JPH05109796A - Manufacture of resin sealing type electronic components - Google Patents

Abstract

PURPOSE:To form a good resin coating layer covering the whole of a support board 5 which supports a semiconductor chip. CONSTITUTION:A first mold cavity row 32, which comprises a plurality of mold cavities 27a to 27d, is installed in a die 12. A second mold cavity row 33, which comprises a plurality of mold cavities 27e to 27h, is installed in parallel in the first mold cavity row 32. A plurality of resin injection pots 19a to 19c are installed between the first and second mold cavity rows 32 and 33. One resin injection pot is connected to four mold cavities out of the first and second mold cavity rows 32 and 33. Each of the mold cavities 27a to 27h has a first gate 28 and a second gate 29 respectively. The second gate 29 uses a slide type 16 and it is closed. After the resin is injected through the first gate 28, the resin is injected from the second gate 29.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a sealing type electronic component having a resin coating layer on the front surface of a supporting plate for supporting electronic components such as transistors and ICs and a thin resin coating layer on the back surface. Regarding

[0002]

2. Description of the Related Art A resin-encapsulated semiconductor device in which substantially the entire surface of a support plate which also serves as a heat dissipation plate is covered with a resin encapsulant is known.
A method of forming a resin encapsulant of a semiconductor device of this kind by molding in two steps is disclosed in, for example, Japanese Patent Laid-Open No. 58-58
No. 151035 is disclosed. Further, Japanese Patent Application Laid-Open No. 60-130129 discloses that a support plate arranged in a molding cavity (cavity) of a die is sandwiched by pins that can freely move back and forth and resin molding is performed.

[0003]

However, in the manufacturing method disclosed in Japanese Patent Application Laid-Open No. 58-151035, there are two problems.
Different types of molds are required, which complicates the manufacturing process. Also,
In the manufacturing method disclosed in Japanese Patent Application Laid-Open No. 60-130129, it is difficult to control the movement timing of the pins and practically applicable. That is, if the pin moving timing is too early, the support plate cannot be stably fixed by the resin, and the resin sealing body cannot be formed on the back surface side of the support plate with a uniform thickness. Further, if the timing of moving the pin is too late and the curing of the resin progresses, the void formed by the movement of the pin cannot be filled with the resin.

Therefore, an object of the present invention is to provide a method capable of easily and satisfactorily forming a resin encapsulant covering both the front surface side and the back surface side of a support plate.

[0005]

The present invention for achieving the above object will be described with reference to the reference numerals of the drawings showing the embodiments. At least first and first elements arranged in parallel in a first direction will be described. Second and third molding cavities 27a, 27b, 27c
A first row of molding cavities 32, and at least fourth, fifth and sixth molding cavities 27e arranged in parallel with each other,
27f and 27g, and the first, second and third molding cavities 27a, 27b and 27c face the fourth, fifth and sixth molding cavities 27e, 27f and 27g. A second molding cavity row 33 arranged parallel to one molding cavity row 32 and the first molding cavity row 32, 33 so as to be parallel to the first and second molding cavity rows 32, 33. At least the first, second, third, and fourth resin injection ports 19 arranged between the molding cavity row 32 and the second molding cavity row 33.
Resin injection port row 34 including a, 19b, 19c, and 19d
And the first, second, third, fourth, fifth and sixth molding cavities 27a, 27b, 27c, 27e, 2
7f and 27g have first and second resin injection ports 28 and 29, respectively, and the first resin injection port 28 of the first and fourth molding cavities 27a and 27e facing each other is The second resin injection port 29a is connected to the first resin injection port 19a, and the second resin injection port 29 of each of the first and fourth molding cavities 27a and 27e is connected to the second resin injection port 19b. The second and fifth molding cavities 2 facing each other
The second resin injection ports 29 of 7b and 27f are connected to the second resin injection port 19b, respectively, and the first resin injection port 2 of the second and fifth molding cavities 27b and 27f is connected.
8 is connected to the third resin charging port 19c,
The third and sixth molding cavities 27c, 2 facing each other
The 7 g of the first resin injection port 28 is connected to the third resin injection port 19c, and the third and sixth molding cavities 27c, 27g of the second resin injection port 29 are 4 of the resin injection ports 19d, and the first, second, third, fourth, fifth, and sixth molding cavities 27, respectively.
a, 27b, 27c, 27e, 27f, 27g, a step of preparing a molding die 12 having movable bodies 15, 16 for closing the second resin injection port 29 in the molding cavity, A single or a plurality of lead frames each having a supporting plate 5 and external leads 6 connected to one end of the supporting plate 5, and an electronic element 3 mounted on one main surface of the supporting plate 5. The step of preparing the assembly 1 of
The second, third, fourth, fifth and sixth molding cavities 27a, 2
7b, 27c, 27e, 27f, 27g to the support plate 5
The one or more assemblies 1 are arranged in the molding die 12 so that they are respectively arranged, and the other end side of the support plate 5 is fixed by the movable bodies 15 and 16 and the external leads 6 are arranged. Is clamped by the molding die 12 to fix the support plate 5 in a state in which the other main surface thereof is separated from the surface of the molding cavity, and the second resin injection port 29 allows the movable body 15, The first resin injection port 2 is closed from the first and third resin injection ports 19a and 19c.
8 through the first, second, third, fourth, fifth and sixth
Molding cavities 27a, 27b, 27c, 27e, 27f,
The step of injecting the fluidized resin into 27 g, moving the movable bodies 15 and 16 to release the blockage of the second resin injection port 29, and moving the movable bodies 15 and 16 to the space created by the movement. And a step of injecting the fluidized resin through the second resin injection port 29 from the second and fourth resin injection ports 19b and 19d. Is.

