shown in FIG. A protruding electrode 11 having a structure is formed.

Returning to FIG. 1 to FIG. 3, the description will be further continued. The method of forming the bonding pad 14 on the circuit board 12 generally differs depending on the base material such as a ceramic circuit board or a glass epoxy circuit board, but various forming methods are known and will not be described in detail here. Bonding pad 1
Although Cu is generally used as the material of No. 4, Ni and Au are plated on Cu in consideration of the contact resistance of the conductive resin 13 with the conductive filler. Circuit board 12
As a matter of course, the upper bonding pad 14 is arranged at a position facing the protruding electrode 11 of the semiconductor chip 10.

Further, as shown in FIG. 3, the semiconductor chip 1
A conductive resin 13, which is a connecting member between the bump electrode 11 and the bonding pad 14, is transferred to the tip of the bump electrode 11 of 0 in the minimum amount necessary so as not to short-circuit the adjacent bump electrodes 11.

Transfer of the conductive resin 13 will be described with reference to FIG. The conductive resin 13 is filled in a thin dish-shaped container 20, the surface of the filled conductive resin 13 is smoothed with a squeegee, and then the semiconductor chip 10 is placed in the container 20.
And is transferred to contact with the conductive resin 13 filled only in the tip of the bump electrode 11. Conductive resin 13
The transfer amount can be controlled by the amount of the semiconductor chip 10 dropped into the container. In this embodiment, the height is 40μ.
The tip 10 μm of the projection electrode 11 of m was immersed in the conductive resin 13 and transferred.

Now, the conductive resin 13 will be described. The main function required of the conductive resin 13 used in the present invention is to obtain an electrical connection between the protruding electrode 11 of the semiconductor chip 10 and the bonding pad 14 of the circuit board 12 with a low connection resistance value. As far as the adhesive force is concerned, the conductive filler contained in the conductive resin 13 from the transfer of the conductive resin 13 to the protruding electrodes 11 until the sealing resin is filled between the semiconductor chip 10 and the circuit board 12 and cured. However, it is only necessary to aggregate them so as not to scatter or flow out and to obtain the auxiliary adhesive strength of the adhesive for temporarily fixing the semiconductor chip 10 to the circuit board 12.

Therefore, the conductive resin 13 used in the examples of the present invention was kneaded with a thermosetting epoxy resin so that the weight ratio of the conductive filler contained in the conductive resin 13 was 95% with an emphasis on connection resistance. . The metal powder used as the conductive filler is silver palladium in the form of scales having a size of several μm. The adhesive strength of the conductive resin 13 is about 40 kgf / cm ²
Thus, the adhesive strength of the conductive filler, which emphasizes the adhesiveness of the conductive resin, of 75% is very weak as compared with the adhesive strength of the conductive resin of about 140 kgf / cm ² .

Regarding the connection resistance, when the diameter of the bonding portion at the tip of the bump electrode 11 is φ80 μm, the connection resistance value at one connection terminal is several hundreds mΩ to 1Ω in the case of the conductive resin in which the weight ratio of the conductive filler is 75%. It will be an order of
The connection resistance value at one place of the connection terminal of the conductive resin 13 used in the examples of the present invention is 10 to 50 mΩ.

Next, the adhesive 15 shown in FIGS. 2 and 3 will be described. The adhesive 15 used in the examples of the present invention is made of the same resin component as the resin component except the conductive filler component in the conductive resin 13, and is an epoxy resin component of the conductive resin 13. Further, of course, in order to enhance the adhesive force, the conductive filler is not included. The adhesive 15 is simultaneously cured when the conductive resin 13 transferred to the tip of the protruding electrode 11 of the semiconductor chip 10 is cured,
Both heat curing processes can be made common. Of course, assuming that the curing work for both is a separate step, an adhesive having another component having a stronger adhesive force and being easy to handle may be used.

The application position of the adhesive 15 is such that the bonding pad 14 of the circuit board 12 is not covered, and when the semiconductor chip 10 is mounted on the circuit board 12, the adhesive 15 is applied to the protruding electrodes 11 and the bonding pads 14. The distance between the bonding pads 14 of the circuit board 12 is set sufficiently wide so as not to spread and make contact. In addition, as shown in FIG. 1, the protruding electrode 11 is not provided on the element formation surface of the semiconductor chip 10 facing the application position of the adhesive 15.

