JPH01169936A - Resin seal molding method for semiconductor element and its equipment - Google Patents

Abstract

PURPOSE:To perform resin seal while retaining a lead frame in a specified posture, by installing a retaining means to hold the lead frame at a specified position in a metal mold cavity until a specified time passes after resin injection. CONSTITUTION:A lead frame 16, on which a semiconductor is mounted, is set at a specified position of a cavity part 13, 14 between an upper mold 11 and a lower mold 12. By a plunger 20, melted resin material is injected into the cavity 13, 14, and a semiconductor is resin-sealed. The retaining members 211, 222 of retaining means 21, 22 engaged with the metal molds 11 and 12 so as to be able to go forward and back, interlink both surfaces of a lead frame 16, and retain it at a specified position in the cavity. When a specified time passes after resin is injected, the retaining means 21, 22 retire upward and downward, respectively, so that the cavity is filled with resin.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for sealing and molding a semiconductor element with a resin material, and to improvements in a molding apparatus for the same.

(Prior Art) A transfer resin encapsulation molding apparatus has been conventionally used as an apparatus for encapsulating a semiconductor element with a resin material.

For example, as shown in FIG.
Cavities 3 and 4 for resin molding are provided opposite to the surface (parting line), and a passageway (gate 5) for transferring the molten resin material that communicates the pot for supplying the resin material with the above-mentioned cavity is provided. There is. Note that the reference numeral 6 in the figure is a semiconductor lead frame, and a semiconductor element 7 is mounted on the lead frame.

Resin molding using the conventional equipment described above begins with both molds (1 and 2).
) is opened, and then the lead frame 6 is fitted and set in a predetermined position in the cavity part of both molds, then both molds (1 and 2) are clamped again, and then the resin material is This is done by heating and melting it and injecting it under pressure into both cavities 3 and 4 through the transfer passage 5.

(Problems to be Solved by the Invention) By the way, when the lead frame 6 with the semiconductor element 7 mounted thereon is supplied and set into the cavities (3 and 4) of both molds (1 and 2) and the molds are clamped. In particular, in the case where the portion fitted into both cavities (3 and 4) is supported on one side, there are the following problems in resin sealing molding.

That is, since the fitting portion of the lead frame 6 is in an unstable support state, for example, both the cavities (3 and 4
) The fitting part may vibrate or become curved due to the pressure applied when the resin material is pressurized and injected into the inside, the pressure applied when the injected resin material flows, or other external forces. It is in a comfortable condition. For this reason, both cavities (3
-4) The above-mentioned fitting portion in the resin molded body filled and molded is often sealed in a state different from the predetermined position and orientation, as shown by the chain line in FIG.

Therefore, there is a serious problem that the intended purpose of maintaining airtightness and improving mechanical stability cannot be fully achieved by sealing the fitting portion of the lead frame 6 with a resin material. Yes, for example, the wire for electrical connection between the semiconductor element 7 and the external lead may be deformed or disconnected.
Alternatively, the sealing function of the semiconductor element 7 may be insufficient, resulting in the formation of voids (bubbles) inside and outside the resin molding, impairing moisture resistance, and reducing the high quality and reliability of this type of product. This has the disadvantage of significantly reducing the

In particular, the present invention provides a semiconductor that can securely seal the fitting part with a resin while maintaining a predetermined position and posture even when the part of the lead frame fitted into the cavity is supported on one side. It is an object of the present invention to reliably solve the above-mentioned conventional problems by providing a resin-sealing molding method for an element and an apparatus therefor.

(Means for Solving the Problems) In order to solve the above-mentioned conventional problems, the resin encapsulation molding method of the present invention involves placing a lead frame (16) mounted with a semiconductor element (17) into a mold cavity for resin molding. (13/14
) supplying and setting the semiconductor lead frame to the predetermined position of the part, and mold clamping of the mold to fit the semiconductor element on the lead frame and the required resin sealing area of the lead frame into the mold cavity. and a process in which the lead frame fitted into the mold cavity is held at a predetermined position and posture by supporting both sides of the lead frame through supporting means (21 and 22), respectively. a step of supporting the lead frame; a step of injecting a molten resin into the mold cavity after the step of supporting the lead frame; and a step of injecting the resin into the mold cavity. After a predetermined period of time has elapsed after injection, a lead frame support retraction step of retracting the front end surfaces of the supports (211 and 221) in the lead frame support means to a predetermined position on the mold cavity surface side; Continuing to the above molten resin material injection step,
A method characterized by comprising a resin material filling step in which a molten resin material is filled into a mold cavity, and a product removal step in which a resin molded body and a semiconductor lead frame molded in the mold cavity are released from the mold. It is.

