JP2003324116A - Resin sealing metal mold and resin sealing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin sealing metal mold and a resin sealing device capable of enhancing reliability and productivity. <P>SOLUTION: In a cope 13, a core pin 24 is disposed inside a through hole 19a of a cope cavity insert 19. A backup hole 26 is formed in a part opposite to the through hole 19a of a cope chase block 18. A spring member 27 is disposed in the backup hole 26, and the core pin 24 can be slid in the through hole 19a in response to the expansion and contraction of the spring member 27. In a state that the cope 13 is closed to a drag 12, the core pin 24 comes into elastic contact with a drag cavity insert 16. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-sealing die and a resin-sealing device for resin-sealing an object to be sealed such as a semiconductor chip.

[0002]

2. Description of the Related Art Semiconductor chips are used by being packaged with resin, ceramics or the like for insulation and protection from moisture. A transfer mold method is known as a method of sealing (packaging) a semiconductor chip with a resin. In the transfer molding method, a lead frame (lead frame assembly) to which a semiconductor chip is fixed is sandwiched between a pair of sealing dies, and a resin is placed in a sealing space (cavity) formed between the pair of sealing dies. Inject and cure.

A conventional sealing die used in the transfer molding method is shown in FIG. The sealing die 101 shown in FIG. 5 includes an upper die 102 and a lower die 103.

The upper die 102 includes an upper die cavity insert 104, an upper die cull insert 105, and an upper die chase block 106. The upper mold cavity insert 104 and the upper mold cull insert 105 are composed of blocks having a predetermined shape. The upper die chase block 106 fixes the upper die cavity insert 104 and the upper die cull insert 105. The upper chase block 106 is connected to a drive mechanism (not shown) and can move up and down.

The lower mold 103 includes a lower mold cavity insert 107, a lower mold cull insert 108, and a lower mold chase block 109. The lower mold cavity insert 107 and the lower mold cull insert 108 are composed of blocks having a predetermined shape. The lower die chase block 109 fixes the lower die cavity insert 107 and the lower die cull insert 108.

As shown in FIG. 5, the upper mold 102 and the lower mold 10
3 and the upper mold cavity insert 104 and the lower mold cavity insert 107 in a state where they are bound together.
And form a cavity 110 that is a sealed space. At the time of resin sealing, the lead frame assembly 113 including the semiconductor chip 111 and the lead frame 112 is sandwiched between the upper mold 102 and the lower mold 103, whereby the lead frame assembly 113 is housed in the cavity 110.

The upper die cull insert 105 and the lower die cull insert 108 form a hollow runner 114. The runner 114 constitutes a flow path of resin in a molten state that flows due to the pressure of the plunger. The cavity 110 and the runner 114 are formed so as to communicate with each other, and the connecting portion constitutes a so-called gate 115.

Using the above-mentioned sealing die 101, the resin sealing of the semiconductor chip 111 is performed as follows. First, the lead frame assembly 113 is prepared, sandwiched between the upper mold 102 and the lower mold 103, and placed in the cavity 110. Next, the molten resin is injected into the cavity 110 through the runner 114 and the gate 115 by pressing with the plunger. After the injection, heat treatment is performed at a predetermined temperature for a predetermined time to cure the thermosetting resin in the cavity 110. Thus, the resin sealing body 116 having an outer shape that matches the outer shape of the cavity 110 is formed in the cavity 110. After that, the resin sealing body 116 is released from the sealing mold 101 by an eject pin (not shown). Next, the runner 114 and the like are punched out and removed by a resin punch. Thus, the resin sealing process is completed.

In the packaging process as described above, the screw hole 117 of the resin sealing body 116 is formed in the sealing die 10.
1 is a rod-shaped core pin 11 extending in the cavity 110.
It is formed by providing 8. Core pin 118
Are supported by, for example, the upper mold cavity insert 104 while penetrating through the upper mold cavity insert 104. The portion of the cavity 110 where the core pin 118 is present is not filled with resin, and as a result, the screw hole 117 is formed in the cured resin sealing body 116.