The amount of adhesive 15 applied is equal to that of the semiconductor chip 10.
And the amount of adhesive strength required for fixing the circuit board 12, and the amount of swelling of the applied adhesive 15 is larger than the gap between the semiconductor chip 10 and the circuit board 12 when the semiconductor chip 10 is mounted on the circuit board 12. Also needs to be big.

The coating amount of the adhesive 15 according to the embodiment of the present invention will be described. First, as shown in FIG. 4, the maximum diameter D _b of the bump electrode 11 is φ120 μm, the height h of the bump electrode 11 is 40 μm, and the size D _{P of the} bonding pad 14 is D _p.
Is 130 μm, and the semiconductor chip 10 is the circuit board 1
The gap G between the semiconductor chip 10 and the circuit board 12 after being mounted on No. 2 is about 45 μm. Further, the diameter d of the adhesive portion is φ80 μm.

In our experience, when a semiconductor chip is temporarily fixed to a circuit board using a conductive resin having a weight ratio of the conductive filler of 75%, the gap between the semiconductor chip and the circuit board is filled with the sealing resin. It is extremely rare for the semiconductor chip to drop off or the electrical connection to be opened at the connection point until it is cured and fixed. The adhesive strength of the semiconductor chip when temporarily fixed with 148 protruding electrode portions is about 1036 gf when the diameter of the adhesive portion per protruding electrode is φ80 μm.

On the other hand, when the conductive resin used in the examples of the present invention was used for the conductive resin in which the weight ratio of the conductive filler was 95% and the connection resistance was emphasized, temporary fixing was performed only with 148 protruding electrode portions. The adhesive strength of the semiconductor chip is about 296 gf when the diameter of the adhesive portion for each protruding electrode is φ80 μm. In this case, the semiconductor chip is often dropped or the electrical connection is opened at the connection point before the sealing resin is filled in the gap between the semiconductor chip and the circuit board, cured, and fixed.

In view of this, in the present invention, the semiconductor chip 10 having different weight ratios of the conductive filler contained in the conductive resin is used.
Difference in adhesive strength of temporary fixing of 1036-296 = 740 gf
Is supplemented with the adhesive strength of the adhesive 15. That is, when the adhesive 15 is applied to four places as shown in FIG. 2, an adhesive strength of 185 gf or more per one place is required. Since the adhesive strength of the adhesive 15 used in this example is about 200 kgf / cm ² ,
The required adhesive strength can be obtained if the diameter of one bonded portion is 350 μm or more.

Actually, an adhesive 15 made of the same resin as the resin component except the conductive filler component in the conductive resin 13
Is dripped on the resist layer covering the surface of the circuit board 12 by using a microdispenser, and about 3 × 10 ⁻³ ml is dropped,
Due to the relationship between viscosity and wettability, the adhesive 15 has a diameter of about 600μ.
m, and the rising height is about 86 μm. As described above, the gap h between the semiconductor chip 10 and the circuit board 12 after mounting the semiconductor chip 10 on the circuit board 12 is about 45 μm.
Therefore, the adhesive 15 touches the semiconductor chip 10 as shown in FIG. 6, and the diameter φ350 μm or more of the adhesive portion at which the necessary adhesive strength is obtained is the semiconductor chip 10 and the adhesive 15
It can also be secured at the contact part of.

The spacing between the bonding pads 14 on both sides at the application position of the adhesive 15 in FIG. 2 is 1470 μm.
Since there is an adhesive 15, the semiconductor chip 10 and the circuit board 1
Even if it is crushed and spread by 2, the adhesive 15 does not contact the bonding pad 14 and the protruding electrode 11 and obstruct electric conduction as long as it is applied to substantially the center of the bonding pad 14 on both sides of the adhesive 15. .

Thus, the protruding electrode 1 of the semiconductor chip 10
The arrangement of 1 and the arrangement of the bonding pad 14 of the circuit board 12 have some restrictions in order to avoid the adhesive 15. However, in reality, no matter how many pins the semiconductor is required to have, it is impossible to arrange the protruding electrodes at a fine pitch, for example, a pitch of 200 μm, on the entire surface of the semiconductor chip on which the elements are formed. This is because the semiconductor chip requires a very small number of input / output terminals with respect to the number of formed elements, and the protruding electrodes are not required on the entire element forming surface of the semiconductor chip. Further, even if the protruding electrodes are formed on the entire surface of the element formation surface of the semiconductor chip with a fine pitch, the wiring from the bonding pad cannot be drawn out due to the restriction of patterning on the circuit board side.

