BRIEF DESCRIPTION OF THE INVENTION
FIGS. 1A to 1D respectively illustrate a configuration of a wiring board according to a first embodiment of the present invention;
FIGS. 2A to 2E respectively illustrate a method for manufacturing a resin-molding type semiconductor device using the wiring board illustrated in FIGS. 1A to 1D;
FIGS. 3A and 3B respectively illustrate a shape of a resin in the resin-molding type semiconductor device manufactured using the wiring board illustrated in FIGS. 1A to 1D;
FIG. 4 illustrates a configuration of a wiring board according to a second embodiment of the present invention;
FIG. 5 illustrates a configuration of a wiring board according to a third embodiment of the present invention;
FIG. 6 illustrates a configuration of a wiring board according to a fourth embodiment of the present invention;
FIGS. 7A and 7B respectively illustrate a configuration of a wiring board according to a fifth embodiment of the present invention;
FIG. 8 illustrates a configuration of a wiring board according to a sixth embodiment of the present invention;
FIG. 9 illustrates a configuration of a wiring board according to a seventh embodiment of the present invention;
FIG. 10 illustrates a configuration of a wiring board according to an eighth embodiment of the present invention;
FIGS. 11A and 11B respectively illustrate a configuration of a wiring board according to a ninth embodiment of the present invention;
FIGS. 12A to 12C respectively illustrate a configuration of a wiring board according to a tenth embodiment of the present invention;
FIGS. 13A to 13C respectively illustrate a configuration of a wiring board according to an eleventh embodiment of the present invention;
FIGS. 14A to 14C respectively illustrate a conventional wiring board; and
FIGS. 15A to 15D respectively illustrate a conventional method for manufacturing a resin-molding type semiconductor device using the wiring board illustrated in FIGS. 14A to 14C.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, description will be given of preferred embodiments of the present invention with reference to the drawings.
FIGS. 1A to 1D respectively illustrate a configuration of a wiring board according to a first embodiment of the present invention. More specifically, FIG. 1A is a plan view illustrating an element mount face (a front face) of the wiring board, FIG. 1B is a plan view illustrating an electrode terminal face (a back face) of the wiring board, FIG. 1C is a sectional view taken along a line A-A′ in FIG. 1A, and FIG. 1D is a sectional view taken along a line B-B′ in FIG. 1A.
As illustrated in FIGS. 1A to 1D, the wiring board 1 has the following configuration. That is, a plurality of element regions 6 each having a mount region 2 on which a semiconductor element is mounted and an electrode wire 21 serving as a product circuit are arranged in a matrix form to form a product region 7, and a peripheral region 8 surrounds the product region 7. Further, a plurality of seal regions 9 each including such product region 7 and such peripheral region 8 sealed with a resin collectively are arranged side by side with slits 10 interposed therebetween.
Herein, the electrode wire 21 includes wires 3 provided on or around a mount region 2 so as to be electrically connected to a semiconductor element, via holes 4 for internal layer interconnection from which the wires 3 are led out toward the back face of the wiring board 1, and electrode terminals 5 formed on the back face of the wiring board 1. The electrode wire 21 is made of Cu or the like, and the wiring board 1 is made of a glass epoxy material as a base material.
The wiring board 1 according to this embodiment is different from a conventional wiring board (see FIGS. 14A to 14C) in the following point that through holes 17 are formed on a peripheral region 8 surrounding a product region 7, that is, a region serving as a spacing upon performance of dicing.
Through holes 17 each formed into a circular shape are provided around a product region 7 while being spaced uniformly. Specifically, through holes 17 are provided at both ends of each row of element regions 6 arranged in a certain direction. More specifically, through holes 17 are provided at right and left ends of each row of element regions 6 arranged in a lateral direction. Further, through holes 17 are provided at top and bottom ends of each row of element regions 6 arranged in a vertical direction. Herein, each through hole 17 is formed on a region corresponding to an end side of an element region 6 (i.e., a width of a row of element regions 6), is located at a center of the end side, and has a dimension smaller than that of the endside. Such through holes 17 can be formed together with slits 10. Therefore, it is unnecessary to increase a particular step upon fabrication of the wiring board 1.
