JP2013089607A - Molding apparatus and molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding apparatus configured in consideration of avoiding damage to a semiconductor element and deformation of an electrode plate.SOLUTION: A molding apparatus is configured to: arrange an intermediate assembly W, which is composed of a semiconductor element 2, electrode plates 4 and 5 provided on front and rear surface sides of the semiconductor element 2 and a frame-shaped insulator 6, in a molding room R which is formed by an upper mold 8 and a lower mold 9 being abutted to the respective electrode plates 4 and 5 and being moved into a clamped state; and manufacture a semiconductor device 1 by filling the molding room R, which has the intermediate assembly W therein as an insert, with a resin material and molding the intermediate assembly W. Here, a mold-matching surface 10 between the upper and lower molds 8 and 9 directly clamps a direct clamping part 4a formed at a part of the upper electrode plate 4, whereas parts of the upper and lower molds 8 and 9 that abut to the electrode plates 4 and 5 other than the direct clamping part 4a are formed as rockable floating molds 8b and 9b.

Description

  The present invention relates to a molding apparatus and a molding method for molding a semiconductor element or the like with a resin. More specifically, the present invention relates to a mold in which an intermediate assembly in which electrode plates are arranged on both front and back surfaces of a semiconductor element is used as an insert and filled with a resin material. The present invention relates to a molding apparatus (molding) and a molding method.

  This type of molding technique is proposed in Patent Document 1. In the technique described in Patent Document 1, when molding a semiconductor device in which a heat sink is attached to both sides of a semiconductor element, the semiconductor device is pressed and restrained with a pair of molds to surround the semiconductor device. The mold chamber is formed so as to be isolated, and one die is provided with a slide member and a moving member so that the pressing force exerted on the semiconductor device can be adjusted.

JP 2007-320102 A

  However, in the technique described in Patent Document 1, a semiconductor device is pressed and restrained by a pair of molds, and a lead frame as an electrode protruding from the semiconductor device is directly formed on a mold-matching surface between the pair of molds. Therefore, depending on the dimensional variation of the semiconductor device including the lead frame and the inclination of the heat sink, an excessive pressing force may act on the semiconductor device, resulting in damage to the semiconductor element and lead frame deformation. Still, there is room for improvement.

  The present invention has been made paying attention to such problems, and in particular, an object of the present invention is to provide a molding apparatus and a molding method that are considered so as to avoid breakage of semiconductor elements and deformation of electrodes.

  The present invention follows the molding method substantially similar to the conventional one as described above, and the electrodes other than the direct clamping portion that directly clamps a part of one of the electrode plates of both molds on the mold mating surface. This is a floating type structure that can swing the portion that contacts the plate.

  According to the present invention, a part of both molds has a floating structure, so that even if the intermediate assembly to be molded as an insert has a dimensional error or an inclination of the electrode plate, it is absorbed. Therefore, damage to the semiconductor element and deformation of the electrode plate due to excessive input can be prevented, and leakage of the resin material from the mold chamber can also be prevented.

Sectional explanatory drawing of the semiconductor device used as the manufacture object in the molding apparatus which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows embodiment in 1st Embodiment of the molding apparatus which concerns on this invention, (A) is sectional explanatory drawing in alignment with the B1-B2 line | wire of the same figure (B), (B) is A1- of the same figure (A). Cross-sectional explanatory drawing which follows A2 line. Cross-sectional explanatory drawing which follows the A1-A3 line | wire of (A) of FIG. Process explanatory drawing which shows the shaping | molding procedure in the molding apparatus shown to FIG. Cross-sectional explanatory drawing which shows the 2nd form of the molding apparatus which concerns on this invention. Cross-sectional explanatory drawing which shows the 3rd form of the molding apparatus which concerns on this invention.

  1 to 3 show a more specific first embodiment of a molding apparatus according to the present invention. In particular, FIG. 1 shows a sectional view of a semiconductor device 1 to be manufactured. 2 and 3 show the structure of a molding apparatus for manufacturing the semiconductor device 1 to be manufactured.

  As shown in FIG. 1, a semiconductor device 1 includes a plurality of semiconductor elements 2 such as so-called power ICs for large currents, and the semiconductor elements 2 are parallel to each other via solder layers 3 a and 3 b on both front and back surfaces. A large and small or upper and lower electrode plates 4, 5 that also function as a heat sink, and a resin such as PPS arranged so as to straddle between both electrode plates 4, 5. The insulator 6 is made of a rectangular frame and is formed of a resin mold layer 7 filled and sealed in a space formed between the electrode plates 4 and 5 and the insulator 6. The electrode plates 4 and 5 function as so-called bus bars for electrically connecting the semiconductor element 2 to an external device (not shown) such as a power supply device or an external power supply load.