[0006]

According to the present invention, the movable bodies 15 and 16 for preventing the support plate 5 from tilting during resin injection block the second resin injection port 29. Therefore, the void formed by the movement of the movable bodies 15 and 16 directly communicates with the second resin injection port 29. Therefore, after the support plate 5 is reliably positioned by the resin injected into the molding cavity, the movable body 15,
Even if 16 is moved, this void can be filled with resin well. Further, the resin injection port communicating with the second resin injection port 29 and the resin injection port communicating with the first resin injection port 28 belong to the same resin injection port row and are between two parallel molding cavity rows 32, 33. The molding die can be space-saving (high-density mounting) because it is arranged at. Furthermore, the length of the resin flow passage between the molding cavity and the resin inlet can be made equal.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method of manufacturing a resin-sealed semiconductor device according to an embodiment of the present invention will be described below with reference to FIGS. First, the lead frame assembly 1 shown in FIG. 1 is prepared. The lead frame assembly 1 is composed of a long lead frame 2, a semiconductor chip 3, and a thin lead wire 4. The lead frame 1 includes a plurality of metal supporting plates 5 juxtaposed in the longitudinal direction, an outer lead 6 arranged on one end side thereof, and a strip 7 connecting the outer leads 6 to each other.
Eight. The semiconductor chip 3 formed of a transistor chip is fixed to one main surface of the support plate 5 by soldering by a well-known die bonding method, and the lead thin wire 4 is, for example, a gold thin wire and is a well-known wire bonding method. 3 and the external lead 6 are electrically connected. The lead frame 2 is initially shown in FIG.
As indicated by the dotted line, the other end side of the support plate 5 is held by the support lead 9 and the support lead connecting strip 10 to form a ladder shape. The supporting leads 9 and the connecting strips 10 are removed after the lead frame 2 is subjected to die bonding and wire bonding in sequence.

Next, in order to form the resin encapsulation body 11 shown by the dotted line in FIG. 1 on the above-mentioned lead frame assembly 1 by the well-known transfer molding, the metal mold or molding die 12 shown in FIGS. 2 and 3 is prepared. To do. As shown in FIG. 2, the molding die 12 has a pair of upper die 13 and lower die 14 each of which is a movable die and the other is a fixed die, and a pair of movable bodies which are arranged so as to be movable back and forth. It is composed of an upper slide mold 15 and a lower slide mold 16.