FIGS. 2A to 2E respectively illustrate a method for manufacturing a resin-molding type semiconductor device. As illustrated in FIG. 2A, first, a semiconductor element 11 is die bonded to a mount region 2 of each element region 6 (i.e., a product region 7) in the wiring board 1 through an adhesive such as an Ag paste. Then, electrodes on a circuit face of the semiconductor element 11 are electrically connected to electrode pads of wires 3 through metal thin wires 12 made of Al or Au. Alternatively, bumps (e.g., solder bumps or Au bumps) are previously formed on the electrodes on the circuit face of the semiconductor element 11, and are connected to the electrode pads of the wires 3 in a state that the circuit face of the semiconductor element 11 is directed downward (so-called flip-chip connection).
As illustrated in FIGS. 2B and 2C, next, a seal region 9 larger in size than the product region 7 is sealed with a resin 13 such as an epoxy resin by collective molding; thus, a resin-molded body 14 is formed. In order to form such resin-molded body 14, the wiring board 1 is inserted into a heated mold such that the seal region 9 is placed in a cavity of the mold, and then the resin 13, which is melted, is fed into the cavity and is cured.
Herein, the resin 13 is filled into through holes 17. Expansion/contraction of the wiring board 1, which occurs by such sealing, is absorbed by the slits 10. In addition, such expansion/contraction does not occur locally because the through holes 17 are provided around the product region 7 while being spaced uniformly. Therefore, it is possible to suppress occurrence of a connection failure due to variations in temperature upon performance of such sealing. After formation of the resin-molded body 14, the wiring board 1 is divided at the slits 10 if necessary.
As illustrated in FIG. 2D, next, a dicing tape 15 is affixed to a resin face of the resin-molded body 14 such that the resin-molded body 14 is fixed. In this state, the resin-molded body 14 is subjected to dicing by means of a dicing blade 16 from a back face side of the wiring board 1; thus, the resin-molded body 14 is divided for each semiconductor device corresponding to the element region 6.
Herein, as illustrated in FIG. 2E, the resin-molded body 14 is sequentially cut along cutting lines La, Lb, Lc and Ld in a vertical direction (an X direction), and then is sequentially cut along cutting lines Le, Lf, Lg and Lh in a lateral direction (a Y direction). In other words, the resin-molded body 14 is divided into narrow resin-molded body pieces, and then the resin-molded body pieces are divided into semiconductor devices.
Upon division of the resin-molded body pieces, the resin 13 is filled into the through holes 17 provided on the peripheral region 8. Therefore, the resin 13 is fixedly bonded to the wiring board 1 because of an increase in close-contact area and an anchor effect, as compared with a case where such through hole 17 is not provided. In addition, the through holes 17 are provided at both ends of each row of the element regions 6. Therefore, even when the sealed-resin body pieces are cut along any of the aforementioned cutting lines, the resin 13 in a spacing to be cut is fixedly bonded to the wiring board 1. Moreover, each through hole 17 is formed on a region corresponding to an end side of the element region 6. Therefore, even when the resin 13 filled into the through hole 17 is cut by the dicing blade 16, a stress generated by such cut is not increased.
Accordingly, even when the dicing blade 16 is rotated at a high speed or is moved rapidly as compared with a conventional case, a stress generated from the dicing blade 16 is effectively absorbed by the wiring board 1. As a result, it is possible to prevent the resin 13 in the spacing to be cut from being peeled off from the dicing tape 15 and to prevent the cut spacing from being scattered. Hence, it is possible to prevent the resin in a corner of a semiconductor device from becoming chipped or cracked due to scattering of a spacing and to prevent the dicing blade 16 from being damaged. In addition, it is possible to improve productivity since it is unnecessary to increase a particular step upon fabrication of the wiring board 1 as described above.