Therefore, in the embodiment of the present invention, FIG.
The realistic arrangement of the protruding electrode 11 and the bonding pad 14 as shown in FIG. Even in this arrangement, the semiconductor chip 10
The number of connecting terminals can be sufficiently increased compared to the case where the protruding electrodes and the bonding pads are arranged only in the peripheral portion of the semiconductor chip. A small amount of adhesive 1
5 for applying the bump electrode 11 and the bonding pad 1
Since there are few restrictions on the arrangement of No. 4, it is possible to cope with the increase in the number of pins of the semiconductor chip within a realistic required range.

Next, the conductive resin 1 is attached to the tip of the protruding electrode 11.
3 is transferred to the bonding pad 14 of the circuit board 12.
From the state of FIG. 3 in which the adhesive 15 is applied between the two, the positions of the protruding electrodes 11 of the semiconductor chip 10 and the bonding pads 14 of the circuit board 12 which face each other are aligned and then the semiconductor chip 10 is circuited as shown in FIG. It is mounted on the substrate 12.

Further, the semiconductor chip 10 is connected to the circuit board 12
In the state of FIG. 6 mounted on the top, heating is performed at 120 ° C. for 30 minutes to simultaneously cure the conductive resin 13 and the adhesive 15. As a result, the semiconductor chip 10 is temporarily fixed on the circuit board 12 and at the same time the protruding electrodes 1 of the semiconductor chip 10 are
1 and the bonding pad 14 of the circuit board 12 can be electrically connected. Of course, this is the case of the adhesive 15 made of the same resin as the resin component excluding the conductive filler component in the conductive resin 13, and when an adhesive made of another component is used, the curing conditions of the adhesive are In accordance with the above, a hardening operation different from the hardening of the conductive resin 13 may be performed.

At this point, the connection and operation of the semiconductor chip 10 are electrically inspected from the side of the circuit board 12, and if a defect is found, the semiconductor chip 10 is removed for repair. At this time, since the gap between the semiconductor chip 10 and the circuit board 12 is not yet filled with the sealing resin,
The removal of the semiconductor chip 10 does not require so much force and does not particularly damage the circuit board 12 or the bonding pad 14. Further, when the semiconductor chip 10 is removed, the conductive resin 13 and the adhesive 15
When heated, the removal force is less.

The adhesive 15 left on the circuit board 12 is
Very small amount. It is easy to scrape off with a sharp blade.

If the above inspection determines that the product is non-defective, the gap between the semiconductor chip 10 and the circuit board 12 is filled with the sealing resin 16 and the sealing resin 16 is cured, as shown in FIG.
The semiconductor device of this embodiment is completed. The sealing resin 16 not only completely fixes the semiconductor chip 10 to the circuit board 12, but also mechanically protects the semiconductor chip 10 and the semiconductor chip 1.
0, the stress caused by the difference in the coefficient of thermal expansion between the circuit board 12 and the circuit board 12 is protected, the entire semiconductor device is protected from humidity, and the protruding electrode 11 and the bonding pad 14 are caused by the curing and shrinkage of the sealing resin 16.
There are various functions to improve the reliability of the semiconductor device, such as a decrease in the connection resistance of the semiconductor device.

Next, the structure of the second embodiment in which the dummy protruding electrode 37 is provided on the semiconductor chip 30 is shown in FIG.
The configuration of the semiconductor device according to the embodiment of the present invention will be described with reference to FIGS. FIG. 8 is a view of the semiconductor chip 30 forming the semiconductor device as seen from the element formation surface. In addition, FIG.
FIG. 3 is a view of a circuit board 32 constituting a semiconductor device as seen from a surface on which a semiconductor chip 30 is mounted. FIG. 10 shows a cross section of the semiconductor chip 30 and the circuit board 32 immediately before the semiconductor chip 30 is mounted on the circuit board 32.

A plurality of protruding electrodes 31 and a plurality of dummy protruding electrodes 37 are formed on the element forming surface of the semiconductor chip 30.
The semiconductor chip 30 has a square shape with a side of 5.4 mm, a thickness of 0.625 mm, and 148 projecting electrodes 31 with an interval of 200 μm arranged as shown in FIG. The dummy protruding electrodes 37 are arranged at equal intervals with the protruding electrodes 31.
I arranged them individually.