Moreover, the resin molding apparatus of the present invention for carrying out the method of the present invention described above has resin molding cavities (13 and 14).
at least a pair of molds (11 and 12), and a resin material supply pot (18) disposed in one of the molds when the molds are clamped; and a pot (18) fitted into the pot. A plunger (20) for pressurizing the resin material, and a passageway (1) for transferring the molten resin material that communicates the pot and the cavity.
5), and supporting means (21 and 22) for the lead frame (16) fitted in the mold cavity, and the supporting means for the lead frame is a supporting member for the lead frame in the cavity. (211 and 22), and advance/retreat adjustment mechanisms for advancing and retracting the support body in the forward direction to the position where it is engaged with the lead frame and in the backward direction toward the cavity surface side, respectively. It is something to do.

(Operation) According to the method and configuration of the present invention, the fitting portion of the lead frame within the cavity can be reliably supported via the supporting means.

Therefore, even when the fitting portion of the lead frame is supported on one side, its position and position may vary depending on the pressure applied to the fitting portion during pressurized injection of the resin material, the pressure when the resin material flows, etc. It is possible to reliably prevent the posture from being changed. Therefore, the fitting portion of the lead frame can be reliably sealed with resin while maintaining its predetermined position and posture.

(Example) Next, the present invention will be explained based on embodiment figures.

1 to 3 show essential parts of a resin sealing molding apparatus for a semiconductor element according to the present invention.

This device includes a fixed upper mold 11 and a movable lower mold 12 arranged opposite each other, cavities 13 and 14 for resin molding provided on the P and L surfaces of both molds, and a resin molding mold provided on the lower mold 12 side. a supply pot 18, the bot 18 and the cavity 13;
- A passage 15 for transferring molten resin material consisting of a cull 15 and a gate 152 communicating with the molten resin material 14 is provided.

Further, the transfer passage 15 is provided so as to communicate the position where the bot 18 is disposed and the required number of cavities 13 and 14 disposed around the bot 18 at approximately equal distance intervals. . Further, a plunger 20 for pressurizing the resin material 19 is fitted into the bot 18 .

In addition, both the molds 11 and 12 have cavities 13 and 14.
Supporting means 21 and 2 for the lead frame 16 fitted inside
2 are provided respectively. These supporting means 21 and 22
are the support bodies (support bins on the Japanese side) 211 and 221 of the lead frame 16, and the support bodies 211 and 22.
1 is fixed to the plates 212 and 222, and the plate 2
It is composed of a forward/backward adjustment mechanism (not shown) of 1□ and 222. Also, the plates 212 and 222 are moved forward and backward (up and down) at predetermined times during resin molding, which will be described later, so that the supports 21t and 22! The leading end surface of the lead frame 16 in the cavities 13 and 14
The upper and lower sides of the upper and lower sides (front and back) are moved forward to engage with both sides, respectively, and conversely, the upper and lower sides are moved back to a predetermined position on the side of the cavity 13 and 14, for example, a position where the cavity surface and the road surface are the same. It is constructed so that it can be freely adjusted in forward and backward directions.

Note that the reference numeral 17 in the figure is a semiconductor element mounted on the lead frame 16. Further, the same reference numeral 23 is a groove for fitting and setting the lead frame 16 provided on the P and L surfaces on the lower mold 12 side, and the same reference numeral 24 is a groove for fitting and setting the lead frame 1 provided on the lower mold 12 side.
The positioning pin 6, the same reference numeral 25, is a fitting hole with the above-mentioned pin 24 provided on the upper mold 11 side, and when the molds are clamped, the pin 24 is inserted into the pin drilled in the lead frame 16. Hole 1
61 so that the lead frame 16 can be supplied and set at a predetermined position in the cavities 13 and 14. Further, the same reference numeral 26 is an ejector turbine provided in the cull 151 portion on the upper mold 11 side, and the bin 26 is moved up and down at a predetermined time by an ejector plate and a vertical movement mechanism (not shown) during resin molding, which will be described later. is configured to be moved.

Hereinafter, a resin sealing molding method using a molding apparatus having the configuration of the above embodiment will be explained.

First, a step is performed in which the lead frame 16 with the semiconductor element 17 mounted thereon is supplied and set at a predetermined position in the cavities 13 and 14. In this case, as described above, when the positioning pin 24 of the lower mold is inserted into the pin hole 161 of the lead frame, the lead frame 16 is fitted into the groove 23 of the lower mold and is positioned at a predetermined position. is set to

Next, as shown in FIGS. 1 and 3, the lower mold bot 1
While supplying the resin material 19 into the inside of the lead frame 16, the semiconductor element 17 on the lead frame 16 and the lead frame 16 are
A mold clamping process is performed for the molds 11 and 12 in which the required resin sealing range is fitted into the cavities 13 and 14 of the molds 11 and 12.

