JP2012238740A - Semiconductor device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that, in a transfer mold method using a molding die as a method of encapsulating a semiconductor device, a sufficient amount of resin material including not just a resin amount equivalent to the cubic volume of cavities but also a resin amount to be filled in runners needs to be prepared, and that, since the resin body formed in the runners is ultimately cut off from the finished product, some of the resin materials used is wasted.SOLUTION: In a semiconductor device manufacturing method, a planar substrate having a number of unit device regions is accommodated between an upper and a lower mold so that the unit device regions respectively will correspond to a number of mold cavities formed between the two molds, in which way the unit device regions each are encapsulated with resin. In such a semiconductor device manufacturing method, the invention applied herein aims to carry out resin encapsulation by supplying a resin tablet to portions corresponding to the respective mold cavities to reduce the thickness of at least part of the mold cavities including a pot portion.

Description

  The present invention relates to a technique effective when applied to a resin sealing technique in a method of manufacturing a semiconductor device (or a semiconductor integrated circuit device).

  In Japanese Patent Laid-Open No. 10-258441 (Patent Document 1), in a transfer mold such as a semiconductor element using a thermosetting resin, a resin tablet installation portion is provided in the vicinity of each cavity, and each cavity is provided. In addition, a technique is disclosed in which a molten sealing resin is transferred into a cavity by a plunger.

  Japanese Unexamined Patent Publication No. 2003-133352 (Patent Document 2) discloses a compression molding technique in a MAP (Mold Array Package) system using an integrated resin tablet and a wiring board on which a large number of device regions are formed. .

JP-A-10-258441 JP 2003-133352 A

  In a sealing process of a resin-sealed semiconductor device in which a semiconductor chip is sealed with a resin, a molding die is generally used. As a resin sealing method using a molding die, for example, a resin material (tablet) is supplied to a pot portion serving as a resin supply source, and a plurality of cavity portions (semiconductor chips) provided at positions away from the pot portion There is a transfer mold method in which resin is supplied to a portion through which a resin is supplied via a runner portion (a passage connecting the pot portion and the cavity portion).

  However, in the case of the transfer mold method, it is necessary to prepare a resin material that provides not only the amount of resin corresponding to the volume of the cavity portion but also the amount of resin filled in the runner portion. In addition, since the resin body (sealing body) formed in the runner part is finally cut off from the finished product (molded product, semiconductor device), the resin material to be used is wasted.

  Further, in the case of the above-described method, since resin is usually supplied to a large number of cavity portions via the runner portion, there is a problem that it is difficult to make the injection conditions uniform in each cavity portion.

  Accordingly, one object of the present invention is to provide a sealing technique (that is, a semiconductor device manufacturing process) capable of saving resources (reducing the amount of resin used).

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  The following is a brief description of an outline of typical inventions disclosed in the present application.

  That is, in one invention of the present application, a planar substrate having a large number of unit device regions is formed on both sides so that each unit device region corresponds to a large number of mold cavities formed between the upper mold and the lower mold. In a manufacturing method of a semiconductor device that is housed between molds and encapsulates each unit device region with resin, a resin tablet is supplied to a portion corresponding to each mold cavity, and at least each mold cavity including a pot portion Resin sealing is performed by reducing a part of the thickness.

  The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.

  That is, a planar substrate having a large number of unit device areas is accommodated between both molds so that each unit device area corresponds to a large number of mold cavities formed between the upper mold and the lower mold. In the manufacturing method of a semiconductor device in which each unit device region is sealed with resin, a resin tablet is supplied to a portion corresponding to each mold cavity to reduce the thickness of at least a part of each mold cavity including the pot portion. By performing the resin sealing, the use efficiency of the sealing resin can be improved.

1 is a schematic plan view of a chip mounting surface of a lead frame for explaining an outline of a planar structure of a lead frame after resin sealing in a manufacturing method of a semiconductor device according to an embodiment of the present application; FIG. 2 is a plan view of a chip mounting surface of a lead frame before resin sealing in a lead frame partial cutout region R1 of FIG. FIG. 3 is an enlarged plan view of a unit device region 5 in FIG. 2. It is a schematic cross section of the X-X 'cross section of FIG. FIG. 2 is a plan view of a chip mounting surface of a lead frame after resin sealing in a lead frame partial cutout region R1 of FIG. It is a schematic cross section of the A-A 'cross section of FIG. FIG. 6 is an enlarged schematic plan view of a chip mounting surface of a lead frame in a unit device region 5 of FIG. 5. It is a schematic cross section of the B-B 'cross section of FIG. FIG. 9 is a perspective view of a completed package corresponding to FIGS. 7 and 8. It is a whole model top view of the mold apparatus used for the resin mold process in the manufacturing method of the semiconductor device of the said one embodiment of this application. It is a schematic top view of the part corresponding to the unit device area | region 5 of the lower mold of the molding apparatus of FIG. It is a perspective view of the resin tablet which shows the relationship between the pot part which comprises some mold cavity parts of a lower metal mold | die, and a resin tablet in FIG. Mold mold corresponding to unit device region 5 for explaining the position of the resin tablet in the mold cavity at the time of mold clamping (resin mold process) in the method of manufacturing a semiconductor device according to the embodiment of the present application It is a schematic cross section of a metal mold | die and a lower metal mold | die. Mold die corresponding to the unit device region 5 for explaining the cross-sectional shape of the mold cavity at the time when the plunger is most elevated (resin mold process) in the die clamp in the method of manufacturing a semiconductor device according to the embodiment of the present application. It is a schematic cross section of an upper mold and a lower mold). It is a mold process time chart for demonstrating the whole flow of the mold process (basic process regarding a single-sided package) in the manufacturing method of the semiconductor device of the said one embodiment of this application. Corresponding to the BB ′ cross section of FIG. 7 corresponding to two unit device regions for explaining the entire flow of the molding process (basic process relating to single-sided package) in the semiconductor device manufacturing method of the embodiment of the present application. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of a resin tablet set). Corresponding to the BB ′ cross section of FIG. 7 corresponding to two unit device regions for explaining the entire flow of the molding process (basic process relating to single-sided package) in the semiconductor device manufacturing method of the embodiment of the present application. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of a lead frame setting) to perform. Corresponding to the BB ′ cross section of FIG. 7 corresponding to two unit device regions for explaining the entire flow of the molding process (basic process relating to single-sided package) in the semiconductor device manufacturing method of the embodiment of the present application. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of metal mold clamping). Corresponding to the BB ′ cross section of FIG. 7 corresponding to two unit device regions for explaining the entire flow of the molding process (basic process relating to single-sided package) in the semiconductor device manufacturing method of the embodiment of the present application. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of the plunger pushing-up start for resin transfer in a mold cavity) to perform. Corresponding to the BB ′ cross section of FIG. 7 corresponding to two unit device regions for explaining the entire flow of the molding process (basic process relating to single-sided package) in the semiconductor device manufacturing method of the embodiment of the present application. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of completion of resin transfer). Corresponding to the BB ′ cross section of FIG. 7 corresponding to two unit device regions for explaining the entire flow of the molding process (basic process relating to single-sided package) in the semiconductor device manufacturing method of the embodiment of the present application. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of mold opening) to perform. Corresponding to the BB ′ cross section of FIG. 7 corresponding to two unit device regions for explaining the entire flow of the molding process (basic process relating to single-sided package) in the semiconductor device manufacturing method of the embodiment of the present application. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of eject operation | movement) to perform. Mold process for explaining the entire flow of the mold process (lead frame preceding process for single-sided package) relating to a modification of the molding process (lead frame preceding process for single-sided package) in the method of manufacturing a semiconductor device according to the one embodiment of the present application It is a time chart. BB ′ cross section of FIG. 7 corresponding to two unit device regions for explaining the entire flow of the molding process (lead frame preceding process relating to single-sided package) in the semiconductor device manufacturing method according to the embodiment of the present application. FIG. 16 is a schematic cross-sectional view of a mold (corresponding to FIG. 16 as an order and corresponding to FIG. 17 as a processing content) in each molding process step (at the time of setting a lead frame). BB ′ cross section of FIG. 7 corresponding to two unit device regions for explaining the entire flow of the molding process (lead frame preceding process relating to single-sided package) in the semiconductor device manufacturing method according to the embodiment of the present application. FIG. 18 is a schematic sectional view of a mold (corresponding to FIG. 17 as an order and corresponding to FIG. 16 as a processing content) in each mold process step (when a resin tablet is set). FIG. 6 is an enlarged schematic plan view of a chip mounting surface of a lead frame corresponding to a unit device region 5 in FIG. 5 regarding a modification (double-sided package) of a target device in the method for manufacturing a semiconductor device according to the embodiment of the present application. It is a schematic cross section of the C-C 'cross section of FIG. It is an expansion schematic plan view of the back surface of FIG. FIG. 29 is a perspective view of a completed package corresponding to FIGS. 26 to 28. Unit device for explaining the position of the resin tablet in the mold cavity at the time of mold clamping (resin molding process) related to the modified example (double-sided package) of the target device in the method of manufacturing a semiconductor device according to the embodiment of the present application 6 is a schematic cross-sectional view of a mold (upper mold and lower mold) corresponding to a region 5. FIG. Unit for explaining the cross-sectional shape of the mold cavity at the time when the plunger is most elevated (resin mold process) in the mold clamp in relation to the modified example (double-sided package) of the target device in the method of manufacturing a semiconductor device according to the one embodiment of the present application 3 is a schematic cross-sectional view of a mold (upper mold and lower mold) corresponding to a device region 5. FIG. FIG. 7 corresponding to two unit device regions for explaining the entire flow of the molding process (double-sided package process) related to the modified example (double-sided package) of the target device in the method of manufacturing a semiconductor device according to the one embodiment of the present application. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of resin tablet setting) corresponding to a BB 'cross section. FIG. 7 corresponding to two unit device regions for explaining the entire flow of the molding process (double-sided package process) related to the modified example (double-sided package) of the target device in the method of manufacturing a semiconductor device according to the one embodiment of the present application. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of a lead frame setting) corresponding to a BB 'cross section. FIG. 7 corresponding to two unit device regions for explaining the entire flow of the molding process (double-sided package process) related to the modified example (double-sided package) of the target device in the method of manufacturing a semiconductor device according to the one embodiment of the present application. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of metal mold clamping) corresponding to a BB 'cross section. FIG. 7 corresponding to two unit device regions for explaining the entire flow of the molding process (double-sided package process) related to the modified example (double-sided package) of the target device in the method of manufacturing a semiconductor device according to the one embodiment of the present application. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of the plunger pushing-up start for resin transfer in a mold cavity) corresponding to a BB 'cross section. FIG. 7 corresponding to two unit device regions for explaining the entire flow of the molding process (double-sided package process) related to the modified example (double-sided package) of the target device in the method of manufacturing a semiconductor device according to the one embodiment of the present application. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of the resin transfer completion) corresponding to a BB 'cross section. FIG. 7 corresponding to two unit device regions for explaining the entire flow of the molding process (double-sided package process) related to the modified example (double-sided package) of the target device in the method of manufacturing a semiconductor device according to the one embodiment of the present application. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of mold opening) corresponding to a BB 'cross section. FIG. 7 corresponding to two unit device regions for explaining the entire flow of the molding process (double-sided package process) related to the modified example (double-sided package) of the target device in the method of manufacturing a semiconductor device according to the one embodiment of the present application. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of eject operation | movement) corresponding to a BB 'cross section.

