JPH10335528A - Semiconductor package and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor package having a highly reliable through hole type connection part, and to provide the manufacturing method of the above-mentioned semiconductor package. SOLUTION: This semiconductor package has a substrate 6 wherein the liquid crystal polymer, on which external connection terminals are arranged on one main surface, is used as an insulator, a conductive bump group 6b, one end of which is electrically connected to each external connection terminal 6a which is inserted to the thickness direction of a substrate 6, and a semiconductor chip 7 on which the other end of each conductive bump 6b is connected to the surface of an electrode 7a, Also, a conductive bump 6b is provided on the surface of the electrode 7a of a semiconductor chip 7, and a conductive metal layer 6a is superposingly arranged on the surface of the semiconductor chip 7 through a liquid crystal sheet 6 in this manufacturing method. Then, the tip side of the conductive bump 6b, which penetrates the liquid crystal polymer sheet 6, is connected to the surface of the conductive metal layer 6a, the conductive metal layer 6a is patterned, and an external connection terminal part 6a is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor device and a method of manufacturing the same, and more particularly, to a semiconductor module having a bare chip mounted face down on a substrate surface and a method of manufacturing the same.

[0002]

2. Description of the Related Art With the miniaturization of electronic devices, the number of external connection electrodes of a semiconductor chip has increased to several hundreds, and a BGA (Ball Grid) having external connection terminals with solder balls in a matrix on the back surface of a semiconductor package. Arrey) packages and
CSP (Chip Sise Package) is rapidly spreading. These packages are generally based on copper-clad boards made of glass epoxy resin or various resin films (sheets).
After etching and patterning this, Au
A semiconductor package in which an IC chip or the like is mounted on an interposer substrate surface subjected to plating or the like, and the substrate electrodes and the electrodes of the IC chip are electrically connected.

[0003] By the way, as a semiconductor chip mounting / mounting technique, generally, a wire bonding method, a TAB (TaB) method is used.
pe Automated Bonding) method, flip chip method, CO
The G (Chip on Glass) method is widely used. Among them,
Flip-chip and COG methods, or so-called face-down mounting methods, have attracted attention because they can achieve higher density mounting and lower costs.

[0004] The connection of the semiconductor chip in this face-down mounting method includes (a) a flip chip using solder bumps, and (b) a bonding using a resin film containing conductive particles (anisotropic conductive film). (For example, JP-A-4-323841).

FIG. 4 is a sectional view showing an example of a configuration of the CSP semiconductor package using the face-down mounting method. In FIG. 4, 1 is a substrate having a wiring pattern including a connection terminal 1a on a main surface, 2 is a semiconductor chip mounted on the substrate 1, and an Al electrode 2a of the semiconductor chip 2
It is electrically connected to the corresponding connection terminal 1a via the Au ball bump or the conductor bump 3. Reference numeral 4 denotes an external connection terminal through which the substrate 1 is inserted and led out in the thickness direction in order to secure the electrical connection. Reference numeral 5 denotes a connection portion including the Au pole bump or the conductor bump 3 for sealing and bonding. Is a sealing resin layer to be formed.

[0006] Such a semiconductor package is
It is obtained by separately producing an interposer substrate and an IC chip, mounting and mounting the IC chip on the interposer substrate, and cutting the interposer substrate to an appropriate size.

[0007]

[Problems to be Solved by the Invention] The above-mentioned mounting method is intended to improve the mounting density or make the semiconductor module more compact by avoiding wire bonding and arranging the external connection terminals on the back side. Further improvements are desired in terms of higher density, reliability, and the like. That is, a configuration in which the external connection terminals 4 are inserted and led out in the thickness direction of the substrate 1 is generally such that a through hole is formed at a predetermined position of the substrate, and the inside of the hole or the inner wall surface of the hole is made conductive. (Through hole connection).

However, the diameter of the through-hole is limited in terms of drilling and the conductivity is also limited, so that the number of the external connection terminals 4 or the high density arrangement is restricted. That is, it is not possible to sufficiently cope with the increase in the number of terminals, the enhancement of functions, and the reduction in size of the semiconductor module.