Although the protruding electrode 31 is formed on the input / output terminal of the semiconductor chip 30, the dummy protruding electrode 37 is formed on the dummy input / output terminal of the semiconductor chip 30 or on the protective film of the semiconductor chip 30. It may be formed on. The detailed structures of the bump electrode 31 and the dummy bump electrode 37 are the same as those shown in FIG. In this embodiment, the bump electrode 31 is formed with a maximum diameter of 120 μm and a height of 40 μm, and the dummy bump electrode 37 is formed with a maximum diameter of 300 μm and a height of 40 μm.

At the tip of the protruding electrode 31 of the semiconductor chip 30, a minimum amount of conductive resin 33, which is a connecting member between the protruding electrode 31 and the bonding pad 34, is formed so as not to short-circuit adjacent protruding electrodes 31. It has been transcribed.

Transfer of the conductive resin 33 will be described with reference to FIG. The conductive resin 33 is a thin dish-shaped container 38.
After smoothing the surface of the filled conductive resin 33 with a squeegee, the semiconductor chip 30 is lowered into the container to contact the filled conductive resin 33 only at the tip of the protruding electrode 31. Transcribed. The transfer amount of the conductive resin 33 can be controlled by the amount of the semiconductor chip 30 dropped into the container. In this embodiment, the height is 40 μm
The tip 10 μm of the protruding electrode 31 was dipped in the conductive resin 33 and transferred.

However, the conductive resin 33 is not transferred to the tip of the dummy protruding electrode 37. As shown in FIG. 12, the concave portion is provided at a position facing the dummy protruding electrode 37 of the container 38 to prevent the conductive resin 33 from being transferred to the tip of the dummy protruding electrode 37.

As the conductive resin 33, a conductive filler made of silver palladium scale having a weight ratio of 95% is used so as to obtain a low connection resistance. The grounds for this are as described in the first embodiment.

On the other hand, at the position of the circuit board 32 facing the dummy protruding electrode 37 of the semiconductor chip 30, the adhesive 35 does not cover the bonding pad 34 of the circuit board 32, and the semiconductor chip 30 is mounted on the circuit board 32. The adhesive 35 is applied in an extremely small amount so that the adhesive 35 does not spread and contact the protruding electrode 31 and the bonding pad 34 when mounted on the top.

In this embodiment, the adhesive 35 made of the same resin as the resin component excluding the conductive filler component in the conductive resin 33, which is the same as in the first embodiment, is used. It is also the same as in the first embodiment that an adhesive having another component that is easy to use may be used.

The adhesive strength required for the adhesive 35 is about 740 gf or more as in the first embodiment, and about 82 gf or more is required for the adhesive strength of each dummy protruding electrode 37. Become. Since the adhesive strength of the adhesive 35 used in the present embodiment is about 200 kgf / cm ² , the required adhesive strength can be obtained if the diameter of one adhesive part is 230 μm or more. As described above, since the maximum diameter of the dummy bump electrode 37 is 300 μm, the bonding area between the dummy bump electrode 37 and the circuit board 32 can be sufficiently secured.

At this time, since the gap between the semiconductor chip 30 and the circuit board 32 after mounting the semiconductor chip 30 on the circuit board 32 is about 45 μm, and the height of the dummy protruding electrode 37 is 40 μm, the dummy The distance from the tip of the protruding electrode 37 to the surface of the circuit board 32 is about 5 μm.
That is, it is clear that the adhesive 35 applied to the position of the circuit board 32 facing the dummy protruding electrode 37 may be smaller than that of the first embodiment.

Since the adhesive 35 is extremely small and the distance from the tip of the dummy protruding electrode 37 to the surface of the circuit board 32 is short, the semiconductor chip 30 is mounted on the circuit board 32 as shown in FIG. The spread of the adhesive 35 after mounting can be suppressed to be small, and the distance to the surrounding protruding electrodes 31 and the bonding pads 34 can be designed to be short. This means that the protruding electrode 31 of the semiconductor chip 30 is
It is shown that the restriction on the arrangement position of can be relaxed.

Here, after the adhesive 35 is cured, an electrical inspection of the connection and operation of the semiconductor chip 30 is performed from the side of the circuit board 32. If a defect is found, the semiconductor chip 30 is repaired. To remove. At this time, since the gap between the semiconductor chip 30 and the circuit board 32 is not filled with the sealing resin, a great force is not required to remove the semiconductor chip 30, and especially the circuit board 32 and the bonding pad 34 are not removed. No damage will occur. Further, when the conductive resin 33 and the adhesive 35 are heated at the time of removing the semiconductor chip 30, the removing force is small.