[Outline of Embodiment]
First, an outline of a typical embodiment of the invention disclosed in the present application will be described.

1. A semiconductor device manufacturing method including the following steps:
(A) a step of setting a resin tablet in each of a plurality of mold cavities of the heated lower mold in a state where the lower mold and the upper mold are opened;
(B) The lower mold in an open state in which a planar substrate on which a semiconductor chip is mounted in each of a large number of unit device regions is opened so that each unit device region corresponds to a position of each of the large number of mold cavities. And setting between the upper molds;
(C) after the steps (a) and (b), closing and clamping the lower mold and the upper mold;
(D) After the step (c), in a state where the lower mold and the upper mold are clamped, at least each mold cavity formed between the lower mold and the upper mold By reducing a part of the thickness, each mold cavity is filled with a sealing resin in which the resin tablet is melted, and a resin sealing body for sealing the semiconductor chip in each of the multiple unit device regions is formed. The step of:
(E) A step of opening the lower mold and the upper mold after the step (d).

  2. In the method of manufacturing a semiconductor device according to the item 1, the lower mold includes the multiple mold cavities and pot portions directly connected to the main portions of the multiple mold cavities. The small width is larger than the diameter of the pot portion which is a part of the small width.

  3. In the method for manufacturing a semiconductor device according to the item 2, the horizontal sectional shape of the resin tablet is substantially circular, and the diameter thereof is smaller than the diameter of the pot portion.

  4). 4. In the method of manufacturing a semiconductor device according to any one of items 1 to 3, the thickness reduction of each mold cavity is caused by the pot portion provided in each of the plurality of mold cavity portions of the lower mold. And is performed by pushing up the plunger.

  5). In the method for manufacturing a semiconductor device according to the item 4, the plunger is pushed up such that the upper end of the plunger exceeds the bottom surface of the mold cavity around the pot.

  6). 6. In the method of manufacturing a semiconductor device as described above in any one of 1 to 5, in the step (d), the planar shape of each mold cavity is substantially rectangular, and outside each of the four corner portions, A connected flow cavity is formed.

  7). 7. In the method of manufacturing a semiconductor device according to any one of 1 to 6, in the step (b), the planar substrate is set with a surface on which the semiconductor chip is mounted facing down.

  8). 8. In the method for manufacturing a semiconductor device according to any one of 1 to 7, the step (b) is performed before the step (a).

  9. 9. In the method of manufacturing a semiconductor device according to any one of 1 to 8, the resin sealing body is not substantially formed on a surface side of the planar base where the semiconductor chip is not mounted.

  10. 10. The method for manufacturing a semiconductor device according to any one of items 1 to 9, wherein the planar substrate is a lead frame.

11. The method for manufacturing a semiconductor device according to any one of 1 to 10 further includes the following steps:
(F) After the step (e), the step of releasing the planar substrate on the lower side without using a release film.

  12 12. In the method of manufacturing a semiconductor device according to any one of 1 to 6 and 8 to 11, in the step (b), the planar substrate is set with a surface on which the semiconductor chip is mounted facing upward. Is done.

  13. In the method for manufacturing a semiconductor device according to any one of 1 to 7 and 9 to 12, the step (b) is performed after the step (a).

  14 In the method for manufacturing a semiconductor device according to any one of 1 to 8 and 10 to 13, the resin sealing body is also formed on a surface side of the planar base where the semiconductor chip is not mounted.

15. 15. The method for manufacturing a semiconductor device according to 1 to 10 and 12 to 14, further includes the following steps:
(F) A step of releasing the planar substrate after the step (e) without using a release film.

  16. 16. The method for manufacturing a semiconductor device according to the item 15, wherein the planar substrate is a lead frame.

[Description format, basic terms, usage in this application]
1. In the present application, the description of the embodiment will be divided into a plurality of sections for convenience, if necessary, but these are not independent from each other unless otherwise specified. Regardless of the front and rear, each part of a single example, one is a part of the other, or a part or all of the modifications. Moreover, as a general rule, the same part is not repeated. In addition, each component in the embodiment is not indispensable unless specifically stated otherwise, unless it is theoretically limited to the number, and obviously not in context.

  2. Similarly, in the description of the embodiment, etc., regarding the material, composition, etc., “X consisting of A” etc. is an element other than A unless specifically stated otherwise and clearly not in context. It is not excluded that one of the main components. For example, as for the component, it means “X containing A as a main component”. For example, the term “silicon member” is not limited to pure silicon, but also includes SiGe alloys, other multi-component alloys containing silicon as a main component, and other members containing other additives. Needless to say. In addition, the term “gold-plated”, “copper layer”, “nickel-plated”, etc. includes not only pure materials, but also members mainly composed of gold, copper, nickel, etc. unless otherwise specified. Shall be.

  3. Similarly, suitable examples of graphics, positions, attributes, and the like are given, but it is needless to say that the present invention is not strictly limited to those cases unless explicitly stated otherwise, and unless otherwise apparent from the context. For example, the term “rectangular” or “substantially rectangular” includes not only exact squares or rectangles but also those similar to them. For example, a deformed square with four corners chamfered or rounded is a rectangle. Taking a square as an example, when the area of a portion excluded from the ideal square is generally less than 15% of the area of the ideal square due to chamfering or the like, the deformed square is a rectangle.

  4). In addition, when a specific number or quantity is mentioned, a numerical value exceeding that specific number will be used unless specifically stated otherwise, unless theoretically limited to that number, or unless otherwise clearly indicated by the context. There may be a numerical value less than the specific numerical value.

  5). “Wafer” usually refers to a single crystal silicon wafer on which a semiconductor device (same as a semiconductor integrated circuit device and an electronic device) is formed, but is an SOI wafer, an epitaxial wafer, a composite of an insulating substrate and a semiconductor layer, etc. Needless to say, wafers are also included.

  6). The term “semiconductor chip” generally refers to a die or the like on which a semiconductor device or a semiconductor integrated circuit is formed after a wafer dividing process (blade dicing, laser dicing or other pelletizing process). Here, a silicon-based chip will be mainly described as an example, but a GaAs-based or other device chip may be used.

  7). The sealing method mainly handled in the present application (referred to as “individual compression molding method”) uses a pot part directly connected to the mold cavity, or a mold mold having a pot part integrated with the mold cavity. Seeing the resin tablet (sealing resin material) as a process of transferring the resin in a fluid state to the main part of the mold cavity, that is, the main part (mold cavity part after reduction), and filling the reduced mold cavity with molten resin Can do. Therefore, although it may be possible to be a kind of transfer mold method, it is different from a typical transfer mold method because it is not transferred from the outside via a gate or a runner. On the other hand, although it is formally similar to a compression molding method (referred to as a “batch compression molding method”) applied in a batch molding method such as a MAP (Mold Array Package) method, the batch compression molding method ( In general, simply called “compression molding method” is a method in which a large number of unit device regions are sealed together, whereas the individual compression molding method is used for each unit device region. It is different in that it is sealed.