To cope with such a situation, for example, a glass-epoxy resin prepreg sheet (insulator layer) is arranged and laminated on a copper foil surface on which minute conductive bumps are implanted, and the laminated body is pressed by pressure. Means for forming the through-hole type connection portion by penetrating the insulating layer through the tip side of the conductive bump has been developed. In the case of this method, the boring process can be omitted, and there is a possibility that the arrangement of the through-hole connection portions can be increased. In other words, this means can greatly improve the manufacturing process of the multilayer wiring board, but cannot sufficiently cope with further increase in the number of terminals of the semiconductor module, higher functionality, or downsizing.

In the method of manufacturing a semiconductor package, since one semiconductor chip is mounted for each interposer substrate, there is a problem that the cost is increased.

The inventors of the present invention have made intensive studies in consideration of the above circumstances, and as a result, when a liquid crystal polymer or the like is used as an insulator, the tip of the minute conductive bump is not damaged by the insulator layer. The electrical connection between the conductive bumps and the conductor layer in contact with the conductive layer, that is, the interlayer connection can be performed only by thermocompression bonding. At the same time, the through hole is easily inserted into a predetermined position, and the through hole type is highly accurate and highly reliable. It has been found that a connecting portion is formed. They also found that liquid crystal polymers have little hygroscopicity, good adhesion to semiconductor chip surfaces and conductor layers, and that the thermal expansion coefficient can be made almost the same as that of Si, making it possible to form more reliable connections. Was.

In particular, in the case of a circuit board using a liquid crystal polymer having a thermal expansion coefficient equivalent to that of Si as an insulator, stress is applied to the bonding surface between the electrodes of the semiconductor chip and the conductive bumps even in a temperature cycle with respect to the semiconductor package and in a use environment. A reliable connection is realized without any occurrence.

The present invention has been made based on the above findings, and has as its object to provide a semiconductor package having a highly reliable through-hole type connection portion and a method of manufacturing the same.

[0014]

According to a first aspect of the present invention, there is provided a circuit board having an external connection terminal group disposed on one main surface thereof, and one end connected to each external connection terminal by penetrating the substrate in a thickness direction. A semiconductor, comprising: a conductive bump group to be electrically connected; and a semiconductor chip disposed face-down on the other main surface of the substrate and having the other end of each conductive bump connected to an electrode surface. Package.

According to a second aspect of the present invention, in the semiconductor package of the first aspect, the external connection terminal group on one main surface is dispersedly arranged by wiring.

According to a third aspect of the present invention, in the semiconductor package of the first or second aspect, a conductive bump is provided on each of the external connection terminal surfaces on one main surface.

According to a fourth aspect of the present invention, in the semiconductor package according to any one of the first to third aspects, the circuit board is formed using a liquid crystal polymer as an insulator.

According to a fifth aspect of the present invention, there is provided a step of providing a conductive bump on an electrode surface of a semiconductor chip, and arranging a conductive metal layer on the semiconductor chip surface on which the conductive bump is provided via an insulating sheet. Pressurizing the superimposed body, contacting and connecting the front end side of the conductive bump penetrating the insulating sheet to the surface of the conductive metal layer, and patterning the conductive metal layer for external connection Forming a terminal portion.

According to a sixth aspect of the present invention, there is provided a semiconductor wafer comprising: a step of providing conductive bumps on each semiconductor element electrode surface of a semiconductor wafer; and a step of laminating a conductive metal layer via an insulating sheet on the semiconductor chip surface provided with the conductive bumps. A step of aligning and arranging, and a step of pressing the overlapped body to contact and connect a tip end of a conductive bump penetrating an insulating sheet to a conductive metal layer surface, and patterning the conductive metal layer. A method of manufacturing a semiconductor package, comprising: a step of forming an external connection terminal portion; and a step of cutting the laminated body having the external portion connection terminal portion formed therein.

According to a seventh aspect of the present invention, in the method for manufacturing a semiconductor package according to the fifth or sixth aspect, a conductive bump is further provided on the surface of the external connection terminal portion.

According to an eighth aspect of the present invention, in the method of manufacturing a semiconductor package according to any one of the fifth to seventh aspects, the insulating sheet is a liquid crystal polymer sheet.

In the present invention, the insulator of the circuit board may be made of various thermoplastic resins or thermosetting resins.

Embedded image Aromatic polyester-based liquid crystal polymer represented by is preferred, this kind of aromatic polyester-based liquid crystal polymer,
It is marketed under the trade name "VECTRA" or LCP-A, LCP-C. Here, the choice of the insulator is made when the use environment of the semiconductor package is not severe, in other words, when not so high reliability is required, for example, a resin similar to a liquid crystal polymer such as a bismaleimide triazine resin and a polyphenyl ether resin. Kind.

The thickness of the circuit board is generally 20 to
It is about 80 μm, and the width and length are selected according to the use of the semiconductor device and manufacturing conditions. Further, since the thermal expansion coefficient of a circuit board or an insulator can be changed by about -7 to 60 ppm / ° C. (measured by the TMA method) by a heat treatment such as a semiconductor packaging process, such properties are taken into consideration.

In the present invention, conductive bumps formed by penetrating an insulating sheet such as a liquid crystal polymer sheet to form a through-hole type connection portion include, for example, conductive carbon powder, Au particles, Ni particles, Ag particles, Pb particles, Sn particles. It is formed by printing and drying a mixed / dispersed system (conductive paste) of conductive particles such as Cu, Cu and solder particles with epoxy resin, phenol resin, acrylic resin, etc., or by plating conductive metal. . That is, it is formed by repeating screen printing and drying using a stainless steel screen plate or the like, or by selectively growing a conductive metal by chemical plating or the like. The conductive bumps are generally formed on the electrode surface of the semiconductor chip, but may be formed on the copper foil surface on which external connection terminals are formed. The semiconductor chip is an IC chip or the like, and usually has an electrode terminal group (input / output terminal) made of, for example, Al on one main surface.

In the present invention, if necessary, the conductive bumps disposed on the surface of the external connection terminal of the substrate may be formed by a method of forming a ball bump by local melting of Au wire or the like, a Cu plating method, a Ni plating method, or the like. Can be formed.

According to the first to fourth aspects of the present invention, the electrode surface of the semiconductor chip is electrically connected to the external connection terminal of the substrate by a conductive bump having one end joined to the electrode surface and an insulator layer penetrating therethrough. Connected. In this configuration, the liquid crystal polymer forming the insulator layer has excellent moisture resistance, a small dielectric constant, and good bump-punching properties. As a result, the reliability of the semiconductor package is improved.

According to the fifth to eighth aspects of the present invention, a liquid crystal polymer sheet having excellent moisture resistance, a small dielectric constant, and a good bump punching property is used as an insulating layer.
A semiconductor package in which reliability such as electrical characteristics and placement accuracy is improved can be produced with high yield without requiring complicated operations.

[0028]

1 and 2 (a) to (c) and FIG.
An example will be described with reference to FIG.

FIG. 1 is a sectional view showing the structure of a main part of a semiconductor package (semiconductor module) according to the first embodiment. In FIG. 1, reference numeral 6 denotes a substrate having a liquid crystal polymer as an insulator having a group of external connection terminals 6a disposed on one main surface, and 6b, one end of each of the external connection terminals 6a penetrating the substrate 6 in the thickness direction. These are conductive bumps (through-hole connection portions) that are electrically connected. Here, the substrate 6 is, for example, about 30 μm thick, 13 × 13
Each external connection terminal 6a is a 12 μm thick copper foil photo-etched and partially extended with a wiring pattern.
External connection terminals 6a in a matrix at intervals of about 0.5mm
Is installed. The conductive bump 6b is formed of, for example, an Ag paste using an epoxy resin as a binder component, and generally has a substantially columnar or conical shape.

Reference numeral 7 denotes a semiconductor chip which is disposed face-down on the other main surface of the substrate 6 and the other end of each of the conductive bumps 6b is connected to the surface of the electrode 7a. Here, the semiconductor chip 7 is, for example, a 13 × 13 mm IC chip, and the input / output electrodes 7a are Al pads or metal coated pads.

In this configuration, the external connection terminal 6a is generally covered with a cover coat on the surface on which the external connection terminal 6a is formed by exposing the external connection terminal 6a. With bumps provided, GA (Grid
Arrey) The package may be easily mounted and mounted on a mounting wiring board or the like.

