JPH09121015A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable adherence of a vertical mounting package to a printed circuit board with a contact surface portion and prevent inclination or fall of the package with respect to the printed circuit board, by abutting a solder mounting portion of an outer lead against each land of the printed circuit board so that the lower surface of the contact surface portion of a resin-sealed body is abutted against the upper surface of the printed circuit board. SOLUTION: A vertical mounting package 18 has a plurality of outer leads 4 led out downward from an elongated rectangular lower surface of a resin- sealed body 14. Each of the outer leads 4 is bent to be perpendicular to and coplanar with the lower surface of the resin-sealed body 14, thus forming a solder mounting portion 4a. On the resin-sealed body 14, a contact surface portion 15 is formed which has a lower surface 16 coinciding with the surface including the group of solder mounting portions 4a.

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 more particularly to a semiconductor device in which a package is arranged vertically to a mounting surface of a mounting substrate and surface mounted, and for example, high density mounting such as a memory is required. The present invention relates to a technique effectively applied to a semiconductor device.

[0002]

2. Description of the Related Art The ultimate in high-density packaging is three-dimensional packaging.
Even if the QFP / IC or SOP / IC is laid flat on the printed wiring board, a high packaging density cannot be obtained. As a method of utilizing the space in the vertical direction, there is a method of vertically arranging semiconductor devices on a printed wiring board. There are a single in-line package and a zip in-line package in the form of a form that stands upright on the printed wiring board, but these are insertion type packages.

On the other hand, a surface mount type vertical mount package has been developed. As this type of conventional package, a vertical surface mount package (hereinafter referred to as VSMP) has been proposed.
This VSMP is a thin package such as a thin small outline package (TSOP) that pulls the outer leads from the edges and stands vertically directly on the printed wiring board. The outer leads are gathered on the bottom surface to form an L shape. It has a structure in which the leads are bent and projectingly provided on both ends of the lower surface so as to erect the package.

Incidentally, as an example in which VSMP is described,
Nikkei BP Co., Ltd. Published May 31, 1993 "Practical course VLSI packaging technology (below)" P179-P1
There is 81.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In P, the outer lead group and the supporting leads are temporarily bonded to the printed wiring board by solder paste or the like before being vertically mounted on the printed wiring board by the reflow soldering process. Since the force is insufficient, the vertical arrangement state of the VSMP with respect to the printed wiring board becomes unstable, and there is a problem in that the soldering state of the vertical mounting becomes defective.

An object of the present invention is to provide a semiconductor device provided with a surface mounting type vertical mounting package capable of surely ensuring proper vertical mounting.

[0007] The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0008]

The outline of a typical invention among the inventions disclosed in the present application is as follows.

That is, a semiconductor device in which a package including a resin encapsulant and a plurality of outer leads drawn out from the resin encapsulant is arranged perpendicular to the mounting surface of a mounting substrate and surface-mounted In, the outer leads are bent at right angles to the direction of withdrawing from the resin encapsulant and are bent so as to be included in the same plane to form a soldering mounting portion. Part of the lead-out side end surface of the outer lead group in is formed in contact with the surface including the soldering mounting section group to form a contact surface section.

[0010]

When the above-mentioned semiconductor device is vertically arranged on the printed wiring board and surface-mounted, when the soldering mounting portion of each outer lead is aligned and abutted with each land of the printed wiring board, resin sealing is performed. Since the contact surface portion of the body comes into contact with the facing surface of the printed wiring board, the semiconductor device is connected to the printed wiring board by the adhesive layer between the contact surface portion and the facing surface of the printed wiring board. Can be strongly bonded. Since the semiconductor device is securely fixed to the printed wiring board by this adhesion state, it is possible to reliably prevent the semiconductor device from tilting or falling with respect to the printed wiring board, and as a result, the soldering of each outer lead. The attachment mounting portion is appropriately reflow soldered to each land of the printed wiring board.