The upper mold 13 has a plurality of recesses 17 for forming molding cavities, a plurality of upper slide mold holes 18 connected to the recesses 17, and a plurality of resin charging ports (hereinafter referred to as pots) 19a. , 19b, 19c, 19d, 19e are formed. The upper slide mold 15 is inserted into the hole 18. The upper slide die 15 is guided by the hole 18 and moves up and down. Further, a pressing die (hereinafter referred to as a plunger) 21 is arranged inside the pots 19a to 19e so as to be vertically movable. The pin 22 protruding downward from the recess 17 is for forming a hole for inserting a mounting screw in the completed resin sealing body 11.

The lower mold 14 has a plurality of recesses 23 for molding cavities.
The outer lead insertion groove 24, the resin passage groove 25, and a plurality of downward slide mold holes 26 communicating with the recess 23 are formed. The lower slide die 16 is arranged in the hole 26, and the lower slide die 16 is guided by the hole 26 and can move up and down.

By clamping the upper die 13 and the lower die 14, the recess 17 of the upper die 13 and the lower die 1 are formed in the molding die 12.
A plurality of molding cavities 27a to 27h that coincide with the resin sealing body 11 to be formed are formed by the concave portions 23 of No. 4. In addition, a plurality of runners are formed between the groove 25 of the lower mold 14 and the lower surface of the upper mold 13, and each runner is connected to the molding cavities 27a to 27h through a resin injection port or gate having a small cross section. There is. In this embodiment, as shown in FIG.
First and second gates 28 and 29 are formed at 27h, respectively, and first and second runners 30 and 31 are connected to them.

As is apparent from FIG. 3, the molding die 12 has a first molding cavity row 32 composed of a plurality of molding cavities 27a, 27b, 27c and 27d arranged in parallel in the left-right direction, A second molding cavity row 33 composed of a plurality of molding cavities 27e, 27f, 27g, 27h arranged in parallel with the first molding cavity row 32. First and second
A plurality of pots 19 are provided between the rows of molding cavities 32 and 33.
A pot row 34 composed of a to 19e is arranged. Although the lower mold 14 is provided only with the lower portions of the pots 19a to 19e, this portion will also be called a pot in FIG. Molding cavities 27a to 27 of the first molding cavity row 32
d and the molding cavities 27e to 27h of the second molding cavity row 33 are arranged to face each other. The pots 19a to 19e are arranged such that the centers thereof substantially coincide with the centers of the molding cavities 27a to 27d and the centers of the molding cavities 27e to 27h.

When resin-molding, a plurality of lead frame assemblies 1 shown in FIG. 1 are prepared and correspond to the first molding space row 32 and the second molding space row 33 of the molding die 12, respectively. As shown in FIG. 2, the upper mold 13 is attached to the lower mold 14
And the lower mold 14 is clamped. The other end of the support plate 5, that is, the end on the side where the external lead 6 is not connected, is formed in the molding space 27a.
It opposes the surface on which the gates 28 and 29 of ~ 27h are formed. The outer lead 6 is housed in the groove 24 of the lower mold 14 and sandwiched between the upper mold 13 and the lower mold 14. Before the upper mold 13 and the lower mold 14 are closed or after the upper mold 13 and the lower mold 14 are closed, the upper slide mold 15 is lowered in the hole 18 and the lower slide mold 16 is raised in the hole 26 to support the support plate. The other end side of 5 is held by slide molds 15 and 16. As a result, both ends of the support plate 5 are supported, and the lower surface of the support plate 5 is positioned so as to be separated from the lower surfaces of the molding cavities 27a to 27h. Further, a part of the second gate 29 is a lower slide type 1
Blocked by 6.

Next, odd-numbered pots 19a, 19c,
19e is filled with a sealing resin 35 made of epoxy resin or the like, and then this is pressed by the plunger 21, and a plurality of molding cavities 27 are passed through the first runner 30 and the first gate 28.
The fluidized sealing resin is simultaneously injected under pressure into a to 27h. As is apparent from FIG. 3, the pots 19a, 19
c and 19e are four molding cavities 27a to 27a connected to this.
The sealing resin is injected into 7h. Since the support plate 5 is supported by both ends, it does not tilt due to the pressure of the injected resin during this resin injection.

