JP2003100786A - Method for sealing electronic component with resin and mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent break or deformation of a wire 8 for connecting an electronic component 3 mounted on a lead frame 4 to a lead. SOLUTION: When a molten resin 16 is injected from a gate 13 which is arranged so as to connect to a mold cavity 6/7 in which an electronic component 3 mounted on a lead frame is fitted in the mold cavity 6/7, the molten resin 16 is continuously vibrated by an ultrasonic vibration mechanism 17 using ultrasonic vibration at the gate 13 while injected into the mold cavity 6/7. Herewith, the wire 8 is sealed with resin in a state substantially held in its shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a resin encapsulation molding method for an electronic component and a die for encapsulating a lead frame mounted with an electronic component such as an IC with a resin material (resin tablet). .

[0002]

2. Description of the Related Art Conventionally, resin molding of electronic parts has been carried out by a transfer method. This method is, for example, for resin molding by a fixed upper mold and a movable lower mold. Usually, it is performed as follows using a mold.

That is, in advance, the mold is heated to a resin sealing molding temperature to open the molds. Next, the lead frame having the electronic component mounted thereon is set at a predetermined position on the lower mold surface, and the resin tablet is supplied into the lower mold pot. Next, the lower mold is moved upward to clamp the both molds. At this time, the electronic component and the lead frame around the electronic component are fitted and set in the upper and lower cavities for resin molding opposite to the molds, and the resin tablets are heated and sequentially melted. Next, the resin material heated and melted in the pot is pressed against the cull portion of the upper mold by pressing with a plunger for resin pressurization, and further, the molten resin is passed through the runner portion and the gate portion to the upper and lower portions. When injected into both cavities, the electronic component and the lead frame around it in both the upper and lower cavities are sealed and molded in a resin molded body corresponding to the shapes of the upper and lower cavities. Therefore, after the required time for curing the molten resin has passed, the two molds are opened,
The lead frame and the resin molded body (sealed lead frame) described above and the resin cured in the cull portion / runner portion / gate portion are released (see FIGS. 1 and 2).

[0004]

However, when the molten resin is injected from the gate portion in both upper and lower cavities of the mold, the molten resin causes a jetting phenomenon in the mold cavity. That is, in the direction of the electronic component mounted on the lead frame from the gate opening in the mold cavity (in the injection direction of the molten resin).
The injected molten resin is scattered in the form of a mist having hard and fine particles. Since there is a wire that electrically connects the electronic component and the lead of the lead frame in the injection direction of the molten resin, the impact that the scattered molten resin cuts or deforms the wire with respect to the wire Since the force is directly applied, there is an adverse effect of cutting or deforming the wire.

Therefore, the present invention provides a resin encapsulation molding method and a mold for an electronic component, which can efficiently prevent the wire connecting the electronic component mounted on the lead frame and the lead from being cut or deformed. The purpose is to do.

[0006]

The resin encapsulation molding method for an electronic component according to the present invention for solving the above technical problem is a mold cavity in which an electronic component mounted on a lead frame is fitted and set. A resin encapsulation molding method for an electronic component, which comprises encapsulating a wire connecting at least the electronic component and a lead in the mold cavity by injecting a molten resin from the inside of the gate portion. It is characterized in that the molten resin is injected into the mold cavity while being vibrated to be sealed and molded while the shape of the wire is substantially maintained.

Further, a method for resin-sealing and molding an electronic component according to the present invention for solving the above-mentioned technical problem is
The above-mentioned ultrasonic vibration is applied.

Further, a method for resin-molding and molding an electronic component according to the present invention for solving the above-mentioned technical problem is
One cycle of the ultrasonic vibration action applied to the molten resin is configured such that first, the molten resin is gently pressed with a predetermined pressing force, and then the pressing force with respect to the molten resin is rapidly attenuated. It is characterized by

Further, in the resin encapsulation molding die for an electronic component according to the present invention for solving the above-mentioned technical problem, at least a wire for connecting the electronic component mounted on the lead frame and the lead is fitted. A mold for resin encapsulation and molding of an electronic component, which comprises a mold cavity that is mounted and set, and a gate portion that communicates with the mold cavity, wherein a vibration applying mechanism for molten resin is provided in the gate portion. Characterize.

Further, in the resin encapsulation molding die for an electronic component according to the present invention for solving the above-mentioned technical problems, an ultrasonic vibration mechanism is provided as a vibration imparting mechanism of the molten resin. It is characterized by

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, the present invention is an ultrasonic vibration mechanism provided in a gate part connected to a cavity of the mold in a mold for resin-sealing molding of electronic parts, wherein the gate part is used. This is a configuration in which ultrasonic vibration is applied to the molten resin injected from the inside into the mold cavity (configuration in which the molten resin is vibrated). That is, by applying an ultrasonic vibration action to the molten resin, the molten resin can be prevented from scattering in the mold cavity, and the molten resin can be formed into a lump having flexibility. In addition, since the molten resin can be smoothly injected into the mold cavity by gradually adjusting the injection speed in the mold cavity, the molten resin can be used as an electronic component mounted on the lead frame. It is possible to efficiently prevent the wire that electrically connects the lead from being given an impact force that cuts or deforms the wire. Therefore, when the above-mentioned molten resin to which the ultrasonic vibration action is applied is injected into the mold cavity, the wire is resin-sealed and molded in a state in which the wire is substantially held without being cut or deformed. It Therefore, it is possible to efficiently prevent the wire connecting the electronic component mounted on the lead frame and the lead from being cut or deformed.

[0012]

Embodiments will be described below with reference to the drawings. Figure 1
FIG. 2 shows a resin sealing molding die according to the present invention.

That is, the mold shown in FIGS. 1 and 2 is provided with a mold for resin-sealing molding which comprises a fixed upper mold 1 and a movable lower mold 2 which is arranged so as to face the upper mold 1, and at the same time, A lower surface of the lower mold 2 is provided with a setting recess 5 for supplying and setting a lead frame 4 on which an electronic component 3 is mounted.
Is provided with a heating means 15 for heating the molds 1 and 2 to a predetermined temperature. In addition, upper and lower cavities 6 and 7 for resin molding are provided on the mold surfaces of both the molds 1 and 2, and when the molds 1 and 2 are clamped, the upper and lower cavities 6 and 7 are described above. The electronic component 3 and the lead frame 4 around the electronic component 3 can be fitted and set,
The electronic component 3 and the lead of the lead frame 4 are electrically connected by a wire 8. Also,
On the mold surface of the lower mold 2 described above, a pot 9 for supplying a resin material is provided.
And a plunger 1 for resin pressurization fitted in the pot 9.
0, and a cull portion 11 for distributing molten resin is provided on the mold surface of the upper mold 1 so as to face the pot 9. Further, on the mold surface of the upper mold 1, the upper cavity 6 and the cull part 11 are passed through a runner part 12 communicating (connecting) with the cull part 11 and a gate part 13 communicating (connecting) with the upper cavity 6. It is configured to communicate (connect), and when the molds 1 and 2 are clamped, the resin material 14 heated and melted in the pot 9 is pressed by the plunger 10, so that the cull portion 11 is formed. The molten resin 16 is configured to be injected into the upper and lower cavities 6 and 7 through the runner portion 12 and the gate portion 13, and the electronic component 3 and the peripheral portion thereof in the mold cavity 6 and 7 can be injected. The lead frame 4 and the wires 8 are configured so that they can be sealed and molded in a resin molding (not shown) corresponding to the shape of the mold cavities 6 and 7. As shown in the drawing, the electronic component 3 and the wire 8 are provided so as to communicate (connect) with the upper mold gate portion 13 side (gate opening) when the molds 1 and 2 are clamped. The upper cavity 6 is configured to be fitted and set.

A vibration applying mechanism (ultrasonic vibrating mechanism) 1 for continuously applying vibration to the molten resin 16 injected into the upper and lower cavities 6 and 7 in the upper mold gate portion 13.
7 is provided so that the vibration applying mechanism 17 can apply a vibration action to the injected molten resin. That is, the ultrasonic vibration mechanism 17 is provided with a piezoelectric element such as a piezoelectric element, and the piezoelectric element is configured to generate ultrasonic vibrations in the ultrasonic vibration mechanism 17. Therefore, the ultrasonic vibration mechanism 17
By inputting a sinusoidal voltage to the (piezoelectric element), the injected molten resin 1 is applied by the ultrasonic vibration mechanism 17.
6 is configured to be able to apply a vibration action corresponding to the sinusoidal voltage. In addition, the inventor of the present invention has found that the inside of the mold cavities 6 and 7 (that is, the gate opening of the upper mold gate portion 13 inside the upper cavity 6)
It was found from an experiment that the jetting phenomenon as described above can be prevented by applying an ultrasonic vibration action to the injected molten resin 16 at the gate portion 13. That is, the ultrasonic-vibration-applied molten resin 16 does not scatter in the upper cavity 6 and the vibration-applied molten resin 1
6 is a lump having flexibility, and the injection speed of the molten resin 16 in the mold cavities 6 and 7 can be configured slowly so that the molten resin 16 can be smoothly moved into the mold cavities 6 and 7. It was confirmed that it could be injected (smoothly) into the. Therefore, the mold cavities 6 and 7
By injecting the vibrating action-providing molten resin 16 into the inside, the electronic component 3 and the lead frame around the electronic component 3 in a state in which the wire 8 substantially holds its shape without cutting or deforming the wire 8 4 can be resin-molded in the mold cavities 6 and 7. The ultrasonic vibrating mechanism 17 is provided in the cull portion 1 described above.
1 or in the runner portion 12, the effect of the vibration imparting action on the molten resin 16 does not continue up to the upper cavity 6, and the above-mentioned jetting phenomenon occurs in the upper cavity 6.

That is, as shown in FIG. 1, first, the two molds 1 and 2 are opened, and the lead frame 4 having the electronic component 3 mounted thereon is set in the setting recess 5, and then the both molds 1 and 2 are set.
・ Clamp 2 At this time, the electronic component 3 and the lead frame 4 around the electronic component 3 are connected to the upper and lower cavities 6 and 7.
It is fitted and set inside. In addition, in the upper mold 2, the electronic component 3 and the wire 8 are the upper mold gate portion 13
Since it is arranged in the upper cavity 6 communicating with the above, the wire 8 exists at least in the injection direction of the molten resin in the mold cavities 6 and 7. Next, the resin material heated and melted in the pot 9 is pressed by the plunger 10, so that the molten resin 16 is passed through the cull portion 11, the runner portion 12, and the gate portion 13 in the upper and lower cavities 6 and 7. Will be injected into. At this time, the ultrasonic vibration mechanism 17 injects the molten resin 16 of the gate portion 13 while continuously applying an ultrasonic vibration action. That is, by injecting the molten resin 16 of the gate portion 13 while continuously applying an ultrasonic vibration action, the molten resin 16 becomes a lump having flexibility, and the molten resin 16 is smoothly injected at a slow injection speed. Since the wire 8 is injected into the cavity 6, the wire 8 is resin-sealed and molded with the shape of the wire 8 maintained substantially without being cut or deformed. Therefore, it is possible to efficiently prevent the wire 8 connecting the electronic component 3 mounted on the lead frame 4 and the lead from being cut or deformed.

In the above embodiment, the gate portion 1
Although the configuration in which the ultrasonic vibration action is continuously applied to the molten resin 16 of 3 has been exemplified, for example, a configuration in which the molten resin 16 is injected while the ultrasonic vibration action is intermittently applied can be adopted, It was possible to obtain the same effect as that of the above-described embodiment.

Further, in the above-described embodiment, by appropriately modulating the frequency and period of the sinusoidal voltage input to the ultrasonic vibration mechanism 17, the molten resin 16 is vibrated in accordance with an arbitrary wave shape. Can be given. For example, with respect to the pressing force on the molten resin 16, within a cycle of the ultrasonic vibration action, first, the molten resin 16 is pressed slowly (with a longer time) with a predetermined pressing force, and then, It is possible to adopt a configuration in which the pressing force on the molten resin 16 is rapidly (shortened) attenuated. That is, by gently pressing the molten resin 16 with a predetermined pressing force, the injection speed into the mold cavities 6 and 7 is made slower than that in the above-described embodiment, and smooth injection is performed. Since it has been found that this is possible, the molten resin 16 can be smoothly injected into the mold cavities 6 and 7 at a slow injection speed and in a flexible lump state.
Therefore, the molten resin 16 to which the ultrasonic vibration action is applied does not scatter in the upper cavity 6, and the molten resin 16 becomes a lump and is slowly injected into the upper cavity 6, so that the wire 8 Without cutting or deforming
The wire 8 is resin-sealed and molded with its shape being substantially retained.

The present invention is not limited to the above-mentioned embodiment, and within the scope of the present invention,
It can be arbitrarily and appropriately changed / selected and adopted as needed.

Further, the gist of the present invention can be adopted, for example, in a structure (so-called one-sided molding) in which an electronic component (including a wire) mounted on a plastic circuit board such as a PC board is resin-sealed. it can. That is, the electronic component provided on the substrate is fitted and set in the resin molding cavity provided in only one mold of the resin sealing mold (both upper and lower molds), and the gate portion provided in the one mold. Then, it is possible to adopt a configuration in which ultrasonic vibration is injected into the cavity while continuously (or intermittently) applying ultrasonic vibration to the molten resin by the ultrasonic vibration mechanism. At this time, the wire in the mold cavity exists in the injection direction of the molten resin. Therefore, in this embodiment, similarly to the above-mentioned embodiments, the wire is resin-sealed and molded while the shape of the wire is substantially maintained, and the wire connecting the electronic component mounted on the lead frame and the lead is cut. Alternatively, the deformation can be efficiently prevented. It should be noted that, in the present embodiment, similarly to the above-described embodiment, the modified examples of the above-described embodiment can be adopted.

[0020]

According to the present invention, a resin encapsulation molding method and a mold for an electronic component capable of efficiently preventing the wire connecting the electronic component mounted on the lead frame and the lead from being cut or deformed. It has an excellent effect of being able to provide.

[Brief description of drawings]

FIG. 1 is a partially cutaway vertical sectional view showing a resin-sealing molding die for an electronic component according to the present invention, showing a die-opened state of the die.

FIG. 2 is a partially cutaway vertical sectional view showing a mold corresponding to FIG. 1, showing a mold clamping state of the mold.

[Explanation of symbols]

1 Fixed upper mold 2 movable lower mold 3 electronic components 4 lead frame 5 recess 6 Upper cavity 7 Lower cavity 8 wires 9 pots 10 Plunger 11 Cull part 12 Runner section 13 Gate 14 Resin material 15 Heating means 16 Molten resin 17 Vibration imparting mechanism (ultrasonic vibration mechanism)

Claims (5)

[Claims] 1. A wire for connecting at least the electronic component and the lead in the mold cavity by injecting a molten resin into a mold cavity in which an electronic component mounted on a lead frame is fitted and set. A method of resin-sealing an electronic component to be molded by encapsulation, wherein the molten resin is injected into the mold cavity while vibrating the molten resin at the gate portion to seal the wire in a state in which its shape is substantially retained. A resin encapsulation molding method for an electronic component, characterized in that the molding is carried out. 2. The resin encapsulation molding method for an electronic component according to claim 1, wherein ultrasonic vibration is applied. 3. A cycle of ultrasonic vibration applied to the molten resin is first gently pressed against the molten resin with a predetermined pressing force, and then the pressing force against the molten resin is rapidly attenuated. The resin encapsulation molding method according to claim 1, wherein the resin encapsulation molding method comprises: 4. A resin encapsulation molding of an electronic component, comprising: a mold cavity in which a wire connecting at least an electronic component mounted on a lead frame and a lead is fitted and set; and a gate portion communicating with the mold cavity. A mold for
A mold for resin encapsulation molding of an electronic component, wherein a vibration applying mechanism for molten resin is provided in the gate portion. 5. The mold for resin encapsulation molding of electronic parts according to claim 4, wherein an ultrasonic vibration mechanism is provided as a vibration applying mechanism for the molten resin.