[0011]

1 shows a mounted state of a semiconductor device according to an embodiment of the present invention. (A) is an external perspective view, (b) is a side surface taken along line bb of (a). FIG. FIG. 2 shows a state after the pellet and wire bonding steps in the method for manufacturing the semiconductor device,
(A) is a partially omitted plan view and (b) is a sectional view taken along the line bb of (a). FIG. 3 is a longitudinal sectional view showing a resin encapsulant molding process, FIG. 4 shows the same after molding, (a) is a partially cutaway plan view, and (b) is a b- of (a). FIG. FIG. 5 also shows the outer lead forming process, wherein (a) is a front view before forming and (b) is a front view after forming.

In the present embodiment, the semiconductor device according to the present invention is configured as a semiconductor device 19 having a surface mounting type vertical mounting package (hereinafter referred to as a package) 18. The package 18 includes a resin encapsulant 14 formed in a rectangular flat plate shape and a resin encapsulant 14
A plurality of outer leads 4 that are drawn out from one elongated side surface (hereinafter, referred to as a lower surface) of the package 18 with respect to the mounting surface (hereinafter, referred to as an upper surface) of the printed wiring board 51. Are vertically arranged and surface-mounted. A semiconductor pellet (hereinafter referred to as a pellet) 9 in which a semiconductor integrated circuit is formed inside the resin encapsulant 14, an inner lead 5 integrally connected to each outer lead 4, and a pellet 9. Each electrode pad 9a and the bonding wire 12 bridging the inner lead 5 are resin-sealed.

Each outer lead 4 is bent at right angles to the direction of extraction from the resin encapsulant 14 and is bent so as to be included in the same plane to form a soldering mounting portion 4a. Outer lead 4 in body 14
A part of the pull-out side end face (lower face) of the group is the soldering mounting portion 4
The contact surface portion 15 is formed so as to match the surface including the group a.

The details of the structure of this semiconductor device will be described below along with the manufacturing method thereof. In the present embodiment, the semiconductor device manufacturing method uses the multiple lead frame 1 shown in FIG. 2, and the multiple lead frame 1 is manufactured by a multiple lead frame molding process and prepared. To be done. The multiple lead frame 1 is made of a thin plate made of a material having good conductivity such as iron-nickel alloy or phosphor bronze, and is integrally formed by an appropriate means such as punching press or etching. The surface of the multiple lead frame 1 is partially or entirely plated with silver (Ag) or the like (not shown) so that the wire bonding described later can be properly performed. In the multiple lead frame 1, a plurality of unit lead frames 2 are arranged in a row in the horizontal direction. In principle, the description and illustration are only given for one unit.

The unit lead frame 2 is provided with an elongated flat plate-shaped outer frame (frame) 3 having positioning holes 3a. One outer side of the outer frame 3 has a plurality of outer leads 4 in the longitudinal direction. It projects at a right angle at equal intervals. Each inner lead 5 is integrally connected to the tip of each outer lead 4. A bus bar 6 is connected to the outer leads 4 at both ends of the plurality of outer leads 4, and the bus bar 6 is wired in a U-shape so as to bypass the inner lead 5 group for signal transmission. A dam bar 7 is installed between the outer leads 4 and 4 which are adjacent to each other in a portion of the outer lead 4 where the inner lead 5 and the bus bar 6 are connected. Is configured to get.

Pellets 9 are bonded to the multiple lead frame 1 having the above structure as shown in FIG. In the so-called pre-process in the manufacturing process of the semiconductor device, the pellet 9 is formed with an integrated circuit including semiconductor elements in the state of a semiconductor wafer, and is divided into a rectangular flat plate shape in the dicing process. The main surface (hereinafter referred to as the first main surface) of the pellet 9 on the side where the integrated circuit including the semiconductor element is formed is covered with the passivation film 10, and the insulating sheet 11 is provided on the passivation film 10. It is glued. The pellet 9 is brought into contact with one main surface of the unit lead frame 2 on the insulating sheet 11 and bonded by an adhesive layer (not shown),
Pellet bonding is performed on the multiple lead frame 1.
In this state, the tip portion of each inner lead 5 is pellet 9
Are arranged so as to be orthogonal to each other at equal intervals, and the bus bar 6 is wired on the opposite side of the inner lead group 5 with the electrode pad 9a arranged on the first main surface of the pellet 9 interposed therebetween. .

Subsequently, as shown in FIG. 2, wire bonding work is carried out between the pellet 9 and the unit lead frame 2. That is, the bonding wire 12 is provided between the electrode pad 9a of the pellet 9 and the tip portion of the inner lead 5, and between the electrode pad 9a and the opposing position of the bus bar 6, such as an ultrasonic thermocompression bonding wire bonding device. By using an appropriate wire bonding device (not shown), both ends thereof are respectively bonded and bridged. As a result, the integrated circuit built in the pellet 9 is electrically pulled out to the outside via the electrode pad 9a, the bonding wire 12, the inner lead 5, the bus bar 6 and the outer lead 4.

As described above, pellets and wires
For the bonded assembly 13 shown in FIG. 2, the transfer molding apparatus 20 shown in FIG. 3 is used, and the resin encapsulant 14 having the contact surface portion 15 that enhances the adhesive force is shown in FIG. Molded as shown in.

The transfer molding apparatus 20 shown in FIG. 3 includes a pair of upper mold 21 and lower mold 22 which are clamped together by a cylinder device (not shown).
The upper mold cavity recess 2 is formed on the mating surface between the lower mold 22 and the lower mold 1.
A plurality of sets (only one set is shown) are recessed so that the lower mold cavity recess 23b and the lower mold cavity 3a cooperate with each other to form a rectangular plate-shaped cavity 23. In the present embodiment, the lower mold cavity recess 23b
Is formed in a rectangular hole shape whose shorter side is longer than the rectangular hole shape of the upper mold cavity recess 23a, so that the contact surface portion 15 is integrally molded over the entire length of the long side by this extra large cavity portion. It has become.

A pot 24 is provided on the mating surface of the upper mold 21, and a cylinder device (not shown) is provided in the pot 24.
The plunger 25 advanced and retracted by is inserted so that a liquid resin (hereinafter referred to as a resin) as a molding material can be fed. On the mating surface of the lower mold 22, culls 26 are arranged in a position facing the pot 24 and are buried therein, and a plurality of runners 27 are arranged in a radial pattern so as to be connected to the pot 24, respectively. ing. Each runner 2
The other end of 7 is connected to the lower cavity recess 23b, and a gate 28 is formed at the connecting portion so that the resin can be injected into the cavity 23.
Further, in order to allow the escape recess 29 to escape the thickness of the multiple lead frame 1 on the mating surface of the lower die 22, the rectangular shape is slightly larger than the outer shape of the multiple lead frame 1, and the dimension is substantially equal to the thickness thereof. It is buried in the depth.

At the time of transfer molding, the assembly 13 is housed in an escape recess 29 which is recessed in the lower mold 22. As a result, the inner peripheral edge of the dam bar 7 in the unit lead frame 2 is aligned with the outer peripheral edge of the lower mold cavity recess 23b on the side protruding from the upper mold cavity recess 23a, thereby forming a dam. . Further, the pellet 9, the inner lead 5 group and the wire 12 are accommodated in the lower mold cavity recess 23b.

Next, the upper die 21 and the lower die 22 are clamped, and the portion of the unit lead frame 2 closer to the outer frame 3 than the dam bar 7 is sandwiched between the mating surfaces of the upper die 21 and the lower die 22. . Subsequently, the resin 30 formed by heating and melting a tablet (not shown) put in the pot 24 is fed from the pot 24 by the plunger 25 to each cavity 23 through the runner 27 and the gate 28 and is press-fitted.

After the injection, when the resin 30 is thermoset and the resin encapsulant 14 is molded, the upper mold 21 and the lower mold 22 are opened, and the resin is encapsulated by ejector pins (not shown). The body group 14 is released. As shown in FIG. 4, the pellet 9, the inner lead 5 group, and the wire 12 group are resin-sealed inside the released resin sealing body 14. In this state, the portion of each outer lead 4 closer to the outer frame 3 than the dam bar 7 is in a state of protruding from the lower surface 16 of the contact surface portion 15.
The portion closer to the inner lead 5 than the dam bar 7 is exposed on a side surface (hereinafter, referred to as a notched side surface) 17 of the resin sealing body 14 corresponding to a mating surface with the upper mold 21 of the contact surface portion 15. .

A molded product as a semi-finished product molded with the resin sealing body 14 is subjected to a lead cutting process after the outer frame 3 and the dam bar 7 are cut off for each unit lead frame in a lead cutting process (not shown). The outer lead 4 is bent into an L shape by the lead forming device 40 shown in FIG.

The lead forming apparatus 40 shown in FIG. 5 is provided with an upper die 41 and a lower die 42. The upper die 41 and the lower die 42 have a holding recess 43 for holding the resin sealing body 14, respectively.
44 are respectively recessed so that the resin sealing body 14 can be housed therein. A bending roller 45 is rotatably mounted on one side of the upper die 41 and the lower die 42 so as to vertically move in the vertical direction. The bending roller 45 rolls while being pressed against the outer lead 4 so that the outer lead 4 is configured to be bent into an L shape.

Next, the lead forming device 40 having the above-mentioned structure.
A method of bending the outer lead 4 will be described.

First, as shown in FIG. 5 (a),
The resin encapsulant 14 is arranged in a holding recess 44 formed on the upper surface of the lower mold 42. At this time, the notch side surface 17 of the contact surface portion 15 is made to face downward and is brought into contact with the outer side portion of the pressing concave portion 44 on the upper surface of the lower mold 42. Subsequently, the upper mold 41 and the lower mold 42 are clamped, so that the resin sealing body 14
Are pressed by the upper and lower pressing recesses 43 and 44.

Next, when the bending roller 45 is moved vertically downward, the bending roller 45 rolls the outer surface of the outer lead 4 while pushing the outer lead 4 downward, as shown in FIG. 5 (b). As described above, the outer lead 4 is bent in an L shape with the shoulder of the lower mold 42 as a starting point. At this time, since the notch side surface 17 is pressed by the upper surface of the lower mold 42, the outer lead 4 is properly bent into an L shape. When the outer lead 4 is bent into an L shape, the outer lead 4 projects at a right angle to the notch side surface 17, and the solder mounting portion 4a is formed. The soldering mounting portions 4a are aligned in the same plane, and the resin sealing body 14
The contact surface portion 15 is in a state of forming substantially the same surface as the lower surface 16.

By the above manufacturing method, the semiconductor device 19 including the surface mounting type vertical mounting package 18 having the above-described structure shown in FIG. 1 is manufactured. As shown in FIG. 1, the semiconductor device 19 is surface-mounted in a state where it is erected vertically on the printed wiring board 51.

That is, a plurality of lands 52 are arranged on the printed wiring board 51 so as to correspond to the outer leads 4 of the package 18 of the semiconductor device 19, and are formed in a substantially rectangular thin plate shape. Is coated with solder paste (not shown). Semiconductor device 1
When 9 is surface-mounted on the printed wiring board 51,
The package 18 is provided on each land 52 of the printed wiring board 51.
The outer leads 4 are aligned and abutted. When the group of outer leads 4 is brought into contact with the group of lands 52, the lower surface 1 of the bonding surface portion that is flush with the outer lead 4 group at the contact surface portion 15
6 is in contact with the upper surface of the printed wiring board 51. Therefore, since the adhesive layer 53 is provided between the lower surface 16 of the contact surface portion and the upper surface of the printed wiring board 51, the lower surface 16 of the contact surface portion can be strongly adhered to the upper surface of the printed wiring board 51. An accident that the package 18 of the semiconductor device 19 tilts or falls with respect to the printed wiring board 51 can be reliably prevented.

In general, a semiconductor device provided with a surface mount type package is often temporarily attached to a printed wiring board with a solder paste and then transported to a heating furnace or the like for reflow soldering. SOP / IC and QFP / IC
In such a horizontally mounted package, the package hardly tilts or falls with respect to the printed wiring board during the transportation. However, in a semiconductor device equipped with a surface mount type vertical mount package, the contact area with the printed wiring board is small and the center of gravity is high, so an accident such as a fall or tilt due to lateral inertial force during transportation may occur. Easy to do.

However, in the present embodiment, the contact surface lower surface 16 is provided on the upper surface of the printed wiring board 51 by providing the adhesive layer 53 between the lower surface 16 of the contact surface portion and the upper surface of the printed wiring board 51. Since it can be strongly bonded, even in the case of the semiconductor device 19 including the surface mounting type vertical mounting package 18, the vertical mounting package 18 can be securely tilted or fallen with respect to the printed wiring board 51. Can be prevented.

When the reflow soldering process is performed,
Since each outer lead 4 in the package 18 of the semiconductor device 19 is properly and evenly formed with each soldering portion 54 on each land 52 in the soldering mounting portion 4a, the package 18 of the semiconductor device 19 is mounted on the printed wiring board 51. On the other hand, it becomes a state where it is surface-mounted exactly vertically.

According to the above embodiment, the following effects can be obtained. (1) Temporary bonding by solder paste between the outer lead group and the land group by projecting a contact surface portion having a lower surface flush with the soldering mounting portion of the outer lead on the resin sealing body in the surface mounting type vertical mounting package. In this state, since the temporary adhesive force can be supplemented by the lower surface of the contact surface portion and the upper surface of the printed wiring board, even a semiconductor device including a surface mounting type vertical mounting package,
Accidents in which the vertically mounted package tilts or falls with respect to the printed wiring board can be reliably prevented.

(2) Since three-dimensional mounting can be realized by surely surface-mounting a semiconductor device having a surface-mounting type vertical mounting package vertically on a printed wiring board, the mounting density is dramatically increased. Can be increased to

FIG. 6 shows a semiconductor device according to a second embodiment of the present invention, (a) is an external perspective view and (b) is a bottom view.

The second embodiment is different from the first embodiment in that the soldering mounting portions 4a of the outer leads 4 and the contact surface portions 15 of the resin sealing body 14 are alternately turned and arranged in a zigzag pattern. That is the point.

Also in the second embodiment, the solder mounting portion 4a of the outer lead 4 is formed by the lower surface 16 of the contact surface portion 15.
Since the shortage of the temporary adhesive force due to the solder paste with the land 52 can be compensated, it is possible to prevent accidents such as tilting and falling of the vertical mounting package 18 in advance.

FIG. 7 shows a mounted state of the semiconductor device according to the third embodiment of the present invention, in which (a) is an external perspective view,
(B) is a side sectional view taken along the line bb of (a).

The third embodiment differs from the first embodiment in that the contact surface increasing portion 1 is provided on the contact surface portion 15 of the resin sealing body 14.
5a is formed so as to project in a direction opposite to the solder mounting portion 4a of the outer lead 4.

According to the third embodiment, since the contact area with the printed wiring board 51 is increased, it is possible to more reliably prevent accidents such as tilting and falling of the vertically mounted package 18.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above-described embodiments, and can be variously modified without departing from the gist thereof. Needless to say.

For example, the pellet is not limited to be bonded to a lead frame in a lead-on-chip (LOC) structure, but may be bonded to a substrate such as a tab or a header.

Since the contact area of the vertically mounted package with the printed wiring board is increased by the lower surface of the contact surface portion, it becomes easier to maintain the upright position. Therefore, the lower surface of the contact surface portion is bonded to the upper surface of the printed wiring board through the adhesive layer. You don't have to.

