JPH1140607A - Manufacture of semiconductor device and sealing member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability on humidity resistance of a semiconductor device, and further, shorten the manufacture process of the device. SOLUTION: At a semiconductor chip 11, an electrode 12 is arranged only at its peripheral section. A projection 15 is provided at the center of the face to mount the semiconductor chip 11 in the package substrate 13, that is, the section surrounded by the semiconductor electrode 12. When an anisotropic conductive film(ACF) 16 is joined onto the package substrate 13 provided with this projection 15, the surface on the side on which to mount the semiconductor chip 11 of the anisotropic conductive film(ACF) 16 becomes convex. Accordingly, when the semiconductor chip 11 is pressure-bonded from above, the semiconductor chip 11 and the anisotropic conductive film(ACF) 16 are joined in order from the center to the peripheral section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a CSP (Chip Si
The present invention relates to a method for manufacturing a semiconductor device having a ze Package) and an MCM (Multi Chip Module) structure, and a method and an apparatus for manufacturing a sealing member.

[0002]

2. Description of the Related Art Along with the recent high-density packaging, a new package structure has been developed in which a top surface area of a package when mounting a semiconductor chip is almost equal to the area of the semiconductor chip or a plurality of CSPs or a single package substrate. MCMs with semiconductor chips have appeared.

A case of a semiconductor device having a CSP structure will be described. Substrate for mounting semiconductor chips (hereafter,
I will call it a package substrate. An electrode is formed on the surface of the semiconductor chip, and an electrode is formed on a surface of the semiconductor chip that is electrically connected to the package substrate at a position facing the electrode on the package substrate. These electrodes are electrically connected to solder balls as external terminals on the back surface (the surface on which the semiconductor chip is not mounted) of the package substrate by a circuit formed on the package substrate. As the package substrate, a ceramic substrate or an organic substrate is used.

In recent years, the joining portion between a semiconductor chip and a substrate has been miniaturized, and in order to electrically connect them, a conductive material having a high flexibility, especially an anisotropic conductive film (Anisotropic Conductive Film) has been used. : ACF) is applied.

This anisotropic conductive film (ACF) is an organic film in which fine conductive particles are dispersed,
The conductive particles are brought into contact between the electrode of the semiconductor chip and the electrode of the package substrate by solidifying by applying pressure between the semiconductor chip and the package substrate. The electrodes of the semiconductor chip and the electrodes of the package substrate are electrically connected by the conductive particles.

[0006]

However, in a semiconductor device in which the above-described anisotropic conductive film (ACF) is sandwiched between a semiconductor chip and a package substrate, the two are electrically connected to each other. When (ACF) is bonded to a package substrate on which electrodes are arranged, irregularities are formed on the bonding surface of the anisotropic conductive film (ACF) with the semiconductor chip due to the thickness of the electrodes. Therefore, particularly when a large-sized semiconductor chip is used, air bubbles called entrapment voids are likely to be generated at the joint between the semiconductor chip and the anisotropic conductive film (ACF).

The entrapment void contains moisture in the air, and the moisture in the atmosphere also enters the entrapment void through the anisotropic conductive film. If the temperature of the semiconductor device becomes high in this state, the water evaporates and tries to go out of the semiconductor device.

At this time, since the amount of moisture that can go out of the semiconductor device is limited, the moisture (steam) that cannot go out of the semiconductor device expands and damages the package and the like. Invite. That is, heat resistance (reflow resistance) when mounting the package substrate is deteriorated. Also,
Even if the above problems do not occur when mounting the board,
When actually used, the moisture resistance deteriorates, resulting in malfunction.

An object of the present invention is to eliminate the above-mentioned problems and improve the moisture resistance reliability and reflow resistance of a semiconductor device. Further, the present invention is applicable to various semiconductor chips, shortens the device manufacturing process, The aim is to reduce the management of components.

[0010]

According to the present invention, the above-mentioned object is achieved by using the following means. In the method of manufacturing a semiconductor device, a projection is provided on a bonding surface of the package substrate with the sealing member in order to improve the humidity resistance of the semiconductor device. The protrusion is provided in a region surrounded by the electrode on the package substrate. Then, the shape of the convex portion is such that the shape of the sealing member joined on the package substrate starts to be joined from the central portion of the semiconductor chip when the semiconductor chip and the package substrate are joined, and then joined in order toward the peripheral portion of the semiconductor chip. It has a shape that can be made into a shape that can be done.

