JPH06244229A - Semiconductor device and package molding method thereof as well as molding device used for the same - Google Patents

Abstract

PURPOSE:To enable the consumption of the molding material during the resin sealing package molding step to be cut down by a method wherein the gate traces of resin sealing package are to be positioned either on the main surface opposite to that of a semiconductor pellet or on the main surface in the opposite side. CONSTITUTION:A semiconductor device 28 is provided with a semiconductor pellet 22 with an electronic circuit integrated with the main surface thereof, multiple leads 19 electrically connected to the pellet 22 to be externally extended and a package 25 resin sealing the pellet 22 and the parts of respective leads 19. In such a semiconductor device 28 wherein the resin sealing package 25 is molded by pressure molding step, the gate traces 27 during the pressure molding step are to be positioned at least either on one main surface opposing to that of the semiconductor pellet 22 or on the main surface in the opposite side in the resin sealing package 25. Furthermore the gate traces 27A during the pressure molding step are to be formed on the outer peripheral edge of the main surface in the side whereon the gate traces 27 are positioned.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device having a resin-sealed package, a method for molding the resin-sealed package, and a molding apparatus used for the same, and more particularly to a method for molding the resin-sealed package. The present invention relates to a technique for reducing the amount of molding material used, for example, in a semiconductor integrated circuit device (hereinafter, may be referred to as QFP / IC) equipped with a quad / flat / resin-encapsulated package that is required to be small in size and low in price. Regarding effective technology to use.

[0002]

2. Description of the Related Art In general, a QFP / IC is a semiconductor pellet in which an electronic circuit is built, a plurality of leads radially arranged on four sides of the semiconductor pellet, each electrode pad of the semiconductor pellet, and each lead. A group of wires radially arranged by bridging between the inner tip of the leads and a semiconductor pellet, a resin-sealed package in which a part of each lead and the group of wires are resin-sealed. There is.
The QFP / IC resin-sealed package is usually pressure-molded by a transfer molding device.

A transfer molding apparatus for molding this resin-encapsulated package is substantially formed between an upper die and a lower die which are fitted to each other and a mating surface of the upper die and the lower die. And a gate that is opened in the cavity, and a runner that is fluidly connected to the gate and transfers the resin from the pot to the cavity through the gate. . In the case of a molding device for molding a QFP / IC, the gate for press-fitting the molding material into the cavity is arranged in a square corner portion, and the resin injected into the cavity advances diagonally. I'm supposed to go.

By the way, Japanese Patent Laid-Open Publication No. 4-246516 and Japanese Patent Laid-Open Publication No. 4-246516 are intended to improve the yield of the molding resin, improve the quality of the product package after the molding process, and perform the resin molding process. There is disclosed a resin molding device for an electronic component, which aims to solve the problems that have occurred in the post-process device.

That is, as shown in FIG. 18 (a), the resin molding device for this electronic component is directly connected to the upper mold 2 or the lower mold 1 and to the cavity 3 formed therein. A resin tablet holding hole 4 that is vertically penetrating is provided. This resin tablet holding hole 4
A resin tablet 5 is loaded therein by a tablet loading device 6. Then, as shown in FIG. 18B, the injected resin tablet 5 or the melted product thereof is projected on the injection jig 7 to be inserted into each resin tablet insertion hole 4
It is directly injected into the cavity 3 by the injection pin 8 formed so that it can be inserted into the cavity 3.

[0006]

As described above, the molding material heated and melted in the pot is extruded into the runner by the plunger, transferred to the gate through the runner, and further pressed into the cavity from the gate. In the conventional transfer molding apparatus configured, since a large amount of molding material is used in the pot, runner, and gate, compared to the amount of molding material used for molding the product, that is, the resin-sealed package, Other than that, there is a problem that the amount of wasted molding material is much larger.

In particular, the thickness of the resin-sealed package is 1.0
This tendency is remarkable in a thin QFP / IC or the like having a thickness of about 10 mm, and a molding material in an amount of 10 to 100 times the amount used for a product may be wasted in vain.

Further, in the resin molding apparatus disclosed in the above publication, the gate is opened on the bottom surface or ceiling surface of the cavity in the molding die. However, the concrete points necessary for the realization are as follows. It was revealed by the present inventor that there is a problem that it cannot be realized because the technology is not taken into consideration.

(1) Since the tablets put in the tablet holding holes are heated by the radiant heat from the inner peripheral surface of the holding holes, the melting becomes insufficient. Since the resin that is not sufficiently melted has a high viscosity, when it is injected into the cavity, the resin having a high viscosity causes defects such as wire deformation and tab displacement.

(2) Since the gate is opened directly on the bottom surface or ceiling surface of the cavity in the molding die, it is difficult to carry out the cleaning work, and the life of the gate, which is the most worn, makes the molding die difficult. Lifespan is decided.

A first object of the present invention is to provide a molding technique capable of reducing the amount of molding material used when molding a resin-sealed package.

A second object of the present invention is to provide a molding technique capable of realizing the placement of the gate at a position corresponding to the bottom surface or ceiling surface of the cavity of the molding die.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0014]

The typical ones of the inventions disclosed in the present application will be outlined below.

That is, a semiconductor pellet having an electronic circuit formed on its main surface, a plurality of leads electrically connected to the semiconductor pellet and extending outward, one of the semiconductor pellet and each lead. In a molding device for molding the resin-sealed package in a semiconductor device including a resin-sealed package in which a portion is resin-sealed, a cavity for molding the resin-sealed package is formed. A molding die in which the semiconductor pellet and a part of each lead are housed in a cavity, and a molding material outside the cavity of the molding die for molding the resin-sealed package is a solid material. A pot to be accommodated in a state and a gate are opened, and the gate is placed at one end opening of the pot and one end opening of the cavity of the molding die. And a gate plate provided in the cavity so as to communicate with each other, a heater for heating at least the pot and the mold, and a liquid molding material obtained by heating and melting the molding material housed in the pot. And a plunger that transfers from the pot into the cavity through the gate.

