JP3398556B2 - Method for manufacturing semiconductor device - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a BGA type (Ball Grid A) capable of improving productivity and mounting reliability.
rray) semiconductor device, in particular, a BGA type using a semiconductor element mounting substrate configured by bonding a metal substrate sheet having a lead pattern on one surface side of a resin substrate and a semiconductor element mounting region on the other surface side. And a method for manufacturing a semiconductor device.

[0002]

2. Description of the Related Art Conventionally, when mounting a semiconductor device such as an IC or an LSI, a plurality of outer leads formed in a required shape such as a J type and a gull wing type are protruded along the outer peripheral edge of the semiconductor device, and the outer leads are formed. Printed wiring board (P
This is performed by using solder to connect to a mounting pad of a wiring pattern formed on a mounting board such as WB). However, this mounting method has a problem in that it requires a mounting area having a relatively large area and cannot be made smaller in size. Therefore, in recent years, in response to miniaturization of semiconductor elements, downsizing of semiconductor devices, and cost reduction, an apparatus for mounting solder balls on a mounting board using solder balls for a plurality of external connection terminals of the semiconductor device ( (Referred to as BGA), for example, JP-A-3-99.
No. 456, Japanese Patent Laid-Open No. 4-277636, and the like. According to these devices, the semiconductor device is positioned and placed on the plurality of mounting pads on the mounting substrate provided corresponding to each of the plurality of solder balls, and then the semiconductor device is easily melted by heating. Since the solder balls can be reflowed and connected to the mounting board at the same time,
There is an advantage that the semiconductor device can be easily mounted.

The BGA type semiconductor device is manufactured, for example, by the following method. That is, a metal substrate sheet having a plurality of unit regions including element mounting portions closely aligned in the vertical and horizontal directions on a metal base sheet having thermal conductivity and a circuit board sheet sheet to be joined to the metal substrate sheet sheet are joined in a multi-layered state. . This circuit board sheet sheet is a predetermined electrically insulating resin base sheet having a copper foil layer on one side,
An opening corresponding to the semiconductor element is formed in the central portion, a lead pattern including a plurality of conductor leads radially arranged along the opening and surrounding the opening, and the conductor leads are exposed in an area array form. A plurality of unit regions composed of a solder resist film having a plurality of spaces are closely arranged in the vertical and horizontal directions. The semiconductor element mounting substrate sheet thus formed is cut and separated along the vertical and horizontal boundaries that divide each unit area, and a large number of individual semiconductor element mounting substrates 60 as shown in FIG. 4 are formed. The semiconductor element mounting board 60 is mounted on a carrier or individually supplied to an assembly line of a semiconductor device for positioning, and the semiconductor element 61 is mounted by interposing a conductive adhesive. Next, one end of each of the bonding wires 62 is connected to one of the wire bonding pads, and the other end thereof is connected to one of the electrode terminals provided on the semiconductor element 61 to form an electrical conduction circuit. To do. Thereafter, as shown in FIG. 5, potting mold is performed in which the semiconductor element 61, the bonding wires 62, and the wire bonding pads are resin-sealed with the potting resin 63. Then, the solder balls 66 are respectively connected in a protruding state on the plurality of external connection terminals 65 exposed in a grid array on the solder resist film 64 formed in advance to manufacture individual semiconductor devices 67.

[0004]

However, in the method of manufacturing a semiconductor device according to the conventional example described above, the metal substrate sheet sheet and the circuit substrate sheet sheet having a plurality of individual unit partition regions are integrated. Since the individual semiconductor element mounting substrates 60 are formed by cutting and separating from the semiconductor element mounting substrate sheet that has been thermocompression bonded, handling such as transportation and positioning of the individual semiconductor element mounting substrates 60 becomes complicated and misalignment occurs. There is a problem that the quality is deteriorated due to the damage during the handling and the working efficiency of the semiconductor element mounting is lowered, and the productivity is significantly hindered. Furthermore, an expensive mounting facility is required to position the individual semiconductor element mounting substrate 60 on the carrier, which causes an economical problem of increasing the manufacturing cost of the semiconductor device. In addition, since the semiconductor element 61 is mounted on the semiconductor element mounting substrate 60 and wire bonding is performed from thereover, there is a problem that mounting is difficult when the semiconductor element 61 is a little thick. The present invention has been made in view of such circumstances, when mounting a semiconductor element or the like, it is possible to improve workability such as conveyance and positioning, and to easily mount the semiconductor element or the like. Is a BG that can be easily mounted even when the semiconductor element itself is slightly thick and can improve the productivity of the semiconductor device.
An object of the present invention is to provide a method of manufacturing a semiconductor device in an A type semiconductor device.