  In the present application, lead frames, wiring boards (including ceramic wiring boards, rigid wiring boards such as organic wiring boards, flexible wiring boards such as polyimide wiring boards, etc.), and other flat wiring substrates are referred to as “ Although referred to as a “planar substrate”, even if “planar” is used, there are some unevenness and height differences to adjust the interrelation between leads, die pad support bars (so-called tab-suspended leads), die pads, frames, etc. Is considered a plane.

  Moreover, when saying "horizontal cross section" etc. about a resin tablet etc., the horizontal cross section in the state set to the pot part shall be pointed out.

  Further, in the present application, the term “release film” refers to a film that is laid so as to cover a region where a cavity portion of a mold having a large number of cavity portions is formed at the time of molding. And so-called "lead frame tape" etc. that mainly refers to the purpose of promoting mold release, pasted on one side of the lead frame etc. in advance and advances many assembly processes as a unit Not included in this.

  8). In the present application, the “single-sided package” is basically only on one side of a planar substrate such as a lead frame (a resin sealing body is formed in the central portion corresponding to the thickness of the lead frame or the like). Or a package form in which a resin sealing body is formed. On the other hand, the “double-sided package” is a package form in which a resin sealing body is formed basically on both sides of a planar substrate such as a lead frame. Here, a typical example of the single-sided package is a QFN (Quad Flat Non-Leaded Package), and a typical example of the double-sided package is a QFP (Quad Flat Package).

  Note that the case where the planar substrate is an organic wiring substrate is particularly referred to as a “substrate-type package” in comparison with a “lead-frame type package” using a lead frame. Here, typical examples of the lead frame type package are QFN, QFP and the like, and typical examples of the substrate type package are BGA (Ball Grid Array) and the like.

[Details of the embodiment]
The embodiment will be further described in detail. In the drawings, the same or similar parts are denoted by the same or similar symbols or reference numerals, and description thereof will not be repeated in principle.

  In the accompanying drawings, hatching or the like may be omitted even in a cross section when it becomes complicated or when the distinction from the gap is clear. In relation to this, when it is clear from the description etc., the contour line of the background may be omitted even if the hole is planarly closed. Furthermore, even if it is not a cross section, it may be hatched to clearly indicate that it is not a void.

  In the following embodiments, various dimensions and the like are illustrated, but these numerical values are shown for more specific explanation and limit the scope of application of the invention and the embodiments. Not what you want.

1. Description of an example of a target device (single-sided package) in the method of manufacturing a semiconductor device according to an embodiment of the present application, and outlines of related main manufacturing processes (mainly FIGS. 1 to 9)
In this section, as an example of a single-sided package, that is, a package type in which a resin sealing body is basically formed only on one side of a planar substrate such as a lead frame (including the maximum thickness portion of the planar substrate itself). , QFN (Quad Flat Non-Leaded Package) will be described in detail. However, the following examples are not limited thereto, and can be applied to QFP (Quad Flat Package), BGA (Ball Grid Array), and the like. Needless to say.

  FIG. 1 is a schematic plan view of a chip mounting surface of a lead frame for explaining an outline of a planar structure of the lead frame after resin sealing in the method of manufacturing a semiconductor device according to an embodiment of the present application. FIG. 2 is a plan view of the chip mounting surface of the lead frame before resin sealing in the lead frame partial cutout region R1 of FIG. FIG. 3 is an enlarged plan view of the unit device region 5 of FIG. FIG. 4 is a schematic cross-sectional view taken along the line X-X ′ of FIG. 3. FIG. 5 is a plan view of the chip mounting surface of the lead frame after resin sealing in the lead frame partial cutout region R1 of FIG. FIG. 6 is a schematic cross-sectional view taken along the line A-A ′ of FIG. 5. FIG. 7 is an enlarged schematic plan view of the chip mounting surface of the lead frame in the unit device region 5 of FIG. FIG. 8 is a schematic cross-sectional view of the B-B ′ cross section of FIG. 7. FIG. 9 is a perspective view of the completed package corresponding to FIGS. Based on these, an example of the target device (single-sided package) in the method of manufacturing a semiconductor device according to the embodiment of the present application, an outline of a related main manufacturing process, and the like will be described.

  First, a lead frame 1 (planar substrate) used for assembly is shown in FIG. What is shown in FIG. 1 is an arrangement state of the resin sealing body 3 (device package) on the lead frame 1 when the resin sealing is completed. As shown in FIG. 1, usually, a single lead frame 1 (for example, copper as a main component and a patterned copper-based metal thin film having a thickness of, for example, about 0.125 mm) in a matrix form. A large number (for example, about several tens) of resin sealing bodies 3 are arranged. Although the outer surface of each resin sealing body 3 has concave and convex portions such as a concave portion 14 by a plunger and a concave portion 15 by an ejector pin and a chamfered portion of a corner portion, the planar outer shape is square or relatively close to a square. A rectangle such as a rectangle. Note that the three-dimensional figure has a structure similar to a flat rectangular parallelepiped.

  Next, FIG. 2 shows a top view of the lead frame partial cutout region R1 in FIG. 1 before resin sealing (a view seen from the chip mounting surface 1a side of the lead frame 1). As shown in FIG. 2, this portion corresponds to six unit device regions 5. Each unit device region 5 is held by a lead frame frame portion 6, and at least one semiconductor chip 2 (for example, approximately square 2... Is provided on the chip mounting surface 1 a (front surface) of each unit device region 5. 5 mm square and chip thickness (for example, about 60 micrometers) are mounted. A laminated chip may also be used.

  Next, an enlarged plan view of one unit device region 5 is shown in FIG. As shown in FIG. 3, the semiconductor chip 2 is fixedly mounted on the central die pad 8, and, for example, gold is interposed between a large number of bonding pads 12 and a large number of leads 4 on the device surface 2 a of the semiconductor chip 2. A bonding wire 11 such as a wire (for example, a diameter of about 20 micrometers) is connected. The peripheral portions of these multiple leads 4 are held by the lead frame frame portion 6. The die pad 8 is held by the peripheral lead frame frame portion 6 by, for example, a die pad support bar 9 (tab suspension lead) having four corners.

  Next, FIG. 4 shows an X-X ′ cross section of FIG. 3. As shown in FIG. 4, the semiconductor chip 2 has its device surface 2a facing upward on the die pad 8 which contacts the chip mounting surface 1a side of the lead frame 1 (the back surface opposite to the device surface 2a is the chip mounting surface 1a). The bonding pads 12 provided on the device surface 2 a and the leads 4 are interconnected by bonding wires 11. A part of the back side of the lead 4 (the back side 1b side of the lead frame 1) has a protruding shape and constitutes a terminal portion 10. Note that the front end surface of the terminal portion 10 and the back surface of the die pad 8 (the back surface 1b of the lead frame 1) have substantially the same height. In QFN, in order to prevent flash burrs, the assembly process is often performed with a lead frame tape (different from the release film) stretched on the back surface 1b of the lead frame 1. In order to avoid this, illustration and description are omitted.

  Next, FIG. 5 shows a plan view seen from the chip mounting surface 1a side at the time of resin sealing completion corresponding to FIG. 2 (when taken out from between the upper and lower molds). As shown in FIG. 5, the surface 3 a of the resin sealing body 3 has the concave portion 14 by the plunger and the concave portion 15 by the ejector pin as described above, and outside the four corners of the resin sealing body 3, There is a resin piece 16 corresponding to the flow cavity.

  Next, FIG. 6 shows a cross section A-A ′ of FIG. 5. As shown in FIG. 6, adjacent resin sealing bodies 3 are separated from each other, and the resin sealing body 3 includes the device surface 2a of the semiconductor chip 2, the bonding wires 11, and the chip mounting surface 1a of the lead frame. It is formed so as to cover the side (including the thickness portion of the lead frame). Moreover, as described above, the concave portion 14 by the plunger is formed on the surface 3 a of the resin sealing body 3. On the back surface 1b side of the lead frame 1, the back surface 3b of the resin sealing body 3, the back surface of the die pad 8, the terminal portion 10, and the back surface of the lead frame frame portion 6 are exposed so as to form the same plane. Yes.

  Next, FIG. 7 shows an enlarged plan view of the unit device region 5 of FIG. 5 as viewed from the surface 3a side of the resin sealing body 3. As shown in FIG. 7, in this example, when viewed in a plan view, the die pad 8 is inside the concave portion 14 formed by the plunger, and the semiconductor chip 2 is inside the die pad 8.

  Next, FIG. 8 shows a B-B ′ cross section of FIG. 7. As shown in FIG. 8, in this cross section, the lead frame 1 is divided into a lead frame frame portion 6, a die pad 8 on which the semiconductor chip 2 is mounted, and a die pad support bar 9 that connects the die pad 8 to the lead frame frame portion 6. Yes. On the chip mounting surface 1a (front surface) of the lead frame 1, a resin sealing body 3 is formed so as to seal the semiconductor chip 2, and each corner portion of the resin sealing body 3 has a flow cavity. Corresponding resin pieces 16 are formed. Further, a concave portion 14 by a plunger is formed on the surface 3 a of the resin sealing body 3.