In order to prevent damage to the mold, the conventional core pin 118 is formed with a length that does not contact the lower mold 103 when the upper mold 102 and the lower mold 103 are stacked. Therefore, one end of the resin encapsulant 116 immediately after release from the mold is burr 1.
A screw hole 117 closed at 19 is formed. The burr 119 of the screw hole 117 is removed by punching the screw hole 117 with a resin punch.

Here, when the screw hole 117 is punched out with a resin punch, if the burr 119 is thin, it may remain without being completely removed due to its large elasticity. On the other hand, if the burr 119 is thick and its elasticity is small, the sealing body may be damaged during punching by the resin punch. Therefore, it is important that the burr 119 of the screw hole 117 is formed with an appropriate constant thickness.

[0012]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the method for manufacturing the resin encapsulant 116 having the core pin 1
Since the resin flows into the gap (burr forming portion) between the lower mold cavity insert 18 and the lower mold cavity insert 107, the core pin 11
The tip portion of 8, particularly the corner portion, is easily worn. Therefore,
As the sealing operation is repeated, the screw holes 117, in particular,
The thickness of the burr 119 at the peripheral portion gradually increases. Therefore, if the thickness of the burr 119 is kept as constant as possible, the replacement cycle of the sealing die 101 including the core pin 118 will be accelerated.

Further, even in the step of punching and removing the burr 119, the resin punch and the die are easily worn, and the exchange cycle of these equipments becomes faster. Therefore, the productivity of the entire resin sealing process is reduced, and the consumption cost is increased, such as the facility down time being increased due to die replacement and the like.

If the burr 119 is formed thick due to wear of the core pin 118 after a long exchange cycle, the resin sealing body 116 may be cracked due to impact in the punching process using the resin punch. May deteriorate product quality.

As described above, when the conventional resin sealing method using the core pin 118 is used, the screw hole 117 is formed into the burr 11.
Since the formation is allowed with the generation of No. 9, the equipment replacement cycle of the mold, resin punch, etc. is fast. Such an increase in equipment replacement frequency increases manufacturing cost and lowers productivity. As described above, the conventional resin sealing method has a problem that it is difficult to manufacture a resin sealing body having a screw hole at low cost with high reliability and productivity.

In view of the above circumstances, it is an object of the present invention to provide a resin encapsulation mold and a resin encapsulation device capable of producing a resin encapsulation body having a through hole with high productivity and reliability. To do.

[0017]

In order to achieve the above object, a resin-sealed mold according to a first aspect of the present invention accommodates an object to be sealed in a state of being stacked facing each other. A pair of sealing molds forming a cavity, and one of the pair of sealing molds, which penetrates the cavity and elastically contacts the other of the pair of sealing molds facing each other And a pin member for forming a through hole in the sealed body of the object.

In the above structure, in a state where the pair of sealing dies are stacked, the pin member is in contact with the other of the pair of sealing dies so as to press the other.

In the above structure, for example, an elastic body is provided between the pin member and the one of the pair of sealing dies.

In the above structure, for example, the elastic body is made of a spring material.

In the above structure, for example, the elastic body is made of a rubber material.

In the above configuration, for example, the pin member and the other of the pair of sealing dies are configured to be in close contact with each other.

In the above structure, for example, the contact portion between the pin member and the other of the pair of sealing molds forms a flat surface.

In order to achieve the above object, a resin sealing device according to a second aspect of the present invention is characterized by including the resin sealing mold according to the first aspect.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION A resin sealing mold according to an embodiment of the present invention will be described below with reference to the drawings. In this embodiment, a case where a lead frame assembly including a semiconductor chip and a lead frame is resin-sealed will be described as an example.

FIG. 1 shows a cross-sectional structure of a resin-sealing mold 11 according to this embodiment. As shown in FIG. 1, the resin sealing mold 11 includes a lower mold 12 and an upper mold 13. Also,
FIG. 2 shows a state in which the lower die 12 and the upper die 13 are bound with the lead frame assembly 14, which is an object to be sealed, sandwiched therebetween.

The lower die 12 is a lower die chase block 15.
And a lower mold cavity insert 16 and a lower mold cull insert 17.

The lower mold cavity insert 16 and the lower mold cull insert 17 are each composed of a block having a predetermined shape. As will be described later, the lower mold cavity insert 16 constitutes a part of the outer shape of the cavity,
The lower mold cull insert 17 constitutes a part of the outer shape of the runner.

