JP3368242B2 - Resin sealing method and resin sealing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin encapsulation method for resin-encapsulating a mounted component such as a semiconductor device and a resin encapsulation apparatus using the resin encapsulation method.

[0002]

2. Description of the Related Art Conventionally, in a mold used for resin-sealing a mounting component such as a semiconductor device, as shown in FIG. 8, it is held by a spacer 202 located behind a cavity block 201 of a stationary mold 200. The elastic pins 203 (including elastic blocks and springs) absorb variations in the thickness of the substrate such as the lead frame (up to about 0.02 mm).

[0003]

However, in recent years,
The number of substrates made of resin such as substrates is increasing, and the variation in the thickness of the substrates is also increasing (up to about 0.2 mm). For this reason, a normal elastic pin cannot absorb this variation in thickness, and burrs are generated at a position corresponding to the mating surface of the fixed-side mold 200 and the movable-side mold 204. Further, the elastic pin 202 cannot cope with an increase in the amount of displacement, and is susceptible to fatigue fracture, and needs to be replaced early (a spring or the like also has a problem of fatigue fracture).

For this reason, a mechanical or hydraulic floating mechanism has come to be used. In this method, however, the resin substrate is deformed by an excessive clamping force, and mounting components such as semiconductor devices, especially , Wires, etc. are easily damaged. On the other hand, if the clamping force is suppressed so that the substrate is not deformed, a gap is created between the substrate and the mold, and similarly to the above, it is impossible to prevent the occurrence of burrs.

Therefore, an object of the present invention is to provide a resin encapsulation method and a resin encapsulation apparatus capable of simultaneously solving the two problems of damage to mounting components and occurrence of burrs.

[0006]

As a means for solving the above-mentioned problems, the present invention forms a cavity by clamping a fixed side mold and a movable side mold and forms a cavity between the two molds. In a resin sealing method of filling a resin into the cavity and sealing a mounted component on the surface of the substrate with a resin substrate clamped to the substrate, the substrate using a clamp member forming a part of the mold. The first clamping step of performing the above clamping with a force that does not cause the mounting component to malfunction due to the deformation of the substrate, and the first filling step of filling the resin into the cavity until the mounting component is almost covered. A resin filling step, and a second clamping step of clamping the substrate with the clamping member with a normal force,
The second resin filling step of completing the filling of the resin into the cavity is performed.

Then, in the first clamping step, clamping is performed with a force of 70 to 80% of the normal time, and in the first resin filling step, the resin is filled up to the amount of 80 to 90% at the completion of the filling. do it.

Further, as a means for solving the above-mentioned problems, the present invention molds a fixed side mold and a movable side mold to form a cavity and forms a resin substrate between the two molds. In a resin encapsulation device for encapsulating a resin in the cavity and encapsulating the mounted components on the surface of the substrate with the resin clamped, at least a region of the movable die for clamping the resin substrate is clamped in the clamping direction. A driving mechanism configured to move the clamp member, and to clamp the substrate with a clamping force that moves the clamping member and does not cause a defect due to the deformation of the substrate in the mounted component and a normal clamping force. Be prepared.

The drive mechanism is composed of a hydraulic pressure generating cylinder mechanism for operating the clamp member by the hydraulic pressure balance between the pushing liquid chamber of the piston and the drawing liquid chamber, and the hydraulic pressure generating cylinder of the hydraulic pressure generating cylinder mechanism. Of these, a pressure sensor for detecting the liquid pressure of the extrusion liquid chamber is provided, and based on the pressure detected by the pressure sensor, by driving and controlling the liquid pressure generating cylinder mechanism, the substrate is normally or, The electronic component mounted on the substrate may be clamped with a clamping force that does not cause a defect due to deformation.

The pushing fluid chamber and the drawing fluid chamber of the fluid pressure generating cylinder are adjusted by separate and independent fluid pressure adjusting devices based on the pressure detected by a pressure sensor provided corresponding to each fluid chamber. This is preferable in that the substrate can be clamped more appropriately.

[0011]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a multi-plunger type resin sealing device according to this embodiment. This resin sealing device is roughly composed of a mold device 1 and a hydraulic pressure adjusting device 2.

As shown in FIG. 2, the mold apparatus 1 comprises a fixed mold 3 and a movable mold 4. The fixed-side mold 3 is a fixed-side mold set 5 in which a fixed-side chess 6 is detachably provided. In the fixed mold set 5, the fixed base plate 7 and the pair of side blocks 8 form a fixed space 9. The fixed space 9 is open downward and one side. A guide protrusion 10 extending toward the side opening is formed on the facing surface of the side block 8. The fixed-side chess 6 is one in which a cavity block 12, a cull block 13, and a chess space block 14 are assembled to a holder base plate 11. A fixed side cavity 15 is formed in the cavity block 12. In addition, the fixed side chess 6 has a pin plate 16,
An ejector plate 17 and a support pin (not shown) are provided. A guide groove 19 that engages with the guide protrusion 10 of the side block 8 is formed on the side surface of the fixed side chess 6, and a handle 20 is provided on the end surface. An operator can easily attach and detach the fixed side chess 6 in the fixed side space 9 by holding the handle 20.

The movable side mold 4 is a movable side mold set 2
In FIG. 1, the movable chess 22 is detachably provided. In the movable mold set 21, a space block 24 and a movable chess base plate 25 are sequentially arranged on a movable base plate 23, and a side block 26 is provided on the movable chess base plate 25. The movable-side chess base plate 25 and the side blocks 26 form a movable-side space 27 that opens upward and one side.

A constant pressure cylinder block 28 is provided at the center of the movable side base plate 23. The equal pressure cylinder block 28 has a rear end portion connected by a transfer plate 29, and is moved back and forth by a drive mechanism (not shown).

Between the space blocks 24, pressure cylinders 30 are arranged on both sides of a constant pressure cylinder block 28. Each pressurizing cylinder 30 is an independently driven one in which a piston 33 is arranged in liquid chambers 34 and 35 formed by a cylinder block 31 and a cylinder cover 32. A pressure receiving port 34a is formed in a lower liquid chamber 34 that is an extruding liquid chamber partitioned by a piston 33, and a back pressure port 35a is formed in an upper liquid chamber 35 that is a drawing liquid chamber.
Oil is supplied or discharged from a hydraulic pressure adjusting device 2 described later. The rod 36 extending from the piston 33 penetrates the cylinder cover 32 and the movable-side chess base plate 25, and is exposed on the upper surface of the movable-side chess base plate 25. The exposed end of the rod 36 is a substantially rectangular parallelepiped locking portion 37. The pressurizing cylinder 30 is used for the movable side chess base plate 2
It may be configured to be built in 5.

The movable chess 22 has a cavity bar 3
8, center block 39, holder base plate 4
0, a chess space block 41, and a support pin 42 are combined and integrated. The cavity bar 38 is connected to a locking portion 37 at the tip of the rod 36 via a detachable block 44. The center block 39 is provided with a through hole through which the plunger tip 28a connected to the tip end of the constant pressure cylinder block 28 slides to form a pot portion 43. The pot portion 43 is supplied with resin for filling the cavity.
The guide protrusion 45 is formed on the facing surface of the side block 26, and the guide groove 46 and the handle 47 which are engaged with the guide protrusion 45 are formed on the side surface of the movable side chess 22. It is similar to the mold set 5.

The hydraulic pressure adjusting device 2 drives the pressurizing cylinder 30 provided in the movable mold 4 by operating the electric hydraulic pressure generating cylinder 49 by the servo motor 48.