[0016]

When the resin-sealed package is molded by the above-mentioned means, the work is made to extend in advance to each electrode pad of the semiconductor pellet on which the electronic circuit is built and to the outside of the semiconductor pellet. It is manufactured in a state where the inner ends of the plurality of leads that are wired are electrically connected. Then, at the time of molding the resin-sealed package, the prefabricated work is set in the cavity of the molding die.

On the other hand, the molding material for molding the resin-sealed package is contained in the pot in the form of a solid. A gate plate is placed over the opening at one end of the pot with the gate communicating with the inside of the pot. A molding die is disposed at a position on the opposite side of the pot of the gate plate with the gate communicating with the cavity.

The molding material contained in the pot is heated and melted by the heater, and the liquid molding material is transferred from the pot through the gate into the cavity by the plunger.

When the liquid molding material transferred into the cavity is cured by heating with a heater, the resin molding package is molded by the cavity.

According to the above-mentioned means, since the molding material is filled from the pot arranged in the vicinity of the cavity through the gate directly connected to the cavity, the wasteful consumption of the molding material is extremely reduced. Become.

Further, since the gate is provided on the gate plate which is attachable to and detachable from the pot and the molding die, the gate and the gate plate can be easily cleaned, and as a result,
It becomes feasible to place the gate on the main surface of the cavity.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 and subsequent figures are QFPs according to an embodiment of the present invention.
It is each explanation drawing which shows each process explaining the manufacturing method of IC.

In the present embodiment, the semiconductor device according to the present invention is an IC (hereinafter referred to as a semiconductor integrated circuit device for realizing a low thermal resistance) equipped with a resin-sealed quad flat package having good heat dissipation. , Low thermal resistance type QFP ・
Sometimes referred to as IC or simply IC. ) Is configured as.

A method of manufacturing the low thermal resistance type QFP / IC which is an embodiment of the present invention will be described below. This description will clarify the details of the configuration of the low thermal resistance type QFP IC.

In this embodiment, a low thermal resistance type QFP.I
In the manufacturing method of C, the multiple lead frame 11 shown in FIG. 2 is used. This multiple lead frame 1
1 is a thin plate made of a spring material having a relatively large mechanical strength such as an iron-nickel alloy or phosphor bronze, which is integrally formed by a suitable means such as punching press working or etching working. The surface of the multiple lead frame 11 is partially or wholly plated with silver (Ag) or the like so that wire bonding described later can be properly performed. ). Further, although not shown, the surface of the multiple lead frame 11 is subjected to a palladium treatment for forming an antioxidant coating on the lead frame.

On this multiple lead frame 11, a plurality of unit lead frames 12 are arranged side by side in a row. However, only one unit is shown. In order to make the description easy to understand, the description will be given in units of one unit.

The unit lead frame 12 has a positioning hole 13
There is provided a pair of outer frames 13 in which a is provided, and both outer frames 13 are arranged in parallel at a predetermined interval and extend in series. Adjacent unit lead frame 1
A pair of section frames 14 are provided between the outer frame 13 and the outer frame 13,
The unit lead frames 12 are arranged in parallel with each other between the 13 and are integrally installed. The unit lead frame 12 is formed in a substantially square frame body (frame) formed by the outer frame and the section frame.

In each unit lead frame 12, a dam suspension member 15 is provided at the connecting portion of the outer frame 13 and the section frame 14 so as to be disposed in a substantially right angle direction and integrally projected. The four dam members 16 are arranged so as to have a substantially square frame shape and are integrally suspended. Four radiating fin leads 17 are arranged at each of four corner portions of each dam member 16 and integrally provided so as to project in a diagonal direction.

Radiating fins 18 are integrally projectingly provided on the outer ends of the four radiating fin leads 17, and the radiating fins 18 have a shape and an arrangement corresponding to an outer portion 19b of a lead 19 which will be described later. Are formed respectively. A tab 20 having a substantially square shape is arranged concentrically with the frame shape at the inner tip of each heat radiation fin lead 17, and is integrally connected so as to be suspended by these heat radiation fin leads 17. Each radiating fin lead 17 is a tab 20
The radiating fin leads 17 are bent in the vicinity, and the radiating fin lead 17 is bent so that the tab 20 is lowered from the surface of the lead group 19 described later by the thickness of the pellet 22 described later (so-called tab lowering).

Further, a plurality of leads 19 as electric wiring are arranged on the dam member 16 at equal intervals in the longitudinal direction, and are integrally projected so as to be parallel to each other and orthogonal to the dam member 16. . The inner ends of the leads 19 are arranged so that their ends surround a tab 20 for bonding a pellet, which will be described later, to form inner parts 19a. On the other hand, the outer extended portion of each lead 19 has its tip connected to the outer frame 13 and the section frame 14 to form an outer portion 19b.
Then, the adjacent leads 19 and 1 in the dam member 16
The portion between 9 substantially constitutes a dam 16a for stopping the flow of the resin at the time of molding a package which will be described later.

For the multiple lead frame thus constructed, pellet bonding work and then wire bonding work are carried out for each unit lead frame. These bonding operations are sequentially performed for each unit lead frame by laterally pitching multiple lead frames.

First, a pellet 22 as a semiconductor integrated circuit structure in which an integrated circuit is formed in a so-called pre-process in a semiconductor device manufacturing process by a pellet bonding operation is shown in FIGS. 3 (a) and 3 (b). As shown in FIG.
It is arranged in the substantially central portion above and is bonded by being mechanically fixed by a bonding layer 21 formed between the tab 20 and the pellet 22. As a method for forming the pellet bonding layer 21, a bonding method using a gold-silicon eutectic layer, a soldering layer, a silver paste adhesive layer, or the like can be used. However, it is desirable to form the bonding layer 21 so that it does not become a barrier of heat transfer from the pellet to the tub, if necessary.

Then, by wire bonding work,
As shown in FIGS. 3 (a) and 3 (b), tab 2
Electrode pad 2 of pellet 22 bonded on
2a and leads 19 in each unit lead frame 12
By using a suitable wire bonding device (not shown) such as an ultrasonic thermocompression bonding wire bonding device or the like, the both ends of the bonding wire 23 are bonded to the inner portion 19a of Bridged. As a result, the integrated circuit built in the pellet 22 includes the electrode pad 22a, the bonding wire 23, the inner portion 19a of the lead 19 and the outer portion 19 of the lead 19.
It will be electrically drawn to the outside through b.

Even if the lead frame 12 is heated during the pellet bonding work and the wire bonding work, since the surface of the multiple lead frame 11 is coated with a palladium film (not shown), the surface of the lead frame 12 is not covered. It does not oxidize or discolor.

As described above, pellets and wires
In the bonded assembly 24, a group of packages 25, which are resin-sealed for each unit lead frame, are provided in FIGS.
~ Transfer molding apparatus 2 as shown in Figure 10
9 are used and molded simultaneously for a unit lead frame group.

Next, QFP.I, which is an embodiment of the present invention,
The resin-sealed package molding device of C will be described.

The QFP / IC resin-sealed package molding apparatus according to one embodiment of the present invention is configured as a transfer molding apparatus. The transfer molding device 29 includes a machine base 30, and a guide pole 31 is provided on the machine base 30.
Are arranged in four corners and are vertically erected. A base 33 is installed at the center of the machine base 30, and a pot block 34 is attached to the base 33. A pot 35 is opened in the pot block 34, and a plunger 36 is fitted in the pot 35 so as to be vertically slidable.

The plunger 36 is vertically driven via a plate 39 by a hydraulic cylinder device 38 installed vertically upward on the machine base 30. The upper end surface of the plunger 36 has a gate fitting protrusion 37.
Are arranged so as to face a gate, which will be described later, and are formed so as to be fitted into the gate so as to project.

A guide post 32 for a gate plate is erected vertically in the center of the machine base 30, and a gate plate 40 is rotatably mounted on the guide post 32 in a horizontal plane and vertically slidable. It is movably supported. The gate plate 40 is formed in a rectangular plate shape whose short side width is larger than the length of the multiple lead frame 11 described above, and the gate plate 40 has a gate 41 corresponding to each unit lead frame 12 described above. Has been established. Gate 4
1 is formed as a truncated cone-shaped through hole that becomes narrower as it goes upward, and is arranged so as to correspond to a corner portion of a cavity described later.

A recess 42 is submerged in the lower surface of the gate plate 40, and the recess 42 is configured to be fitted into a projection 43 protruding from the upper surface of the pot block 34. The fitting of the concave portion 42 and the convex portion 43 ensures the positioning of the gate plate 40 and the pot block 34.

A gate plate operation plate 44 is erected between a pair of guide poles 31, 31 erected at one end (hereinafter, left end) of the machine base 30 and movably supported up and down. The plate 44 is configured to be driven in the vertical direction by a hydraulic cylinder device 45 installed vertically upward on the machine base 30. The right end of the plate 44 is engaged with the gate plate 40 from below, and the gate plate 40 is moved up and down as the plate 44 moves up and down.

Although illustration is omitted, the gate plate 40 is configured to be rotationally driven by a driving device such as a hydraulic cylinder device, and reciprocally rotated within a predetermined angle range around the gate plate guide post 32. It is designed to be operated dynamically.

A lower die 46 is erected above the gate plate operation plate 44 between the four guide poles 31 and is supported so as to be vertically movable. The lower die 46 is vertically upward on the machine base 30. It is configured to be driven in the vertical direction by the installed hydraulic cylinder device 52.

A recess 47 is recessed in the lower surface of the lower mold 46, and this recess 47 is configured to be fitted into a projection 48 protruding from the upper surface of the gate plate 40. By fitting the concave portion 47 and the convex portion 48, the gate plate 40 and the lower mold 4 are
Positioning with 6 is ensured. Also,
A convex portion 49 is provided on the upper surface of the lower mold 46, and the convex portion 49 is located in the positioning hole 13 of the multiple lead frame 11.
The protrusion 49 and the positioning hole 13a are fitted to each other so that the lower die 46 and the multiple lead frame 11 can be positioned with each other.

The lower die 46 is provided with a lower die ejector pin 50 at a position corresponding to an appropriate position such as the outer frame 13 of the multiple lead frame 11, and the ejector pin 50 is always urged upward by a spring. It is configured to be. As will be described later, the ejector pin 50 pushes the multiple lead frame 11 upward to release the molded product from the lower mold 46.

The lower mold 46 is provided with a lower mold cavity recess 51b corresponding to each unit lead frame 12 described above. This cavity recess 51b cooperates with an upper mold cavity recess 51a, which will be described later, to produce a cavity. It is formed so as to form the tee 51. The lower mold cavity recess 51b is formed in a truncated pyramid shape that becomes thinner as it goes downward, and its lower surface is opened. The lower surface opening is configured to be closed by the gate plate 40 when the gate plate 40 is in contact with the lower surface of the lower mold 46. In this state, the gate 41 of the gate plate 40 is closed.
Are communicated with the lower mold cavity recess 51b.

An upper die 53 is erected above the lower die 46 between the four guide poles 31 and movably supported up and down. The upper die 53 is a hydraulic cylinder device (only the piston rod portion is shown. 55) so that it is driven in the vertical direction. The hydraulic cylinder device 55 is installed vertically downward on a beam (not shown) installed between the upper ends of the guide poles 31.