The lower die chase block 15 is composed of a plate-shaped member in which a groove 15a is formed, and the lower die cavity insert 16 and the lower die cull insert 17 are fixed in a fitted state in the groove 15a. There is. The lower chase block 15 is connected to a drive mechanism (not shown) and is movable up and down, for example.

The upper die 13 is an upper die chase block 18
And an upper mold cavity insert 19 and an upper mold cull insert 20.

The upper die chase block 18 is composed of a plate-shaped member in which a groove 20a is formed, and the upper die cavity insert 19 and the upper die cull insert 20 are fixed in a fitted state in the groove 20a. There is. The upper chase block 18 is connected to a drive mechanism (not shown) and is movable up and down, for example.

The upper mold cavity insert 19 and the upper mold cull insert 20 are each composed of a block having a predetermined shape. As shown in FIG. 2, the upper mold cavity insert 19 constitutes a cavity (sealing space) 21 in a state where the upper mold 13 and the lower mold 12 overlap each other. The contour of the cavity 21 formed by the upper mold cavity insert 19 and the lower mold cavity insert 16 constitutes the product outer shape of the resin sealing body to be formed.

The upper mold cull insert 20 and the lower mold cull insert 17 form a runner 22. Runner 2
Reference numeral 2 constitutes a flow path through which the molten resin pressed by a plunger (not shown) flows. The cavity 21 and the runner 22 are connected via a so-called gate 23.

Referring to FIG. 1, the upper mold cavity insert 19 has a through hole 19a formed therethrough. The through hole 19a is formed in the upper chase block 18
Has a large diameter, and a step 19b is formed.

Inside the through hole 19a, a substantially cylindrical core pin 24 is arranged. That is, the core pin 24
Are arranged so as to penetrate the upper mold cavity insert 19. The core pin 24, inside the cavity 21,
For example, it is arranged so as to extend substantially perpendicularly to the main surface of the upper chase block 18.

The core pin 24 is provided to form a hole 25a (in this example, a screw hole) in the resin sealing body 25 formed by the resin sealing mold 11. Core pin 24
By filling the inside of the cavity 21 with resin in the state of being arranged, a hollow portion corresponding to the volume of the core pin 24 is formed in the obtained resin sealing body 25, and as a result, the screw hole 25a is formed. The diameter of the core pin 24 is set to the diameter of the screw hole 25a to be formed in the resin sealing body 25.

Upper chase block 18 of core pin 24
One end on the side is formed to have a larger diameter than the other portion, and the step 24
a is formed. One end of the large diameter of the core pin 24 is set to be substantially the same as or slightly smaller than the one end of the large diameter of the through hole 19a, and the step 24a of the core pin 24 is configured to be caught by the step 19b of the through hole 19a. There is. That is, the other end of the core pin 24 does not protrude from the through hole 19a toward the lower mold 12 for a predetermined length or more.

The upper chase block 18 has a through hole 1
A backup hole 26 is formed at a position overlapping with 9a. The backup hole 26 is formed larger than, for example, the diameter of one end of the core pin 24 having a large diameter so that a part of the core pin 24 can be buried.

A spring member 27, for example, a flat spring is arranged inside the backup hole 26, and is fixed to the bottom surface of the backup hole 26, for example. The spring member 27 is in contact with one end of the core pin 24. As a result, the core pin 24 is configured to be slidable inside the through hole 19a according to the expansion and contraction of the spring member 27. At this time, the spring member 2
When 7 shrinks, part of the core pin 24 is buried in the backup hole 26.

The core pin 24 has the step 24a in contact with the step 19b of the through hole 19a, and the upper die 13 and the lower die 1
2 is set to have a length such that the front end thereof contacts the lower mold cavity insert 16 when they are bound. Thereby, in a state where the upper die 13 and the lower die 12 are bound, the core pin 24 elastically contacts the lower die cavity insert 16 by the expansion and contraction of the spring member 27. That is, the core pin 24 contacts the lower mold cavity insert 16 in a pressed state.