In addition, in the case where not only a semiconductor chip in which electrodes are arranged on only one peripheral portion of a semiconductor chip but also a semiconductor chip arranged in the whole area are joined to a package substrate, the humidity resistance of the semiconductor device is improved. In order to achieve this, in the method of manufacturing a semiconductor device, a sealing member having a convex central section is used.

Further, a step of forming a sealing member having a central section having a cross-sectional shape, and a step of bonding a semiconductor chip and a package substrate with the sealing member interposed therebetween in order to shorten the device manufacturing process and reduce member management. In the same step.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention is described as a CSP (Chip).
In the case where the present invention is applied to (Size Package), description will be made below with reference to the drawings.

FIG. 1 shows a method of manufacturing a semiconductor device according to a first embodiment of the present invention. As shown in FIG. 1A, a semiconductor chip 11 has an electrode 1 only on a peripheral portion thereof.
2 are arranged. On the other hand, the electrode 14 is also arranged on the surface of the package substrate 13 on which the semiconductor chip 11 is mounted (the surface of the package substrate) at a position facing the electrode 12 of the semiconductor chip 11. A convex portion 15 is provided at a substantial center portion of a range (bonding area) surrounded by the electrode 14 of the package substrate. The convex portion 15 has a shape in which the height from the surface of the package substrate on which the semiconductor chip is mounted is substantially highest at the substantially central portion and gradually decreases toward the peripheral edge portion. When the semiconductor chip and the package substrate are electrically connected to each other with an anisotropic conductive film (ACF) 16 interposed therebetween, the protrusion 15 is formed by a gap between the uppermost surface of the protrusion 15 and the semiconductor chip 11. Is provided so as to be wider than the distance between the electrode 12 of the semiconductor chip 11 and the electrode 14 of the package substrate 13. 16 is an anisotropic conductive film (AC
F), which is an organic film that is highly flexible and has fine conductive particles dispersed therein.

Next, as shown in FIG. 1B, when an anisotropic conductive film (ACF) 16 is bonded to the surface of the package substrate 13 provided with the convex portions 15, the anisotropic conductive film (ACF) 16 is a shape reflecting the shape of the above-mentioned convex portion 15.

Next, as shown in FIG. 1C, the semiconductor chip 11 and the package substrate 13 are brought close to each other for electrical connection. At this time, first, the anisotropic conductive film (ACF) 16 in which the central portion of the semiconductor chip 11 is convex
Contact with.

Thereafter, as shown in FIG. 1 (d), when the semiconductor chip 11 is further pressed from above, the semiconductor chip 11 and the anisotropic conductive film (ACF) 16 are moved from the central portion to the peripheral portion thereof. In order. At this time, air is simultaneously pushed out from the central portion of the semiconductor chip 11 toward the peripheral portion.

Accordingly, it is possible to prevent the occurrence of a entangled void between the semiconductor chip 11 and the package substrate 13. Further, by providing the protrusions 15, the amount of the anisotropic conductive film (ACF) 16 included in the inside of the semiconductor device can be reduced by the volume of the protrusions 15 compared to the related art. When the amount of the anisotropic conductive film (ACF) 16 contained in the semiconductor device decreases, the amount of moisture absorption of the anisotropic conductive film (ACF) 16 absolutely decreases.

When the semiconductor chip and the package substrate are electrically connected to each other with an anisotropic conductive film (ACF) 16 interposed therebetween, the convex portion 15 is connected to the uppermost surface of the convex portion 15 and the semiconductor chip 11. Of the electrode 1 of the semiconductor chip 11
2 is provided so as to be wider than an interval between the electrode 2 and the electrode 14 of the package substrate 13. That is, the semiconductor chip 1
1 and the package substrate 13 are connected by an anisotropic conductive film (AC
F) The protrusion 15 does not come into contact with the semiconductor chip 11 even if the semiconductor chip 11 is press-fitted so as to be electrically connected with the interposition of the semiconductor chip 11. Therefore, the semiconductor chip 11 is not damaged or warped by the projection 15.

As a result, the amount of water absorbed in the semiconductor device can be reduced without damaging or warping the semiconductor chip, that is, the reliability of the semiconductor device can be improved.
It is possible to prevent a decrease in package reflow resistance due to moisture absorption during storage of the semiconductor device.