When it is judged as a non-defective product in the above-mentioned inspection, as shown in FIG. 13, the sealing resin 36 is filled in the gap between the semiconductor chip 30 and the circuit board 32, and the sealing resin 36 is hardened. The example semiconductor device is completed. Sealing resin 36
In addition to completely fixing the semiconductor chip 30 to the circuit board 32, the mechanical protection of the semiconductor chip 30, the dispersion of stress caused by the difference in the coefficient of thermal expansion between the semiconductor chip 30 and the circuit board 32, and the humidity of the entire semiconductor device Protection from resin, sealing resin 36
Electrode 31 and bonding pad 3 due to hardening and shrinkage of
4 has various functions such as a decrease in connection resistance, which improves the reliability of the semiconductor device.

[0076]

As is apparent from the above description, in the present invention, as a connecting member between the protruding electrode formed on the semiconductor chip and the bonding pad of the circuit board, the metal powder of the conductive filler is used in a weight ratio of 90. Since the conductive resin containing ˜95% is used, the electrical connection between the protruding electrode of the semiconductor chip and the bonding pad of the circuit board can be achieved with a low connection resistance value.

Further, in a part of the region where the semiconductor chip and the circuit board are opposed to each other, except for the protruding electrodes that contribute to the electrical connection between the semiconductor chip and the circuit board, the semiconductor chip and the circuit board are formed in the conductive resin. It is the same resin as the resin component excluding the conductive filler component, and since the adhesive is fixed by the adhesive that does not contain the conductive filler, the adhesive strength of the temporary fixing of the semiconductor chip before sealing resin filling is Sufficiently obtained, the probability that the semiconductor chip will drop out during the process or open at any connection point will be low, the yield can be secured and the workability is excellent, and it will be possible in a part of the area excluding the protruding electrodes of the semiconductor chip. Since it may be fixed, the arrangement of the protruding electrodes on the semiconductor chip is not significantly restricted.

Since the protruding electrode of the semiconductor chip and the bonding pad of the circuit board are already connected by the conductive resin, the semiconductor chip is electrically connected and operated electrically from the circuit board side before filling the sealing resin. Inspection is possible. Here, even if a defect is found and the semiconductor chip is to be removed for repair, it is not adhesively fixed in the entire gap between the semiconductor chip and the circuit board by the sealing resin, but in the area where the semiconductor chip and the circuit board face each other. Since the adhesive is partially fixed, the semiconductor chip can be easily removed. Further, the adhesives left on the circuit board are very small, and it is easy to remove them.

Next, if the adhesive is the same resin component as the resin component excluding the conductive filler component in the conductive resin,
Since the curing conditions for the adhesive and the conductive resin are the same,
By curing both at the same time, the number of steps can be reduced.

Further, in the semiconductor device of the present invention, the semiconductor chip is provided with the protruding electrode that contributes to the electrical connection between the semiconductor chip and the circuit board and the dummy protruding electrode that does not contribute to the electrical connection. By fixing the circuit boards with an adhesive, the amount of adhesive applied can be minimized and the spread of the adhesive can be avoided. It can be further reduced.

In this way, while maintaining the temporary fixing strength of the semiconductor chip before filling the encapsulating resin, the connection resistance is lowered, the restrictions on the arrangement of the protruding electrodes are reduced, and the semiconductor device is easy to repair. Thus, it is possible to extend the applicable range of flip-chip mounting using a conductive resin as a connecting member to a ceramic circuit board or a glass epoxy circuit board while responding to high speed and high pin count of a semiconductor device.

[Brief description of drawings]

FIG. 1 is a plan view of a semiconductor chip 10 constituting a semiconductor device according to a first exemplary embodiment of the present invention, as viewed from an element formation surface.

FIG. 2 is a plan view of the circuit board 12 constituting the semiconductor device according to the first embodiment of the present invention, as viewed from the surface on which the semiconductor chip 10 is mounted.

FIG. 3 is a cross-sectional view of the semiconductor chip 10 and the circuit board 12 in a state immediately before mounting the semiconductor chip 10 constituting the semiconductor device according to the first embodiment of the present invention on the circuit board 12.

FIG. 4 is a cross-sectional view showing a structure of a bump electrode 11 of a semiconductor chip 10 which constitutes a semiconductor device according to a first embodiment of the present invention.

FIG. 5 is a plan view of the semiconductor device according to the first embodiment of the present invention.
3 is a cross-sectional view showing a method for transferring No.