The contact portion of the lower mold cavity insert 16 with the other end of the core pin 24 is formed flat.
Further, the tip portion of the other end of the core pin 24 is formed substantially horizontally with respect to the bottom surface of the lower mold cavity insert 16. Therefore, as shown in FIG. 2, the core pin 24 and the lower mold cavity insert 16 are in close contact with each other when the upper mold 13 and the lower mold 12 are bound.

The core pin 24 arranged as described above is
When the upper die 13 and the lower die 12 are bound together, the tip thereof is always in contact with the lower die cavity insert 16 in a state of being almost in close contact. As a result, in the resin sealing body 25 formed in the cavity 21, the core pin 24 forms a through hole (screw hole 25a) in which burr generation is substantially prevented.

By providing the core pin 24 in this way, it is not necessary to punch out the screw hole 25a with a resin punch in order to remove burrs. Therefore, it is not necessary to use a resin punch and a die for punching out the screw holes 25a, and the equipment can be simplified. In this case, of course, screw holes 2
It is no longer necessary to consider the abrasion of the resin punch and die associated with the punching of 5a.

Further, since the core pin 24 and the lower mold cavity insert 16 are in close contact with each other, the wear of the tip portion of the core pin 24 due to the inflow of resin due to friction is prevented. Therefore, the resin sealing mold 11 including the core pin 24
It is possible to prolong the replacement cycle, thereby reducing the consumption cost and high productivity.

A method of sealing a semiconductor chip with resin using the resin sealing mold 11 will be described below.

First, the lead frame assembly 14 including the semiconductor chip 14a and the lead frame 14c connected to the semiconductor chip 14a by the wires 14b is prepared and set on the lower die 12. Next, when the upper die 13 is lowered, the lead frame assembly 14 is bound by the upper die 13 and the lower die 12, and the lead frame assembly 14 is housed in the cavity 21. In this state, the resin sealing mold 11 and the lead frame assembly 14 are preheated to a predetermined temperature.

At this time, the core pin 24 slightly slides in the direction of the upper die 13, and the stress of the spring member 27 causes the lower die 1 to move.
Pressing 2. Further, the tip of the core pin 24 is in contact with the bottom surface of the lower mold cavity insert 16 so as to be substantially in close contact therewith.

Thereafter, the molten resin is injected into the runner 22 by pressing a plunger (not shown). As a result, the resin is injected into the cavity 21 via the gate 23. The resin is supplied so as to fill the entire cavity 21.

After the resin is filled, the resin sealing mold 11 and the lead frame assembly 14 are heated to the curing temperature of the resin. The resin is cured by heating for a predetermined time, and the resin sealing body 25 having an outer shape that matches the outer shape of the cavity 21 is formed. Here, with the core pin 24, the resin sealing body 2
5 has a screw hole 25a formed therein.

Next, the resin sealing mold 11 and the lead frame assembly 14 are cooled to a predetermined temperature. After cooling, the upper mold 13 rises, the ejector pins (not shown) descend, and the resin sealing body 25 is released. The resin sealer 25 thus obtained is subjected to removal of the runner 22 and burrs using a resin punch, whereby a desired resin sealant 25 is obtained. The resin encapsulation process of the semiconductor chip is thus completed.

As described above, in the present embodiment,
The core pin 2 installed on the upper die 13 via the spring member 27.
4 elastically contacts the lower mold 12 due to the expansion and contraction of the spring member 27. The tip of the core pin 24 is formed so as to be in close contact with the lower die 12. Therefore, the resin does not flow between the core pin 24 and the lower die 12.

From this, it is possible to form the screw hole 25a while substantially preventing the burr from being generated while preventing the core pin 24, especially the tip end thereof from being worn. For this reason,
The life of the core pin 24 can be extended, so that the frequency of replacement of the entire resin sealing mold 11 can be reduced.

Further, since the resin punch and the die for removing the burr of the screw hole 25a are not necessary, the equipment can be simplified and the abrasion of the resin punch and the die can be prevented to delay the replacement cycle of these. can do. As described above, since it is possible to prevent the deterioration of the mold, the resin punch and the like, it is possible to improve the productivity by reducing the consumption cost and the operation stop time.

