JP4563426B2 - Resin mold - Google Patents

Description

  The present invention relates to a configuration of a resin mold for resin-sealing a semiconductor device. In particular, the present invention relates to a configuration of a resin mold for resin-sealing a semiconductor device using a thin substrate.

  With the development of technology in recent years, semiconductor devices have become thinner and smaller, along with the application of thinner substrates, semiconductor element thinning technology, and low bonding wire technology, the resin that protects semiconductor elements is also becoming thinner. is there. When such a thin object to be molded is resin-sealed, warpage of the substrate, which is the object to be molded when resin-sealing, becomes an obstacle during molding, causing problems such as resin leakage.

  The following patent document is disclosed with respect to such a malfunction. In Patent Document 1, a groove is provided at a desired position of a material called a sealing tape or a resin mold as a lead frame or a resin wrap prevention material. A technique is disclosed in which gas in the gap between the lead frame and the sealing tape or between the sealing tape and the mold is allowed to escape from these grooves to prevent warping or deformation of the lead frame due to the remaining gas. A drawing (FIG. 1) disclosed in the literature is shown in FIG. FIG. 5A shows a lead frame attached with a sealing tape, and FIG. 5B shows a cross-sectional view during resin sealing. The gas at the time of resin sealing is released to the outside by the groove 16 to the area exposed to the outside air.

  In patent document 2, the part which sets a to-be-molded object is comprised with a porous material, the to-be-molded object is air-adsorbed through a porous material, and the gas in the clearance gap between a to-be-molded object and a metal mold | die set surface is released outside. Yes. And the technique of correcting the curvature by the heat | fever of a to-be-molded object by air adsorption is disclosed. Drawings (FIGS. 1 and 3) disclosed in the literature are shown in FIG. 6A is a plan view of the lower mold of the mold, and FIGS. 6B and 6C are a plan view and a sectional view of the cavity insert. The cavity insert 30 is made of a porous material, and gas is released to the outside by the ventilation groove 30a. Patent Document 3 discloses a mold in which a runner and a cavity are connected by a plurality of gates.

Japanese Patent No. 3456683 JP 2001-277306 A JP-A-7-290487

  However, in the resin mold mold disclosed in the above-mentioned patent document, when the substrate, which is a molding object, becomes thinner, warping and deformation due to heat cannot be sufficiently corrected. In the conventional resin mold mold clamping structure and air adsorption, when the substrate is clamped, the substrate is not warped or deformed by heat. Therefore, the deformation concentrates in the space of the runner portion, and a gap is generated between the substrate and the mold that is the set surface. If the sealing resin is injected in this state, a problem (resin leakage) that the sealing resin flows out from the gap between the side end surfaces of the substrate occurs.

  In recent years, when manufacturing a thin semiconductor device, a substrate in which a sealing tape is attached to one surface of a lead frame to prevent the sealing resin from flowing around, a resin substrate formed of metal and organic matter, a TAB tape This is due to the fact that a substrate called “N” has been generally used. As described above, a substrate formed of a composite of a metal and an organic material tends to have a large amount of warpage and deformation due to different thermal expansion of each material due to the heat of the mold. Therefore, the deformation of the substrate concentrated in the space of the runner portion when the substrate is clamped becomes large, and resin leakage is likely to occur. Further, when the thickness of the substrate is as thin as 150 micrometers or less, the rigidity of the substrate is extremely lowered, so that warpage or deformation due to heat is increased, and problems due to resin leakage become remarkable.

  Moreover, in the system which adsorbs the molding object of patent document 2 by air, the set surface of the board | substrate which is a molding object is comprised with the porous material. The porous material has a low rigidity, and the clamping force is weak compared to a set surface of a metal body having a high rigidity, and resin leakage is likely to occur. In addition, since the set surface of the substrate is composed of a porous material, when the sealing resin that has flowed out from the gap between the substrate and the mold reaches the porous material portion, the sealing resin blocks the pores of the porous material, There is also a problem that the air adsorption function is lost.

  In view of the above problems, an object of the present invention is to provide a resin mold that can avoid warping and deformation of a thin substrate due to heat and prevent resin leakage.