The upper die 53 is provided with an upper die ejector pin 54 at a position corresponding to an appropriate position such as the outer frame 3 of the multiple lead frame 1, and the ejector pin 54 is always urged downward by a spring. It is configured to be. As will be described later, the ejector pin 54 pushes down the multiple lead frame 1 to release the molded product from the upper mold 53.

The upper die 53 has an upper die recess 51a corresponding to each of the unit lead frames 12 set therein. The cavity recess 51a cooperates with the lower die cavity recess 51b to form a cavity. 51 is formed. The upper mold cavity concave portion 51a is formed in a quadrangular pyramid shape that becomes thinner as it goes upward.

Inside the pot block 34, the plunger 36, the gate plate 40, the lower mold 46, and the upper mold 53, a heater 56 using an electric heater or the like is appropriately laid, and the heater 56 allows the pot block. Three
4, the plunger 36, the gate plate 40, the lower mold 46 and the upper mold 53 are heated. This heater 56
Is pot block 34, plunger 36, gate plate 4
0, the lower die 46 and the upper die 53 are configured to control heating operation based on temperature sensors (not shown) embedded in the die. The heater 56 is not limited to the one in which an electric heater or the like is embedded, but may be integrally formed with the plunger 36 or the like by using a resistance heating element such as a ceramic heater.

As shown in FIG. 9, a gate plate cleaning device 60 is installed near the machine base 30. That is, the gate plate cleaning device 60 is arranged so as to correspond to the retracted position of the gate plate 40 rotated by 90 degrees, and is configured to perform the cleaning operation of the gate plate 40 at this retracted position.

As shown in FIG. 10, the gate plate cleaning device 60 has a hydraulic cylinder device installed vertically downward and a hydraulic cylinder device installed horizontally. A gate residue remover 62 is provided on the piston rod of the vertical hydraulic cylinder device 61.
The removal tool 62 is configured to drop the gate residue from the inside of the gate 41 by being lowered by the hydraulic cylinder device 61. Also,
A resin burr removing tool 64 is attached to the piston rod of the horizontal hydraulic cylinder device 63.
The hydraulic cylinder device 63 is laterally moved to scrape off the resin burrs 4 adhered to the surface of the gate plate 40.

Further, as shown in FIG. 9, the machine base 3
A loading device 65 is installed on the upstream side of 0, and the loading device 65 is configured to automatically load the multiple lead frame assembly 24 as a work onto the position of the lower die 46. Further, an unloading device 66 is installed on the downstream side of the machine base 30,
The unloading device 66 is configured to automatically unload the multiple lead frame molded product 26 as a molded work from the lower mold 46.

Further, as shown in FIG. 9, a tablet supply device 67 is installed at an appropriate position near the machine base 30, and the tablet supply device 67 uses the tablet 71 as a molding material in the pot 35. Is configured to be automatically supplied to.

Usually, the tablet 71 is a solid molding material formed by compacting a powder of an epoxy resin mixed with an inorganic substance such as silica and a curing agent into a cylindrical shape. In the present embodiment, the tablet 71 is preliminarily weighed so as to have a value slightly larger than the volume of the resin-sealed package 25, which is the product to be molded, that is, the volume of the cavity 51. The preformed tablet 71 is stored in the tablet supply device 67 and automatically supplied to the pot 35 by the tablet supply device 67.

Next, in one embodiment of the present invention, the transfer molding device 29 configured as described above is used to mold the resin-sealed package 25 on the assembly 24 having the above-mentioned structure as a work. A method for molding a resin-sealed package of a certain QFP / IC will be described.

As shown in FIG. 4, the plunger 3
6 is lowered by the hydraulic cylinder device 38,
The tablet 71 is provided in the pot 35 with the tablet 71.
It is automatically turned on by 7.

After the tablet 71 is loaded into the pot 35, as shown in FIG. 5, the gate plate 40 is aligned right above the pot 35 and is lowered by the hydraulic cylinder device 45 so that the gate plate 40 is lowered. 40 is placed over the pot block 34. At this time, since the convex portion 43 of the pot block 34 is fitted into the concave portion 42 of the lower surface of the gate plate 46, the gate plate 40 and the pot block 34 are accurately positioned.

In this positioning state, the gate plate 40
Is in a state in which the upper surface opening of the pot 35 is closed, and the gate 41 opened in the gate plate 40 is in communication with the inside of the pot 35.

Next, as shown in FIG. 6, the lower mold 46 is lowered by the hydraulic cylinder device 52 and is superposed on the gate plate 40. At this time, since the projection 48 on the upper surface of the gate plate 40 is fitted into the recess 47 on the lower surface of the lower mold 46, the lower mold 46 and the gate plate 40 are accurately positioned.

In this superposed state, the lower surface opening of the cavity concave portion 51b of the lower mold 46 is the gate plate 4.
The gate plate 40 is closed by 0.
The gate 41 opened at the lower mold cavity recess 51b
And the pot 35 are in communication with each other.

Subsequently, as shown in FIG. 6, the assembly 24 as a work is supplied by the loading device 65 right above the lower mold 46 and placed on the upper surface of the lower mold 46. At this time, the outer frame 13 of the multiple lead frame 11
Since the positioning projections 49 projecting from the upper surface of the lower mold 46 are fitted into the positioning holes 13a formed in the lower mold 46, the lower mold 46 and the assembly 24 are accurately positioned. In this positioning state, the regions of the pellet 22 and the wire 23 of each unit lead frame 12 in the assembly 24 are aligned with the lower mold cavity recess 51b.