Further, since it is possible to substantially prevent the occurrence of burrs, it is possible to substantially avoid the occurrence of cracks or the like when punching the screw holes by the resin punch, which deteriorates the product quality and the yield. . Therefore, highly reliable resin sealing is possible.

The present invention is not limited to the above embodiment, but various modifications and applications are possible. Hereinafter, modifications of the above-described embodiment applicable to the present invention will be described.

In the above embodiment, the upper die 13 is provided with the core pin 24. However, the core pin 24 may be provided on either the upper mold 13 or the lower mold 12.

In the above embodiment, one end of the large diameter core pin 24 is partially buried in the backup hole 26 when the spring member 27 is contracted. However, the length of one end of the core pin 24 may be set shorter than the length of the through hole 19a so that only the inside of the through hole 19a moves.
In this case, for example, as shown in FIG. 3, the backup hole 26 is not provided and the spring member 27 is replaced by the upper chase block 1.
It may be installed on the flat surface of No. 8.

In the above embodiment, the screw hole 25a
The resin punch for punching was not used.
However, for example, when the core pin 24 is fixed in the returned state and burrs are generated due to damage of the screw member 27 or the like, a resin punch for punching may be provided. However, such a resin punch is only for occurrence of an abnormality. In addition, in the present embodiment, since burr does not occur during normal operation, the resin punch is hardly worn and can be used without substantially considering its replacement cycle.

In the above-described embodiment, the spring member 27 is provided at one end of the core pin 24 so that the core pin 24 and the lower mold cavity insert 16 are elastically in contact with each other. However, the present invention is not limited to this, and another elastic material, for example, a heat resistant rubber material 40 as shown in FIG. 4, may be provided at one end of the core pin 24.

In the above embodiment, the case where the resin sealing body 25 is provided with the screw hole 25a has been described as an example. But,
The present invention can be applied to any case where a hole passing through the resin sealing body 25 is formed. Further, in the above embodiment, the case where the semiconductor chip is resin-sealed has been described as an example. However, the present invention is not limited to this,
It can be applied to any case of sealing or molding with resin.

[0061]

According to the present invention, there are provided a resin encapsulation mold and a resin encapsulation device which can improve reliability and productivity.

[Brief description of drawings]

FIG. 1 is a view showing a cross section of a resin sealing mold according to an embodiment of the present invention.

FIG. 2 is a diagram showing a state in which the resin sealing mold shown in FIG. 1 is bound.

FIG. 3 is a diagram showing a modification of the embodiment of the present invention.

FIG. 4 is a diagram showing a modification of the embodiment of the present invention.

FIG. 5 is a view showing a cross section of a conventional resin sealing mold.

[Explanation of symbols]

11 Resin sealing mold 12 Lower mold 13 Upper mold 14 Lead frame assembly 15 Lower chase block 16 Lower mold cavity insert 17 Lower Cull Insert 18 Upper Chase Block 19 Upper mold cavity insert 20 Upper die cull insert 21 cavity 22 Lanna 23 gates 24 core pins 25 Resin encapsulant 25a screw hole 26 Backup hole 27 Spring member

Claims (8)

[Claims] 1. A pair of sealing dies that form a cavity for accommodating an object to be sealed in a state of being stacked facing each other, and provided in one of the pair of sealing dies and penetrating the cavity. And a pin member for elastically contacting the other of the pair of sealing molds facing each other for forming a through hole in the sealed body of the object to be sealed. Stop mold. 2. The pin member is in contact with the other of the pair of sealing dies so as to press the other of the pair of sealing dies in a state where the pair of sealing dies are overlapped with each other. Resin sealing mold. 3. The resin encapsulating mold according to claim 1, wherein an elastic body is provided between the pin member and the one of the pair of encapsulating dies. 4. The resin-sealed mold according to claim 3, wherein the elastic body is made of a spring material. 5. The elastic body is made of a rubber material,
The resin-sealed mold according to claim 3, wherein. 6. The pin member and the other of the pair of sealing molds are configured so as to be in close contact with each other and to come into contact with each other. The resin-sealed mold according to 1. 7. The resin-sealed mold according to claim 6, wherein a contact portion between the pin member and the other of the pair of sealing molds forms a flat surface. 8. A resin encapsulation apparatus comprising the resin encapsulation mold according to claim 1. Description: