JPH11251360A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device and a method which can facilitate the handling of a flip-chip junction and improve its quality and reliability, by improving the strength of a semiconductor element. SOLUTION: In this semiconductor device, a metallic heat radiating frame 12 is mounted on a non-electrode formation surface of a semiconductor chip 11, and a mold coated layer 13 of insulating resin is formed integrally on the electrode formation surface and the side peripheral faces of the chip 11 except for electrode terminals 11a. Pb/Sn-based solder bumps 14 are formed respectively on the respective terminals 11a by electroplating or the like with the use of the mold coated layer 13 as a mask. Such a chip 11 is arranged faced-down and jointed onto a Cu wiring layer 10 of a glass epoxy wiring board via the bumps 14. Furthermore, only the frame 12 is exposed on its one end face without being covered with the mold coated layer 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a method of manufacturing the same, and more particularly to a CSP (Chip Scale Pachage) type semiconductor device having good high-frequency characteristics.
The present invention relates to a method for manufacturing such a semiconductor device.

[0002]

2. Description of the Related Art Conventionally, as one of bare chip mounting techniques for directly mounting and connecting a semiconductor chip to a substrate or the like, there is flip chip bonding. FIG. 7 shows an example of a semiconductor device on which a semiconductor chip is mounted by flip chip bonding.

In this semiconductor device, solder bumps 2 are formed on each electrode terminal 1a of a semiconductor chip 1 by a plating method using a photoresist mask, and these solder bumps 2 are formed on a printed wiring board or the like. Of the wiring board 3 on the corresponding Cu wiring layer 4, and is heated and melted and bonded (flip chip bonding). In addition, these junctions and the outside of the semiconductor chip 1
A sealing layer 5 of an insulating resin such as an epoxy resin is formed by potting or the like. In addition, the code | symbol 6 in a figure is:
Ni—Au layer laminated on Cu wiring layer 4, reference numeral 7
Indicates a solder resist layer.

A semiconductor device in which the semiconductor chip 1 is flip-chip bonded as described above has a smaller mounting area than a semiconductor device mounted by wire bonding.
Since no bonding wire is used, there are advantages such as a small inductance component and the like, which is indispensable in a mobile communication field such as a mobile phone requiring high-density mounting of high-frequency components.

[0005]

However, in such a conventional semiconductor device, the semiconductor chip 1 is in a bare chip state until the final step of forming the resin encapsulating layer 5, so that during storage, the die sort test is performed. There is a possibility that the semiconductor chip 1 may be damaged at the time of a later test or at the time of mounting on the wiring board 3. In particular, a compound semiconductor substrate such as Ga-As used for a high-frequency circuit has lower mechanical strength (lower rigidity) than a silicon substrate.
Therefore, as shown in FIG. 8, when the semiconductor chip 1 is mounted on the wiring board 3 by sandwiching the semiconductor chip 1 from both sides by the sandwiching members 8, cracks are generated due to the clamping force applied to the side portions of the semiconductor chip 1 and the semiconductor chip 1 is broken. Therefore, it was difficult to maintain high quality and reliability.

The present invention has been made in order to solve these problems. A semiconductor device having improved strength and improved ease of handling in flip chip bonding and improved quality and reliability has been developed. It is an object to provide a method for manufacturing such a semiconductor device.

[0007]

According to the present invention, there is provided a semiconductor device comprising:
A wiring board having a wiring layer disposed on at least one main surface of a plate-shaped insulating base material, and a face-down disposed wiring board joined to the wiring layer of the wiring board via bumps provided on the electrode terminals, respectively; And a mold covering layer of an insulating resin is formed on each of the electrode forming surface and the side peripheral surface of the semiconductor device except for the electrode terminals.

Further, a method of manufacturing a semiconductor device according to the present invention
A molding step of forming a covering layer of an insulating resin by molding using a mold on an electrode forming surface and a side peripheral surface of a semiconductor device in which a required circuit element is formed on a semiconductor substrate except for an electrode terminal. Forming a bump on the electrode terminal of the semiconductor element by using the resin coating layer formed in the molding step as a mask, and disposing the semiconductor element on which the bump is formed in the step face-down, Bonding via a bump to the wiring layer formed on at least one main surface of the insulating base material.

In the semiconductor device and the method of manufacturing the same according to the present invention, as the semiconductor element, in addition to the silicon semiconductor element, for example, I of the periodic table such as Ga-As or In-P may be used.
An element in which required circuit elements such as electrodes are formed on a substrate of a compound semiconductor of a group II element and a group V element can be used. A semiconductor device on which such a compound semiconductor element is mounted can be used as an optical device or an ultra-high-speed device due to the high electron mobility of the compound semiconductor.

[0010] Further, as a coating sealing layer of an insulating resin provided on an electrode forming surface other than the electrode terminals of such a semiconductor element, for example, a coating layer made of an epoxy resin can be mentioned. This coating layer is preferably formed by transfer molding an epoxy resin using a mold having a predetermined cavity shape.

Further, as a bump provided on each electrode terminal of the semiconductor element on which the mold covering layer of the insulating resin is formed, a bump of Pb / Sn based solder or the like can be given. The bumps are preferably formed by electrolytic plating of solder on the electrode terminals, and the photoresist layer is formed by plating using the resin mold coating layer formed on the outer periphery of the semiconductor element except on the electrode terminals as a mask. And a masking process using a series of photo processes of exposing, developing, and peeling can be omitted, and the bump forming process is simplified.

In the present invention, as a wiring board on which such a semiconductor element is mounted by flip-chip bonding, for example, a prepreg obtained by impregnating an insulating resin such as an epoxy resin into a glass cloth is used as a single layer or a laminate. A glass-epoxy wiring board having a glass cloth-resin impregnated board formed as a base material and having a wiring layer formed on at least one main surface thereof by etching of a copper foil or the like is used. In addition to such a wiring board, a wiring board using a ceramic substrate or a glass substrate as an insulating base material can be used.

In the present invention, examples of the metal heat radiating member include a plate-shaped member made of copper or aluminum. In such a heat dissipation member, one main surface is in contact with a surface (hereinafter, referred to as a non-electrode formation surface) opposite to the electrode formation surface of the semiconductor element, and at least a part thereof is a mold coating layer of an insulating resin. By being arranged to be exposed from
The heat from the semiconductor element is efficiently released to the outside, and the thermal resistance is reduced. In addition, as such a plate-shaped heat radiation member,
A single plate large enough to cover the entire non-electrode formation surface of the semiconductor element may be used, or a plurality of narrow copper plates or aluminum plates may be used in parallel.

Further, by extending such a metal heat radiating member long outside the mold coating layer and electrically connecting its end to the wiring layer of the wiring board, grounding is secured as a ground layer. , Can shield electromagnetic waves.

According to the present invention, in a semiconductor device which is flip-chip bonded to a wiring layer of a wiring board via a bump made of solder or the like provided on an electrode terminal, the electrode formation except for the electrode terminal which is a bump forming portion is formed. On the surface and side peripheral surfaces, etc.
Since the mold coating layer of insulating resin is formed, the mechanical strength of the semiconductor element is improved and handling is easy, preventing damage to the semiconductor element when mounting it on a wiring board and improving reliability. Semiconductor device with high reliability can be obtained. Further, the bumps can be efficiently formed using the mold covering layer of the insulating resin as a mask, and the bump forming process is simplified.

[0016]

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

FIG. 1 is a sectional view showing a first embodiment of the semiconductor device of the present invention. In FIG.
Denotes a glass cloth-epoxy resin impregnated substrate (glass epoxy substrate), and a Cu wiring layer 10 is provided on one main surface of the substrate by etching of a copper foil or the like, thereby forming a glass epoxy wiring board. Reference numeral 11 denotes a semiconductor chip in which circuit elements such as electrode terminals 11a are formed on a silicon or GaAs semiconductor substrate and divided for each required functional unit. A heat radiation frame 12 made of metal such as copper is attached to the heat radiation frame 12. Also, the electrode terminals 11a of the semiconductor chip 11
A mold coating layer 13 of an insulating resin such as an epoxy resin is integrally formed on the heat-radiating frame 12 on the electrode forming surface and the side peripheral surface except for the upper side, and on the non-electrode forming surface side. 12 is exposed without being covered by the mold coating layer 13. Further, on the electrode terminals 11a of the semiconductor chip 11, Cr-
Via an intermediate metal layer such as Cu-Au (not shown),
A ball-shaped bump 14 made of Pb / Sn-based solder is provided. And such a semiconductor chip 11
Are arranged face-down, and are joined via solder bumps 14 to a Ni-Au layer 15 laminated on the Cu wiring layer 10 (wiring pad) of the glass epoxy wiring board. Reference numeral 16 in the drawing indicates a solder resist layer provided on the glass epoxy wiring board for preventing short circuit between wirings and for damping the solder bumps 14, respectively.

The semiconductor device of the first embodiment having such a structure is manufactured as described below. That is, first, as shown in FIG. 2A, the non-electrode forming surface of the semiconductor chip 11 is bonded and fixed to the metal heat dissipation frame 12 by a metal eutectic mounting method or a paste mounting method using an adhesive paste. I do. Next, as shown in FIG. 2B, the semiconductor chip 11 is
Mold 1 designed to prevent mold resin from adhering to the part
After the mold 7 is positioned and set, a mold insulating resin such as an epoxy resin is press-fitted into the mold cavity, and the mold coating layer 13 is integrally formed. At this time, an electrode terminal 11a on which a bump is formed in a step described later.
Around the part, it is desirable to shape the shape of the corresponding part of the mold 17 so that the end face of the mold coating layer 13 has a tapered shape.

Next, as shown in FIG. 2C, using the mold coating layer 13 thus formed as a mask, an intermediate metal layer such as Cr-Cu-Au is formed on the electrode terminals 11a of the semiconductor chip 11. After the solder is electrolytically plated, the solder bumps 14 are formed by reflow. Further, a portion of the heat dissipation frame 12 fixed to the non-electrode forming surface of the semiconductor chip 11 and protruding outward from the mold coating layer 13 is cut and removed. Next, as shown in FIG. 2D, the semiconductor chip 11 on which the heat radiation frame 12 and the like are attached and the mold coating layer 13 is formed on the outer periphery is
It is arranged face down and mounted on a glass epoxy wiring board, and solder bumps 14 are Ni-Au of Cu wiring pads.
After being brought into contact with the layer 15, the solder is heated and melted to join the electrode terminals 11 a of the semiconductor chip 11 and the Cu wiring layer 10.

In the semiconductor device of the first embodiment manufactured as described above, the semiconductor chip bonded to the Cu wiring layer 10 of the glass epoxy wiring board via the solder bumps 14 formed on the respective electrode terminals 11a. In FIG. 11, since the mold coating layer 13 of an insulating resin is provided on the heat radiation frame 12 on the electrode forming surface and the side peripheral surface excluding the solder bump 14 forming portion and on the non-electrode forming surface side, the semiconductor chip 11 The mechanical strength of the semiconductor chip 11 is improved, and damage to the semiconductor chip 11 during mounting on a wiring board or the like is prevented. Further, since the solder bumps 14 can be formed by plating such as electrolysis using the insulating resin mold coating layer 13 as a mask, the bump forming process is simplified, and efficient bump formation is possible. Further, since a metal heat dissipation frame 12 is attached to the non-electrode formation surface of the semiconductor chip 11 and one end surface of the heat dissipation frame 12 is exposed outside the mold coating layer 13, heat dissipation is enhanced. Thus, an improvement in reliability is achieved.

Next, another embodiment of the semiconductor device according to the present invention will be described with reference to FIGS. In addition,
In these drawings, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

In the second embodiment of the present invention, as shown in FIG. 3, the left and right end surfaces of the metal heat radiating frame 12 and the main surface of the non-attached side to the semiconductor chip 11 (the upper surface in FIG. 3). ) Are exposed without being covered by the insulating resin mold coating layer 13, respectively. In the insulating resin molding step, as shown in FIG. It can be manufactured by performing molding using a mold 17 having a cavity shape designed so that the molding resin does not adhere to the main surface.

In the semiconductor device of this embodiment, the mold covering layer 13 made of an insulating resin is provided on the electrode forming surface and the side peripheral surface of the semiconductor chip 11 excluding the solder bump 14 forming portion. In addition to improving the mechanical strength of 11 and preventing breakage, the process of forming the solder bumps 14 is simplified. Further, since not only the end surfaces on both sides of the heat dissipation frame 12 but also the main surface on the non-adhesive side are exposed outside the mold coating layer 13, the heat dissipation is further improved, and the reliability is improved.

In the third embodiment of the present invention, as shown in FIG. 5, the left and right ends of the metal heat radiating frame 12 extend to the outside of the mold covering layer 13 made of an insulating resin. At the same time, the extending portion 12a is bent downward, and the bent both ends are respectively joined via the Cu wiring layer 10 and the Ni-Au layer 15 of the glass epoxy wiring board. In the semiconductor device according to the third embodiment, a metal heat dissipation frame 12 disposed in contact with the non-electrode forming surface of the semiconductor chip 11 includes:
Since the end portions of the extending portions 12a on both sides are extended outside the mold coating layer 13 and are electrically connected to the Cu wiring layer 10, respectively, the grounding is secured by using the heat dissipation frame 12 as a ground layer. The effect of shielding electromagnetic waves is high.

In the semiconductor device having the heat dissipation frame 12 extending on both sides, as shown in FIG. 6, the main surface (upper surface) of the heat dissipation frame 12 on the non-adhesive side is also provided.
Is exposed without being covered by the mold covering layer 13, it is possible to further enhance the heat dissipation and improve the reliability.

[0026]

As is apparent from the above description, according to the present invention, the semiconductor element to be flip-chip bonded to the wiring layer of the wiring board is formed on the electrode forming surface or the side peripheral surface excluding the electrode terminals. Since the mold coating layer of the insulating resin is formed by molding using a mold or the like, the mechanical strength of the semiconductor element is improved, and damage to the semiconductor element during mounting on a wiring board is prevented. . Further, since bumps can be formed on the electrode terminals of the semiconductor element using the mold coating layer of the insulating resin as a mask, the process can be simplified and the bumps can be formed efficiently.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a semiconductor device of the present invention.

FIGS. 2A and 2B are cross-sectional views sequentially showing each process for manufacturing the semiconductor device of the first embodiment.

FIG. 3 is a sectional view showing a second embodiment of the semiconductor device of the present invention.

FIG. 4 is a sectional view showing a resin molding step for manufacturing the semiconductor device of the second embodiment.

FIG. 5 is a sectional view showing a third embodiment of the semiconductor device of the present invention.

FIG. 6 is a sectional view showing a fourth embodiment of the semiconductor device of the present invention.

FIG. 7 is a cross-sectional view showing an example of a conventional flip-chip bonded semiconductor device.

FIG. 8 is a cross-sectional view illustrating a problem in a conventional semiconductor device.

[Explanation of symbols]

 9 Glass epoxy substrate 10 Cu wiring layer 11 Semiconductor chip 11a Electrode terminal 12 Heat dissipation frame 12a Extension 13 Mold coating layer of insulating resin 14 solder bump 16 solder resist layer 17 mold

Claims (6)

[Claims] 1. A wiring board having a wiring layer disposed on at least one main surface of a plate-shaped insulating base material, and a wiring board disposed face down and via bumps provided on electrode terminals, respectively. A semiconductor element joined to the wiring layer,
A semiconductor device, wherein a mold coating layer of an insulating resin is formed on each of an electrode forming surface and a side peripheral surface of the semiconductor element except on the electrode terminals. 2. The semiconductor device according to claim 1, wherein said semiconductor element is formed by forming a required circuit element on a III-V compound semiconductor substrate. 3. A metal heat radiating member is provided so as to be in contact with the surface of the semiconductor element opposite to the electrode forming surface, and at least a part of the heat radiating member is provided outside the mold coating layer. The semiconductor device according to claim 1, wherein the semiconductor device is exposed. 4. The semiconductor device according to claim 3, wherein an end of said metal heat radiating member is connected to a wiring layer of said wiring board. 5. A coating layer of an insulating resin by molding using a mold on an electrode forming surface and a side peripheral surface of a semiconductor element on which a required circuit element is formed on a semiconductor substrate except for an electrode terminal. Forming a bump on the electrode terminal of the semiconductor element using the resin coating layer formed in the molding step as a mask, and face down the semiconductor element on which the bump is formed in the step. Arranging and bonding via a bump to a wiring layer formed on at least one main surface of a plate-shaped insulating base material. 6. In the molding step, a metal heat radiating member has one main surface abutted on a surface opposite to the electrode forming surface of the semiconductor element, and a part thereof projects outside the mold. 6. The method for manufacturing a semiconductor device according to claim 5, wherein the semiconductor device is disposed in a mold.