The servomotor 48 includes pulleys 50a, 50
The driving force is transmitted to the ball screw 52 via the timing belt 51 hung around b. The ball screw 52 is screwed into a nut portion 54 held by a bracket 53. The bracket 53 is rotatably supported by the block 56 via a bearing 55. The block 56 is fixed to the body bracket 2a. A movable plate 60 is connected to a lower end portion of the nut portion 54 via a shaft 59, and the movable plate 60 is vertically slidable along four guide shafts 58 penetrating via a bush 57. Has become. A piston rod 61 of a hydraulic pressure generating cylinder 49 is connected to the central portion of the lower surface of the movable plate 60. In the hydraulic pressure generating cylinder 49, an upper liquid chamber 63 and a lower liquid chamber 64 are formed by a piston 62 arranged inside the cylinder. The upper liquid chamber 63 has a first hose 65a.
Is connected to the back pressure port 35a via
0 of the upper liquid chamber 35. The lower liquid chamber 64 is connected to the pressure receiving port 34a via the second hose 65b and communicates with the lower liquid chamber 34 of the pressurizing cylinder 30. A single acting cylinder 66 is provided in the middle of the first hose 65a. The single-acting cylinder 66 serves as a buffer when the substrate is clamped. A pressure sensor 67 is provided in the middle of the second hose 65b.
The hydraulic pressure detected by 7 is input to the control device 68. The controller 68 drives and controls the servo motor 48 based on the detected hydraulic pressure. It is also possible to control the position of the constant pressure cylinder block 28 by detecting the reduced pressure state by the pressure sensor 67.

Next, the operation of the resin sealing device will be described.

In the initial state (original position) shown in FIG. 3A, the movable side mold 4 is lowered by the action of a drive mechanism (not shown) and separated from the fixed side mold 3 (sealing preparation step). . At this time, the constant pressure cylinder block 28 descends,
The pot portion 43 is formed on the center block 39. Further, the piston 62 is moved upward by the driving of the servo motor 48 shown in FIG.
Also, the liquid pressure in the upper liquid chamber 35 of the pressurizing cylinder 30 rises. As a result, the piston 33 descends and the cavity bar 38 retreats to a position where it does not contact the cavity block 12 of the stationary mold 3 even if the mold is closed. Therefore,
As shown in FIG. 3B, the substrate P is automatically supplied to the movable die 4 by a transfer device (not shown) for positioning, and the molding resin R is supplied to the pot portion 43 (material supplying step). .

Then, as shown in FIG. 3 (c), the movable mold 4 is raised to close the mold (mold clamping step).
Further, as shown in FIG. 3D, by supplying oil to the lower liquid chamber 34 of the pressurizing cylinder 30, the piston 3
3 is raised and the substrate P is clamped by the cavity bar 38 (first clamping step). The clamping force at this time is 70 to 80% of that in normal times. As a result, the amount of deformation of the automatically-supplied resin substrate P is suppressed, and the extension and cutting of the wire extending from the surface-mounted electronic component is also prevented.

Subsequently, as shown in FIG. 4 (a), the equal pressure cylinder block 28 is raised to melt the resin R supplied to the pot portion 43 and fill the cavity (first resin filling step). ). Isobaric cylinder block 28
For example, as shown in FIG. 6A, the initial movement amount may be increased and then the movement amount may be reduced to a constant speed. Further, the filling amount of the resin at this time is set to 80 to 90% of that at the time of completion of the filling, and is suppressed to a level that substantially covers the electronic components and wires mounted on the substrate P. This is because by covering the electronic component and the wire, the influence of the deformation in the next second clamping step is mitigated and the resin does not leak even with a weak clamping force.

Then, as shown in FIG. 4B, oil is further supplied to the lower liquid chamber 34 of the pressurizing cylinder 30 to increase the clamping force of the substrate P by the cavity bar 38 to 100% (first). 2 clamping process). In this case, the electronic components and wires mounted on the substrate P are made of resin,
Because it's covered (completely or partially),
Even if the substrate P is slightly deformed by the increased clamping force,
There is no adverse effect such as deformation of electronic parts or wires.