[0005]

A method according to the above-mentioned object.
According to the method for manufacturing a semiconductor device described above, a semiconductor element is mounted in the center, and a periphery thereof has a lead pattern including a plurality of leads connected to a plurality of electrode pads of the semiconductor element via bonding wires, and A method for manufacturing a semiconductor device in which a plurality of solder balls or bumps, which are arranged in a grid array and serve as connection terminals, are provided on each of the leads, and a required number of the semiconductor devices are arranged side by side vertically and horizontally. A metal substrate sheet having good thermal conductivity is prepared, and a recess is formed in the element mounting portion of each semiconductor device to form a lower portion than its periphery, and a predetermined undercoating is performed on its surface. In the first step, openings corresponding to the element mounting portions of the plurality of semiconductor devices formed on the metal substrate sheet are formed, and around the openings, A second step of preparing a circuit board sheet in which a lead pattern connected to a semiconductor element arranged in the opening is formed by an etching process, and a metal board sheet manufactured in the first step. A third step of manufacturing the prepared circuit board sheet by joining the prepared circuit board sheets to the respective element mounting portions so that the openings are aligned with each other, and positioning the semiconductor element mounting substrate sheet on the transport plate. The semiconductor element mounting substrate sheet is moved by a predetermined distance in the X direction and the Y direction, the semiconductor element is mounted on each element mounting portion, and predetermined wire bonding is performed to perform terminal bonding of each semiconductor element and the lead. The fourth step of connecting the pattern and the semiconductor element and the wire-bonded portion are connected to each other by potting mold or A fifth step of resin-sealing with an injection mold, a sixth step of forming the solder balls or bumps on the external connection terminal lands of the lead pattern, and a connection in which semiconductor devices are arranged side by side vertically and horizontally by the above steps. A seventh step of cutting and separating a single semiconductor device from the semiconductor device. A semiconductor device manufacturing method according to a second aspect of the present invention is the method of manufacturing a semiconductor device according to the first aspect, wherein the recessing process in the first step is performed by a press process. A method for manufacturing a semiconductor device according to claim 3 is the method according to claim 1.
In the method of manufacturing a semiconductor device described above, the recess processing in the first step is performed by etching. A method of manufacturing a semiconductor device according to claim 4 is the second method in the method of manufacturing a semiconductor device according to any one of claims 1 to 3.
In the step, a solder resist film is formed on the portion of the circuit board sheet excluding the external connection terminal lands. In the above invention, the metal substrate sheet having good thermal conductivity includes a pure copper substrate and a copper alloy substrate.

In the method for manufacturing a semiconductor device according to any one of claims 1 to 4, a metal substrate sheet having a plurality of semiconductor devices arranged in a matrix is prepared, and a circuit substrate sheet having a predetermined lead pattern is attached to the metal substrate sheet. To make a semiconductor element mounting board,
Since a semiconductor element is mounted on this, predetermined wire bonding is performed, and resin sealing is performed, a large number of semiconductor devices can be manufactured on one substrate. Since the element mounting portion on which the semiconductor element is mounted is recessed and is formed at a position lower than its periphery, it is natural that a thin semiconductor element can be mounted. Can be installed. In particular, in the method for manufacturing a semiconductor device according to the second aspect, since the depression is formed by pressing, the depression having a predetermined shape can be performed in a short time, and the depth of the depression can be set arbitrarily. Further, in the method for manufacturing a semiconductor device according to claim 3, since the recess processing is performed by an etching process, the process is easy and a special mold or the like is not required, but the thickness of the metal substrate sheet. Limits its depth. In the method for manufacturing a semiconductor device according to claim 4, a solder resist film is formed on a portion of the circuit board sheet excluding the external connection terminal lands, so that the solder balls can be easily fixed, and further, the leads can be used. It is possible to prevent corrosion of the pattern and prevent unnecessary contact with other circuits when the semiconductor device is mounted.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Next, referring to the attached drawings, an embodiment in which the present invention is embodied will be described to provide an understanding of the present invention. 1 is a partial sectional view of a semiconductor device manufactured by the method for manufacturing a semiconductor device according to the first embodiment of the present invention, FIG. 2 is a plan view of the same, and FIG. 3 is a second embodiment of the present invention. FIG. 6 is a partial cross-sectional view of the semiconductor device manufactured by the method of manufacturing a semiconductor device according to the above embodiment.

First, a single unit of the semiconductor device 10 manufactured by the method of manufacturing a semiconductor device according to the first embodiment will be described. As shown in FIG. 1, the semiconductor device 10
Is a copper substrate 11 which is an example of a metal substrate having good thermal conductivity.
And a circuit board 12 using as an insulating material a glass cloth epoxy resin plate 12a, which is an example of an insulating resin base material bonded thereon, and an element mounting formed by forming a recess in the center of the copper substrate 11. Semiconductor element 14 mounted on the part 13
A bonding wire 17 for connecting a terminal portion (electrode pad) of the semiconductor element 14 and an inner end portion of each lead 16 of the lead pattern 15 on the circuit board 12, and an external connection terminal at an outer end portion of each lead 16. Solder balls 19 fixed to lands 18 respectively, and potting resin 20 for covering semiconductor element 14 and bonding wires 17
And a solder resist film 21 that covers the surface of each lead pattern 15.

The element mounting portion 13 is subjected to a pressing process to form a recess having a thickness of about a plate thickness, and the semiconductor element 1 to be mounted is mounted.
The height of 4 does not project excessively from the surface of the copper substrate 11. The circuit board 12 is formed with an opening 22 corresponding to the element mounting portion 13 so that the semiconductor element 14 is exposed. The external connection terminal lands 18 are formed on the outside of the element mounting portion 13 vertically and horizontally and at a constant pitch, and the solder balls 19 joined to the external connection terminal lands 18 are arranged in a grid array. There is. The solder resist film 21 covers the surface of the circuit board 12 excluding the external connection terminal lands to help the solder balls 19 adhere to predetermined positions and protect the lead pattern 15 on the surface. I am trying. Hereinafter, a method of manufacturing the semiconductor device 10 having such a structure will be described.

In FIG. 2, a plurality of semiconductor devices 10 are connected vertically and horizontally (20 in this example) to form a connected semiconductor device 2.
3, a copper substrate sheet having a thickness of 0.25 to 0.55 mm, which is an example of a metal substrate sheet having the same width as the connected semiconductor device 23, is prepared as shown in FIG. A portion of each semiconductor device 10 on which the semiconductor element 14 is mounted is subjected to a pressing process, which is an example of dent processing, to form a plurality of element mounting portions 13 at a predetermined pitch slightly below the surface. Then, the copper substrate sheet is subjected to predetermined plating (for example, Ni plating) to form the base plating layer 24. Further, in order to further improve the corrosion resistance or the brazing property, it is free to further plate gold, silver, palladium or the like on the base plating layer 24 (the above is the first step). ).

A glass cloth epoxy resin base sheet (plate thickness 0.3 to 0.5 mm, FR-4 or FR-5) which is an example of an electrically insulating member having the same size as the copper substrate sheet.
And a copper foil layer having a thickness of about 32 μm is provided on one side thereof, and the other side is an example of a thermosetting adhesive,
A prepreg layer 25 having a thickness of about 50 to 100 μm is provided in advance. The substrate sheet having such a structure is first subjected to a press process to form a plurality of openings 22 corresponding to the respective element mounting portions 13 formed on the copper substrate sheet. Then, the copper foil layer on the surface is etched by a known method to form the lead pattern 15 around each opening 22 to manufacture a circuit board sheet (above, the second step).