  Next, FIG. 9 shows a perspective view of the device package 3 when the device is completed. As shown in FIG. 9, the side end portion of the lead 4 is exposed from the side surface 3 s of the device package 3, and the concave portion 14 by the plunger and the concave portion 15 by the ejector pin are visible on the surface 3 a of the device package 3. Here, the thickness of the package is, for example, about 0.5 millimeters.

  The transition process from the state of FIGS. 5 to 8 to the state of FIG. 9 is usually performed by a separation process by package dicing using a rotating blade or the like, or a cutting process by a cutting die. In the QFP as described in sections 6 to 8, a cutting process using a cutting die is common.

2. Description of an example of a molding apparatus used for a resin molding process in the method of manufacturing a semiconductor device according to the embodiment of the present application (mainly FIG. 10)
In this section, a resin mold integrated apparatus is illustrated as an example of an apparatus for resin molding of the device described in section 1.

  FIG. 10 is an overall schematic top view of a molding apparatus used for a resin molding process in the method of manufacturing a semiconductor device according to the embodiment of the present application. Based on this, an example of a molding apparatus used for the resin molding process in the method of manufacturing a semiconductor device according to the embodiment of the present application will be described.

  FIG. 10 shows a schematic top view of an example of a molding apparatus 51 used in the resin molding process in the method of manufacturing a semiconductor device according to the embodiment of the present application. As shown in FIG. 10, the lead frame 1 in the state of FIG. 2 introduced into the molding apparatus 51 is first accommodated in the lead frame loader 52, and then transferred to the lead frame alignment unit 53 where it is aligned. . Thereafter, the lead frame is transported from the lead frame transport section 54 to one of a plurality of (for example, four) prepared press sections 55 by the lead frame transport mechanism 60, and between the upper mold 61 and the lower mold 62. Set.

  Before and after this, the plurality of resin tablets 7 aligned in the resin tablet alignment unit 56 are conveyed to the previous press unit 55 by the resin tablet conveyance unit 57 and set there.

  Thereafter, sealing is performed, and when this is completed, a large number of resin sealing bodies 3 are formed from between the upper mold 61 and the lower mold 62 to the lead frame take-out portion 58 by the lead frame transport mechanism 60. The lead frame 1 is taken out and then transferred to the lead frame unloader 59. Finally, the lead frame 1 is discharged to the outside of the molding apparatus 51.

3. Description of main processes in the method of manufacturing a semiconductor device according to the embodiment of the present application (mainly FIGS. 11 to 14)
The resin mold process, which is a main process in the method of manufacturing a semiconductor device according to the embodiment, is a pot in which a source of sealing resin is formed as a part of a mold cavity or connected integrally therewith. The entire mold cavity is filled with a sealing resin by reducing the thickness of a part of the mold cavity. In this section, the shape of the resin tablet, which is an example of the source of the sealing resin to be introduced, the shape of the mold, the important operating state of the mold, and the like will be described.

  FIG. 11 is a schematic top view of a portion corresponding to the unit device region 5 of the lower mold of the molding apparatus of FIG. FIG. 12 is a perspective view of the resin tablet showing the relationship between the pot portion constituting the part of the mold cavity portion of the lower mold in FIG. 11 and the resin tablet. FIG. 13 is a mold corresponding to the unit device region 5 for explaining the position of the resin tablet in the mold cavity during mold clamping (resin mold process) in the method of manufacturing a semiconductor device according to the embodiment of the present application. It is a schematic cross section of a mold (upper mold and lower mold). FIG. 14 shows a mold corresponding to the unit device region 5 for explaining the cross-sectional shape of the mold cavity when the plunger is most elevated (resin mold process) in the mold clamp in the method of manufacturing a semiconductor device according to the embodiment of the present application. It is a schematic cross section of a metal mold | die (upper metal mold | die and lower metal mold | die). Based on these, the main process in the manufacturing method of the semiconductor device of the one embodiment of the present application will be described.

  When the resin sealing body 3 as shown in FIG. 5 is formed on the lead frame 1, a mold is used in the press portion 55 shown in FIG. 10. The lower mold constituting the mold A top view of 62 is shown in FIG. 11 (a portion corresponding to the unit device region 5 in FIG. 5) (this figure has a relationship between FIG. 7 and the mold and the molded product thereby). As shown in FIG. 11, an ejector pin 72 is provided in the mold cavity portion 63 of the lower mold 62, and the central portion of the mold cavity portion 63 is a pot portion 69 (the planar shape is, for example, a circle). It has become. The outside of the pot portion 69 is a peripheral bottom surface 63p, and the inside portion is a pot cylinder 64 (a planar shape is, for example, a cylindrical shape). The pot portion 69 accommodates, for example, a cylindrical resin tablet 7 (the height is, for example, about 3 millimeters, and the range is, for example, about 2 to 9 millimeters). A flow cavity 66 is connected to each corner portion of the mold cavity portion 63 of the lower mold 62 through a flow gate 67. The flow cavity 66 is a part that receives excess sealing resin together with voids and the like, and a vent 74 is provided at the end thereof. Note that the flow cavity 66 is not essential, and a vent may be provided at each corner instead. That is, the cavity shape (the shape of the resin sealing body is the same as shown in FIG. 9) is rectangular (square or rectangular) in plan view or almost rectangular (including the case where the corner is chamfered is also included in the rectangle). In addition, void absorption mechanisms such as flow cavities and vents can be provided at all corners, so that the filling characteristics of the package can be improved (in addition, semiconductor chips, die pads, etc. are generally rectangular or almost rectangular in the same orientation) Is). In other words, unlike the side gate type transfer mold, this mold has one of the structural features that there is no gate (resin injection gate) at the corner. Also, unlike the top gate type transfer mold, one of the structural features is that there is no top gate (resin injection gate) at the center of the upper mold or the like.

  Here, as shown in FIGS. 11 and 12, in this example, the diameter W1 of the resin tablet 7 is smaller than the inner diameter W4 (for example, about 6 millimeters) of the pot portion 69, and the inner diameter W4 of the pot portion 69. Is smaller than the minimum width W3 (for example, about 10 millimeters) of the mold cavity 63 of the lower mold 62. The side length W5 (long side length) of the die pad 8 is smaller than the diameter W1 (for example, about 7 millimeters) of the resin tablet 7, and the side length W2 (long side) of the semiconductor chip 2 is set. (For example, about 2.5 millimeters) is smaller than the side length W5 of the die pad 8 (the length of the long side, for example, about 3.5 millimeters) (like a so-called small tab than the chip). Alternatively, a method using a die pad with a small area may be used). Note that making the inner diameter of the resin tablet 7 smaller than the inner diameter W4 of the pot portion 69 is effective in increasing the certainty of setting the resin tablet. Further, the diameter W1 of the resin tablet 7 can be equal to or smaller than the side length W2 of the semiconductor chip 2 and the side length W5 of the die pad 8. Making the diameter W1 of the resin tablet 7 larger than the side length W2 of the semiconductor chip 2 and the side length W5 of the die pad 8 has an advantage of reducing the flow rate and flow path length of the molten resin during filling.

  The shape of the resin tablet 7 (sealing resin material) may be basically any shape. That is, it may be a rectangular parallelepiped, a sphere, a cylinder, a prism, or a tablet, but it may be liquid, powder, or shot. However, considering the main manufacturing method of the resin tablet, it is desirable to have an integral three-dimensional structure having a cylindrical or circular horizontal cross section like a tablet. On the other hand, the size of the resin tablet having a size and a shape substantially matching the rectangular shape of the large cavity is reduced so as to match the individual compression molding method, as in the batch compression molding method, and the individual compression molding method It is also possible to apply to. However, this method can be expected to have a merit in sealing properties and the like, but there is a risk that there may be a demerit in producing a resin tablet.

  Next, the mold when the resin tablet 7 is set in the pot portion 69 in FIG. 13 and the upper mold 61 and the lower mold 62 are closed and clamped (corresponding to the broken upper mold 61 being closed). A cross section (lead frame 1 etc. are omitted) is shown schematically. As shown in FIG. 13, a mold cavity 68 corresponding to the mold cavity portion 63 of the lower mold 62 is formed between the lower surface 61 b of the upper mold 61 and the upper surface 62 a of the lower mold 62. At this time, since the plunger 65 is lowered, the thickness T1 of the mold cavity 68 at a portion where the pot portion 69 which is a part of the mold cavity 68 is present (portion overlapping the pot portion 69 in plan view). The (initial mold cavity thickness) is the thickest compared to the other parts.

  Next, FIG. 14 schematically shows a cross section of the mold when the resin filling is completed (the lead frame 1 and the like are omitted). As shown in FIG. 14, since the plunger 65 is raised at this point, the plunger upper end 65t is, for example, the peripheral bottom surface 63p of the mold cavity 63 of the lower mold 62 (in this example, the pot 65 It is slightly above the upper end of the cylinder 64). Therefore, the thickness T2 (mold cavity thickness when resin filling is completed) of the mold cavity 68 in this portion (the portion overlapping the pot portion 69 in plan view) is thinner than the thickness of the other main portion of the mold cavity 68. It has become. Of course, the mold cavity thickness T2 when the resin filling is completed is thinner than the initial mold cavity thickness T1.