As shown in FIG. 4, almost the entire other region of the molding cavities 27a to 27h except the portion where the upper slide mold 15 and the lower slide mold 16 are arranged is almost entirely the sealing resin 3.
After being filled with 5, the upper slide mold 15 and the lower slide mold 16 are moved away from the support plate 5 as shown in FIG. 5, and the holding of the support plate 5 by the slide molds 15 and 16 is released. As a result, the support plate 5 is cantilevered. However, the molding cavities 27a to 27h
Since a sufficient amount of the sealing resin 35 has already been injected into the inside and the fluidity of the initially injected sealing resin 35 has decreased, the support plate 5 is formed in the molding cavities 27a to 27h. It is positioned by the sealing resin 35 and is not inclined.

Next, the even-numbered pots 19b and 19d are filled with the sealing resin 35, and then the plungers 21 are pressed by the plungers 21 and slid through the second runner 31 and the second gate 29 as shown in FIG. The fluidized sealing resin 35 is pressure-injected into the cavities 36 and 37 created by the movement of the molds 15 and 16. As is clear from FIG. 3, the sealing resin 35 is injected from each of the even-numbered pots 19b and 19d into the four molding cavities 27a to 27h connected thereto. Since the lower slide mold 16 is arranged so as to close a part of the second gate 29, the void 37 formed by the movement of the lower slide mold 16 directly communicates with the second gate 29. Further, since the upper slide die 15 faces the lower slide die 16 at a short interval corresponding to the thickness of the thin portion of the support plate 5, the space 36 created by the movement of the upper slide die 15 is also located in the lower slide die 16. It can be considered that it leads to the second gate 29 through the void 37 created by the movement. Therefore, even if the surrounding resin is slightly hardened, the sealing resin 35 can be satisfactorily injected into the void created by the movement of the slide molds 15 and 16.

When the sealing resin 35 is filled in the cavities 36 and 37 created by the movement of the slide molds 15 and 16 and the sealing resin 35 in the molding cavities 27a to 27h is cured, the upper mold 13 and the lower mold 13 are lowered. The lead frame assembly 1 is taken out from the molding die 12 by unclamping the die 14. Finally, the strips 7 and 8 are removed to obtain an individual resin-sealed semiconductor device as shown in FIG. According to the resin-sealed semiconductor device manufactured in this embodiment, the entire surface of the support plate 5 can be covered with the resin-sealed body 11. The hole 11a is formed on the basis of the pin 22 of the upper mold 13, a part of the resin sealing body 11 is also formed on the inner peripheral side, and the support plate 5 is not exposed.

According to the above method, the slide molds 15, 1
The entire molding cavities 27a to 27h excluding the portion where the 6 is located are filled with the sealing resin 35, whereby the support plate 5
The support plate 5 is clamped by the slide molds 15 and 16 until is fixed. Therefore, the inclination of the support plate 5 is completely prevented. Further, since the void created by the movement of the slide molds 15 and 16 communicates with the gate 29, the sealing resin can be well injected into this void. Further, the pot row 34 is arranged between the first and second molding cavity rows 32 and 33, and the pots 19a to 19e respectively inject the resin into the four molding cavities, so that space saving is achieved. Has been done. Further, since the lengths of the runners 30 and 31 are equal, each molding space 27
The resin injection amounts for a to 27e are equalized, and it becomes easy to set the movement timing of the slide molds 15 and 16.

[0019]

[Modification] The present invention is not limited to the above-described embodiment, but can be modified as follows. For example, the first and second embodiments are possible.
The lead frame assemblies 1 arranged in the molding cavity rows 32 and 33 can be integrated into one assembly.

[0020]

As is apparent from the above, according to the present invention, since the support plate is supported by the movable body and the resin is injected, both the front surface side and the back surface side of the support plate are satisfactorily covered with the resin. be able to. Further, the void created by moving the movable body is well filled with the resin injected from the resin injection port closed by the movable body. In addition, a plurality of resin injection ports (pots) are provided between the first and second rows of molding cavities.
Since the resin is injected from one resin injection port into four molding cavities, the length of the passage (runner) from the resin injection port (pot) to the resin injection port (gate) must be the same. It becomes possible to easily set the movement timing of the movable body.

[Brief description of drawings]

FIG. 1 is a plan view showing a part of an assembly of a lead frame and a semiconductor chip used for manufacturing a resin-sealed electronic component according to an embodiment of the present invention.