This circuit board sheet is thermocompression-bonded to the copper board sheet via a prepreg layer. In this case, the positions of the element mounting portions 13 of the copper board sheet and the openings 22 of the circuit board sheet are aligned with each other. Join in the state of being made. After this,
External connection terminal land 1 by conventional screen printing method
The solder resist film 21 is formed with 8 exposed. As a result, the semiconductor element mounting substrate sheet is completed (the above is the third step). Next, this semiconductor element mounting substrate sheet is positioned and mounted on a carrier plate (not shown), and the carrier plate is moved in the X direction and the Y direction by a predetermined distance, and the mounted semiconductor element mounting substrate sheet is moved to a predetermined position. In the state where it is moved to the position, a predetermined semiconductor element 14 is sequentially mounted on each element mounting portion 13 and predetermined wire bonding is performed. Here, since the element mounting portion 13 is dented, the position of the terminal pad 26 of each semiconductor element 14 is lowered, and a bonding wire connecting each terminal pad 26 and the inner end portion of the lead 16 is formed into a circuit. It will not protrude from the surface of the substrate sheet (the above is the fourth step).

After passing through the above steps, a predetermined amount of potting resin 20 is poured into each element mounting portion 13 to seal the semiconductor element 14, the bonding wire 17 and their joints with resin (the above fifth step). . Next, the solder balls 19 are fixed to the external connection terminal lands 18, which are the outer ends of the leads, to complete the coupled semiconductor device 23 (the sixth step). In use, a single semiconductor device 10 is manufactured by cutting and separating the vertical and horizontal cutoff lines 27 shown in FIG. 2 with a jig / milling machine or other cutters (the seventh step). The copper substrate 11 promotes heat dissipation of the semiconductor element 14, and at the same time, the semiconductor element 14
It has a function of electrically sealing and blocking external noise.

Next, the semiconductor device 30 manufactured by the method for manufacturing a semiconductor device according to the second embodiment of the present invention shown in FIG. 3 will be described. The semiconductor device according to the first embodiment will be explained. The same components as those of the semiconductor device 10 manufactured by the manufacturing method are designated by the same reference numerals, and detailed description thereof will be omitted. A slightly thick copper substrate 31 is used as a copper substrate 31 which is an example of a metal substrate used for the semiconductor device 30, and an element mounting portion 32 formed in the center thereof has a thickness of 1/3 to 1/3 of a plate thickness by a well-known etching process.
About 2/3 of the recess is processed. by this,
The position of the mounted semiconductor element 14 can be lowered, and a thinner semiconductor device 30 can be provided as a whole.

In the manufacturing method, an etching process is used instead of the depression process by the press process in the semiconductor device manufacturing method according to the first embodiment.
The element mounting portion 32 is formed, and the other points are the same. In this semiconductor device 30, since a relatively thick copper substrate is used, heat dissipation is further improved.
Since one side of the semiconductor device 30 is flat, there is an advantage that a thinner device (for example, an IC card) can be provided without being bulky in the thickness direction.

In the above-mentioned embodiment, the material and thickness of the metal substrate are specified and explained, but the present invention is applicable regardless of whether it is thinner or thicker. Moreover, although the number of semiconductor devices is specified and described for the coupled semiconductor device, the present invention is not limited to that number. Furthermore,
Although the solder balls are fixed to the external connection terminal lands in each of the above-described embodiments, bumps can be formed on these portions. In addition, in the above-described embodiment, each semiconductor device is manufactured by potting resin molding, but each semiconductor device may be manufactured by injection resin molding.

[0017]

In the method for manufacturing a semiconductor device according to the first to fourth aspects of the present invention, since a plurality of semiconductor devices are manufactured simultaneously in a connected state, efficient mass production at low cost is possible. And
Since the semiconductor element is mounted by providing the recessed portion on the metal substrate, a thinner BGA type semiconductor device can be provided. Particularly, in the method of manufacturing a semiconductor device according to claim 2,
Since the recess processing is formed by the press processing, accurate batch processing can be performed in a short time. Further, in the method for manufacturing a semiconductor device according to the third aspect, since the recessing process is performed by the etching process, the process is simple and no special mold or the like is required. Since the side surface of the metal substrate can be held flat, a thinner semiconductor device can be provided. Furthermore, the internal residual stress retained in the metal substrate sheet is reduced, the deformation of the metal substrate sheet can be prevented, and the flatness is remarkably improved. As a result, the coplanarity of the solder balls or bumps can be improved. In the method for manufacturing a semiconductor device according to claim 4, since the solder resist film is formed on a portion of the circuit board sheet excluding the external connection terminal lands,
The solder balls can be easily fixed and the lead pattern can be protected.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a semiconductor device manufactured by a method of manufacturing a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a plan view of a coupled semiconductor device in which the same semiconductor device is vertically and horizontally connected.

FIG. 3 is a partial cross-sectional view of a semiconductor device manufactured by a method of manufacturing a semiconductor device according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a method of manufacturing a semiconductor device according to a conventional example.

FIG. 5 is an explanatory diagram showing a method of manufacturing a semiconductor device according to a conventional example.

[Explanation of symbols]

10 semiconductor device 11 copper substrate (metal substrate) 12 circuit board 12a glass cloth epoxy resin plate 13 element mounting portion 14 semiconductor element 15 lead pattern 16 lead 17 bonding wire 18 external connection terminal land 19 solder ball 20 potting resin 21 solder resist film 22 Opening 23 Connected semiconductor device 24 Base plating layer 25 Prepreg layer 26 Terminal pad 27 Cutting line 30 Semiconductor device 31 Copper substrate (metal substrate) 32 Element mounting part

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Claims (4)

(57) [Claims] 1. A semiconductor element is mounted in the center, and a lead pattern composed of a plurality of leads connected to a plurality of electrode pads of the semiconductor element via bonding wires is provided around the semiconductor element, and each of the leads is provided. Is a method for manufacturing a semiconductor device in which a plurality of solder balls or bumps, which are arranged in a grid array and serve as connection terminals, are provided. Prepare a metal substrate sheet with good conductivity, process the recess of the element mounting part of each semiconductor device,
A first step of forming a predetermined undercoat on the surface of the metal substrate sheet, and forming an opening corresponding to the element mounting portion of the plurality of semiconductor devices formed on the metal substrate sheet, Moreover, the second step of preparing a circuit board sheet around the opening is provided with the lead pattern connected to the semiconductor element arranged in the opening by the etching process, and the first step. On the metal substrate sheet, the second
A third step of manufacturing the circuit board sheet prepared in the step by bonding the circuit board sheets to the element mounting portions with their openings aligned with each other, and positioning the semiconductor element mounting substrate sheet on the transport plate. Then, the semiconductor element mounting substrate sheet is moved by a predetermined distance in the X and Y directions, the semiconductor element is mounted on each element mounting portion, and predetermined wire bonding is performed to form a terminal pad of each semiconductor element. A fourth step of connecting the lead pattern, a fifth step of resin-sealing the semiconductor element and the wire-bonded portion with a potting mold or an injection mold, and external connection terminal lands of the lead pattern. The sixth step of forming the solder balls or bumps on the A single semiconductor device is cut and separated from a connected semiconductor device in which devices are arranged side by side in a longitudinal direction.
A method of manufacturing a semiconductor device, comprising: 2. The method of manufacturing a semiconductor device according to claim 1, wherein the recessing process in the first step is performed by a press process. 3. The method of manufacturing a semiconductor device according to claim 1, wherein the recessing process in the first step is performed by an etching process. 4. The semiconductor device according to claim 1, wherein, in the second step, a solder resist film is formed on a portion of the circuit board sheet excluding the external connection terminal lands. Production method.