Next, an example of a method of manufacturing the semiconductor package having the above configuration will be described.

First, as shown in cross section in FIG. 2A, a predetermined screen plate is used on each electrode 7a surface of a semiconductor wafer 8 (cut and separated into a plurality of semiconductor elements or semiconductor chips 7). Then, after printing and drying the Ag-based conductive paste, the process of printing and drying again the Ag-based conductive paste is repeated to form a group of conical conductive bumps 6b 'having a height of about 30 to 80 μm. Provide. Here, the semiconductor wafer 8
In general, an insulating coat or a passivation film (not shown) is provided on a surface other than the electrode 7a surface, and these insulating coats and passivation films are
It is preferable that a roughening treatment or a plasma treatment is performed in advance to increase the adhesive strength with the insulator. The conductive bumps 6b 'group may be formed by, for example, solder plating instead of printing the Ag-based conductive paste.

Next, as shown in cross section in FIG.
On the surface of the semiconductor wafer 8 provided with the conductive bumps 6b ',
A conductive metal layer (for example, a 12 μm-thick electrolytic copper foil) 6 a ′ is placed one over the other via a liquid crystal polymer sheet 6 ′.

Thereafter, when the laminated body is heated and pressed, as shown in FIG.
The front end side of b 'penetrates the liquid crystal polymer sheet 6' and contacts and connects to the opposing surface of the electrolytic copper foil (conductive metal layer) 6a '. That is, the tip of the conductive bump 6b 'penetrating the liquid crystal polymer sheet (insulator layer) 6' is electrically and mechanically connected to the opposing surface of the electrolytic copper foil 6a 'while performing plastic deformation or the like. At the same time, the surface of the semiconductor wafer 8 is mechanically bonded to the surface of the electrolytic copper foil 6a 'via the liquid crystal polymer sheet 6'.
Subsequently, the electrolytic copper foil 6a 'is patterned,
The external connection terminals 6a are formed. In forming the group of external connection terminals 6a, the external connection terminals 6a are sometimes arranged in a dispersed manner in consideration of the number, interval, pitch, and the like of the electrodes 7a of the semiconductor wafer 8, so that the shape including a part of the wiring pattern is used. Sometimes adopted.

Thus, the liquid crystal polymer sheet 6 '
The semiconductor wafer 8 and the electrolytic copper foil 6a 'are joined through
In addition, the locally connected integral conductor pattern is cut by dicing into individual semiconductor packages. That is, it is possible to obtain a semiconductor package having an external connection terminal using the interposer substrate.

In the semiconductor device configured as described above, even when the conductive bumps 6b forming the through-hole connection portion are fine and arranged at a fine pitch, the conductive bumps 6b may be misaligned or short-circuited between adjacent conductive bumps 6b. There is no danger, and the connection is electrically low resistance and mechanically strong. That is, the characteristics of the liquid crystal polymer forming the insulator layer are effectively used, and the semiconductor module functions as a highly reliable semiconductor module. That is, since the conductive bumps have good penetrability in the liquid crystal polymer layer, and there is almost no formation of a thin resin layer at the bonding interface with the electrolytic copper foil 6a ', which is likely to occur when an adhesive layer such as an epoxy resin is used. A highly reliable electrical connection is formed.

FIG. 3 is a cross-sectional view showing a configuration of a main part of a semiconductor package (semiconductor module) according to a second embodiment. The structure is the same as that of the semiconductor package according to the first embodiment except that the configuration of the conductive bump 6b forming the through-hole connection portion is different. That is, in the semiconductor package example according to the first embodiment, although the conductive bump 6b are formed only in the Ag paste systems, in the semiconductor package according to the second embodiment, the plated bump 6b ₁ and Ag paste systems bumps It is formed of a composite type 6b _2, and adopts a configuration in which Ag paste systems bump 6b ₂ side is joined to the external connection terminal 6a. Then, also in the case of this semiconductor package, as in the case of the first embodiment, it functions as a highly reliable semiconductor module.