Subsequently, as shown in FIG. 1, the upper die 53 is lowered by the hydraulic cylinder device 55, and the lower die 4
6 is overlaid and the mold is clamped. In this mold clamped state, the cavity recess 51a of the upper mold 53 and the lower mold 4 are
The cavity 51 is formed when the cavity concave portions 51b of 6 are aligned with each other. Then, the pellet 22 and the wire 2 of the assembly 24
3 and the inner portions 19a of the leads 19 are enclosed in the cavity 51. In addition, each lead 19
The outer regions of the outer portion 19b, the outer frame 13, the section frame 14, and the like are sandwiched between the mating surfaces of the upper mold 53 and the lower mold 46.

The heater 56 is energized to supply the pot block 3
When 4 is heated, the tablet 71 contained in the pot 35 is melted and becomes a liquid molding material (hereinafter referred to as resin) 72. At this time, since the heater 56 is built in the pot block 34, the plunger 36, and the gate plate 40, the tablet 71 housed in the pot 35.
Is heated very effectively from all directions.
Therefore, the tablet 71 melts quickly and uniformly in the pot 35.

The viscosity of the resin 72 shows a characteristic curve as shown in FIG. Therefore, when the viscosity of the resin 72 approaches the minimum viscosity (melting minimum viscosity),
The plunger 36 is raised in the pot 35 by the hydraulic cylinder device 38.

As shown in FIG. 7, the plunger 3
When 6 is moved up in the pot 35, the resin 72 in the pot 35 is transferred into the cavity 51 through the gate 41 and filled. At this time, since the resin 72 has a uniformly low viscosity, the resin 72 is
1 is properly filled from the gate 41. The plunger 36 continues to rise until the resin 72 is completely transferred to the cavity 51 side. The resin 72 filled in the gate 41 at the top dead center of the plunger 36 is pressed into the cavity 51 by fitting the convex portion 37 protruding from the upper surface of the plunger 36 into the gate 41. .

As shown in FIG. 12, when the resin 72 is injected from the gate 41 into the cavity 51,
Since the gate 41 is opened at a corner portion which is a position deviated from the center of the cavity 51, the resin 72 injected from the gate 41 into the cavity 51 has the other pair along the diagonal line of the cavity 51. Head towards the corner,
At the same time, it is in a state in which it gradually diffuses in the direction of the diagonal line orthogonal to each other. Therefore, the resin 72 is in a state of being evenly filled in the cavity 51. Also, this resin 7
With the uniform filling of 2, the air in the cavity 51 is also discharged very effectively from each part of the cavity.

When the upper mold 53 and the lower mold 46 are heated by the heater 56 after the resin 72 in the pot 35 is completely transferred and filled in the cavity 51, the resin 5
Since 8 is cured by a thermal crosslinking reaction, a resin body 73 is formed by the cured resin.
3 causes the resin-sealed package 25 to be substantially molded (see FIG. 8). The mold clamping state of the upper mold 53, the lower mold 46 and the gate plate 40 is maintained until the resin body 73 is molded.

As shown in FIG. 8, the resin body 7
After 3 is molded, the upper die 53 and the lower die 46 are simultaneously clamped by the hydraulic cylinder devices 55 and 52 and are raised with respect to the gate plate 40 and the pot block 34. Due to this rise, the lower surface of the resin body 73 surrounded by the cavity 51 is released from the upper surface of the gate plate 40, and the residue 74 in the gate 41 connected to the lower surface of the resin body 73 is removed from the gate 41. Are separated so as to be torn off at the smallest diameter part of the.

In separating the gate residue 74,
Since the minimum diameter part in the tapered shape of the gate 41 is just the chocolate break point, the separation point between the resin body 73 and the gate residue 74 is always constant, and
The cut will be very clean.

Thereafter, the upper die 53 is moved to the hydraulic cylinder device 55.
Is raised with respect to the lower mold 46 and is held at a standby position of a predetermined height. When the upper mold 53 is separated from the lower mold 46,
Since the upper ejector pin 54 loses its support and is protruded downward by the spring, the ejector pin 54
Thus, the multiple lead frame 11 as a work is pushed down. By this pushing down, the molded product 26 as the processed work in which the resin sealing package 25 is molded is released from the upper mold 53. That is, the resin-sealed package 25 is released from the upper mold cavity recess 51a.

Similarly, when the upper die 53 is separated from the lower die 46, the lower die ejector pin 50 loses its support and is projected upward by the spring, so that the lower die ejector pin 50 raises the multiple lead frame 11 upward. Pushed up to. By this pushing up, the molded product 26 is released from the lower mold 46. That is, the resin-sealed package 2
5 is released from the lower mold cavity recess 51b.

Molded product 2 separated from the upper and lower dies 53 and 46
6 is the upper and lower molds 53,
6 and then unloading (Fig. 9
reference).

On the other hand, when the upper and lower molds 53 and 46 are raised,
The gate plate 40 is lifted by the hydraulic cylinder device 45 and separated from the pot block 34. continue,
The gate plate 40 is rotated by, for example, 90 degrees in a horizontal plane about the guide post 31 by a rotation driving device (not shown), and is moved to the gate plate cleaning device 60.

As shown in FIG. 10, in the gate plate cleaning device 60, the vertical hydraulic cylinder device 61 is used.
The gate residue removing tool 62 is pushed down by this, and the removing tool 62 is inserted into the gate 41, so that the gate residue 74 remaining in the gate 41 is pushed down.
At this time, since the gate residue 74 is formed into a sufficiently small size by fitting the convex portion 37 of the plunger 36 into the gate 41, the gate residue 74 can be easily and cleanly removed.

Further, the resin residue removing tool 64 is moved laterally by the horizontal hydraulic cylinder device 63, and the resin burr adhering to the surface of the gate plate 40 is scraped off by the removing tool 64. At this time, since the resin 72 in the pot 35 is entirely transferred into the cavity 51, the resin burr on the gate plate 40 is formed extremely thin, so that the removing tool 64 rubs the resin burr easily and cleanly. Can be dropped.