The resin mold mold according to the present invention includes a first region having a mechanism for injecting a sealing resin on one of an upper mold and a lower mold of the mold, a third region in which a resin molded portion is formed, and an injection. And a second region in which a runner serving as a resin flow path for supplying the sealing resin to the resin molding portion is formed, and a recess is provided in the second region separately from the runner. A convex crush projecting against the mating surface of the upper mold and the lower mold at the time of clamping at a portion parallel to the resin flow path direction at the periphery of the runner and the recess in the second region, It is characterized by clamping an object .

  The resin mold according to the present invention is provided with a portion (concave portion) where a workpiece is not clamped at a position away from a runner that is a resin flow path by a certain distance. Warpage and deformation of the substrate, which is a molding object, is accommodated in the escape portion (concave portion), and the substrate is clamped flat and reliably in the vicinity of the runner where the resin flows. ADVANTAGE OF THE INVENTION According to this invention, the resin mold metal mold | die which prevents the leakage of sealing resin reliably can be provided.

  Next, an embodiment for carrying out the present invention will be described in detail with reference to the drawings as an example.

  The first embodiment will be described in detail with reference to FIGS. In FIG. 1, the top view of the resin mold metal mold | die in Example 1 is shown. FIG. 2 is a sectional view of the mold taken along the line A-A ′ of FIG. 1. FIG. 3 shows a cross-sectional view (a) of the first embodiment and a cross-sectional view (b) of the conventional example in order to explain the deformation of the substrate along the line A-A ′. The resin mold mold of this embodiment is for resin-sealing a molding object on which a large number of semiconductor elements are mounted in a matrix on one surface of a thin substrate 6.

  A resin mold 100 shown in FIG. 1 is constituted by an upper and lower mold having a pot 1, a runner block 4, a cavity block 10 including a resin molding portion 5, and a guide block 11 provided with substrate positioning pins 7. Has been. The substrate 6 is set in a region indicated by a dotted line. The resin from the pot 1 flows through the runner 2 and fills the molding object in the resin molding portion 5. The runner block 4 includes a runner 2 in which the resin from the pot 1 flows, a crushing 8 for clamping the substrate 6 to the peripheral portion of the runner 2 and the longitudinal end of the substrate 6 as a molding (the horizontal direction in the drawing), and It is constituted by a relief 3 that does not clamp the substrate 6.

  The runner block 4 of the upper mold 101 is provided between the pot 1 of the lower mold 102 and the resin molding portion 5 of the upper mold 101. The runner block 4 is composed of a rigid metal body having a width of about 2 mm at a position along the side end surface of the substrate 6, and clamps the substrate 6 when sealing with resin. The width of the runner block 4 is not necessarily 2 mm, but it is necessary to secure an area for securely clamping the workpiece. The portion of the lower mold 102 where the substrate 6 is mounted has a flat surface with the same height in order to support the substrate 6 in a flat shape. In the guide block 11, substrate positioning pins 7 are provided on the lower mold 102 side in order to prevent displacement of the mounting position of the substrate 6 that is a molding target. A hole facing the substrate positioning pin 7 is provided on the upper mold 101 side.

  FIG. 2 is a cross-sectional view taken along the line AA ′ of the resin mold 100 shown in FIG. 1 according to the first embodiment of the present invention, and is shown along the line AA ′ from the left side to the right side of the figure. Yes. In this drawing, only the cross sections of the runner block 4 and the substrate 6 of the upper mold 101 and the lower mold 102 of the resin mold are shown, and an enlarged view of the periphery of the runner 2 of the upper mold 101 is shown. The lower mold 102 is configured such that the substrate 6 that is a molding target is supported flat on the flat surface of the upper surface of the lower mold 102. The upper mold 101 is provided with a runner 2 serving as a resin flow path, a convex crush 8 protruding toward the lower mold 102 at the periphery of the runner 2 and the longitudinal end of the substrate 6, and a concave relief 3. ing. The side surface of the runner 2, the side surface of the relief 3, and the side surface of the squashed 8 are formed in the same plane and are made of a metal body.

