JPH06333983A - Semiconductor device and its manufacture - Google Patents

Abstract

PURPOSE:To obtain stable connection without the increment of connection resistance by bonding an aluminum electrode and the bump electrode of a semiconductor element by means of a conductive binder mixed wherein conductive particles are mixed, and then, charging hardening and shrinkable synthetic resin into the periphery of connection between both. CONSTITUTION:Gold bump electrodes 3 about 70mum in height and about 80mum in diameter made on about 150 pieces of electrode pads arranged at the pitches of 150gm on an IC chip 1 and the electrodes 6 made, in the same number and at the same pitches as the electrode pads 2, on the circuit board 5 being the substrate constituting a liquid crystal display, out of aluminum layers about 3000Angstrom in thickness are connected with each other by means of conductive binders 4, and then fillers 7 consisting of hardening and shrinkable synthetic resin are charged between the IC chip 1 and the circuit board 5. Conductive particles consisting of globular nickel particles 8, harder than aluminum and 5mum in average diameter and scale-shaped silver-platinum particles 9 about 1mum in average diameter are mixed in the conductive binder 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device on which a semiconductor element such as an IC chip or an LSI chip is mounted, and a method for manufacturing the same, and more particularly, the semiconductor element is faced down by a micro bump method and connected to an electrode on a circuit board. The present invention relates to a manufacturing method for mounting by mounting.

[0002]

2. Description of the Related Art In a recent flat panel display such as a liquid crystal display, it is necessary to mount a large number of semiconductor elements. Therefore, in order to reduce the mounting area and to use the semiconductor element efficiently, a bare semiconductor element is required. Are directly attached to the terminal electrodes on the circuit board made of glass. As a method for electrically connecting the semiconductor element and the electrode of the circuit board, there is a method of connecting the protruding electrode formed on the electrode pad of the semiconductor element by adhering it to the electrode of the circuit board using a conductive adhesive. Known from the past. Also, as liquid crystal displays and the like become larger and finer, the number of outputs per chip of the liquid crystal driving IC increases and the clock pulse frequency increases, so efforts are made to reduce wiring resistance and connection resistance. ing. On the other hand, recently, the mainstream of the electrode material for liquid crystal displays has been indium-tin oxide, but when this electrode material is used, the wiring resistance and contact resistance are large, and the voltage drop causes a reduction in the response speed. Since this phenomenon is observed especially in the case of a liquid crystal panel using a thin film transistor because normal image display may not be possible, there is a movement to reduce the resistance by using aluminum or an alloy containing aluminum as an electrode material. ing.

Next, a conventional mounting method for directly mounting the above semiconductor element on an electrode of a circuit board and a mounted semiconductor device will be described with reference to FIGS. 2 and 3. Figure 2
3A to 3F show steps of a conventional IC chip mounting method, and FIG. 3 is a cross-sectional view of essential parts of the mounted semiconductor device. In the figure, reference numeral 1 denotes an IC chip, on which about 150 electrode pads 2 arranged at a pitch of 150 μm are formed with bump electrodes 3 called gold bumps having a height of about 70 μm and a diameter of about 80 μm. . 5
Is a circuit board such as a liquid crystal panel, and the end portion thereof has the same number and pitch as the electrode pads 2 of the IC chip 1 and a film thickness of about 30.
An electrode 6 made of 00Å aluminum or an alloy containing aluminum is formed. Reference numeral 10 is a conductive adhesive composed of conductive particles 11 made of scaly silver having an average particle diameter of about 1 μm and a thermosetting resin. Reference numeral 12 is a silicone thermosetting resin. 13 is a film forming blade 1
4 is a support for forming a film of the conductive adhesive 10 by using No. 4.