Next, both upper and lower surfaces of the lead frame 16 fitted into the cavities 13 and 14 are attached to a support member 21 in the support means.
A step is performed in which the lead frame 16 is held at a predetermined position and posture by supporting it through 1 and 22t, respectively. Note that this lead frame support process is performed for both types 1 and 1.
It may be performed after the mold clamping steps 1 and 12, but for example, the second
As shown in the figure, the supports 211 and 22! The tip surface of
In advance, the upper and lower height positions (213, 223
), and in that state, both types 11 and 1
There is no problem even if the mold clamping process of 2 is performed.

Next, the resin material 19 in the bot 18 is heated with a heater and pressurized with a plunger 20 to melt the resin material, and the resin material is injected into the cavities 13 and 14 through the passage 15 under pressure. Perform the process.

In addition, during the step of injecting resin into both cavities 13 and 14, after a predetermined time has elapsed after injecting the resin material, the support body 21. which supports both the upper and lower surfaces of the lead frame 16.・
221, for example, into the cavities 13 and 14.
Vertical height position (214/224
).

Also, here, after a predetermined period of time has elapsed after resin material injection,
After the molten resin material injected from the gate 152 fills both cavities 13 and 14 from around the gate 1520, and the required resin viscosity provides the effect of supporting both sides of the lead frame 16. , meaning. That is, as described above, the double-sided supporting action for the lead frame 16 is initially provided by the supporting means 21 and 2.
2, the predetermined position and posture of the lead frame fitting portion are reliably maintained. However, after such double-sided supporting action of the lead frame 16 is obtained by the injected resin material, the supporting action by the above-mentioned supporting means 21 and 22 is no longer necessary, and
In order to prevent holes corresponding to the shapes of the supports 211 and 22□ from being formed in the resin molded bodies molded in the cavities 13 and 14, the end surfaces of the supports are set at the above height. This is to retreat to the position (214/224).

Next, following the molten resin material injection step described above, a step of continuously injecting and filling the molten resin material into both cavities 13 and 14 is performed.

Next, a step of releasing the resin molded body and the semiconductor lead frame molded in the cavities 13 and 14 is performed. In addition, in this mold release process, the solidified resin molded in the upper mold cull 151 is transferred to its dedicated ejector turbine 2.
By moving 6 downward, it can be projected downward. In addition, the mold release action of the resin molded body and semiconductor lead frame molded in both cavities 13 and 14 is as follows.
By effectively utilizing the supporting means 21 and 22, the mold can be released simultaneously with the mold release of the resin solidified in the cull. That is, the support body 21.・22. By respectively advancing the above-mentioned upper and lower height positions (213, 223) or further advancing them, a protruding action similar to that of the ejector turbine 26 can be obtained. It is something.

In the embodiment shown in FIGS. 1 to 3, a cavity 13 is formed in the upper mold 11, but the upper mold cavity 13 may be omitted to simplify the structure. . That is, for example, as shown in FIG. 4, the lower mold cavity (14) side is formed to be lower by the height corresponding to the upper mold cavity (13), and the P of the upper mold (11) is lowered by the height corresponding to the upper mold cavity (13).
, so that the L surface substantially becomes the upper mold cavity (13) surface. Also, at this time, the lower mold cavity (14
) and Cull (151) may be communicated through gates 153 formed on the P and L surfaces of the lower mold (12). Other configurations and effects are substantially the same as those of the previous embodiment.

Further, the present invention has the following features: (1) A configuration consisting of one pot, one plunger, and one cavity communicating with the pot via a passage for transferring molten resin material; A configuration consisting of a plurality of cavities each communicating with each other via passages for transferring molten resin material at equidistant intervals; ■Multiple pots and plural plungers; A configuration consisting of cavities of the same number as the number of pots, which are separately communicated; ■Multiple pots and plural plungers, and each of the bots are individually communicated with each other via passages for transferring molten resin material spaced at approximately equal distance intervals; It is preferable to adopt a structure consisting of a large number of cavities.