FIG. 2 shows a second embodiment of the present invention. In FIG. 2A, an electrode 22 or an electrode 24 is formed on the semiconductor chip 21 and the package substrate 23, respectively, and the electrode 22 and the electrode 24 are located at positions facing each other. These electrodes are located around or on the entire surface of the semiconductor chip 21 or the package substrate 23.
26 is an anisotropic conductive film (ACF) which is rich in flexibility,
Further, it is an organic film in which minute conductive particles are dispersed. In addition, the anisotropic conductive film (ACF) 26 has at least one film surface having a convex central section.

Next, as shown in FIG. 2B, after the anisotropic conductive film (ACF) 26 is bonded onto the package substrate 23, the semiconductor chip 21 is pressed from above.
The semiconductor chip 21 and the anisotropic conductive film (ACF) 26 start to be joined from the central portion thereof, and then are joined in order toward the peripheral portion as shown in FIG. At the same time, air is pushed out from the central portion of the joining portion between the semiconductor chip 21 and the anisotropic conductive film (ACF) 26 toward the peripheral portion. As a result, it is possible to prevent the occurrence of entrapment voids between the semiconductor chip 21 and the package substrate 23, and to improve the moisture resistance reliability.

In the second embodiment, there is no need to provide a projection on the package substrate 23 unlike the first embodiment.
3 can be used as it is, so that an increase in price can be suppressed.

FIG. 3 shows a third embodiment of the present invention, and is a method of manufacturing an anisotropic conductive film (ACF) having a central partial cross-sectional shape formed in a convex shape.

In FIG. 3A, reference numeral 35 denotes a convex anisotropic conductive film forming section having a concave cross section, and 36 denotes an anisotropic conductive film before a central cross section is formed to be convex. It is.

First, as shown in FIG. 3 (b), the anisotropic conductive film (AC
F) The convex anisotropic conductive film forming portion 35 having a concave cross-sectional shape is pressed against 36 to form a convex central cross-sectional shape of the anisotropic conductive film.

Next, as shown in FIG. 3C, the convex anisotropic conductive film forming portion 35 is separated from the anisotropic conductive film. At this time, the temperature of the convex anisotropic conductive film forming portion 35 is maintained near the temperature at which the anisotropic conductive film (ACF) 36 softens, and the temperature of the convex anisotropic conductive film forming portion 35 is maintained. The contact portion with the anisotropic conductive film (ACF) 36 is, for example, processed with Teflon or the anisotropic conductive film (ACF) 36 so that the releasability from the anisotropic conductive film (ACF) 36 is improved. Since it is made of a material with good mold release properties, anisotropic conductive film (AC
Even if the convex anisotropic conductive film forming portion 35 is separated from the F) 36, the anisotropic conductive film (ACF) 37 can be formed while the cross-sectional shape of the central portion is maintained in a convex shape.

Finally, as shown in FIG. 3D, the wafer is cut into a shape having an area larger than the bonding area on the package substrate.

Here, the convex anisotropic conductive film forming portion 35 is shaped so that it can only press the anisotropic conductive film (ACF) 36, but it is necessary that the pressing and the separation can be performed simultaneously. If the shape is as shown in FIG. 3E, the manufacturing process can be shortened.

FIG. 4 shows a method of manufacturing a semiconductor device according to a fourth embodiment of the present invention. First, as shown in FIG. 4A, an anisotropic conductive film (ACF) 46 processed into a size having an area larger than the bonding area on the package substrate is bonded onto the package substrate 43.

Next, as shown in FIG. 4 (b), the convex anisotropic conductive film (ACF) forming portion 45, which maintains the temperature near the softening temperature of the anisotropic conductive film (ACF) 46, is formed. It is pressed against the anisotropic conductive film (ACF) 46 so that the central portion of the anisotropic conductive film (ACF) 46 has a convex sectional shape.

Finally, as shown in FIG. 4 (c), the semiconductor chip 41 is held from above by an anisotropic conductive material using a device 47 which holds the semiconductor chip at the connection temperature between the semiconductor chip 41 and the package substrate 43. It is pressed against the film (ACF) 46. As a result, as shown in FIG. 4D, a semiconductor device in which entrapment voids are prevented from being generated in the semiconductor device can be manufactured.

As described above, the step of forming an anisotropic conductive film (ACF) having a convex cross section at the central portion, the semiconductor chip 41 and the package substrate 4 sandwiching the step.
3 can be performed in the same step, so that it is not necessary to stock an anisotropic conductive film (ACF) for each package. As a result, member management can be reduced.