The conventional IC chip mounting method is first shown in FIG.
As shown in FIG. 2A, the protruding electrode 3 formed on the electrode pad 2 arranged on the IC chip 1 is provided on the support 13 separately prepared as shown in FIG.
2 is immersed in a film made of a uniform conductive adhesive 10 having a film thickness of about 25 μm formed by using No. 4 for 2 seconds as shown in FIG. The conductive adhesive 10 is transferred and applied as shown in d). After that, as shown in FIG. 2E, the conductive adhesive 10 was applied
The C chip 1 is aligned with the electrode 6 of the circuit board 5, and then the protruding electrode 3 of the IC chip 1 is mounted by applying a pressure of about 1 kg / mm ² and then heated at 120 ° C. for 3 hours to form a conductive adhesive. 10 is cured and the protruding electrode 3 of the IC chip 1 and the electrode 6 of the circuit board 5 are adhesively connected. Then, as shown in FIG. 2 (f), a liquid thermosetting resin is injected into the gap between the IC chip 1 and the circuit board 5, and then heated at 120 ° C. for 3 hours to be hardened, so that the IC chip 1 and the circuit board 5 are cured. The thermosetting resin 12 is formed between the IC chip 1 and the resin 5, and the mounting of the IC chip 1 is completed.
As shown in FIG. 3, in the semiconductor device obtained by the above mounting method, the conductive particles 11 in the conductive adhesive 10 are formed on the electrode pads 2 of the IC chip 1 and the electrodes 6 of the circuit board 5. A structure in which both electrodes 3 and 5 are connected to each other in a state of being in contact with the surface of and the thermosetting resin 12 is filled and sealed / insulated around the connection portion and in the gap between the IC chip 1 and the circuit board. Has become.

[0005]

However, in the above-mentioned conventional semiconductor device, since the electrode of the circuit board is formed of aluminum or an alloy containing aluminum, an oxide layer is easily formed on the electrode surface. Moreover, since the conductive particles of the conductive adhesive adhered to the electrode surface are fixed in a state where they are simply in contact with the electrode surface of the circuit board, they should be connected through the oxide layer of aluminum or an alloy containing aluminum. Therefore, there is a problem that the connection resistance becomes large, or the connection between the protruding electrode and the electrode is insufficient, resulting in unstable performance.

The present invention solves the above problems by using aluminum or an alloy containing aluminum for the electrodes of the circuit board, and connecting the electrodes of the circuit board and the electrodes of the semiconductor element through a conductive adhesive. However, it is an object of the present invention to provide a semiconductor device and a method of manufacturing the same that can achieve stable connection without an increase in connection resistance.

[0007]

In order to achieve the above object, in a semiconductor device of the present invention, an electrode of a circuit board is made of aluminum or an alloy containing aluminum, and this electrode and a protruding electrode of a semiconductor element are provided. Are bonded and connected by a conductive adhesive containing conductive particles, and a hardening shrinkable synthetic resin is filled around the both electrode connecting portions.

In the method of manufacturing a semiconductor device according to the present invention, a conductive adhesive mixed with conductive particles is applied to the protruding electrodes of the semiconductor element, and the protruding electrodes of the semiconductor element and aluminum or an alloy containing aluminum. The electrodes of the circuit board made of (1) are aligned with each other, and the two electrodes are bonded together by a conductive adhesive, and then a curing and shrinkable synthetic resin is injected into the periphery of the both electrode bonding parts to be cured.

As the curing shrinkable synthetic resin, either a thermosetting type, a photocuring type, or a combination type of thermosetting and photocuring can be used, and the shrinking force is 20 kg against the protruding electrode. / Mm ² or more is preferable, and if insulating particles are further mixed in, the shrinkage force is evenly transmitted, which is more effective.

The conductive particles of the conductive adhesive are preferably made of a conductive material harder than the electrode material of the circuit board, and are preferably made of at least one of nickel, an alloy containing nickel, and a silver-palladium alloy. And is effective.

Further, the shape of the conductive particles of the conductive adhesive is preferably scaly, spherical, or a mixed shape thereof.

[0012]

According to the present invention constructed as described above, when the synthetic resin filled around the portion where the electrode of the circuit board and the projecting electrode of the semiconductor element are bonded with the conductive adhesive is cured, the resin shrinks and contracts. Since a force is generated and a compressive force is applied between the electrodes due to this contracting force, even if an oxide film is formed on the electrode surface of the circuit board, the conductive particles of the conductive adhesive break the oxide film and , And acts to stabilize the connection without increasing the connection resistance.

In order to apply a sufficient compressive force between the electrodes, the contracting force of the synthetic resin is 20 kg / mm ^{2 with} respect to the protruding electrodes.
The above is preferable, and it is preferable to mix insulating particles in order to uniformly transmit the contracting force.