FIG. 6 is a cross-sectional view of the semiconductor chip 10 and the circuit board 12 immediately after the semiconductor chip 10 constituting the semiconductor device according to the first embodiment of the present invention is mounted on the circuit board 12.

FIG. 7 is a cross-sectional view showing a completed state after the semiconductor device according to the first embodiment of the present invention is filled with the sealing resin 16.

FIG. 8 is a plan view of a semiconductor chip 30 forming a semiconductor device according to a second embodiment of the present invention, as viewed from an element formation surface.

FIG. 9 is a plan view of a circuit board 32 constituting a semiconductor device according to a second embodiment of the present invention, as viewed from a surface on which a semiconductor chip 30 is mounted.

FIG. 10 is a sectional view of the semiconductor chip 30 and the circuit board 32 in a state immediately before mounting the semiconductor chip 30 constituting the semiconductor device according to the second embodiment of the present invention on the circuit board 32.

FIG. 11 is a cross-sectional view of the semiconductor chip 30 and the circuit board 32 immediately after the semiconductor chip 30 constituting the semiconductor device according to the second embodiment of the present invention is mounted on the circuit board 32.

FIG. 12 is a cross-sectional view showing a method of transferring a conductive resin 33 to the protruding electrodes 31 of the semiconductor chip 30 which constitutes the semiconductor device according to the second embodiment of the present invention.

FIG. 13 is a cross-sectional view showing a completed state of the semiconductor device according to the second embodiment of the present invention after being filled with a sealing resin 36.

FIG. 14 is a plan view of a semiconductor chip 40 forming a semiconductor device according to a first conventional example as viewed from an element formation surface.

FIG. 15 is a plan view of a circuit board 42 constituting a semiconductor device according to a first conventional example, as viewed from a surface on which a semiconductor chip 40 is mounted.

FIG. 16 is a cross-sectional view of the semiconductor chip 40 and the circuit board 42 in a state immediately before mounting the semiconductor chip 40 constituting the semiconductor device in the first conventional example on the circuit board 42.

FIG. 17 is a cross-sectional view of the semiconductor chip 40 and the circuit board 42 immediately after the semiconductor chip 40 constituting the semiconductor device according to the first conventional example is mounted on the circuit board 42.

FIG. 18 is a cross-sectional view showing a completed state after the semiconductor device in the first conventional example is filled with the sealing resin 45.

FIG. 19 is a plan view of a semiconductor chip 50 forming a semiconductor device according to a second conventional example, as viewed from an element formation surface.

FIG. 20 is a plan view of a circuit board 52 constituting a semiconductor device according to a second conventional example, as viewed from the surface on which a semiconductor chip 50 is mounted.

FIG. 21 is a cross-sectional view of the semiconductor chip 50 and the circuit board 52 immediately before mounting the semiconductor chip 50 constituting the semiconductor device in the second conventional example on the circuit board 52.

FIG. 22 is a cross-sectional view showing a completed state of a semiconductor device in a second conventional example.

[Explanation of symbols]

 10 Semiconductor Chip 11 Projection Electrode 12 Circuit Board 13 Conductive Resin 14 Bonding Pad 15 Adhesive 16 Sealing Resin 30 Semiconductor Chip 31 Projection Electrode 32 Circuit Board 33 Conductive Resin 34 Bonding Pad 35 Adhesive 36 Sealing Resin 37 Dummy Projection electrode

Claims (3)

[Claims] 1. A conductive resin containing 90 to 95% by weight of a metal powder of a conductive filler is used as a connecting member between a protruding electrode formed on a semiconductor chip and a bonding pad of a circuit board. A semiconductor device flip-chip mounted on the circuit board, wherein the semiconductor chip and the semiconductor chip are part of a region where the semiconductor chip and the circuit board are opposed to each other except for the protruding electrodes that contribute to electrical connection between the semiconductor chip and the circuit board. A semiconductor device, wherein the circuit board is fixed by an adhesive, and a gap between the semiconductor chip and the circuit board is filled with a sealing resin. 2. The adhesive is the same resin component as the resin component excluding the conductive filler component in the conductive resin, and the adhesive does not contain the conductive filler. Semiconductor device. 3. A semiconductor chip is provided with a protruding electrode that contributes to electrical connection between the semiconductor chip and the circuit board and a dummy protruding electrode that does not contribute to electrical connection, and an adhesive is provided between the dummy protruding electrode and the circuit board. 3. The semiconductor device according to claim 1 or 2, wherein the semiconductor device is fixed by.