In particular, the arrangement position of the resin material supply pot 18 and the required plurality of cavities 13 and 14 arranged around the pot
A passageway (15) for transferring molten resin material that communicates with
Remarkable effects can be obtained in those provided so as to communicate at approximately equal distance intervals. In other words, this means that the conventional mold configuration is not suitable for large pots (as shown in FIG. 5, for example).
30, a large number of molding cavities 31, and a runner 3 that communicates the pot 30 with each cavity 31.
2, and a passageway 32 for transferring molten resin material consisting of a gate 322, so that each cavity 3
Therefore, after a predetermined period of time has elapsed after the resin is injected into the cavity, the leading end surface of the support body in the support means of the lead frame is moved between the cavity surface and the road surface. This is based on the fact that it is difficult to set the timing for performing a retraction process of the lead frame support to a position where the lead frame support is retracted to a position where , and the overall configuration of the molding apparatus can be simplified.

However, in the method according to the present invention, the molten resin material transfer path (15 ) do not necessarily have to be communicated at approximately equal distance intervals.

For example, the cross-sectional area of the transfer passage 32 is sequentially decreased toward the cavity position furthest from the gaff 530 position, and the cross-sectional area of each gate 32□ is decreased toward the cavity side furthest from the gaff 530 position. , by adopting a configuration in which the resin material is injected and filled into each cavity 31 in a sequential manner, and by setting the resin material injection filling time into each of the cavities 31 to be substantially the same, the same effects as described above can be obtained. That is clear.

Furthermore, the lead frame support 211 in the method of the present invention
・After a predetermined period of time has elapsed after the retraction step of step 22, that is, the resin is injected into the cavities 13 and 14, the lead frame 16 is removed.
During the process of retracting the end surfaces of the support bodies 21r and 221 in the support means to a position where the surfaces of the cavities 13 and 14 meet the road surface, due to the rapid retreat action of the support bodies 211 and 221. In order to prevent the occurrence of voids, it is preferable to gradually retreat the supports 211 and 221. Setting the most suitable retraction speed of the support body depends on the specific shapes and structures of the cavities 13 and 14 and the lead frame 16, or the placement position of the gates (152 and 153) in the transfer passage, and , can be selected appropriately and arbitrarily, taking into consideration the injection state of the molten resin material that is pressurized and injected into the cavities 13 and 14 from the gate, its viscosity, and the like.

Regarding the arrangement of the above-mentioned molds (upper mold 11 and lower mold 12), as shown in the example diagram, in addition to arranging them in the vertical direction, for example, they can be arranged upside down. Alternatively, they may be arranged horizontally in the left and right directions, and the arrangement positions can be selected arbitrarily.

In addition, the setting groove (23) is configured on the 21 sides of both molds.
For example, the lead frame (16) may be set so that the semiconductor element (17) mounted on the lead frame faces upward. In addition, when the P and L surfaces of both types are disposed in the vertical direction, the aspect of the above-mentioned lead frame (16) fitting set may be either leftward or rightward.

Further, in the combination of the upper mold 11 and the lower mold 12, it is possible to arbitrarily select which of them should be the fixed side or the movable side.

In addition, in the embodiment diagram, the bot 18 and the plunger 2
0 is arranged on the lower mold 12 side, the configuration may be reversed, in which it is arranged on the upper mold 11 side.

In addition, it is also important to determine in which part of the cavities 13 and 14 the support bodies 21r and 22□ are fitted, and whether the support bodies are arranged facing each other or alternately in a staggered manner.
Regarding the number of supports fitted into the cavity, etc.
(152
153), and the injection state and viscosity of the molten resin material that is pressurized and injected into the cavities 13 and 14 from the gate, and can be selected as appropriate and arbitrarily. be.

In addition, if the vertical height position (213, 223) of the tip surface of each support body that supports the lead frame 16 in the cavity is always constant, for example, during resin molding, the support bodies may be supplied sequentially and continuously. For example, if the lead frame 16 has variations in wall thickness, a gap may occur between the lead frame and the end surface of each support, or the end surface of each support may overlap both sides of the lead frame. This may cause problems such as unnecessarily strong pressure, deforming or damaging it, and not being able to obtain an appropriate supporting effect. For this reason, for example, when the mold is clamped as shown in FIG. 1, each support body 2 is
It is preferable to configure so that 1□ and 22□ are supported in a press-contact state by an appropriate pressure. In addition, instead of the above-mentioned press-contact bearing means, for example, each support body 21, 22
t is slidably fitted onto the plates 212 and 222 side, and each of the plate receptors 211 and 22□ is elastically projected in the forward direction toward the lead frame 16 side using a required elastic body such as a spring. Such a configuration may also be adopted.