The semiconductor package according to the second embodiment can be easily manufactured by means according to the method for manufacturing a semiconductor package according to the first embodiment.

The present invention is not limited to the above examples, and various changes can be made without departing from the gist of the invention.

[0041]

According to the first to fourth aspects of the present invention, the liquid crystal polymer or the like forming the insulator layer has excellent moisture resistance, a small dielectric constant, and good bump piercing properties. Even with such an external connection terminal arrangement, a short-circuit between adjacent through-hole connection portions is eliminated, electrical characteristics and the like are excellent, and a semiconductor package having excellent durability or reliability is provided at low cost. When the insulator is a liquid crystal polymer, it has thermal softening properties, so that thermal stress due to a difference in thermal expansion coefficient when the semiconductor package is mounted on an external circuit board is reduced, and damage due to thermal stress is prevented. You.

According to the fifth to eighth aspects of the present invention, the liquid crystal polymer sheet or the like is used as an insulator sheet to form an insulator layer, so that it has excellent moisture resistance, a small dielectric constant, and good bump punching properties. Even with a fine external connection terminal arrangement, short-circuiting between adjacent through-hole connection parts can be avoided, and the electrical characteristics etc. are good, and a semiconductor package with improved reliability can be manufactured without complicated operations. In addition, it can be provided with good yield.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration example of a main part of a semiconductor package according to a first embodiment.

FIGS. 2A and 2B schematically show an example of a method of manufacturing a semiconductor package according to a first embodiment, in which FIG. 2A is a cross-sectional view in which conductive bumps are provided on electrode surfaces of a semiconductor wafer, and FIG. FIG. 3C is a cross-sectional view of a laminated state of a wafer, a liquid crystal polymer sheet, and a conductive material layer, and FIG.

FIG. 3 is a sectional view showing a configuration example of a main part of a semiconductor package according to a second embodiment.

FIG. 4 is a cross-sectional view showing a main part configuration of a conventional semiconductor package.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Board 1a, 6a ... Connection terminal of board 2, 7 ... Semiconductor chip 2a, 7a ... Electrode of semiconductor chip 3 ... Conductor bump 4, 6a ... External connection terminal of board 5 ... Sealing resin Layer 6: Liquid crystal polymer substrate 6a ': Copper foil 6b: Conductive bump (through hole connection) 8: Semiconductor wafer

Claims (8)

[Claims] A circuit board having an external connection terminal group disposed on one main surface thereof; a conductive bump group having one end electrically connected to each external connection terminal by penetrating the substrate in a thickness direction; A semiconductor chip disposed face-down on the other main surface of the substrate, the other end of each conductive bump being connected to an electrode surface;
A semiconductor package comprising: 2. The semiconductor package according to claim 1, wherein the external connection terminal group on one main surface is dispersedly arranged by wiring. 3. The semiconductor package according to claim 1, wherein a conductive bump is provided on each of the external connection terminal surfaces on one main surface. 4. The semiconductor package according to claim 1, wherein the circuit board is formed using a liquid crystal polymer as an insulator. 5. A step of providing a conductive bump on an electrode surface of a semiconductor chip, a step of superposing and arranging a conductive metal layer on a surface of the semiconductor chip provided with the conductive bump via an insulating sheet, and Pressurizing the joined body, contacting and connecting the front end side of the conductive bump penetrating the insulating sheet to the surface of the conductive metal layer, and patterning the conductive metal layer to form an external connection terminal portion And a method of manufacturing a semiconductor package. 6. A step of providing a conductive bump on each semiconductor element electrode surface of a semiconductor wafer, and a step of superposing and arranging a conductive metal layer via an insulating sheet on the semiconductor chip surface provided with the conductive bump. Pressurizing the superimposed body, contacting and connecting the front end side of the conductive bump penetrating the insulating sheet to the surface of the conductive metal layer, and patterning the conductive metal layer to form an external connection terminal portion. And a step of cutting the stacked body on which the external connection terminal portions are formed. 7. The method for manufacturing a semiconductor package according to claim 5, wherein a conductive bump is further provided on the surface of the external connection terminal portion. 8. The method of manufacturing a semiconductor package according to claim 5, wherein the insulating sheet is a liquid crystal polymer sheet.