On the other hand, when the gate plate 40 is moved to the retracted position, the plunger 36 is lowered inside the pot 35 by the hydraulic cylinder device 38 to a predetermined position (see FIG. 4). At this time, the plunger 36 has a capacity such that the capacity inside the pot 35 is slightly larger than the capacity of the cavity 51.
That is, the tablet 71 is lowered to a position substantially equal to the volume of the tablet 71.

After that, by repeating the above-mentioned operation, the resin-sealed package 25 is sequentially molded on the assembly 24.

Inside the package 25 resin-molded as described above, as shown in FIGS. 13 and 14, the pellet 22 and the inner portion 19 of the lead 19 are provided.
a, bonding wire 23 and heat radiation fin lead 1
7 will be resin-sealed. In addition, the radiation fins 18 formed on the outer end side of the radiation fin lead 17
Are projecting from the side surfaces of the corners of the resin-sealed package 25 in the right angle direction.

Further, in this state, the gate mark 27 remains on one corner portion of the lower surface which is one main surface of the resin-sealed package 25. As described above, since the gate residue 74 is finely separated from the gate mark 27, the surface of the gate mark 27 is in a very good condition. Therefore, the gate mark 27 does not reduce the value of the QFP / IC 28 as a product.

A gate plate mark 27A is formed on the outer peripheral edge of the lower surface, which is the main surface of the resin package 25 on which the gate mark 27 remains. The gate plate mark 27A is formed by the gate plate 40 abutting so as to close the lower surface opening of the cavity recess 51a of the lower mold 46, and has a sharper edge shape than the outer peripheral edge of the upper surface. .

Thereafter, the molded product 26 in which the resin-encapsulated package 25 has been molded is subjected to a lead cutting device (not shown) sequentially for each unit lead frame 12 in the lead cutting molding process. From
After the outer frame 13, the section frame 14 and the dams 16a are cut off, the outer portion 19b of the leads 19 and the heat radiation fins 18 are gulled by a lead forming device (not shown).
Each is bent and formed into a wing shape. This allows
The low thermal resistance type QFP shown in FIG. 13 and FIG.
The IC 28 is manufactured.

As described above, according to the above embodiment, the following effects can be obtained. (1) A gate plate is detachably provided between the cavity of the molding die and the pot, and the resin in the pot is transferred into the cavity through a gate provided in the gate plate. As a result, the transfer distance of the resin from the pot to the cavity can be configured to be the shortest, so that the useless amount of the resin can be reduced and the use amount of the resin can be significantly reduced. As a result, the molding material cost can be significantly reduced.

(2) It is possible to transfer all the resin in the pot into the cavity by weighing the tablet, which is the material of the resin, in advance so that its volume becomes equal to the volume of the resin-sealed package. Therefore, the amount of resin used can be reduced to the necessary minimum. Further, by consuming all the resin in the cavity, it is possible to reduce the resin burr in the resin-sealed package, simplify the cleaning work of the molding die and the gate plate, and further, release the mold. The agent and its application work can be reduced.

(3) Since the transfer path from the pot to the cavity is extremely short, the drive control of the plunger which regulates the injection speed and the injection flow rate of the resin into the cavity can be most quickly adapted to the viscosity behavior of the resin. Therefore, the quality and reliability of the resin-sealed package can be improved.

(4) By arranging the gate on the lower surface of the resin-sealed package, in the design of the lead frame, the sub-runner for flowing the resin and the gate receiving portion arranged beside the package outer shape are omitted. Therefore, the number of products acquired in the lead frame can be increased.

(5) In designing the lead frame,
When the structure of a multi-row multi-row lead frame (so-called multi-lead frame) is adopted, the amount of the molding material used for the resin-sealed package can be significantly reduced by the above (1) and (2). Since the material of the lead frame can be significantly reduced by the above (3),
The material cost of the IC provided with the resin-sealed package can be significantly reduced, and the use of the multi-lead frame can dramatically improve the throughput in the resin-sealed package molding process. As a result, It is possible to synergistically reduce the manufacturing cost of the IC provided with the resin-sealed package.

(6) By arranging the gate at the corner of the cavity, the resin injected from the gate into the cavity can be diffused in one direction, so that the resin is kept inside the cavity. It is possible to prevent the generation of voids due to the entrainment of air in the portion to be joined (the so-called weld portion), and it is possible to prevent the deformation of the wire and the deformation of the lead, and as a result,
The quality and reliability of the resin-sealed package can be improved.

(7) By disposing the heater on the pot block, the plunger and the gate plate, the tablet contained in the pot can be heated from all directions of the pot, so that the tablet is melted quickly and uniformly. Can be made. In particular, the plunger is brought into direct contact with the tablet for heat conduction heating, so that the heating efficiency is extremely good. Therefore, since the properly melted resin can be injected from the pot into the cavity through the gate, the resin-sealed package can be properly molded. In other words, if the melting of the tablet is insufficient and uneven, a resin with high viscosity enters a state where it is injected from the pot into the cavity through the gate, and the resin causes defects such as so-called wire flow and tab displacement. However, if the tablet is melted properly, this cause of failure will not occur.

(8) Since the gate plate is configured to be movable with respect to the pot block and the molding die, the gate plate can be cleaned at each position separated from the pot block and the molding die each time the molding operation is performed. The workability can be improved, and appropriate molding quality can always be maintained.

(9) By forming the gate so that its diameter becomes smaller toward the cavity side,
Since the gate residue can be broken into chocolate at its minimum diameter portion, the gate residue can be always cut out in a constant case, and the surface of the gate trace can be always kept clean.

(10) Since the convex portion of the plunger is configured to fit into the gate, the gate residue can be formed small, so that the amount of resin used can be further reduced and the gate residue can be further reduced. Can be more easily removed.