Further, the resin sealing mode of the lead frame 16 may be any mode as long as it can ensure the moisture resistance of the molded resin body (product). Therefore, in the retraction process of the supports 211 and 221, it is not necessary to move each end surface of the supports to the cavity 1.
The vertical height position between the 3.14 surface and the road surface (214.2
24), it is not necessary to retract each support body 21
For example, each of the end surfaces of No. 1 and 221 may be configured to be retracted to a position where the lead frame can be covered with a required thin resin molding layer. In addition,
In this case, a hole corresponding to the retreated position of each support body is formed in the molded resin body, but as described above, the lead frame 16 is resin-sealed with a required thin resin molded layer. Therefore, its moisture resistance can be ensured.

Further, for the purpose of simplifying the overall structure of the molding device, the ejector turbine 26 described above may be configured to be mounted on the plate 212 of the support means 21.

Note that in this case, the eject turbine 26 is attached to the support body 21
In the first retraction step, since the plate 21□ moves forward and backward (moves up and down), the tip end face of the ejector turbine is also moved back (moves up) at the same time as the support end face retreats.

Therefore, during resin molding, a part of the molten resin material flows into the fitting hole of the ejector turbine 26 and is solidified. Since it is integrally formed, it can be released from the mold at the same time as the resin solidified in the cull, so there is no problem.

(Effects of the Invention) According to the method and configuration of the present invention, the fitting portion of the lead frame within the cavity can be reliably supported via the supporting means, so that the fitting portion of the lead frame can be reliably supported within the cavity. Even when the mating part is supported on one side, its position and orientation are reliably prevented from being changed due to the pressure applied to the mating part during pressurized injection of resin material, the pressure when resin material flows, etc. can do.

Therefore, according to the method and configuration of the present invention, there is an excellent effect that the lead frame fitted into the cavity can be reliably sealed with resin while maintaining a predetermined position and a predetermined posture. Furthermore, as mentioned above, the present invention has the excellent effect of reliably solving the conventional problems and improving the quality and reliability of this type of product.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway longitudinal sectional front view showing the main parts of a resin-sealing molding apparatus for a semiconductor element according to the present invention. FIG. 2 is an enlarged partially cutaway M1 sectional front view showing the molding die in an open state. FIG. 3 is a partially cutaway plan view showing the lower mold of the molding die. FIG. 4 is a partially cutaway longitudinal sectional front view showing another embodiment of the molding apparatus of the present invention. FIG. 5 is a partially cutaway plan view showing the lower mold of a conventional molding die. FIG. 6 is a longitudinal sectional front view showing the main parts of a conventional molding die. (Explanation of symbols) 11... Fixed upper mold 12... Movable lower mold 13... Cavity 14... Cavity 15... Transfer passage 151... Cull 152... Gate 153... - Gate 16... Lead frame 17... Semiconductor element 18... Pot 19... Resin material 20... Plunger 21... Support means 21r... Support body 212... Plate 22 ... Support means 221 ... Support body 222 ... Plate 23 ... Setting groove 24 ... Positioning bin 25 ... Fitting hole 26 ... Eject turbine

Claims (2)

[Claims] (1) Semiconductor lead frame supply and setting process of supplying and setting the lead frame with the semiconductor element mounted on it to a predetermined position in the resin molding mold cavity, and the required resin sealing of the semiconductor element on the lead frame and the lead frame. A mold clamping step of the mold fitting the range into the mold cavity, and supporting both sides of the lead frame to be fitted into the mold cavity through supporting means, so that the lead frame is fitted into the mold cavity. a step of supporting the lead frame in the cavity to hold the lead frame in a predetermined position and posture; a resin material injection step of injecting molten resin material into the mold cavity after the support step of the lead frame; A lead frame support that retracts the tip end surface of a support body in a lead frame support means to a predetermined position on the mold cavity surface side after a predetermined time has elapsed after resin injection during a resin injection process into the mold cavity. a resin material filling step of filling the mold cavity with the molten resin material following the molten resin material injection step; and the resin molded body and the semiconductor lead molded in the mold cavity. A method for resin encapsulation molding of a semiconductor element, comprising: a step of removing a product from the mold to release a frame; (2) at least a pair of molds each having a resin molding cavity; a pot for supplying resin material disposed in one of the molds when the molds are clamped; and a resin fitted into the pot. It consists of a plunger for pressurizing the material, a passage for transferring the molten resin material that communicates the pot and the cavity, and a support means for a lead frame fitted in the mold cavity, and a support means for the lead frame. The means includes a support body for the lead frame within the cavity, and a forward/backward adjustment mechanism that moves the support body forward to a position where it engages with the lead frame and in a backward direction toward the cavity surface. A resin encapsulation molding apparatus for a semiconductor element, characterized in that: