JP3499269B2 - Cover frame and resin sealing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cover frame and a resin encapsulation method, and more particularly to a cover frame fitted into a mold for resin encapsulation of a semiconductor device and a semiconductor device resin using the cover frame. The present invention relates to a sealing method.

[0002]

2. Description of the Related Art A resin sealing method using a transfer molding apparatus when resin-sealing a semiconductor device composed of semiconductor elements arranged on a substrate (lead frame, plastic substrate, glass epoxy substrate, TAB tape, etc.) Is often used. In the case of the transfer mold device, the semiconductor device is set in the mold, and the molten resin is filled into the mold cavity in which the semiconductor element is arranged via the pot and the resin passage, thereby performing resin sealing. ing. When the mold is closed, the resin path is formed so as to reach the cavity from the pot through the substrate.

[0003]

However, the above conventional resin encapsulation method for a semiconductor device has the following problems. Since the resin passages are formed on the substrate, the resin in the resin passages adheres to the substrate when it solidifies. The resin solidified in the resin path in the step after resin sealing is removed as scrap, but the scrap resin attached on the substrate is difficult to remove. If a large force is applied for removal, there is a risk of damaging the substrate and the like. Therefore, in order to prevent the resin from adhering to the substrate, a technique has been developed in which a portion corresponding to the resin path on the substrate is plated to easily separate the solidified scrap resin. There is a problem in that a plating treatment step including the above is required, which causes a decrease in productivity and an increase in production cost. Therefore, it is an object of the present invention to provide a cover frame for preventing resin from adhering to a substrate and a resin sealing method using the cover frame.

[0004]

In order to solve the above problems, the present invention has the following constitution. That is, the carrier frame passes through the resin filling pot and the resin path connecting the pot and the cavity into the mold for resin-sealing the semiconductor element of the semiconductor device in which the semiconductor element is mounted on the substrate. It is fitted over a range, with the pot,
A through hole is provided in a portion corresponding to a mold runner which is a part of a resin path connecting the pot and the cavity, and the semiconductor device is set in the mold while being fitted into the mold. when the mold gate portion formed in the mold interposed between the base of the semiconductor device for site passing over the substrate, characterized in that to prevent contact between the resin and the substrate. On the other hand, in the resin sealing method, the cover frame is placed in a mold for resin-sealing the semiconductor element of a semiconductor device in which a semiconductor element is mounted on a base, and a pot for filling the resin, a pot and a cavity. In the step of fitting over the range where the resin path connecting to each other passes and the part where the mold gate part formed in the mold passes on the base body, the cover frame is inserted between the mold and the mold. And setting the semiconductor device in the mold, and filling the cavity with molten resin from the pot through the mold runner and the mold gate portion.

[0005]

[Operation] The operation will be described. The cover frame fitted in the mold exists between the resin path formed in the mold and the base of the semiconductor device when the resin-sealed semiconductor device is set in the mold. Thus, since the resin is prevented from contacting the base, it is possible to prevent the resin from adhering to the base even when the resin is filled.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. (First Embodiment) A first embodiment will be described with reference to FIGS. FIG. 1 is a plan view showing a state in which a cover frame 12 and a semiconductor device (for example, a ball grid array type semiconductor device) 14 to be resin-sealed are set in a lower mold 10 which constitutes a mold, and FIG. The upper die 16 which comprises a metal mold | die with respect to the lower die 10 of 1 is moved downward, and the state which the mold closed was shown. 1 and 2, a plurality of through holes 18 are formed in the cover frame 12 at equal intervals in the length direction. Each through hole 18 is a mold runner that is a part of a resin filling pot 20 and a resin path provided in the lower mold 10 when the cover frame 12 is fitted into a predetermined position of the lower mold 10. It is formed at a position corresponding to 22. The cover frame 12 is formed in a plate shape from a material such as metal having heat resistance and low adhesion to the semiconductor sealing resin.

The cover frame 12 is provided with a plurality of positioning holes 24, which are an example of positioning means. A plurality of guide pins 26 erected on the lower mold 10 are fitted into the respective positioning holes 24 so that the cover frame 12 can be fitted into a predetermined position on the lower mold 10. The cover frame 12 is
It is detachable from the lower mold 10. The gate-corresponding portion 28 of the cover frame 12 includes a cavity 32 formed in the lower mold 10 and a mold gate 30 which is a part of a resin path.
It is formed diagonally according to the connection site with. The position of each semiconductor device 14 on the cover frame 12 is set at a predetermined position by a positioning boss 34 provided on the lower mold 10. The positioning boss 34 is provided at a position where it can contact the four sides of the base 36 of each semiconductor device 14.

FIG. 3 is an enlarged sectional view of the vicinity of the mold gate 30 in the mold closed state of FIG. The semiconductor element 38 is present in the cavity 32 recessed in the parting surface of the lower die 10. In this embodiment, in order to improve the releasability of the resin solidified in the cavity 32, the connecting portion between the inner bottom surface of the cavity 32 and the inner wall surface is formed into a curved surface. After the cover frame 12 is fitted into a predetermined position of the lower mold 10, the semiconductor device 14 is set in a predetermined position, and in a state where the mold is closed, the cover frame 12 has the mold gate 3 formed in the lower mold 10.
0 and the lower surface of the base 36 are inserted. Therefore, the resin sent into the cavity 32 through the mold gate 30 is prevented from coming into contact with the lower surface of the base 36. That is, even if the resin is filled, the resin in the mold gate 30 can be prevented from adhering to the base 36. The thickness of the cover frame 12 is not particularly limited, but is preferably equal to the depth of the cavity 32.

Next, a method of resin-sealing the semiconductor device 14 using the cover frame 12 having the above structure will be described. First, the cover frame 12 is fitted into a predetermined position on the lower die 10, and then the semiconductor device 14 is attached to the lower die 10.
Set it to the predetermined position (state of FIG. 1). However, this order may be reversed depending on the structure of the lower mold 10. When the cover frame 12 and the semiconductor device 14 are set, the upper mold 16 is moved downward to close the mold (states of FIGS. 2 and 3). When the mold closing is completed, the semiconductor element 38 and the like are sealed with resin. The resin sealing is performed by pumping the molten resin into the cavity 32 from the pot 20 in the lower mold 10. The molten resin fed under pressure enters from the pot 20 into the mold cull 40 recessed in the parting surface of the upper mold 16,
It is divided into each mold runner 22, and is filled into each cavity 32 through a mold gate 34. When the resin is filled from the mold gate 30 into the cavity 32, as described above,
Since the cover frame 12 is inserted between the mold gate 30 and the lower surface of the base 36, the molten resin in the mold gate 30 is prevented from contacting the lower surface of the base 36, and the base 3
Adhesion to 6 is prevented.

When the filled resin is solidified, the molded product is released from the mold. The molded product after the mold release is sent to the scrap removing process together with the cover frame 12. In the scrap removal process, for example, the cover frame 12 is held with the molded product held.
The gate is broken by rotating or pushing. When the scrap removal is completed, the semiconductor device 14 is completed. The cover frame 12 that is no longer needed after scrap removal can be reused after removing the scrap such as the adhering molded product gate.

(Second Embodiment) A second embodiment will be described with reference to FIG. The same members as those of the first embodiment are designated by the same reference numerals as those of the first embodiment, and the description thereof will be omitted. In the first embodiment, the semiconductor devices 14 are individually set on the lower mold 10 in a separated state. In the semiconductor device 14 of the second embodiment, a plurality of semiconductor elements 38 are arranged in parallel on a strip-shaped base 36a. Positioning of the base 36a on the lower mold 10 is performed by fitting a guide hole 42 that is transparently provided on the base 36a and a pin 44 that is erected on the lower mold 10. In the case of the second embodiment, the shape and the like of the cover frame 12 are the same as those of the first embodiment. The resin sealing method for the semiconductor device 14 having the strip-shaped substrate 36a is basically the same as that of the first embodiment, but after the gate break, the substrate 36a is cut in order to separate each semiconductor device 14.

(Third Embodiment) A third embodiment will be described with reference to FIG. The same components as those of the preceding embodiment are designated by the same reference numerals as those of the preceding embodiment, and the description thereof will be omitted. In the first and second embodiments, the cover frame 1
2 has a plurality of through holes 18. In the cover frame 12 of the third embodiment, one through hole 18 is bored, and one cover frame 12 forms two semiconductor devices 14.
It corresponds to. The function and effect are similar to those of the preceding embodiment, but the third embodiment has an advantage that the cover frame 12 can be partially replaced.

(Fourth Embodiment) A fourth embodiment will be described with reference to FIGS. 6 and 7. The same components as those of the preceding embodiment are designated by the same reference numerals as those of the preceding embodiment, and the description thereof will be omitted. In each of the preceding embodiments, the mold cull 40 is the upper mold 1
6, the cover frame 12 has a through hole 18 formed therein. In the fourth embodiment, the upper mold 16 is not provided with the mold cull 40, but the lower mold 10 is provided with the pot 20 and the mold cull 40a. Since the mold cull 40 is not provided on the upper mold 16,
The cover frame 12 does not require the through hole 18. In addition,
In the fourth embodiment, a plurality of cover frames 12 are provided in the lower mold 10.
However, one long cover frame 12 similar to the first and second embodiments may be used.

FIG. 8 is a partial view of the completed semiconductor device (common to each embodiment), viewed from the direction of the resin path with the resin path such as the molded product gate removed. Resin sealing part 5
Gate mark 5 of the removed molded product gate at the corner of 0
2, the trace 54 of the cover frame 12 remains, but there is no particular problem. Although various preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. For example, in a semiconductor device, a resin sealing portion is formed on one side of a base. Needless to say, many modifications can be made without departing from the spirit of the invention, such as being formed on both sides.

[0015]

When the semiconductor device is resin-sealed by using the cover frame according to the present invention, the cover frame fitted in the mold is used when the semiconductor device to be resin-sealed is set in the mold. Is inserted between the resin path formed in the mold and the base of the semiconductor device. Therefore, the resin sent into the cavity through the resin passage is prevented from coming into contact with the lower surface of the base. That is, even if the resin is filled, it is possible to prevent the resin in the resin passage from adhering to the substrate, so that it is not necessary to previously perform the plating treatment for resin peeling on the substrate as in the conventional case, and the productivity of the semiconductor device can be improved. It is possible to significantly improve the manufacturing cost and to significantly reduce the manufacturing cost.

[Brief description of drawings]

FIG. 1 is a plan view of a lower mold showing a first embodiment in which a semiconductor device is resin-sealed using a cover frame according to the present invention.

FIG. 2 is a sectional view showing a state in which a cover frame and the like are set in a mold and the mold is closed in the first embodiment.

FIG. 3 is an enlarged cross-sectional view of the vicinity of the mold gate in the mold closed state in the first embodiment.

FIG. 4 is a plan view of a lower mold according to a second embodiment.

FIG. 5 is a plan view of a lower mold according to the third embodiment.

FIG. 6 is a plan view of a lower mold according to a fourth embodiment.

FIG. 7 is a sectional view showing a state in which a cover frame and the like are set in a mold and the mold is closed in the fourth embodiment.

FIG. 8 is a partial view of the completed semiconductor device viewed from the removed resin path direction.

[Explanation of symbols]

10 Lower mold 12 cover frames 14 Semiconductor device 16 Upper mold 24 Positioning hole 30 mold gate 32 cavities 36 base 38 Semiconductor device

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01L 21/56 B29C 45/02 B29C 45/26 B29L 31:34

Claims (5)

(57) [Claims] 1. A mold for resin-sealing the semiconductor element of a semiconductor device in which the semiconductor element is mounted on a substrate,
Resin passage communicating the pot and the pot and the cavity of the resin filling is fitted over a range to pass, the portion corresponding to the pot and the mold runners, which is part of the resin passage communicating the pot and the cavity A semiconductor is provided for a portion where a die gate portion formed in the die passes over the substrate when the semiconductor device is set in the die with a through hole provided and fitted into the die. wherein interposed between the base of the device, the cover frame, characterized in that to prevent contact between the resin and the substrate. 2. The cover frame according to claim 1, wherein the cover frame is formed to have a thickness equivalent to a depth of a cavity provided on a parting surface of the mold. 3. The cover frame according to claim 1 or 2, further comprising a positioning means for positioning and fitting at a predetermined position in the mold. The 4. A cover frame as claimed in any one of claims 1 to 3, the semiconductor element of the semiconductor device in which a semiconductor element is mounted on the substrate into a mold for resin sealing, resin Regarding the step of fitting over the range where the pot for filling and the resin path connecting the pot and the cavity pass, and the part where the die gate part formed in the die passes over the base, the cover frame is A step of setting the semiconductor device in the mold so as to be inserted between the mold and a step of filling the cavity with molten resin from the pot through the mold runner and the mold gate portion; A method for resin sealing a semiconductor device, which is characterized. 5. The resin encapsulating method according to claim 4, wherein the cover frame is fitted to a lower die forming the die.