  The amount of overdrive of the plunger 65 (the difference in height between the plunger upper end portion 65t and the upper end portion of the pot cylinder 64 at the time of maximum rise during filling, that is, the depth of the concave portion 14 in FIG. About 05 millimeters can be exemplified as a suitable one. In addition, as a suitable range, about 0.01 to 0.1 millimeters can be illustrated, for example. This is because if it is too shallow, there will be a problem in the package shape if the portion that should be a recess (allowable as a package shape until complete flatness) becomes a protrusion due to various errors. On the other hand, if the depth of the concave portion 14 becomes too deep, there is a problem such as exposure of the bonding wire (in the case of QFP, exposure of a die pad that should not be exposed originally).

4). Description of the overall flow of the molding process (basic process relating to single-sided packaging) in the method of manufacturing a semiconductor device according to the embodiment of the present application (mainly FIGS. 15 to 22)
In this section, the entire flow from the preparation of the lead frame 1 to the acquisition of the semiconductor device by dividing the lead frame 1 into pieces, the molding process described in sections 1 to 3 together with the operation of the mold, etc. A description will be given in order according to the flow.

  First, a lead frame 1 having a plurality of unit device regions 5 shown in FIG. 2 is prepared.

  Next, the semiconductor chip 2 is mounted on the die pad 8 provided in each unit device region 5 of the lead frame 1.

  Next, a plurality of bonding pads (electrode pads) formed on the device surface 2 a of the semiconductor chip 2 and a plurality of leads 4 provided around the die pad 8 are electrically connected via a plurality of bonding wires 11, respectively. Connecting.

  Next, the lead frame 1 on which a plurality of semiconductor chips 2 are mounted is set in a mold, and molding (sealing process) is performed.

  Here, FIG. 15 is a mold process time chart for explaining the entire flow of the mold process (basic process relating to the single-sided package) in the method of manufacturing a semiconductor device according to the one embodiment of the present application. 16 corresponds to two unit device regions for explaining the entire flow of the molding process (basic process relating to single-sided packaging) in the method of manufacturing a semiconductor device according to the embodiment of the present invention. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of resin tablet setting) corresponding to a cross section. 17 corresponds to two unit device regions for explaining the entire flow of the molding process (basic process relating to single-sided package) in the method of manufacturing a semiconductor device according to the embodiment of the present invention. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of a lead frame setting) corresponding to a cross section. 18 corresponds to two unit device regions for explaining the entire flow of the molding process (basic process relating to the single-sided package) in the method of manufacturing a semiconductor device according to the embodiment of the present invention. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of metal mold clamping) corresponding to a cross section. 19 corresponds to two unit device regions for explaining the overall flow of the molding process (basic process relating to single-sided packaging) in the method of manufacturing a semiconductor device according to the embodiment of the present invention. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of the plunger pushing up start for resin transfer in a mold cavity) corresponding to a cross section. 20 corresponds to two unit device regions for explaining the entire flow of the molding process (basic process relating to single-sided package) in the method of manufacturing a semiconductor device according to the embodiment of the present invention. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of completion of resin transfer) corresponding to a cross section. 21 corresponds to two unit device regions for explaining the entire flow of the molding process (basic process relating to single-sided package) in the method of manufacturing a semiconductor device according to the embodiment of the present invention. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of mold opening) corresponding to a cross section. 22 corresponds to two unit device regions for explaining the entire flow of the molding process (basic process relating to single-sided packaging) in the method of manufacturing a semiconductor device according to the embodiment of the present invention. It is a metal mold | die schematic sectional drawing in each mold process step (at the time of eject operation | movement) corresponding to a cross section. Based on these, the entire flow of the molding process (basic process related to single-sided packaging) in the method of manufacturing a semiconductor device according to the embodiment of the present application will be described.

  First, at time t0 (during preparation) in FIG. 15, the molds (upper mold 61 and lower mold 62) are preheated to about 175 degrees Celsius, and thereafter maintained at the same temperature during the process. Keep it. Then, as shown in FIG. 16, the resin tablet transport unit 57 (FIG. 10) holds the resin tablet 7 with the upper mold 61 and the lower mold 62 opened (the interval is, for example, about 20 centimeters). In this state, intrusion is started between the upper mold 61 and the lower mold 62.

  Next, at a time point t1 in FIG. 15, the plunger 65 starts to move backward, and at a time point t2, the plunger 65 moves backward to a position where the resin tablet 7 is received. Here, as shown in FIG. 16, the resin tablet transport unit 57 (FIG. 10) starts the operation of setting the resin tablet 7 in the heated pot unit 69. At time t3, the resin tablet 7 is set. At the time t4, the resin tablet transport unit 57 (FIG. 10) returns to the original outside position between the upper mold 61 and the lower mold 62.

  Next, as shown in FIG. 17, at time t5 in FIG. 15, the lead frame transport mechanism 60 (FIG. 10) holds the lead frame 1 and starts to enter between the upper mold 61 and the lower mold 62. To do. The setting of the lead frame 1 is started at time t6 in FIG. 15, and the setting of the lead frame 1 on the upper surface 62a of the lower mold 62 is completed at time t7. At this time, the chip mounting surface 1a (front surface) of the lead frame 1 is set downward so that the mounting position of each chip 2 (or unit device region 5) corresponds to each mold cavity 63 of the lower mold 62. The

  When the setting of the lead frame 1 is completed at the time t7 in FIG. 15, the lead frame transport mechanism 60 (FIG. 10) starts to retract, and at the time t8 in FIG. 15, the upper mold 61 and the lower mold 62 are moved. Return to the original position outside.

  Next, as shown in FIG. 18, the press mechanism operates to start closing the upper mold 61 and the lower mold 62 at time t9 in FIG. 15, and the clamping is completed at time t10. Thereby, a mold cavity 68 is formed between the upper mold 61 and the lower mold 62. The clamp pressure can be exemplified as a suitable value of about 550 MPa, for example.

  Next, as shown in FIG. 19, at the time t <b> 11 in FIG. 15, the plunger 65 starts to rise while the upper mold 61 and the lower mold 62 are clamped. At this point, the resin tablet 7 is already in the molten resin 7m.

  Next, as shown in FIG. 20, when the transfer of the resin is completed at time t12 in FIG. 15, the injection pressure (filling pressure) rises rapidly (preferred filling pressure is about 12 MPa, for example). At this point, the molten resin 7m fills the mold cavity 68 and enters the flow cavity 66, where the resin piece 16 corresponding to the flow cavity is being formed.

  Next, as shown in FIG. 21, when the plunger 65 starts to descend at time t <b> 13 in FIG. 15, the injection pressure (filling pressure) rapidly decreases and the clamp is released and the upper mold 61 and the lower mold 61 are lowered. The operation of opening the mold 62 is started, and the mold opening is completed at time t14 in FIG.

  Next, as shown in FIG. 22, at the time t15 in FIG. 15, the plunger 65 starts to rise again, and the ejection operation starts. At this time, the ejector pin provided in the lower mold 62 also rises in the same manner as the plunger 65. When the re-raising of the plunger 65 is completed at time t16 in FIG. 15 and the release of the lead frame 1 from the lower mold 62 is completed, the re-lowering of the plunger 65 is started at time t17, and at time t18. Then, it returns to the standby height which is substantially the same as the peripheral bottom surface 63p of the mold cavity 63 of the lower mold 62. As a result, the mold cycle is completed.

  Thereafter, the lead frame 1 is taken out from the lead frame take-out portion 58 by the lead frame transport mechanism 60 described in FIG. 10, and the next mold cycle is started.

  Here, the time point t2 to the time point t11 is a tablet preheating time (for example, about 10 seconds), the time point t11 to the time point t12 is an injection operation time (for example, about 10 seconds), and the time point t11 to the time point t13 is a curing time. The time point t15 type time point t18 is an ejection operation time (for example, about 15 seconds). Further, the time point t0 to the time point t18 is a mold cycle time (for example, about 120 seconds).

  As shown in this example, the merit of setting the lead frame with the chip mounting surface facing down is to prevent the generation of voids due to the diversification of the supply path, which is a concern when supplying molten resin from the opposite side of the lead. Because. This is because when the molten resin is supplied from the opposite side of the lead, the resin is inevitably supplied through a large number of openings opened in the lead frame, which may promote the generation of voids. On the other hand, the advantage of setting the lead frame with the chip mounting surface facing upward (same as in section 8) is that the wire flow due to the flow of molten resin can be avoided.

  Even when there is no such problem, it is possible to prevent the bonding wire from falling due to its own weight by setting the chip mounting surface of the lead frame facing downward.

  Next, a plating film is formed on a portion of the lead frame 1 (lead 4) exposed from the formed resin sealing body 3.