  The length of the crushing 8 in the direction in which the resin flows is the same as that of the runner block 4, and the protruding amount is about 1 to 10 micrometers with respect to the mating surfaces of the upper mold and the lower mold at the time of clamping. When the resin sealing is performed by the crushing 8, the substrate 6 which is the molding target is slightly crushed and the substrate 6 is securely clamped. The protruding amount of the crushing 8 is not necessarily 1 to 10 micrometers, but it is necessary to ensure the protruding amount for reliably clamping the molded article without causing abnormal deformation. Further, a relief 3 is formed in a concave shape between the crush 8 except the runner 2 in the longitudinal direction of the substrate 6, and the runner block 4 is made of a metal body. The relief 3 is formed with a depth of about several tens of micrometers to 100 micrometers, and can accommodate warpage and deformation due to heat of the substrate 6 that is a molding target. The metal body mentioned above means a metal having rigidity such as hardened steel generally used as a mold application.

  Next, the resin molding process flow will be described using the resin mold having the above-described structure. First, a substrate 6, which is a molding in which a large number of semiconductor elements are mounted on one surface of a lower mold 102 of a mold 100 heated to about 150 ° C. to 200 ° C., is placed with the semiconductor elements facing upward. Arrange so that The substrate 6 is disposed at a predetermined position by the substrate positioning pins 7 and set on the flat surface of the upper surface of the lower mold 102.

  Next, a tablet-shaped sealing resin is put into the pot 1 of the lower mold 102 to perform mold clamping. In clamping, the crush 8 of the upper mold 101 first hits the substrate 6 and clamps the substrate 6 while slightly crushing it. By the crushing 8 provided on the runner block 4 of the upper mold 101 and the runner block 4 of the lower mold 102, the peripheral edge of the resin flow path facing the runner 2 of the substrate 6 and the longitudinal end of the substrate 6 are slightly crushed. By crushing in this way, the warp and deformation due to heat of the substrate 6 are concentrated from the region of the runner 2 to the concave relief 3 that is not clamped, and the substrate 6 corresponding to the region of the crush 8 across the runner 2 is clamped flat.

  When the clamping of the protruding amount of the squeeze 8 is finished, the substrate 6 at a position facing the periphery of the portion filled with other resin other than the region of the squeeze 8 including the resin molding portion 5 is clamped. At this time, the positions of the upper mold and the lower mold reach the position of the mating surface. At this time, the clamping force of the substrate 6, which is the molding object, is not as strong as the portion corresponding to the crushing 8. However, there is almost no gap between the upper mold 101 and the substrate 6, and the sealing resin does not flow out of the clamp portion during the resin sealing. In addition, the structure of the relief 3 that is not clamped as described above is formed as a recess having a depth that can sufficiently accommodate warpage and deformation due to heat of the substrate 6 that is a molding target, so that the deformation of the substrate 6 can be sufficiently accommodated. . By accommodating the deformation of the substrate 6 by the escape 3, the deformed portion of the substrate 6 is not formed in the region of the resin flow path of the runner 2, and there is a gap between the upper surface of the lower mold 102 facing the substrate 6 and the runner 2. It is supported flat.

  FIG. 3 shows an A-A ′ cross-sectional view showing a state for explaining the deformation of the substrate in the mold when the mold is clamped, and a partially enlarged view thereof. FIG. 3 (a) shows a case using a mold according to the present invention, and FIG. 3 (b) shows a case using a conventional mold.

  In FIG. 3A to which the present invention is applied, the substrate 6 corresponding to the area of the crushing 8 sandwiching the runner 2 is flatly supported by the lower mold 102, and the warpage or deformation of the substrate 6, which is the molding object, is deformed in the relief 3. Is missing. As shown in FIG. 3B, the conventional mold has no structure for escaping warpage or deformation due to heat of the substrate 6 as a molding object, and therefore the resin flow path of the runner 2 serves as an escape location. Therefore, the substrate 6 is warped or deformed inside the runner 2 to create a gap between the upper surface of the lower mold 302 and the substrate 6. The sealing resin flows out from the side end surface of the substrate 6 into the gap, and a problem occurs in that the sealing resin adheres to the support surface side of the substrate 6.

  When the mold clamping is completed, the plunger (not shown) rises from below the pot 1 of the lower mold 102 and injects the sealing resin in the pot 1. The sealing resin fills the resin molding part 5 through the runner 2 from a cull part (not shown) of the upper mold 101. A portion of the substrate 6 facing the runner 2 is clamped flat on the lower mold 102 to prevent leakage of the sealing resin from the side end surface of the substrate 6. Therefore, the sealing resin does not flow out to the runner block 4 and other blocks in the flat region on the upper surface of the lower mold 102 that is the support surface of the substrate 6. After filling the sealing resin, the mold is opened after a resin curing time in the mold, and the substrate 6 which is the molding object molded with the sealing resin is taken out to complete the resin molding process flow.

  As described above, when a workpiece is set, the lower mold positioning pins are used to mount the molded object without any positional deviation, and the flat surface of the lower mold is supported flat. The mold is composed of a metal body in which a convex crush protruding to the lower mold side of the upper runner block and a concave relief recessed to the upper mold side are formed. In the mold clamping operation, warpage and deformation due to heat of the workpiece can be accommodated in the concave relief, and the resin flow path inside the runner and the peripheral edge substrate can be clamped flat and reliably by the convex crushing. It becomes. Since the convex crushing is a small area with a small crushing amount, sufficient clamping can be performed without weakening the clamping force even in the peripheral part filled with resin other than the runner block. There is no deformation or warping of the molding due to this crushing.

  The runner block of the mold of this embodiment is provided with a concave relief and a convex crush that are not clamped. At the time of mold clamping, the warp and deformation of the substrate, which is the molded object, are concentrated on the concave relief. Further, by flatly crushing the object to be molded by convex crushing, flat and reliable clamping of the substrate portion facing the runner is possible. Therefore, there is no gap between the substrate and its support surface, and it becomes possible to completely prevent leakage of the sealing resin.

  A second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a cross-sectional view of the upper mold 201 and the lower mold 202 along the line A-A ′ in the runner block, similar to FIG. 2. The second embodiment is an embodiment in which a projection is provided inside the runner and a region for clamping the molding is added in order to clamp the molding in the resin flow path in the runner flat. The resin mold mold of this embodiment is for resin-sealing a molding object on which a large number of semiconductor elements are mounted in a matrix on one surface of a thin substrate 6.

  As in FIG. 1 of the first embodiment, the resin mold 200 includes a pot 1, a runner block 4, a cavity block 10 including a resin molding portion 5, and a guide block 11 on which substrate positioning pins 7 are installed. The upper and lower molds are provided. The resin from the pot 1 flows through the runner 2 and fills the molding object in the resin molding portion 5. The runner block 4 includes a runner 2 in which the resin from the pot 1 flows, a crush 8 that clamps the substrate 6 at the peripheral edge of the runner 2 and a longitudinal end of the substrate 6 that is a molded object, and a relief that does not clamp the substrate 6. 3.

  As in FIG. 1 of the first embodiment, the runner block 4 of the upper mold 201 is provided between the pot 1 of the lower mold 202 and the resin molding portion 5 of the upper mold 201. It is made of a rigid metal body having a width of about 2 mm at a position along the side end surface of the substrate 6, and the substrate 6 is clamped when sealing with resin. The width of the runner block 4 is not necessarily 2 mm, but it is necessary to secure an area for securely clamping the workpiece. The portion of the lower mold 202 on which the substrate 6 is mounted has a flat surface with the same height in order to support the substrate 6 in a flat shape. In the guide block 11, substrate positioning pins 7 are provided on the lower mold 202 side in order to prevent displacement of the mounting position of the substrate 6 that is a molding target. On the upper mold 201 side, a hole facing the substrate positioning pin 7 is provided.

  FIG. 4 shows only the cross sections of the runner block 4 and the substrate 6 of the upper mold 201 and the lower mold 202, and shows an enlarged view of the periphery of the runner 2 of the upper mold 201. The lower mold 202 is configured such that the substrate 6 that is a molding object is supported flat on the flat surface of the upper surface. The upper mold 201 is provided with a runner 2 serving as a resin flow path, and a convex crush 8 protruding toward the lower mold 202 at the peripheral edge of the runner 2 and the longitudinal end of the substrate 6. The side surfaces of the runner 2, the side surface of the relief 3, and the side surface of the crush 8 are formed on the same plane and are made of a metal body.

  The resin flow path in the runner 2 of the upper mold 201 is provided with a convex projection 9 protruding toward the lower mold 202, and the runner block 4 is made of a metal body. The length of the crushing 8 and the protrusion 9 in the direction in which the resin flows is the same as that of the runner block 4, and the protruding amount is about 1 to 10 micrometers with respect to the mating surface of the upper mold and the lower mold at the time of clamping. When the resin sealing is performed using the crushing 8 and the protrusions 9, the substrate 6 that is the molding target is clamped by being slightly crushed. The protrusions of the crushing 8 and the protrusions 9 do not necessarily have to be 1 to 10 micrometers, but it is necessary to secure an amount of protrusion for reliably clamping the workpiece without abnormal deformation.

  Further, a relief 3 is formed in a concave shape between the crush 8 except the runner 2 in the longitudinal direction of the substrate 6, and the runner block 4 is made of a metal body. The depth of the relief 3 is formed to be about several tens of micrometers to 100 micrometers, and can accommodate warpage and deformation due to heat of the substrate 6 that is a molding target.

  As described above, the crushing 8 and the protrusion 9 provided on the runner block 4 of the upper mold 201 and the runner block 4 of the lower mold 202 slightly crush the portion of the substrate 6 that faces the crushing 8 and the protrusion 9. By slightly crushing the substrate 6, warpage and deformation due to heat of the substrate 6 are concentrated from the resin flow path region of the runner 2 to the concave relief 3 that is not clamped. Further, the substrate 6 corresponding to the area of the crushing 8 sandwiching the runner 2 including the protrusion 9 is clamped flatly on the upper surface of the lower mold 202. Therefore, the substrate 6 that is a molding object is supported flat on the upper surface of the lower mold 202 facing the runner 2 without a gap without forming warp or deformed portions due to heat in the region where the resin of the runner 2 flows.

  In particular, when the width RW of the runner 2 is larger than the width FW of the escape 3, there is a risk that the warp or deformation due to heat of the substrate 6 that is a molded object is accommodated inside the runner 2 and resin leaks inside the runner 2. Becomes higher. Therefore, a protrusion 9 is provided inside the runner 2 to make the width rW of the resin flow path of the runner 2 in the runner block 4 region smaller than the clearance width FW. By making the width rW of the resin flow path smaller than the clearance width FW, warping and deformation of the substrate 6 due to heat in the runner 2 can be avoided. Although the projection 9 is described as one projection for one runner, a plurality of projections 9 may be formed inside one runner. The planar shape of the protrusion 9 is not particularly limited, but a shape such as a rhombus, an ellipse, or a triangle that does not hinder the flow of the resin is preferable. The metal body mentioned above means a rigid metal such as a hardened steel generally used as a mold application.

  The resin mold of the present embodiment is provided with a protrusion inside the runner as compared to the first embodiment. Due to the protrusion inside the runner, the warpage and deformation of the substrate, which is a molded object inside the runner, can be more reliably eliminated. Therefore, it is possible to completely prevent the resin leakage from the resin flow path portion. In particular, it is suitable for the above-described mold structure having a wide runner width.

  As described above, the resin mold of the present invention is provided with a concave relief that does not clamp the object to be molded at a position away from the runner that is a resin flow path. Warpage and deformation due to heat of the substrate, which is a molding object, are concentrated on the concave relief. Further, when the width of the runner is larger than the width of the portion where the workpiece is not clamped, a protrusion for clamping the workpiece can be provided inside the runner. The projections are clamped by the protrusions also inside the runner. Furthermore, when clamping a to-be-molded object with an upper mold | type and a lower mold, the crushing which crushes a to-be-molded object slightly is provided.

  With the resin mold structure of the present invention, warpage and deformation due to heat of the molded object can be concentrated on a portion that is not clamped, and the interior of the runner that is a resin flow path can support the molded object flatly. Further, the molded object in the vicinity of the runner has a small clamping area due to partial clamping by crushing, and the clamping force per area can be increased. For this reason, a to-be-molded object can be clamped reliably and the resin sealing without a resin leak is attained. According to the present invention, a resin mold mold capable of resin sealing without resin leakage is obtained.

  Although the present invention has been specifically described above based on the embodiments, the present invention is not limited to the above-described embodiments. Various modifications can be made without departing from the scope of the present application, and it goes without saying that these modified examples are also included in the present application. For example, in the embodiment, the structure in which the relief is provided in the upper die in the same block as the runner has been described, but a structure in which the upper and lower dies are reversed, or the upper and lower dies can be separately configured, and similar effects can be obtained. Moreover, although it demonstrated using the mold metal mold | die which carries out resin sealing only on the single side | surface of a board | substrate, if it is a resin mold metal mold | die which flows resin from the single side | surface of a board | substrate, it applies also when resin-sealing on both front and back surfaces of a board | substrate. be able to. Moreover, it is applicable also to the resin mold metal mold | die which adsorb | sucks and supports a board | substrate like patent document 2 (Unexamined-Japanese-Patent No. 2001-277306). Thus, the runner block of the present invention can be applied to various modified examples, and similar effects can be obtained.

  As an application example of the present invention, there is a resin sealing mold for an electronic device including a semiconductor device that is sealed using a resin.

It is a top view of the resin mold metal mold | die in Example 1 of this invention. It is sectional drawing of the resin mold metal in the A-A 'line in FIG. FIG. 2A is a cross-sectional view for explaining deformation of a substrate along the line A-A ′ in FIG. 1, and FIG. It is sectional drawing of the A-A 'line | wire of the resin mold metal mold | die in Example 2 of this invention. It is sectional drawing (b) at the time of the sealing tape sticking lead frame (a) and resin sealing in a prior art example (patent document 1). It is the top view (a) of the lower mold | type of the resin mold metal mold | die in a prior art example (patent document 2), the top view (b) of a cavity insert, and sectional drawing (C).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pot 2 Runner 3 Escape 4 Runner block 5 Resin molding part 6 Substrate 7 Substrate positioning pin 8 Crushing 9 Protrusion 10 Cavity block 11 Guide block 100 Resin mold die 101 in Example 1 Upper mold of resin mold die in Example 1 102 Lower Mold 200 of Resin Mold Mold in Example 1 Resin Mold Mold 201 in Example 2 Upper Mold 202 of Resin Mold Mold in Example 2 Lower Mold 302 of Resin Mold Mold in Example 2 Resin in Conventional Example Lower mold of mold

Claims (6)

In a resin mold mold for clamping a molding object with an upper mold and a lower mold and resin-sealing a molding portion, a first region having a mechanism for injecting a sealing resin on one of the upper mold and the lower mold And a third region in which a resin molded portion is formed, and a second region in which a runner serving as a resin flow path for supplying the injected sealing resin to the resin molded portion is formed. In the second region, a recess is provided separately from the runner, and the upper die and the lower die at the time of clamping are aligned at the periphery of the runner and the recess in the second region and parallel to the resin flow path direction. A resin mold having a convex crush projecting from a surface and clamping the molding .   In the case where the width of the runner in the second region is larger than the width of the recess, a protrusion protruding to the surface for clamping at least one of the moldings is provided inside the runner. The resin mold die according to claim 1. 3. The resin mold according to claim 2, wherein the protrusion provided in the second region protrudes from 1 to 10 micrometers with respect to the mating surface of the upper mold and the lower mold at the time of clamping. Said second crush provided in regions claims 1 to 3 with respect to the upper and lower molds of the mating surfaces when the clamp 1 from projecting 10 micrometers, characterized by clamping the object to be molded A resin mold according to any one of the above.   5. The resin mold according to claim 1, wherein the recess is recessed by several tens to 100 μm with respect to a mating surface of the upper mold and the lower mold at the time of clamping.   The resin mold according to any one of claims 1 to 5, wherein the molding has a thickness of 150 micrometers or less.

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