If the temperature of the package substrate 43 is heated to the temperature at which the semiconductor chip 41 and the package substrate 43 are connected, the temperature of the device 47 holding the semiconductor chip can be reduced. The stress caused by the thermal shrinkage after the bonding of the package 41 and the package substrate 43 can be reduced. As a result, damage and poor connection of the semiconductor chip 41 and the package substrate 43 can be prevented.

As shown in FIGS. 5 and 6, an MCM (Multi Chip Module) having a plurality of semiconductor chips mounted on a substrate is provided.
e) When manufacturing a semiconductor device having a structure, the above-described first to fourth embodiments can be executed.

[0036]

According to the method of manufacturing a semiconductor device of the present invention, a flexible conductive material (anisotropically conductive material according to the embodiment) bonded on a convex portion provided on a package substrate by the convex portion provided on the package substrate. When the semiconductor chip and the package substrate are joined, the film (ACF) has a shape such that the semiconductor chip is joined in order from the center to the periphery of the semiconductor chip, so that air flows from the center to the periphery of the semiconductor device. Is extruded. Therefore, it is possible to prevent the occurrence of entrapment voids in the semiconductor device and improve the humidity resistance of the semiconductor device.

In the method of manufacturing a semiconductor device according to the present invention, as a sealing member used for electrically connecting a semiconductor chip and a package substrate, the central portion of one surface has a convex sectional shape. Anisotropic conductive film (AC
By using F), the anisotropic conductive film (ACF) is sequentially bonded from the central portion of the semiconductor chip to the peripheral portion when the semiconductor chip is bonded to the package substrate. At this time, since air is pushed out from the central portion of the semiconductor device toward the peripheral portion, it is possible to prevent entrapment voids in the semiconductor device. As a result, the moisture resistance reliability of the semiconductor device can be improved.

In addition, since the central portion of the anisotropic conductive film (ACF) has a convex sectional shape without providing a convex portion at the central portion of the package substrate, the anisotropic conductive film (ACF) Is sandwiched between the semiconductor chip and the package substrate, even if the area bump type semiconductor chip in which the electrodes are arranged on one entire surface of the semiconductor chip is bonded to the package substrate corresponding to the semiconductor chip, the entrapment void in the semiconductor device can be obtained. Can be prevented, and the moisture resistance reliability of the semiconductor device can be improved.

Further, a step of forming an anisotropic conductive film (ACF) having a convex cross section at the center portion, and a step of forming a semiconductor chip and a package substrate with the anisotropic conductive film (ACF) interposed therebetween. Integrating the process of electrically connecting the ACFs in the same device eliminates the need to stock an anisotropic conductive film (ACF) for each package. As a result, member management can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a semiconductor device having a convex portion provided on a package substrate according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a semiconductor device manufactured using an anisotropic conductive film (ACF) in which a cross-sectional shape of a central portion is convex in a second embodiment of the present invention.

FIG. 3 shows a method for manufacturing an anisotropic conductive film (ACF) having a convex central section in a third embodiment of the present invention.

FIG. 4 shows a method for manufacturing a semiconductor device using an anisotropic conductive film (ACF) having a convex central section in a fourth embodiment of the present invention.

FIG. 5 is a diagram illustrating a method of manufacturing a semiconductor device in which a plurality of semiconductor chips are mounted on a package substrate having a convex portion provided at the center of a semiconductor chip mounting surface.

FIG. 6 shows a method of manufacturing a semiconductor device in which a plurality of semiconductor chips are mounted by using an anisotropic conductive film (ACF) having a convex central section.

[Description of References] 11, 21, 41, 51, 61: Semiconductor chip 12, 22, 42, 52, 62: Electrode (semiconductor chip side) 13, 23, 43, 53, 63: Package substrate 14, 24, 44 , 54, 64: Electrodes (package substrate side) 15, 55: Convex parts 16, 26, 36, 46, 56, 66: Anisotropic conductive film (ACF) 35, 45, 65: Convex anisotropic conductive film (ACF) forming part 37: convex anisotropic conductive film (ACF) 38: convex anisotropic conductive film (ACF) forming part 47 capable of simultaneously pressing and separating 47: equipment for holding a semiconductor chip

Claims (17)