Thereafter, as shown in FIG. 4C, the equal pressure cylinder block 28 is further raised to complete the filling of the resin into the cavity (second resin filling step). In this case, since the clamping force is increased to 100% in the second clamping step, the resin does not leak out from the mating surface of the mold and cause burrs.

Finally, as shown in FIG. 4 (d), the movable side mold 4 is lowered to open the mold (mold opening step), and as shown in FIG. 5 (a), an isobaric cylinder block. 28 is lifted above the resin sealing position to lift the product from the mold. Then, the product is gripped by a carrier (not shown) and discharged from the mold (product discharging step). It is also possible to take out the product from the mold only by the carrier without raising the isobaric cylinder block 28 by providing the mold with relief of the claw portion of the carrier.

As described above, according to the resin sealing method,
Even if the clamping force is increased in the second clamping step, the resin is filled to substantially cover the mounted electronic components and the wires extending therefrom while suppressing the deformation of the resin substrate in the first clamping step. No problems such as wire extension or cutting occur.

By the way, in the multi-plunger type resin sealing device, when maintenance is required,
As shown in FIG. 5B, the piston 33 is raised to the top dead center to push out the cavity bar 38, and the cavity bar 38 is lowered from the mold to perform maintenance of the cavity bar 38. According to this mold device, the fixed side chess 6 and the movable side chess 2
2 can be inserted / removed, and when exchanging items, the die items can be exchanged by exchanging only the chess 6, 22 and the constant pressure cylinder block 28. Therefore, the work efficiency of maintenance is very high. Depending on the item, the cavity bar 3 may be used instead of the chess 22.
In some cases, replacement of 8 is sufficient.

In the above embodiment, the pressure cylinder 3
Although the oil is supplied to 0 by the single hydraulic pressure adjusting device 2, it may be provided for each pressurizing cylinder 30.

Further, the upper liquid chamber 35 of each pressurizing cylinder 30.
As shown in FIG. 7, the lower hydraulic chamber 34 and the lower liquid chamber 34 may be separately and independently hydraulically adjusted by different hydraulic adjusting devices 100 and 101. That is, the upper liquid chamber 35 of the pressurizing cylinder 30 is moved through the hose 102 to the hydraulic pressure adjusting device 10.
0 to the lower liquid chamber 103. A pressure sensor 104 is provided in the middle of the hose 102, and the hydraulic pressure on the upper liquid chamber 35 side of the pressurizing cylinder 30 is detected and input to the control device 105. The control device 105 drives and controls the servo motor 106 based on the detected pressure. Similarly, the lower liquid chamber 34 of the pressurizing cylinder 30 also communicates with the lower liquid chamber 108 of the hydraulic pressure adjusting device 101 via the hose 107. The pressure sensor 109 provided in the middle of the hose 107 detects the hydraulic pressure on the lower liquid chamber 34 side of the pressurizing cylinder 30, and the control device 110 drives and controls the servo motor 111 in the same manner.

According to this, when the piston 33 of the pressurizing cylinder 30 is moved back and forth, each of the liquid chambers 34, 35 can be made to have a desired hydraulic pressure, and a smooth and quick operation can be obtained.

Further, in the first and second clamping steps, the clamping force is increased to a predetermined pressure at once, but it is also possible to perform each in multiple stages.

[0033]

As is apparent from the above description, according to the resin sealing method and the resin sealing device of the present invention, the electronic component mounted in the clamped state so as to suppress the deformation of the resin substrate and Since the resin extending to cover the wire extending therethrough is filled with the resin, even if the clamping force is increased in the second clamping step, the wire is not elongated or cut.

[Brief description of drawings]

FIG. 1 is a front cross-sectional view of a resin sealing device according to this embodiment.