Although the invention made by the present inventor has been specifically described based on the embodiments, the invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say.

As shown in FIG. 15, the lower mold 46A
The gate plate 40A can be configured such that the gate plate 40A is close to the tab 20 side which is a part of the work. That is, the tablet 7 housed in the pot 35
This is because the resin can be sufficiently circulated even in a narrow space inside the cavity 51 by sufficiently melting No. 1.

The semiconductor device having the resin-sealed package molded by this molding apparatus has good heat dissipation performance because the resin body under the tab 20 is thin. On the other hand, since a part of the resin body is formed under the tab 20, the insulation performance is not lost.

The number of gates is not limited to one for each cavity, but a plurality of gates 41 may be provided for each cavity as shown in FIG.
A plurality of gates 41, 41 for one cavity
Is provided, the degree of freedom for drive control of the plunger most suitable for the viscosity behavior of the resin with respect to the injection speed and the injection flow rate of the resin can be further improved. In other words, since the tablet 71 housed in the pot 35 is rapidly and uniformly heated and melted over the whole, a plurality of gates 41, 41 ... Are provided for one cavity. can do.

As shown in FIG. 17, the pot 35
The inner diameters of C and the plunger 36C may be smaller than the inner diameter of the gate 41. In this case, the waste amount of the resin can be further reduced and the gate plate 40 can be further reduced.
The resin flash attached to C can be almost eliminated.

The in-gate fitting protrusion provided on the gate plate cleaning device or the plunger may be omitted.

The gate plate, the pot, and their driving devices are not limited to being arranged on the lower mold side, but may be arranged on the upper mold side.

In the above description, the invention made by the present inventor is the field of application which is the background of the invention.
The case of application to an IC has been mainly described, but the present invention is not limited to this and can be applied to all semiconductor devices including a resin-sealed package. In particular, the present invention has a small volume of the resin-sealed package, and the thickness of one main surface of the resin-sealed package is thinner than the thickness of the opposite main surface, and mass production is required. In addition, excellent effects can be obtained by applying it to a semiconductor device manufacturing technique that requires low cost.

[0101]

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

A gate plate is removably provided between the cavity of the molding die and the pot, and the resin in the pot is transferred into the cavity through the gate provided in the gate plate. As a result, the transfer distance of the resin from the pot to the cavity can be configured to be the shortest, so that the useless amount of the resin can be reduced and the use amount of the resin can be significantly reduced. As a result, the molding material cost can be significantly reduced.

By disposing the heater on the pot block, the plunger and the gate plate, the tablet housed in the pot can be heated from all directions of the pot, so that the tablet can be melted quickly and uniformly. it can. In particular, the plunger is brought into direct contact with the tablet for heat conduction heating, so that the heating efficiency is extremely good. Therefore, since the properly melted resin can be injected from the pot into the cavity through the gate, the resin-sealed package can be properly molded. In other words, if the melting of the tablet is insufficient and uneven, a resin with high viscosity enters a state where it is injected from the pot into the cavity through the gate, and the resin causes defects such as so-called wire flow and tab displacement. However, if the tablet is melted properly, this cause of failure will not occur.

Since the gate plate is constructed so as to be movable with respect to the pot block and the molding die, the gate plate can be cleaned at each position separated from the pot block and the molding die each time the molding work is performed, and the cleaning workability is improved. It is possible to improve the molding temperature and always maintain an appropriate molding quality.

[Brief description of drawings]

FIG. 1 is a partially omitted front sectional view showing a step in a method of molding a QFP / IC resin-encapsulated package according to an embodiment of the present invention.

FIG. 2 is a partially omitted plan view showing a multiple lead frame used in the method for manufacturing the QFP / IC.

3A and 3B are diagrams showing a state after a pellet and wire bonding step, in which FIG. 3A is a partially omitted plan view, and FIG.
It is sectional drawing which follows the b line.

FIG. 4 is a partially cutaway partially cut front view showing a QFP / IC resin-sealed package molding apparatus according to an embodiment of the present invention.

FIG. 5 is a partially cut front view showing a step of mounting the gate plate.

FIG. 6 is a partially omitted front view showing a lower die mounting step.

FIG. 7 is a partially omitted front sectional view showing a resin transferring step.

FIG. 8 is a partially cut front view showing a molding separation step.

FIG. 9 is a schematic plan view showing a resin-sealed package molding apparatus for a QFP / IC that is an embodiment of the present invention.

FIG. 10 is a front view of each of the gate plate cleaning devices.

FIG. 11 is a graph showing resin viscosity change characteristics.

FIG. 12 is a view for showing the filling action of the resin,
(A) is a plan sectional view and (b) is a front sectional view.

FIG. 13 is a QFP · which is an embodiment of the present invention and is manufactured by the method of manufacturing a QFP · IC which is an embodiment of the present invention.
It is a partially cut front view which shows IC.

FIG. 14 is a partially cutaway bottom view thereof.

FIG. 15 is a partially cut front view showing a resin-sealed package molding apparatus that is Embodiment 2 of the present invention.

FIG. 16 is a partially cut front view showing a resin-sealed package molding apparatus that is Embodiment 3 of the present invention.

FIG. 17 is a partially cut front view showing a resin-sealed package molding apparatus that is Embodiment 4 of the present invention.

FIG. 18 is a partially omitted front sectional view showing a conventional example.