[Claims] An electrically conductive material having high flexibility between a semiconductor chip having electrodes and a substrate having electrodes formed on a surface on which the semiconductor chip is mounted and opposed to electrodes of the semiconductor chip. In a method of manufacturing a semiconductor device for electrically connecting the semiconductor chip and the substrate by sandwiching the conductive chip, the conductive material starts to join substantially from a central portion of the semiconductor chip, and then the conductive material A method of manufacturing a semiconductor device, comprising a step of sequentially joining the semiconductor chip toward a peripheral portion of the semiconductor chip. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the conductive material is substantially in a first direction that is a normal direction of a surface of the substrate on which the semiconductor chip is mounted. A semiconductor device, wherein the height of the central portion is the highest, and the height of the conductive material in the first direction decreases in order in the second direction perpendicular to the normal direction. Manufacturing method. 3. The method of manufacturing a semiconductor device according to claim 1, wherein the substrate has a substantially central portion of a portion surrounded by an electrode on a surface on which the semiconductor chip is mounted, an uppermost portion thereof, and the semiconductor. A method of manufacturing a semiconductor device, comprising: a projection provided so that an interval between the chip and an electrode of the semiconductor chip is larger than an interval between an electrode of the substrate and the chip. 4. The method of manufacturing a semiconductor device according to claim 3, wherein the height of the projection from a surface on which the semiconductor chip is mounted is substantially highest at a central portion, and the semiconductor chip is mounted. A method for manufacturing a semiconductor device, wherein the height of the semiconductor device is gradually reduced toward a peripheral portion of the surface. 5. The method of manufacturing a semiconductor device according to claim 3, wherein the height of the projection from a surface on which the semiconductor chip is mounted is substantially highest at a central portion, and the semiconductor chip is mounted. A method for manufacturing a semiconductor device, characterized in that the surface is lowered while forming a curved surface or a plane in order toward a peripheral portion of the surface. 6. The method of manufacturing a semiconductor device according to claim 3, wherein the convex portion has a dome shape, a squab shape, a conical shape, or a pyramid shape. 7. The method of manufacturing a semiconductor device according to claim 1, wherein the sealing member has a convex cross-sectional shape substantially at a central portion of at least one surface. Manufacturing method. 8. The method of manufacturing a semiconductor device according to claim 7, wherein the thickness of the sealing member is the largest at a central portion, and is gradually reduced toward a peripheral portion. Semiconductor device manufacturing method. 9. The method for manufacturing a semiconductor device according to claim 7, wherein the sealing member has the largest thickness at a central portion thereof and forms a curved surface or a flat surface toward a peripheral portion of the sealing member. A method for manufacturing a semiconductor device, characterized in that the thickness is sequentially reduced. 10. The method of manufacturing a semiconductor device according to claim 7, wherein at least one surface of the sealing member has a dome shape, a semi-cylindrical shape, a conical shape, or a pyramid shape. Device manufacturing method. 11. A method for manufacturing a sealing member in which at least one surface has a convex central cross-sectional shape, wherein a sealing member manufacturing apparatus in which a shape of a portion of the sealing member is concave. A method for manufacturing a sealing member, characterized by using: 12. The method for manufacturing a sealing member according to claim 11, wherein the sealing member manufacturing apparatus is pressed against the sealing member while the sealing member is kept at its softening point temperature. Manufacturing method of a sealing member. 13. The sealing member manufacturing method according to claim 11, wherein in the sealing member manufacturing apparatus, a shape of a portion of the sealing member is depressed from a peripheral portion toward a central portion. A method for producing a sealing member, characterized in that: 14. The method for manufacturing a sealing member according to claim 11, wherein in the sealing member manufacturing apparatus, a contact portion with the sealing member has a smooth surface with a convex portion of the sealing member. A method for manufacturing a sealing member, characterized in that the sealing member is processed so that it can be manufactured, or is made of a material capable of manufacturing a surface of a convex portion of the sealing member into a smooth shape. . 15. The method for manufacturing a sealing member according to claim 11, wherein a pressing step for forming a sealing member having a convex cross-sectional central portion of at least one surface is performed, and a separating step. And a method for manufacturing a sealing member. 16. The method of manufacturing a semiconductor device according to claim 1, further comprising: forming the sealing member having a size necessary to sandwich the semiconductor chip between the semiconductor chip and the substrate; A step of joining a sealing member, a step of forming a central section cross-sectional shape of a surface of the sealing member to be joined to the semiconductor chip to be convex, and electrically connecting the semiconductor chip and the substrate. A method for manufacturing a semiconductor device, wherein the steps are performed in the same step. 17. The method of manufacturing a semiconductor device according to claim 1, wherein after the step of bonding the sealing member on the substrate, the substrate is electrically connected to the semiconductor chip and the substrate. A method for manufacturing a semiconductor device, comprising heating the substrate to a temperature close to the temperature of the substrate at the time of bonding.