  Thereby, the semiconductor element 2 is sealed and protected in the form of being embedded in the resin mold layer 7. The insulator 6 is in close contact with the lower surface of the upper electrode plate 4 and the outer peripheral surface of the lower electrode plate 5, and the lower surface of the insulator 6 and the lower electrode plate 5 are in close contact with each other. Is located on the same plane. As the electrode plates 4 and 5, for example, those made of copper are used as those having excellent conductivity.

  When manufacturing such a semiconductor device 1, both electrode plates 4, 5 are previously bonded to the front and back surfaces of the semiconductor element 2 via solder layers 3 a, 3 b, and the electrode plates 4, 5 are then bonded to each other. An intermediate assembly W is obtained by joining the insulators 6 together. For example, as described above, the lower electrode plate 5 is used as an insert so that the lower surface of the rectangular frame-shaped insulator 6 and the lower surface of the lower electrode plate 5 are positioned on the same plane. 5 and the insulator 6 are integrally formed in advance, the semiconductor element 2 and the solder layers 3a and 3b are laminated on the lower electrode plate 5, and the upper electrode plate 5 is further formed from above them. The intermediate assembly W is formed by pressing and soldering so that the upper electrode plate 4 is in close contact with the insulator 6.

  As will be described later, this intermediate assembly W is set as an insert in a predetermined mold, and a space formed by separation of both electrode plates 4, 5 and insulator 6 is used as a mold chamber, and a resin material is placed in this mold chamber. The resin mold layer 7 is formed by filling and sealing. In this case, since both the electrode plates 4 and 5 have a function as a heat radiating plate, it is not allowed that the surfaces of both the electrode plates 4 and 5 are covered with the resin layer. In particular, when the semiconductor device 1 is used by placing a heat sink (not shown) on the electrode plates 4 and 5, if the surface of the electrode plates 4 and 5 is covered with the resin layer, Since it becomes a factor which reduces the heat transfer efficiency from 5 to a heat sink, it is not preferable that the surface of the electrode plates 4 and 5 is coat | covered with the resin layer.

  2A is a sectional view taken along line B1-B2 of FIG. 2B as a planar structure of the molding apparatus, and FIG. 2B is a sectional view taken along line A1-A2 of FIG. Each figure is shown. Further, FIG. 3 shows a cross-sectional view taken along line A1-A3 of FIG.

  As shown in FIGS. 2 and 3, the molding apparatus includes an intermediate assembly W composed of the semiconductor element 2 and the solder layers 3a and 3b, both electrode plates 4 and 5, and the insulator 6 as described above. A semiconductor device 1 as shown in FIG. 1 is manufactured by applying a resin mold as an insert. The semiconductor device 1 includes an upper die 8 and a lower die 9. When the intermediate assembly W is disposed between the upper mold 8 and the lower mold 9 and the mold-matching surface 11 is clamped, the upper mold 8 contacts the upper electrode plate 4 and the lower mold 9 The upper electrode plate 4 comes into contact with the upper electrode plate 8 and the lower die 9 at the same time. In addition, the space between the upper and lower electrode plates 4 and 5 and the insulator 6 is sealed, and is formed as a mold chamber (cavity) R for filling the resin material.

  In addition, a pot portion 12 is formed across the upper die 8 and the lower die 9, and a gate portion 13 for connecting the pot portion 12 and the mold chamber R is formed on the die matching surface 11. Prior to filling the mold chamber R with the resin material, the upper mold 8 and the lower mold 9 are both preheated to a predetermined temperature, and the pot portion 12 has an insulating resin material such as an epoxy resin. When the plunger 14 is pushed in after the pellets are inserted, the resin material softened and melted in the pot portion 12 by the transfer molding method is filled into the mold chamber R via the gate portion 13 to seal the semiconductor element 2. Therefore, the resin mold layer 7 shown in FIG.

  Here, as apparent from FIGS. 2 and 3, the upper electrode plate 4 protrudes outside the mold chamber R and further protrudes outside the upper and lower molds 8 and 9. Of these, the protruding portion is directly clamped by the upper mold 8 and the lower mold 9 when the mold is clamped as the clamping section 4a. On the other hand, the portion of the upper die 8 that contacts the upper electrode plate 4 is divided from the die body 8a as a swingable floating die 8b, and the lower electrode plate 5 and the insulator 6 of the lower die 9 are separated. The part that abuts on is divided from the mold body 9a as a swingable mold 9b. The floating die 8b on the upper die 8 side is biased downward by a compression coil spring or other elastic body 15, and the floating die 9b on the lower die 9 side is similarly compressed coil spring or other elastic body 16. Is biased upward. Both of these floating molds 8b and 9b are elastically supported by the mold body 8a or 9a via the elastic body 15 or 16 so that the upper and lower molds 8 and 9 have a predetermined stroke in the mold clamping and mold opening directions. And can be displaced by tilting.

  Here, as described above, the upper electrode plate 4 and the lower mold 9 are firmly pressure-clamped by clamping the projecting portion from the mold chamber R of the upper electrode plate 4 directly as the clamping portion 4a. . In this case, the mold bodies 8a and 9a themselves of the upper and lower molds 8 and 9 are made of, for example, a mold steel that is harder and more rigid than the upper electrode plate 4 made of copper, so that the mold body 8a on the upper mold 8 side. When the pressing portion of the upper electrode plate 4 is directly clamped as the clamping portion 4a with the die main body 9a on the lower die 9 side, the die main bodies 8a, 9a side is set to the upper electrode plate 4 side. A seal bead or the like is used to positively bite or bite. By so doing, a so-called sealing effect for preventing leakage of the resin material at the contact portion of the mold main body 8a, 9a with the upper electrode plate 4 is exhibited, and also in preventing mold damage due to excessive input. It will be advantageous.

  FIG. 4 shows a detailed step-by-step procedure at the time of molding by the molding apparatus shown in FIGS. However, the pot portion 12 and the plunger 14 in FIGS. 2 and 3 are not shown.

  As shown in FIG. 4A, first, in the mold open state of the upper mold 8 and the lower mold 9 of the mold 10, the previous intermediate assembly W is set on the lower mold 9 side. More specifically, the intermediate assembly W is positioned and placed on the floating mold 9b on the lower mold 9 side with the lower electrode plate 5 and the insulator 6 as contact portions. Subsequently, the process proceeds to a mold clamping operation as shown in FIG. 4B, and finally, the intermediate assembly W is pressure-restrained by the upper and lower molds 8 and 9 upon completion of the mold clamping shown in FIG. The state of FIG. 4C is nothing but the state of FIG. 2B, and the protrusions of the upper electrode plate 4 in the intermediate assembly W are the molds of the upper and lower molds 8 and 9 as the direct clamping part 4a. Although the main body 8a and 9a are pressure-clamped by the rigid body, the other parts are elastically restrained by the upper and lower floating molds 8b and 9b.

  When the mold clamping is completed in this way, the process shifts to filling or injection of the resin material in FIG. 4D, and as shown in FIGS. 2 and 3, the upper and lower electrode plates 4, 5 and the insulator 6 are connected. The resin material is fully filled or injected into the mold chamber R formed in isolation, and the semiconductor element 2 is sealed with the solidified resin mold layer 7. Thereafter, the process proceeds to the mold opening operation shown in FIG. 4 (e). Finally, as shown in FIG. 4 (f), the product semiconductor device 1 is removed from the mold 10 while being released, and a series of resins are removed. Complete the mold operation.

  Therefore, as shown in FIG. 2A and FIG. 3, in the clamped state of the upper and lower molds 8 and 9, the protruding portion of the upper electrode plate 4 is directly pressed and clamped to the rigid as the clamping part 4a. Even if it is yes, in the other part of the intermediate assembly W, the floating die 8b on the upper die 8 side is in elastic contact with the upper electrode plate 4 and is in contact with the lower electrode plate 5 and the insulator 6. On the other hand, the floating mold 9b on the lower mold 9 side is elastically contacted, and the intermediate assembly W is elastically pressed and restrained by both the floating molds 8b and 9b.

  Therefore, even when the intermediate assembly W has a thickness error or when the upper and lower electrode plates 4 and 5 have an inclination, the upper and lower floating molds 8b and 9b Since the electrode plates 4 and 5 are swung and displaced to absorb the inclination of the electrode plates 4 and 5, the upper and lower electrode plates 4 and 5 are not excessively deformed by excessive force. The semiconductor element 2 is not damaged by the input. In addition, since the sealing property of the mold chamber R is ensured at the same time, it is possible to prevent the occurrence of a situation in which the surfaces of the electrode plates 4 and 5 are covered with the resin due to the leakage of the resin material. Can do.

  2 and 3, the insulator 6 is in direct contact with the mold body 8a and the upper electrode plate 4 on the upper mold 8 side, and directly on the floating mold 9b on the lower mold 9 side. In other words, the insulator 6 is directly loaded with the clamping force by the upper and lower molds 8 and 9. Therefore, the insulator 6 functions as a spacer that regulates the distance between the upper electrode plate 4 and the lower electrode plate 5, and as a result, the semiconductor element 2 is protected by excessive input from the mold clamping and mold opening directions. It is possible to prevent the semiconductor element 2 from being damaged or tilted. Needless to say, the load exerted on the insulator 6 by the floating mold 9b on the lower mold 9 side is set to be equal to or lower than the load resistance of the insulator 6. Similarly, the upper mold 8 including the floating mold 8b is finally applied. Needless to say, the load applied to the semiconductor element 2 is set to be equal to or lower than the load resistance of the semiconductor element 2.

  Here, the frame-like insulator 6 in the semiconductor device 1 shown in FIGS. 2 and 3 is not necessarily required, and may be omitted depending on the specifications or required functions of the semiconductor device 1. For example, when the resin mold layer 7 of FIGS. 2 and 3 has a corresponding insulating property, the resin mold layer 7 is enlarged to the region of the insulator 6 of FIGS. 6 can be omitted or abolished.

  FIGS. 5 and 6 show more specific second and third embodiments for carrying out the molding apparatus according to the present invention, and the same reference numerals are given to parts common to the first embodiment. is there.

  In FIG. 5, instead of the elastic bodies 15 and 16 such as compression coil springs in FIGS. 2 and 3, a liquid such as oil is put in the space 8 c and 9 c on the back side of the floating molds 8 b and 9 b in the upper and lower molds 8 and 9. A so-called fluid spring is enclosed.

  6, instead of the elastic bodies 15 and 16 such as the compression coil springs in FIGS. 2 and 3, cushion cylinders 25 and 26 filled with a liquid such as oil or a predetermined gas are used, and a so-called fluid is used similarly to the above. A spring is used.

  In these second and third embodiments, the same effects as those of the first embodiment can be obtained.

DESCRIPTION OF SYMBOLS 1 ... Semiconductor device 2 ... Semiconductor element 3a ... Solder layer 3b ... Solder layer 4 ... Upper electrode plate 4a ... Direct clamping part 5 ... Lower electrode plate 6 ... Insulator 7 ... Resin mold layer 8 ... Upper type 8a ... Type Main body 8b ... Floating mold 9 ... Lower mold 9a ... Mold main body 9b ... Floating mold 10 ... Mold 11 ... Mold mating surface 15 ... Elastic body 16 ... Elastic body R ... Mold chamber W ... Intermediate assembly

Claims (13)

An intermediate assembly in which electrode plates are arranged on both the front and back sides of the semiconductor element is arranged in a mold chamber formed with a mold clamping state between one mold and the other mold with the electrode plates as contact portions,
A molding apparatus in which a semiconductor device is manufactured by filling a resin material into a mold chamber using the intermediate assembly as an insert and molding the intermediate assembly.
While sandwiching a part of the one electrode plate directly between the mold matching surfaces of both molds,
A mold apparatus characterized by having a floating type structure capable of swinging a part of both the molds that is in contact with the electrode plate other than the direct clamping part that directly clamps a part of the electrode plate.   2. The molding apparatus according to claim 1, wherein a part of the two molds that is in contact with the electrode other than the direct clamping part is divided from the mold main body to be swingable. The one electrode plate is made of a softer material than both types, and a part of the electrode plate protrudes outside the mold chamber,
3. The molding apparatus according to claim 2, wherein the projecting portion is directly clamped by both types as a direct clamping portion.   The mold apparatus according to claim 3, wherein the floating mold is capable of being clamped by both molds and displaceable in a mold opening direction and tiltingly displaceable.   The mold apparatus according to claim 4, wherein the floating mold is supported on each mold body via an elastic body. A frame-like insulator around the semiconductor in the intermediate assembly;
6. The mold according to claim 5, wherein a part of both molds abuts against the insulator so that the clamping force of both molds is directly applied to the insulator. apparatus.   The molding apparatus according to claim 6, wherein the semiconductor and the electrode plates disposed on both front and back surfaces thereof are bonded in advance. An intermediate assembly in which electrode plates are arranged on both the front and back sides of the semiconductor element is arranged in a mold chamber formed with a mold clamping state between one mold and the other mold with the electrode plates as contact portions,
A molding method in which a semiconductor device is manufactured by filling a resin material into a mold chamber using the intermediate assembly as an insert and molding the intermediate assembly,
While sandwiching a part of the one electrode plate directly between the mold matching surfaces of both molds,
Of the above two types, the mold is performed in a state in which a portion that contacts the electrode plate other than the direct clamping portion that directly clamps a part of the electrode plate has a floating type structure that can swing. Mold method. The one electrode plate is made of a softer material than both types, and a part of the electrode plate protrudes outside the mold chamber,
9. The molding method according to claim 8, wherein the projecting portion is directly clamped by both molds as a direct clamping portion.   10. The molding method according to claim 9, wherein the floating mold is capable of being clamped by both molds and displaceable in the mold opening direction and tiltingly displaceable.   The mold method according to claim 10, wherein the floating mold is supported on each mold body via an elastic body. A frame-like insulator around the semiconductor in the intermediate assembly;
The mold method according to claim 11, wherein a part of both molds abuts against the insulator, and the clamping force of the both molds is directly applied to the insulator.   The molding method according to claim 12, wherein the semiconductor and the electrode plates disposed on both front and back surfaces are bonded in advance.

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