[Explanation of symbols]

11 ... Multiple lead frame, 12 ... Unit lead frame, 13 ... Outer frame, 14 ... Section frame, 15 ... Dam suspension member, 16 ... Dam member, 16a ... Dam, 17 ... Radiating fin lead, 18 ... Radiating fin, 19 ... Lead, 19a ...
Inner part, 19b ... Outer part, 20 ... Tab, 21 ... Bonding layer, 22 ... Pellet, 23 ... Wire, 24 ... Assembly (work), 25 ... Resin sealing package, 26 ... Molded product (molded work), 27 ... Gate mark, 27A ... Gate plate mark, 28 ... QFP / IC (semiconductor device), 29 ...
Transfer molding device, 30 ... Machine base, 31 ... Guide pole, 32 ... Gate plate guide post, 33 ... Base, 3
4 ... Pot block, 35, 35C ... Pot, 36, 3
6C ... Plunger, 37 ... Gate fitting convex part, 38 ... Hydraulic cylinder device, 39 ... Plate, 40, 40A ... Gate plate, 41 ... Gate, 42 ... Recessed part, 43 ... Convex part, 44 ... Gate plate operating plate, 45 ... Hydraulic cylinder device, 46,
46A ... Lower mold, 47 ... Recessed portion, 48 ... Convex portion, 49 ... Convex portion,
50 ... Lower ejector pin, 51 ... Cavity, 51
a ... upper mold cavity recess, 51b ... lower mold cavity recess, 52 ... hydraulic cylinder device, 53 ... upper mold, 54 ... upper mold ejector pin, 55 ... hydraulic cylinder device, 56 ... heater, 60 ... gate plate cleaning device , 61 ... Vertical hydraulic cylinder device, 62 ... Gate residue removing tool, 63 ... Horizontal hydraulic cylinder device, 64 ... Resin flash removing tool, 65 ... Loading device, 66 ... Unloading device, 67 ...
Tablet supply device, 71 ... Tablet, 72 ... Resin, 73 ... Resin body, 74 ... Gate residue.

Front Page Continuation (72) Inventor Takuya Nakajo 5-20-1, Kamimizuhonmachi, Kodaira-shi, Tokyo Hitachi Ltd. Semiconductor Division

Claims (12)

[Claims] 1. A semiconductor pellet having an electronic circuit formed on a main surface thereof, a plurality of leads electrically connected to the semiconductor pellet and extending outward, and one of the semiconductor pellet and each lead. In a semiconductor device having a resin-sealed package in which a portion is resin-sealed, the resin-sealed package is molded by a pressure molding method, and the gate mark used in the pressure molding method is It is positioned on at least one of the main surface of the resin-sealed package that faces the main surface of the semiconductor pellet and the main surface on the opposite side, and the gate plate marks used in the pressure molding method have gate marks. A semiconductor device, which is formed on an outer peripheral edge of a main surface on a side where the semiconductor device is located. 2. The thickness between the main surface of the resin-sealed package on the side where the gate mark is formed and the semiconductor pellet is
The semiconductor device according to claim 1, wherein the semiconductor device is formed thinner than its thickness on the opposite side. 3. A semiconductor pellet having an electronic circuit formed on its main surface, a plurality of leads electrically connected to the semiconductor pellet and extending outward, one of the semiconductor pellet and each lead. In a method of molding a resin-encapsulated package in a semiconductor device including a resin-encapsulated package in which a part is resin-encapsulated, a molding material for molding the resin-encapsulated package is a pot in a solid state. And a gate plate having a gate opened in the thickness direction, which is formed separately from a molding die in which a cavity for molding the resin-sealed package is formed. In the step of covering the gate in communication with the pot, the molding die is located at a position opposite to the pot of the gate plate,
The step of placing the semiconductor pellet and a part of the leads in the cavity while the gate is placed in communication with the cavity and heating the molding material in the pot The step of melting and transferring the liquid molding material from the pot through the gate of the gate plate into the cavity by the plunger, and hardening the liquid molding material transferred into the cavity to seal the resin with the cavity. And a step of forming a stop package, and a method for forming a package of a semiconductor device. 4. The method of molding a package of a semiconductor device according to claim 3, wherein the gate plate is cleaned while being detached from the pot and the molding die. 5. A semiconductor pellet having an electronic circuit formed on its main surface, a plurality of leads electrically connected to the semiconductor pellet and extending outward, one of the semiconductor pellet and each lead. In a molding device for molding the resin-sealed package in a semiconductor device including a resin-sealed package in which a portion is resin-sealed, a cavity for molding the resin-sealed package is formed. A molding die in which the semiconductor pellet and a part of each lead are housed in a cavity; and a molding material for molding the resin-sealed package, which is outside the cavity of the molding die, is a solid material. A pot to be accommodated in a state and a gate are opened, and the gate and the gate are provided at one end opening of the pot and one end opening of the cavity of the molding die. A gate plate provided in a state of being communicated with each other in a bite, a heater for heating at least the pot and the mold, and a liquid molding material obtained by heating and melting the molding material housed in the pot. And a plunger that moves from the inside to the cavity through the gate, and a package forming apparatus for a semiconductor device. 6. A gate plate is movably arranged in a direction intersecting the pot and the molding die, and a cleaning device for cleaning the gate plate is provided at a position different from the pot and the molding die. The package molding apparatus for a semiconductor device according to claim 5, wherein 7. A mold is formed with a plurality of cavities, at least one gate is communicated with each cavity, and these gates are arranged on the same gate plate. The semiconductor device package molding apparatus according to claim 5. 8. The semiconductor device according to claim 4, wherein a plurality of gates are connected to one cavity of the molding die, and these gates are arranged on the same gate plate. Package molding equipment. 9. The package molding apparatus for a semiconductor device according to claim 5, wherein the gate has a small diameter on the cavity side. 10. The package molding apparatus for a semiconductor device according to claim 5, wherein the gate is disposed so as to be offset from the center of the cavity. 11. The package molding apparatus for a semiconductor device according to claim 5, wherein a part of the plunger is configured to be inserted into the gate. 12. The package molding apparatus for a semiconductor device according to claim 5, wherein the pot and the plunger have outer diameters smaller than or equal to the inner diameter of the gate.