If the conductive particles of the conductive adhesive are made of a conductive material that is harder than aluminum or an alloy containing aluminum, the conductive particles will break the oxide film formed on the surface of the electrode of the circuit board, and It is pressed into the surface of the electrode so that a better connection can be obtained, and when the conductive particles are scale-shaped or spherical, the oxide film is more likely to be broken and pressed into the surface of the electrode.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to FIG. 1 which is a sectional view of an essential part of a semiconductor device.

A height of about 70 μ formed on about 150 electrode pads 2 arranged on the IC chip 1 at a pitch of 150 μm.
m, a projection electrode 3 made of gold having a diameter of about 80 μm, and an electrode 6 formed of an aluminum layer having the same number as the electrode pads 2 and a thickness of about 3000 Å on the circuit board 5 which is a substrate constituting the liquid crystal display device. Are bonded and connected by a conductive adhesive 4, and a filling material 7 made of a curing shrinkable synthetic resin is filled between the IC chip 1 and the circuit board 5.

The conductive adhesive 4 is mixed with conductive particles composed of spherical nickel particles 8 which are harder than aluminum and have an average particle size of about 5 μm and scaly silver-platinum alloy particles 9 having an average particle size of about 1 μm. As a filling material 7 made of a hardening and contracting synthetic resin, the filling material 7 is 2 with respect to the protruding electrode 3 of the IC chip 1.
An epoxy thermosetting resin containing 50 wt% of silicon oxide having an average particle size of about 5 μm was used to heat and cure at 120 ° C. for 3 hours so that a curing shrinkage force of 0 kg / mm ² or more was obtained. . The connection resistance value of this semiconductor device is very low as compared with that of the conventional semiconductor device, which is 10Ω or more, and is several hundreds.
It was mΩ. Since there is no standardized measuring method, the curing shrinkage force of the filler 7 was measured by the following simple method. First, the electrode 6 of the circuit board 5 provided with the resistance measuring terminal is mounted on the IC chip 1 capable of measuring the resistance value by the conductive adhesive 4.
And the conductive adhesive 4 was heated and cured at 120 ° C. for 3 hours to prepare a sample. Then, the IC chip 1
The metal block was placed on the back side of the, and the curing shrinkage force of the filling material 7 was obtained by measuring the connection resistance value between the IC chip 1 and the circuit board 5 while applying a point pressure to the central part of the metal block.
As a result, the connection resistance value becomes smaller according to the applied pressure, and the applied pressure becomes stable at 20 kg / mm ² or more, and the decrease rate of the connection resistance value at this time and the resistance decrease rate of the filling material 7 after curing are almost equal. I found out what I was doing.

Spherical nickel particles 8 or scale-like silver-platinum alloy particles mixed in the conductive adhesive 4 due to the contracting force of the synthetic resin filled around the connection site or in the gap between the IC chip 1 and the circuit board 5. A part of 9 is pressed into the electrode 6 of the circuit board 5 and buried therein. Regarding the semiconductor device obtained as described above, when the IC chip 1 was removed from the circuit board 5 and the surface of the connection portion was observed with a microscope, the oxide layer was broken on the surface of the electrode 6 of the circuit board 5 facing the protruding electrode 3. Several recesses were confirmed.

In this embodiment, the thermosetting resin is used as the filler 7, but the same result is obtained by using the photocuring resin or the photocuring / thermosetting resin. ,
Although scale-like and spherical conductive particles are used as the conductive adhesive 4, similar results are obtained by using scale-like or spherical conductive particles.

Further, a mixture of silver-platinum alloy particles and nickel particles was used as the conductive particles, but similar results were obtained by using these alone, and the electrode 6 of the circuit board 5 was made of an alloy containing aluminum. Similar results are obtained even when the above configuration is adopted.

The above semiconductor device is manufactured by the following process, and the manufacturing process is performed by the electrode pad 2 of the IC chip 1.
The step of transferring and applying the conductive adhesive 4 to the plurality of protruding electrodes 3 formed on the upper surface, and the positions of the electrodes 6 made of aluminum formed on the circuit board 5 and the protruding electrodes 3 of the IC chip 1. A step of aligning the IC chip 1 with the IC chip 1 face down and press-bonding onto the circuit board 5;
A step of heating and curing the conductive adhesive 4 to bond the protruding electrodes 3 and the electrodes 6, and the IC chip 1 and the circuit board 5.
And a process of injecting a curing shrinkable synthetic resin into the gap between the two and curing them by heating.