  After that, among the lead frames in which the resin sealing body 3 is formed in each unit device region 5, the lead frame frame portion 6 positioned between the adjacent unit device regions 5 is cut, thereby sealing the resin from the lead frame 1. The unit device region 5 (that is, the semiconductor device) in which the stop body 3 is formed is acquired (separated).

5. Description of Modifications of Mold Process (Lead Frame Preceding Process for Single-sided Package) in the Semiconductor Device Manufacturing Method of the One Embodiment of the Present Application (Mainly FIGS. 23 to 25)
In the molding process described in Section 4, the set of resin tablets preceded the set of lead frames. However, what is described in this section is the first stage of the molding process described in Section 4 (see FIGS. 16 and 16). FIG. 17) is a modified example, and FIG. 18 and subsequent figures are the same in terms of process, and therefore description of the same part will not be repeated. Note that FIG. 23 is basically the same as FIG.

  Note that this example is not limited to the single-sided package described in this section, but will be described later in Section 6, by providing a vacuum suction hole 71 (see FIG. 24) or the like for adsorbing the lead frame portion on the upper die. Needless to say, the present invention can also be applied to such a double-sided package.

  FIG. 23 is a diagram for explaining an overall flow of a molding process (lead frame preceding process for single-sided package) relating to a modification of the molding process (lead frame preceding process for single-sided package) in the method of manufacturing a semiconductor device according to the embodiment of the present application. It is a mold process time chart. 24 corresponds to two unit device regions for explaining the entire flow of the molding process (lead frame preceding process for a single-sided package) in the method of manufacturing a semiconductor device according to the embodiment of the present invention. FIG. 18 is a schematic cross-sectional view of a mold (corresponding to FIG. 16 for the order and FIG. 17 for the processing content) in each mold process step (at the time of setting the lead frame) corresponding to the B ′ cross-section. 25 corresponds to two unit device regions for explaining the overall flow of the molding process (lead frame preceding process for a single-sided package) in the method of manufacturing a semiconductor device according to the embodiment of the present invention. FIG. 18 is a schematic sectional view of a mold (corresponding to FIG. 17 as an order and corresponding to FIG. 16 as a processing content) in each molding process step (when a resin tablet is set) corresponding to a B ′ section. Based on these, a modification of the molding process (lead frame preceding process for a single-sided package) in the method of manufacturing a semiconductor device according to the embodiment of the present application will be described.

  First, as before, at the time t0 (during preparation) in FIG. 23, the molds (upper mold 61 and lower mold 62) are preheated to about 175 degrees Celsius, and after that, Keep at the same temperature.

  In this state, as shown in FIG. 24, the lead frame transport mechanism 60 (FIG. 10) holds the lead frame 1 between the upper mold 61 and the lower mold 62 at time t0 in FIG. Start intrusion. 23, the setting of the lead frame 1 is started, and at the time t2, the setting by the vacuum suction hole 71 to the lower surface 61b of the upper die 61 of the lead frame 1 is completed. At this time, the chip mounting surface 1a (front surface) of the lead frame 1 is set downward so that the mounting position of each chip 2 (or unit device region 5) corresponds to each mold cavity 63 of the lower mold 62. The

  When the setting of the lead frame 1 is completed at time t2 in FIG. 23, the lead frame transport mechanism 60 (FIG. 10) starts to retract, and at time t3 in FIG. 23, the upper mold 61 and the lower mold 62 are moved. Return to the original position outside.

  Next, as shown in FIG. 25, at time t4 in FIG. 23, the resin tablet transport unit 57 (FIG. 10) holds the resin tablet 7 with the upper mold 61 and the lower mold 62 opened. Then, intrusion starts between the upper mold 61 and the lower mold 62.

  Next, at the time point t5 in FIG. 23, the plunger 65 starts to move backward, and at the time point t6, the plunger 65 moves backward to the position where the resin tablet 7 is received. Here, as shown in FIG. 25, the operation of setting the resin tablet 7 on the heated pot portion 69 is started by the resin tablet transporting portion 57 (FIG. 10), and at time t7, the setting of the resin tablet 7 is started. At the time t8, the resin tablet transport unit 57 (FIG. 10) returns to the original outside position between the upper mold 61 and the lower mold 62.

  The subsequent steps are basically the same as those in FIG. The suction by the vacuum suction hole 71 is normally turned off after reaching the state of FIG.

Here, the time point t6 to the time point t11 is a tablet preheating time (for example, about 10 seconds), the time point t11 to the time point t12 is an injection operation time (for example, about 10 seconds), and the time point t11 to the time point t13 is a cure time. The time point t15 type time point t18 is an ejection operation time (for example, about 15 seconds). Also, the time t0 to the time t18 is a mold cycle time (for example, about 125 seconds) As described in this section, the lead frame is set first and then the resin tablet is set later. There is an advantage that the degree of freedom in selecting the injection time is increased. For example, it is possible to avoid the progress of undesired curing of the resin due to the delay of the lead frame setting, which occurs when the setting of the resin tablet precedes.

6). Description of modification of target device (double-sided package), outline of main manufacturing process related to manufacturing method of semiconductor device of one embodiment of the present application (mainly FIGS. 26 to 29)
In this section, a case where the target device is a double-sided package (specifically, QFP) will be described as a modification of the target device of the molding process of sections 1 to 4.

  26 is an enlarged schematic plan view of the chip mounting surface of the lead frame corresponding to the unit device region 5 of FIG. 5 regarding a modification (double-sided package) of the target device in the method of manufacturing a semiconductor device according to the embodiment of the present application. . FIG. 27 is a schematic cross-sectional view of the C-C ′ cross section of FIG. 26. FIG. 28 is an enlarged schematic plan view of the back surface of FIG. FIG. 29 is a perspective view of the completed package corresponding to FIGS. Based on these, a modified example (double-sided package) of the target device in the method of manufacturing a semiconductor device according to the embodiment of the present application, an outline of a related main manufacturing process, and the like will be described.

  Next, FIG. 26 shows an enlarged plan view seen from the surface 3a side of the resin sealing body 3 in the unit device region 5 of FIG. As shown in FIG. 26, in this example, when viewed in a plan view, unlike FIG. 7, only the recess 15 due to the ejector pin is visible in appearance, and the recess 14 due to the plunger is on the opposite side and cannot be seen. This is a state (indicated by a broken line), and there is a die pad 8 inside. Further, the semiconductor chip 2 is provided inside the die pad 8.

  Next, FIG. 27 shows a C-C ′ cross section of FIG. 26. As shown in FIG. 27, in this cross section, the lead frame 1 is divided into a lead frame frame portion 6, a die pad 8 on which the semiconductor chip 2 is mounted, and a die pad support bar 9 that connects the die pad 8 to the lead frame frame portion 6. Yes. A resin sealing body 3 is formed on the chip mounting surface 1a (front surface) of the lead frame 1 and on the opposite surface 1b (back surface of the lead frame) so as to seal the semiconductor chip 2, and the resin sealing is performed. Resin pieces 16 corresponding to the flow cavities are formed at each corner portion of the body 3. In addition, unlike FIG. 8, as shown in FIG. 28, the back surface 3b of the resin sealing body 3 is formed with a concave portion 14 by a plunger (in FIG. 8, on the front surface 3a side).

  Next, FIG. 29 shows a perspective view of the device package 3 when the device is completed. As shown in FIG. 29, the lead 4 protrudes from the side surface 3 s of the device package 3, and the recess 15 due to the ejector pin is visible on the surface 3 a of the device package 3.

7). Description of the principal part process regarding a modification (double-sided package) of the target device in the method of manufacturing a semiconductor device according to the embodiment of the present application (mainly FIGS. 30 and 31)
In this section, the characteristics of the mold corresponding to section 3 and its main function in the case of a double-sided package will be described. The structure of the mold is different from the example of FIGS. 13 and 14 in that the bottom surface of the upper mold is almost flat, but in this example, there are irregularities corresponding to the cavities and the like. . Note that FIG. 11 (in this example, the upper and lower molds have almost the same structure) and FIG. 12 are not structurally fundamentally different, so the description will not be repeated.

  FIG. 30 is a view for explaining the position of the resin tablet in the mold cavity at the time of mold clamping (resin molding process) related to a modification (double-sided package) of the target device in the method of manufacturing a semiconductor device according to the embodiment of the present application. It is a schematic cross section of the mold die (upper die and lower die) corresponding to the unit device region 5 of. FIG. 31 illustrates a cross-sectional shape of the mold cavity at the time when the plunger is most elevated (resin mold process) during the mold clamp in relation to the modified example (double-sided package) of the target device in the method of manufacturing a semiconductor device according to the embodiment of the present application. It is a schematic cross section of the mold die (upper die and lower die) corresponding to the unit device region 5 for. Based on these, a description will be given of a main process relating to a modification (double-sided package) of the target device in the method of manufacturing a semiconductor device according to the embodiment of the present application.

  FIG. 30 shows a cross section of the mold when the resin tablet 7 is set in the pot portion 69 and the upper mold 61 and the lower mold 62 are closed and clamped (corresponding to the position where the upper mold 61 is broken). (Frame 1 etc. are omitted). As shown in FIG. 30, a mold corresponding to the mold cavity portion 73 of the upper die 61 and the mold cavity portion 63 of the lower die 62 between the lower surface 61 b of the upper die 61 and the upper surface 62 a of the lower die 62. A cavity 68 is formed. At this time, since the plunger 65 is lowered, the thickness T1 (initial mold cavity thickness) of the mold cavity 68 in a part of the part of the pot part 69 which is a part of the mold cavity 68 is different from that of the other part. It is the thickest. In this example, an ejector pin 72 is provided on the upper mold 61.

  Next, FIG. 31 schematically shows a cross section of the mold when the resin filling is completed (the lead frame 1 and the like are omitted). As shown in FIG. 31, at this time, since the plunger 65 is raised, the upper end portion 65t of the plunger is, for example, the peripheral bottom surface 63p of the mold cavity portion 63 of the lower mold 62 (in this example, the pot 65 It is slightly above the upper end of the cylinder 64). Therefore, the thickness T2 of the mold cavity 68 in this portion (the thickness of the mold cavity when the resin filling is completed) is thinner than the thickness of the other main portion of the mold cavity 68. Of course, the mold cavity thickness T2 when the resin filling is completed is thinner than the initial mold cavity thickness T1.

8). Description of the overall flow of the molding process regarding a modification (double-sided package) of the target device in the method of manufacturing a semiconductor device according to the embodiment of the present application (mainly FIGS. 32 to 38)
The time chart is the same as FIG. 15, and each cross-sectional view at each step shown below, that is, FIGS. 26 to 29, corresponds to FIGS. 32 to 38, respectively.

  In this example, an example in which a chip mounting surface such as a lead frame is faced upward and set in a mold is specifically described. However, the following embodiments are not limited thereto, and are mounted on a chip. Needless to say, the present invention can be similarly applied to the case where the mold is set with the surface facing downward.

  FIG. 32 corresponds to two unit device regions for explaining the entire flow of the molding process (double-sided package process) related to the modified example (double-sided package) of the target device in the manufacturing method of the semiconductor device of the one embodiment of the present application. It is a metal mold | die schematic cross section in each mold process step (at the time of resin tablet setting) corresponding to the BB 'cross section of FIG. FIG. 33 corresponds to two unit device regions for explaining the overall flow of the molding process (double-sided package process) related to the modified example (double-sided package) of the target device in the manufacturing method of the semiconductor device of the one embodiment of the present application. FIG. 8 is a schematic cross-sectional view of a mold in each mold process step (at the time of lead frame setting) corresponding to the BB ′ cross-section of FIG. FIG. 34 corresponds to two unit device regions for explaining the entire flow of the molding process (double-sided package process) related to the modified example (double-sided package) of the target device in the manufacturing method of the semiconductor device of the one embodiment of the present application. FIG. 8 is a mold schematic cross-sectional view at each mold process step (at the time of mold clamping) corresponding to the BB ′ cross-section of FIG. 7. FIG. 35 corresponds to two unit device regions for explaining the entire flow of the molding process (double-sided package process) related to the modified example (double-sided package) of the target device in the manufacturing method of the semiconductor device of the one embodiment of the present application. FIG. 8 is a schematic cross-sectional view of a mold in each mold process step (at the time of starting to push up a plunger for transferring a resin in a mold cavity) corresponding to the BB ′ cross-section of FIG. FIG. 36 corresponds to two unit device regions for explaining the entire flow of the molding process (double-sided package process) related to the modified example (double-sided package) of the target device in the method of manufacturing a semiconductor device according to the one embodiment of the present application. FIG. 8 is a schematic cross-sectional view of a mold at each mold process step (when resin transfer is completed) corresponding to the cross-section BB ′ of FIG. FIG. 37 corresponds to two unit device regions for explaining the overall flow of the molding process (double-sided package process) related to the modification (double-sided package) of the target device in the method of manufacturing a semiconductor device according to the embodiment of the present application. FIG. 8 is a schematic cross-sectional view of a mold at each mold process step (when the mold is opened) corresponding to the BB ′ cross-section of FIG. FIG. 38 corresponds to two unit device regions for explaining the entire flow of the molding process (double-sided package process) related to the modified example (double-sided package) of the target device in the method of manufacturing a semiconductor device according to the one embodiment of the present application. FIG. 8 is a schematic sectional view of a mold in each mold process step (at the time of ejecting operation) corresponding to the BB ′ section of FIG. Based on these, the entire flow of the molding process regarding the modification (double-sided package) of the target device in the method of manufacturing a semiconductor device according to the embodiment of the present application will be described.

  As in the section 4, first, at the time t0 (during preparation) in FIG. 15, the molds (upper mold 61 and lower mold 62) are preheated to about 175 degrees Celsius, and thereafter the processing is in progress. Is kept at the same temperature. 32, the upper mold 61 and the lower mold 62 are opened and the upper tablet 61 and the lower mold 62 are held in a state where the resin tablet transport unit 57 (FIG. 10) holds the resin tablet 7. Intrusion begins between the molds 62.

  Next, at a time point t1 in FIG. 15, the plunger 65 starts to move backward, and at a time point t2, the plunger 65 moves backward to a position where the resin tablet 7 is received. Here, as shown in FIG. 32, the resin tablet transport unit 57 (FIG. 10) starts the operation of setting the resin tablet 7 in the heated pot unit 69. At time t3, the resin tablet 7 is set. At the time t4, the resin tablet transport unit 57 (FIG. 10) returns to the original outside position between the upper mold 61 and the lower mold 62.

  Next, as shown in FIG. 33, at time t5 in FIG. 15, the lead frame transport mechanism 60 (FIG. 10) holds the lead frame 1 and starts to enter between the upper mold 61 and the lower mold 62. To do. The setting of the lead frame 1 is started at time t6 in FIG. 15, and the setting of the lead frame 1 on the upper surface 62a of the lower mold 62 is completed at time t7. At this time, the chip mounting surface of the lead frame 1 so that the mounting position (or unit device region 5) of each chip 2 corresponds to the mold cavity 73 of the upper mold 61 and each mold cavity 63 of the lower mold 62. It is set with 1a (surface) facing upward, for example.

  When the setting of the lead frame 1 is completed at the time t7 in FIG. 15, the lead frame transport mechanism 60 (FIG. 10) starts to retract, and at the time t8 in FIG. 15, the upper mold 61 and the lower mold 62 are moved. Return to the original position outside.

  Next, as shown in FIG. 34, the press mechanism operates to start closing the upper mold 61 and the lower mold 62 at time t9 in FIG. 15, and the clamping is completed at time t10. Thereby, a mold cavity 68 is formed between the upper mold 61 and the lower mold 62. At this time, the ejector pin 72 is not projected (retracted position).

  Next, as shown in FIG. 35, at the time t11 in FIG. 15, the plunger 65 starts to rise while the upper mold 61 and the lower mold 62 are clamped. At this point, the resin tablet 7 is already in the molten resin 7m.

  Next, as shown in FIG. 36, when the transfer of the resin is completed at time t12 in FIG. 15, the injection pressure (filling pressure) rises rapidly. At this point, the molten resin 7m fills the mold cavity 68 and enters the flow cavity 66, where the resin piece 16 corresponding to the flow cavity is being formed.

  Next, as shown in FIG. 37, when the plunger 65 starts to descend at time t13 in FIG. 15, the injection pressure (filling pressure) rapidly decreases, the clamp is released, the upper mold 61 and the lower mold 61 are moved downward. The operation of opening the mold 62 is started (in conjunction with this, the ejector pin 72 of the upper mold 61 protrudes), and the mold opening is completed at time t14 in FIG.

  Next, as shown in FIG. 38, at the time point t15 in FIG. 15, the plunger 65 starts to rise again, and the ejection operation starts. At this time, if there is an ejector pin in the lower mold 62, the ejector pin is also raised in the same manner as the plunger 65. When the re-raising of the plunger 65 is completed at time t16 in FIG. 15 and the release of the lead frame 1 from the lower mold 62 is completed, the re-lowering of the plunger 65 is started at time t17, and at time t18. Then, it returns to the standby height which is substantially the same as the peripheral bottom surface 63p of the mold cavity 63 of the lower mold 62. As a result, the mold cycle is completed.

  As explained here, the merit of setting the chip mounting surface 1a (front surface) of the lead frame 1 facing upward is that the resin thickness on each surface (front surface or back surface) of the double-sided package is larger than that of the single-sided package. Since it is thinner, if the chip mounting surface is turned down, there is a higher risk of exposure of the wire or the like in the recess 14 generated as a result of the plunger overdrive.

9. General Consideration of the Application and Supplementary Explanations for Each Embodiment In a typical transfer mold method, a resin tablet is set at a position away from a mold cavity in a mold, and a molten resin is melted by heat. This is an effective resin molding method in which a mold cavity is transferred and filled through a cull, a runner, and a gate. However, the number of unit device regions arranged in one lead frame tends to increase year by year, and the number of columns and rows arranged in a matrix form is increasing. It tends to increase threefold.