[0045]

The effects obtained by typical aspects of the invention disclosed in the present application will be briefly described as follows.

By provision of a contact surface portion having a lower surface flush with the soldering mounting portion of the outer lead on the resin sealing body in the surface mounting type vertical mounting package, the outer lead group and the land group are temporarily bonded by solder paste. In this state, since the temporary adhesive force can be supplemented by the lower surface of the contact surface portion and the upper surface of the printed wiring board, even in a semiconductor device having a surface mounting type vertical mounting package, the vertical mounting package is It is possible to reliably prevent an accident such as tilting or falling.

[Brief description of the drawings]

1A and 1B show a mounted state of a semiconductor device according to an embodiment of the present invention, FIG. 1A is an external perspective view, and FIG. 1B is a side sectional view taken along line bb of FIG.

FIG. 2 shows a state after a pellet and wire bonding step in the method for manufacturing the semiconductor device, FIG.
Is a partially omitted plan view, and (b) is a sectional view taken along the line bb of (a).

FIG. 3 is a vertical cross-sectional view showing a resin sealing body molding step.

4A and 4B are views after the molding, in which FIG. 4A is a partially cutaway plan view with a part thereof omitted, and FIG. 4B is a sectional view taken along the line bb of FIG.

FIG. 5 shows a molding process of the outer lead, (a)
Is a front view before molding, and (b) is a front view after molding.

FIG. 6 shows a semiconductor device according to a second embodiment of the present invention, (a) is an external perspective view, and (b) is a bottom view.

7A and 7B show a mounted state of a semiconductor device according to a third embodiment of the present invention, FIG. 7A is an external perspective view, and FIG.
FIG. 6 is a side sectional view taken along line bb of FIG.

[Explanation of symbols]

1 ... multiple lead frame, 2 ... unit lead frame, 3
... Outer frame (frame), 3a ... Positioning hole, 4 ... Outer lead, 4a ... Solder mounting part, 5 ... Inner lead, 6 ...
Bus bar, 7 ... Dam bar, 9 ... Pellet, 9a ... Electrode pad, 10 ... Passivation film, 11 ... Insulating sheet,
12 ... Bonding wire, 13 ... Assembly, 14 ... Resin encapsulant, 15 ... Contact surface portion, 15a ... Contact area increasing portion, 1
6 ... Lower surface, 17 ... Notch side surface, 18 ... Surface mounting type vertical mounting package, 19 ... Semiconductor device, 20 ... Transfer molding device, 21 ... Upper mold, 22 ... Lower mold, 23 ... Cavity, 23a ... Upper mold cabinet Tee recess, 23b ... Lower mold cavity recess, 24 ... Pot, 25 ... Plunger,
26 ... Cull, 27 ... Runner, 28 ... Gate, 29 ... Escape recess, 30 ... Resin, 40 ... Lead forming device, 41 ... Upper mold, 42 ... Lower mold, 43, 44 ... Holding recess, 45 ... Bending roller, 51 ... Printed wiring board, 52 ... Land, 53
... Adhesive material layer, 54 ... Soldering part.

Claims (3)

[Claims] 1. A semiconductor device in which a package including a resin encapsulant and a plurality of outer leads drawn out from the resin encapsulant is arranged perpendicularly to a mounting surface of a mounting substrate and surface-mounted. In the above, each of the outer leads is formed at a right angle with respect to the withdrawal direction from the resin sealing body, and is bent so as to be included in the same plane to form a soldering mounting portion,
A semiconductor device, wherein a part of a lead-out side end surface of the outer lead group in the resin encapsulant is formed in contact with a surface including a soldering mounting section group. 2. The semiconductor device according to claim 1, wherein the soldering mounting portions and the contact surface portions are alternately turned and arranged in a zigzag pattern. 3. The semiconductor device according to claim 1, wherein the contact surface portion is formed with an area increasing portion protruding in a direction opposite to the soldering mounting portion.