As described above, according to the above embodiment, the conductive particles in the conductive adhesive 4 are hardened and contracted by the filler 7, that is, a circuit made of aluminum compressed to the protruding electrodes 3 by 20 kg / mm ² or more. When the electrode 6 of the substrate 5 is pressure-bonded, the connection resistance between the electrode 6 of the circuit board 5 and the IC chip 1 is reduced, and a semiconductor device with stable performance can be obtained.

[0023]

Since the present invention is constructed as described above, it has the following effects. Due to the curing shrinkage force of the curing shrinkable synthetic resin filled around the connection between the protruding electrode of the semiconductor element and the electrode of the circuit board connected via the conductive adhesive, some of the conductive particles of the conductive adhesive are Even if an oxide layer is formed on the surface of the circuit board electrode by pressure bonding to the circuit board electrode, the connection resistance between the circuit board electrode and the IC chip will be low, and highly reliable connection can be realized and the performance will be stable. The semiconductor device described above can be provided.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a schematic explanatory view of a conventional semiconductor device manufacturing process.

FIG. 3 is a sectional view of a main part of a conventional semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 IC chip 2 Electrode pad 3 Protruding electrode 4 Conductive adhesive 5 Circuit board 6 Electrode 7 Filler 8 Nickel particle 9 Silver-platinum alloy particle

Claims (14)

[Claims] 1. An electrode of a circuit board is made of aluminum or an alloy containing aluminum, and the electrode and a protruding electrode of a semiconductor element are bonded and connected by a conductive adhesive mixed with conductive particles. A semiconductor device in which the peripheral portion of the connection is filled with a curing shrinkable synthetic resin. 2. The semiconductor device according to claim 1, wherein the circuit board is a component of the liquid crystal display device. 3. The synthetic resin having a curing shrinkage property is a synthetic resin selected from the group consisting of a thermosetting synthetic resin, a photocuring synthetic resin, and a thermosetting / photocuring combined type synthetic resin.
The semiconductor device described. 4. The semiconductor device according to claim 1, wherein the curing shrinkable synthetic resin is a resin containing insulating particles. 5. The semiconductor device according to claim 1, wherein the conductive particles of the conductive adhesive are a conductive material harder than the electrode material of the circuit board. 6. The semiconductor device according to claim 1, wherein the conductive particles of the conductive adhesive are at least one selected from the group consisting of nickel, an alloy containing nickel, and a silver-palladium alloy. 7. The conductive particles of the conductive adhesive are scaly particles,
7. The semiconductor device according to claim 1, which is a particle selected from the group consisting of spherical particles and mixed particles thereof. 8. A conductive adhesive mixed with conductive particles is applied to a protruding electrode of a semiconductor element, and the protruding electrode of the semiconductor element and the electrode of a circuit board made of aluminum or an alloy containing aluminum are aligned with each other. Then, the two electrodes are adhered to each other with a conductive adhesive, and then a curing shrinkable synthetic resin is injected into the periphery of the adhering portion of the two electrodes to cure the semiconductor device. 9. The shrinkage force of a curing shrinkable synthetic resin is
20kg / mm for pole ² The above is the semiconductor according to claim 8.
Body device manufacturing method. 10. The shrinkable synthetic resin is one kind of synthetic resin selected from the group of thermosetting synthetic resin, photocurable synthetic resin, and combined thermosetting and photocurable synthetic resin. Or a method of manufacturing a semiconductor device according to 9. 11. The method of manufacturing a semiconductor device according to claim 8, wherein the curing shrinkable synthetic resin is a resin containing insulating particles. 12. The method of manufacturing a semiconductor device according to claim 8, wherein the conductive particles of the conductive adhesive are a conductive material harder than the electrode material of the circuit board. 13. The conductive particles of the conductive adhesive are nickel,
13. The method for manufacturing a semiconductor device according to claim 8, wherein the semiconductor device is at least one metal selected from the group consisting of an alloy containing nickel and a silver-palladium alloy. 14. The conductive particle of the conductive adhesive is a kind of particle selected from the group of scale-like particles, spherical particles, and mixed particles thereof, according to claim 8, 12, or 13. Manufacturing method of semiconductor device.