FIG. 2 is an overall perspective view of the resin sealing device shown in FIG. 1 when a chess is inserted.

3A to 3C are process explanatory views showing a resin sealing method according to the present embodiment, (a) is an original position, (b) is material supply, (c) is mold clamping, (d) is cavity bar mold. The tightening states are shown.

FIG. 4 is a process explanatory view showing a resin sealing method according to the present embodiment, where (a) is a first resin filling process, (b) is a second clamping process, (c) is a second resin filling process, and d) shows each state of mold opening.

5A and 5B are process explanatory views showing a resin sealing method according to the present embodiment, where FIG. 5A shows a product removal state and FIG. 5B shows maintenance states.

FIG. 6 is a chart diagram of a transfer position and a substrate clamping force.

FIG. 7 is a front cross-sectional view of a resin sealing device according to another embodiment.

FIG. 8 is a front cross-sectional view of a mold according to a conventional example.

[Explanation of symbols]

1 ... Mold device 2 ... Hydraulic pressure adjustment device 3 ... Fixed side mold 4 ... Movable mold 5: Fixed side mold set 6 ... Fixed side chess 9: Fixed side space 10, 45 ... Guide protrusion 19, 46 ... Guide groove 20,47 ... Handle 21 ... Movable mold set 22 ... Movable side chess 27 ... Movable side space 28 ... Isobaric cylinder block 29 ... Transfer plate 30 ... Pressure cylinder 38 ... Cavity bar (clamp member) 43 ... Pot part 49 ... Hydraulic pressure generation cylinder 66 ... Single-acting cylinder 67 ... Pressure sensor 68 ... Control device

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Claims (5)

(57) [Claims] 1. A mold is clamped between a fixed side mold and a movable side mold to form a cavity, and a resin substrate is clamped between the two molds, and a resin is filled in the cavity. In a resin sealing method for resin-sealing mounted components on the surface of the substrate, clamping of the substrate by a clamp member that forms a part of the mold does not cause defects due to deformation of the substrate in the mounted components. Clamping the substrate with the force of the first clamping step, the first resin filling step of filling the cavity with the resin to the extent that the mounting component is almost covered, and the clamping of the substrate with the clamping member as usual. And a second resin filling step of completing the filling of the resin into the cavity. 2. In the first clamping step, the normal 7
The resin sealing method according to claim 1, wherein the resin is clamped with a force of 0 to 80%, and in the first resin filling step, the resin is filled up to an amount of 80 to 90% when the filling is completed. 3. A mold is clamped between a fixed mold and a movable mold to form a cavity, and a resin substrate is clamped between the molds, and a resin is filled in the cavity. In a resin encapsulation device for encapsulating a mounted component on the surface of a substrate with a resin, at least a region of the movable die for clamping the resin substrate is configured by a clamp member movable in a clamp direction, and the clamp member is A resin sealing device comprising: a drive mechanism that moves and clamps the substrate with a normal clamping force and a clamping force that does not cause the mounting component to malfunction due to the deformation of the substrate. 4. The hydraulic mechanism includes a hydraulic pressure generating cylinder mechanism that operates a clamp member by hydraulic pressure balance between a pushing liquid chamber and a drawing liquid chamber of a piston. Of the generating cylinder, a pressure sensor for detecting the hydraulic pressure of the extruding liquid chamber is provided, and by controlling the driving of the hydraulic pressure generating cylinder mechanism based on the pressure detected by the pressure sensor, the substrate is Alternatively, the resin sealing device according to claim 3, wherein the electronic component mounted on the substrate is clamped with a clamping force that does not cause a defect due to deformation. 5. The liquid chamber for pushing and the liquid chamber for drawing in the hydraulic pressure generating cylinder are liquid-controlled by a separate and independent hydraulic pressure adjusting device based on the pressure detected by a pressure sensor provided corresponding to each liquid chamber. The resin sealing device according to claim 4, wherein the pressure is adjusted.