  In response to such a problem, in each of the above-described embodiments (including modifications), a resin tablet (sealing resin material) is supplied to each portion corresponding to each cavity in the individual compression molding method. By doing so, the resin material is not wasted by supplying the molten resin directly to the sealed portion (unit device region) of the lead frame (planar substrate) without using a gate or the like. .

  Further, in the individual compression molding method described in each of the embodiments (including modifications), the resin conditions are almost the same in any cavity. Since there is no need to inject at high speed, there is no need to significantly reduce the viscosity and the problem of wire flow is not as severe. That is, relatively low-speed filling (transfer) is possible.

  Furthermore, since the resin surface spreads radially from the center of the package toward the outside, it is considered that there is relatively little void entrainment.

  Further, in a typical transfer mold method, when a lead frame having unit device regions arranged in a matrix is sealed, the resin path from the pot portion is inevitably determined depending on where the unit device region is located. Therefore, it is difficult to align the resin filling conditions of all the cavities. On the other hand, in the individual compression molding method described in each of the above embodiments (including modifications), since the pot portion itself is in each cavity, the resin filling conditions of all the cavities are basically the same. Can be easily achieved.

  In addition, it is possible to eliminate non-uniformity due to positions such as the end portion and the center portion of the resin, which is often found in a huge resin tablet in the batch compression molding method.

  Note that it is possible to use a circular resin tablet as shown in FIG. 12 in the batch compression molding method, but on the other hand, there is a high possibility that the filling characteristics of the resin will be uneven.

10. Summary The invention made by the present inventor has been specifically described based on the embodiments. However, the present invention is not limited thereto, and it goes without saying that various changes can be made without departing from the scope of the invention.

  For example, in the above-described embodiment, a specific description has been given by taking, as an example, a device in which a single chip is mounted mainly for one unit device region. However, the present invention is not limited thereto, and one unit device region. Needless to say, the present invention can also be applied to a single-layered or stacked-layered chip mounted with a plurality of chips.

  In the above-described embodiment, the device and the device manufacturing method using the lead frame mainly as the planar substrate have been specifically described. However, the present invention is not limited to this, and the organic substrate ( Needless to say, the present invention can also be applied to a board using a wider insulating wiring board).

  Furthermore, in the above-described embodiment, the mold in which the pot portion is mainly provided on the lower mold side has been described. However, the present invention is not limited thereto, and the pot portion may be provided in the upper mold. Needless to say.

  In the above embodiment, an example in which a part of the lower mold corresponds to the pot part is shown. However, the present invention is not limited thereto, and almost all of the lower mold corresponds to the pot part. It goes without saying that it may be done.

  In the above embodiment, the example in which the resin tablet is set in the pot portion provided in a part of the lower mold has been mainly described. However, the present invention is not limited thereto, A resin tablet may be set in the mold cavity of the mold. Furthermore, even when a resin tablet is set in a pot portion provided in a part of the lower mold, the resin tablet may be set by protruding the part.

  Furthermore, in the said embodiment, although the metal mold | die which has a cavity corresponding | compatible recessed part only in a lower mold was illustrated as an example of a single-sided mold, this invention is not limited to it, A cavity corresponding | compatible recessed part only in an upper metal mold | die. It goes without saying that a certain mold may be used.

  In the above embodiment, an example in which the semiconductor chip is mainly smaller than the die pad has been specifically described. However, the present invention is not limited thereto, and the die pad is smaller in size than the semiconductor chip. It goes without saying that it is also good.

Further, in the above embodiment, the external connection device mainly by wire bonding has been specifically described. However, the present invention is not limited to this, and other connection methods (mixing method with wire bonding are used). Needless to say, it may be included.
Moreover, in the said embodiment, although the example which forms a resin sealing body using the metal mold | die provided with not only a plunger but an ejector pin was demonstrated concretely, this invention is not limited to it. Alternatively, a mold without an ejector pin may be used. When such a mold is used, the lead frame is released using only the plunger.

  In the above embodiment, an example in which a release film or a lead frame tape is mainly not used has been specifically described. However, the present invention is not limited to this, and a release film or a lead frame tape is used. Needless to say, this is applicable to the example used.

  In the above-described embodiment, an example in which a resin tablet is used as the sealing resin material has been specifically described, but the present invention is not limited thereto, and a shot-shaped sealing resin material, a powdered resin material, Needless to say, a liquid resin material or the like may be used.

1 Lead frame (planar substrate)
1a Lead frame chip mounting surface (surface)
DESCRIPTION OF SYMBOLS 1b Back surface of lead frame 2 Semiconductor chip 2a Device surface of chip 3 Resin sealing body or device package 3a Surface of resin sealing body 3b Back surface of resin sealing body 3s Side surface of resin sealing body 4 Lead 5 Unit device area 6 Lead Frame frame portion 7 Resin tablet 7 m Molten resin 8 Die pad 9 Die pad support bar 10 Terminal portion 11 Bonding wire 12 Bonding pad 14 Recessed portion by plunger 15 Recessed portion by ejector pin 16 Resin piece corresponding to flow cavity 51 Resin molding device 52 Lead frame loader 53 Lead frame alignment part 54 Lead frame carry-in part 55 Press part 56 Resin tablet alignment part 57 Resin tablet transport part 58 Lead frame take-out part 59 Lead frame unloader 60 Lead Frame transport mechanism 61 Upper mold 61b Lower surface of upper mold 61c Closed upper mold 62 Lower mold 62a Upper surface of lower mold 63 Mold cavity portion of lower mold 63p Bottom surface of mold cavity portion of lower mold 64 Pot Cylinder 65 Plunger 65t Plunger upper end 66 Flow cavity 67 Flow gate 68 Mold cavity 69 Pot part 71 Vacuum suction hole 72 Ejector pin 73 Mold cavity part of upper mold 74 Vent R1 Lead frame part cutout area T1 Initial mold cavity thickness T2 Resin Mold cavity thickness when filling is complete W1 Diameter of resin tablet W2 Length of semiconductor chip side (long side length)
W3 Minimum width of mold cavity part of lower mold W4 Inner diameter of pot part W5 Length of side of die pad (length of long side)

Claims (16)

A semiconductor device manufacturing method including the following steps:
(A) a step of setting a resin tablet in each of a plurality of mold cavities of the heated lower mold in a state where the lower mold and the upper mold are opened;
(B) The lower mold in an open state in which a planar substrate on which a semiconductor chip is mounted in each of a large number of unit device regions is opened so that each unit device region corresponds to a position of each of the large number of mold cavities. And setting between the upper molds;
(C) after the steps (a) and (b), closing and clamping the lower mold and the upper mold;
(D) After the step (c), in a state where the lower mold and the upper mold are clamped, at least each mold cavity formed between the lower mold and the upper mold By reducing a part of the thickness, each mold cavity is filled with a sealing resin in which the resin tablet is melted, and a resin sealing body for sealing the semiconductor chip in each of the multiple unit device regions is formed. The step of:
(E) A step of opening the lower mold and the upper mold after the step (d).     In the method of manufacturing a semiconductor device according to the item 1, the lower mold includes the multiple mold cavities and pot portions directly connected to the main portions of the multiple mold cavities. The small width is larger than the diameter of the pot portion.     In the method for manufacturing a semiconductor device according to the item 2, the horizontal sectional shape of the resin tablet is substantially circular, and the diameter thereof is smaller than the diameter of the pot portion.     In the method of manufacturing a semiconductor device according to the item 3, the reduction in the thickness of each mold cavity is caused by pushing up a plunger in the pot portion provided in each of the multiple mold cavity portions of the lower mold. Executed.     In the method for manufacturing a semiconductor device according to the item 4, the plunger is pushed up such that the upper end of the plunger exceeds the bottom surface of the mold cavity around the pot.     6. In the method of manufacturing a semiconductor device according to item 5, in the step (d), the planar shape of each mold cavity is substantially rectangular, and a flow cavity connected to each corner is formed outside the four corners. Has been.     In the method of manufacturing a semiconductor device according to the item 6, in the step (b), the planar substrate is set with a surface on which the semiconductor chip is mounted facing downward.     In the method for manufacturing a semiconductor device according to the item 7, the step (b) is performed prior to the step (a).     In the method for manufacturing a semiconductor device according to the item 8, the resin sealing body is not substantially formed on a surface side of the planar substrate on which the semiconductor chip is not mounted.     In the method for manufacturing a semiconductor device according to the item 9, the planar substrate is a lead frame. The method for manufacturing a semiconductor device according to the item 10, further includes the following steps:
(F) After the step (e), the step of releasing the planar substrate on the lower side without using a release film.     In the method of manufacturing a semiconductor device according to the item 6, in the step (b), the planar substrate is set with a surface on which the semiconductor chip is mounted facing upward.     In the method of manufacturing a semiconductor device according to the item 12, the step (b) is performed after the step (a).     In the method of manufacturing a semiconductor device according to the item 13, the resin sealing body is also formed on the surface side of the planar substrate on which the semiconductor chip is not mounted. The method for manufacturing a semiconductor device according to the item 14, further includes the following steps:
(F) A step of releasing the planar substrate after the step (e) without using a release film.     16. The method for manufacturing a semiconductor device according to the item 15, wherein the planar substrate is a lead frame.

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