2 is a state in which the assembly of FIG. 1 is mounted on a molding die; FIG.
It is sectional drawing shown by cutting a part of AA line.

FIG. 3 is a plan view showing a state in which an assembly is arranged in a lower die of the molding die of FIG.

FIG. 4 shows a state in which a resin is injected into the molding space, which is taken along the line B- in FIG.
It is sectional drawing shown by the B line.

FIG. 5 is a cross-sectional view showing a state after moving the slide mold, similar to FIG.

FIG. 6 is a cross-sectional view showing a part of line BB in FIG. 3 in an enlarged manner.

FIG. 7 is a perspective view showing a completed semiconductor device.

[Explanation of symbols]

 5 Support Plates 6 External Leads 12 Molds for Molding 15 Upper Slide Molds 16 Lower Slide Molds 19a to 19e Pots 27a to 27h Molding Spaces 28 First Gate 29 Second Gate

Claims (1)

[Claims] 1. At least first, second and third molding cavities (27a, 27) arranged parallel to each other in a first direction.
b, 27c) and a first row of molding cavities (32) and at least fourth, fifth and sixth molding cavities (27e, 27f, 27g) arranged in parallel with each other, said first , Second and third molding cavities (27a, 27b, 27
c) the fourth, fifth and sixth molding cavities (27e, 2)
7f, 27g) and a second molding cavity row (33) arranged in parallel to the first molding cavity row (32) so as to face each other, and the first and second molding cavities. Row (32, 3
3) at least first, second, third and third arranged between the first row of molding cavities (32) and the second row of molding cavities (33) so as to be parallel to them. And a resin injection port array (34) composed of four resin injection ports (19a, 19b, 19c, 19d), the first, second, third,
Fourth, fifth and sixth molding cavities (27a, 27b, 27
c, 27e, 27f, 27g) have first and second resin injection ports (28, 29), respectively, and are located in the first and fourth molding cavities (27a, 27e) facing each other. The first resin injection port (28) is the first resin injection port (1
9a), and the second resin injection port (29) of the first and fourth molding cavities (27a, 27e), respectively.
Are connected to the second resin injection port (19b), respectively, and face each other to the second and fifth molding cavities (27).
b, 27f), the second resin injection port (29) is connected to the second resin injection port (19b), and the second resin injection port (29b) of the second and fifth molding cavities (27b, 27f) is connected to the second resin injection port (29b). The first resin injection port (28) is the third resin injection port (19c).
And the third and sixth parts that are connected to each other and face each other.
The first resin injection port (28) of the molding cavity (27c, 27g) is connected to the third resin injection port (19c) respectively, and the third and sixth molding voids (27c, 27c, 27c, 27c). 27
The second resin injection port (29) of g) is connected to the fourth resin injection port (19d), respectively, and the first, second, third, fourth, fifth and sixth moldings are performed. Vacancy (27a, 2
7b, 27c, 27e, 27f, 27g) and a molding die (12) having a movable body (15, 16) for closing the second resin injection port (29) in the molding cavity. A step of preparing, a lead frame having a support plate (5) and an external lead (6) connected to one end of the support plate (5), and one main surface of the support plate (5); A step of preparing a single or a plurality of assemblies (1) composed of mounted electronic elements (3), and the first, second, third, fourth, fifth and sixth molding cavities ( 27a, 27b, 27c, 27e, 27f, 27g)
The one or more assemblies (1) are arranged on the molding die (12) so that the support plates (5) are respectively arranged on the other side of the support plate (5). Movable body (1
5, 16) and the outer lead (6) is clamped by the molding die (12) so that the supporting plate (5) is separated from the surface of the molding cavity by the other main surface thereof. And the second resin injection port (29) is closed by the movable body (15, 16), and the first and third resin injection ports (19a, 19c) are connected to the first resin. Through the inlet (28), the first, second, third, fourth, fifth and sixth molding cavities (27a, 27b, 27).
c, 27e, 27f, 27g), and a step of injecting the fluidized resin into the movable body (15, 16) to move the movable body (15, 16) to unblock the second resin injection port (29). 15, 16)
From the second and fourth resin inlets (19b, 19d) to the second resin inlet (2
9) The step of injecting the fluidized resin through the step (9).