As illustrated in FIGS. 3A and 3B, it is also possible to lessen a stress generated from the dicing blade 16 and applied to the resin 13 when the resin 13 in the peripheral region 8 is made smaller in thickness than the resin 13 in the product region 7. Herein, the resin 13 in the corner of the peripheral region 8 includes a lower portion 13a which is different in height from the resin 13 in the product region 7, an inclined portion 13b formed between the resin 13 in the product region 7 and the lower portion 13a, and an inclined portion 13c formed at a periphery of the lower portion 13a. Herein, each of the inclined portions 13b and 13c has a thickness decreased gradually.
In the present invention, the through hole 17 is provided for fixedly bonding the resin 13 to the wiring board 1 and for preventing the spacing or the resin in the spacing from being scattered; therefore, the position and shape thereof are not particularly limited. For example, a through hole 17 may be formed into a shape of a cross as illustrated in FIG. 4. Alternatively, a through hole 17 may be formed into an oval shape as illustrated in FIG. 5. Still alternatively, a through hole 17 may be formed into a polygonal shape such as a rectangular shape as illustrated in FIG. 6. Preferably, such through hole 17 is formed into a shape of a cross because it can be engaged with a resin 13 at many sites. However, the shape may be appropriately changed in accordance with design restrictions.
Alternatively, a through hole 17 may be formed over a peripheral region 8 and a non-seal region located outside the peripheral region 8 as illustrated in FIGS. 7A and 7B. Specifically, through holes 17 are provided at top and bottom ends of each row of element regions 6 arranged in a vertical direction so as not to overlap with slits 10. Each through hole 17 is formed on a region corresponding to an end side of the element region 6, and includes a pair of circular holes formed with a boundary between the peripheral region 8 and the non-seal region interposed therebetween and a slit connecting between the pair of circular holes. Moreover, a size of each through hole 17 is made small such that each through hole 17 is spaced away from a product region 7 as much as possible. When the through hole 17 is formed over the peripheral region 8 and the non-seal region, an anchor effect of fixedly bonding a resin 13 to a wiring board 1 can be enhanced.
In FIG. 8, through holes 17 are provided at both ends of each outermost row of element regions 6 arranged in a matrix form. That is, the through holes 17 are provided at both end sides of an element region 6 at a corner of a product region 7 so as to oppose each other.
In FIG. 9, through holes 17 are provided at one of ends of each outermost row of element regions 6 arranged in a matrix form. That is, the through holes 17 are provided at one of end sides of an element region 6 at a corner of a product region 7. More specifically, in a case where a wiring board 1 is divided for each element region 6 by performance of dicing in a vertical direction (an X direction) and dicing in a lateral direction (a Y direction) in sequence, the through holes 17 are provided at a peripheral region 8 located along a first cutting line (Ly) in the Y direction, and the through holes 17 are provided downstream of the cutting line (Ly) in the Y direction at the peripheral region 8 located along a cutting line (Lx) in the X direction.
In a spacing, a portion (a corner) having a small contact area with a dicing tape 15 is readily scattered. Therefore, it is also effective that through holes are provided only at adjoining portions as illustrated in FIGS. 8 and 9.
In FIG. 10, each through hole 17 is provided at a region corresponding to end sides of adjoining two of element regions 6 arranged in a matrix form. With this configuration, it is possible to reduce through holes 17 in number and to fixedly bond a resin in a spacing to be cut to a wiring board 1. Reduction of through holes 17 in number is effective although such through holes 17 can be formed concurrently with slits 10.
In a case where a wiring board 1 is a double-sided wiring board, that is, a wiring board 1 is of a single-layer structure and wires or electrode terminals are formed on both sides thereof, it is convenient that a through hole 17 is provided as described above. On the other hand, as illustrated in FIG. 11A, in a case where a wiring board 1 is a multilayer wiring board, that is, a wiring board 1 is of a multilayer structure (having a wiring layer and an insulating layer formed therein) and wires or electrode terminals are formed on both sides thereof, a through hole to be provided may be a counter-bored hole 17′ opened only at a surface layer on an element mount face or may be a through hole formed by laser processing so as to penetrate through entire layers. Alternatively, as illustrated in FIG. 11B, in a case where a resist 20 is provided on an element mount face, a through hole to be provided may be a counter-bored hole 17′ opened only at the resist 20.
FIGS. 12A to 12C respectively illustrate a configuration of another wiring board according to the present invention. More specifically, FIG. 12A is a plan view illustrating an element mount face (a front face) of the wiring board, FIG. 12B is a sectional view taken along a line D-D′ in FIG. 12A after performance of sealing with a resin, and FIG. 12C is a sectional view taken along a line E-E′ in FIG. 12A after performance of sealing with a resin.
In the wiring board 1, there are provided circular convex parts 18 positioned and dimensioned as in the aforementioned through holes 17 illustrated in FIGS. 1A to 1D. Each convex part 18 is formed in such a manner that a metal pattern 19 is coated with a resist 20. Such convex part 18 can be formed by using part of a metal layer required for forming a wire 3, and a resist. Therefore, it is unnecessary to increase a particular step upon fabrication of the wiring board 1.
In order to make a height of the convex part 18 high, as illustrated in FIG. 12C, the metal pattern 19 (having a thickness of about several micrometers if it is formed from a metal layer equal to a metal layer configuring a wire 3) serving as a base is coated with the resist 20 plural times. The resist 20 in one coating has a thickness in a range of several micrometers to several tens of micrometers. Herein, a product region 7 is allowed to have a normal resist thickness while covered with a mask.
As in the aforementioned through hole 17, the convex part 18 may be formed into an oval shape (see FIG. 5), a rectangular shape (see FIG. 6) or a shape of a cross (see FIG. 4).
As in the aforementioned through hole 17 (see FIG. 7), the convex parts 18 may be formed over a peripheral region 8 and a non-seal region located outside the peripheral region 8. Thus, an anchor effect of the convex part 18 is exerted throughout a resin 13; therefore, the resin 13 in a spacing is completely prevented from being scattered. As described above, the convex part 18 has the configuration that the metal pattern 19 is coated with the resist 20. Since the resist 20 has elasticity, even when the convex part 18 is crimped by sealing molds, there is no gap formed between the sealing molds. As a result, it is possible to prevent a resin from leakage. In many cases, the resist 20 is made of a photosensitive polymeric material cured by irradiation with light. Examples of such material include polyvinyl-based cinnamate, epoxy resin-based cinnamate, polyvinyl benzalacetophenone, and the like.
The through hole 17 or the convex part 18 formed over the peripheral region 8 and the non-seal region is convenient in a case where the wiring board 1 is effectively used by unifying a size thereof and a sealing mold to be used, even when various types of semiconductor devices are manufactured (accordingly, even when required element regions 6 (product regions 7) differ for each semiconductor device). A seal region 9 has a fixed size in correspondence with the sealing mold; therefore, the peripheral region 8 becomes narrow in width occasionally. However, even when the through hole 17 or the convex part 18 formed over the peripheral region 8 and the non-seal region has one end placed near the non-seal region in the peripheral region 8, an anchor effect is exerted throughout a resin. Herein, a mask used for forming the convex part 18 can be unified irrespective of the width of the peripheral region 8.
FIGS. 13A to 13C respectively illustrate a configuration of still another wiring board according to the present invention. More specifically, FIG. 13A is a plan view illustrating an element mount face (a front face) of the wiring board, FIG. 13B is a sectional view taken along a line F-F′ in FIG. 13A after performance of sealing with a resin, and FIG. 13C is a sectional view taken along a line G-G′ in FIG. 13A after performance of sealing with a resin.
The wiring board 1 is different from the wiring board 1 illustrated in FIGS. 12A to 12C in the following point that a plurality of convex parts 18 are provided in a staggered form along end sides of element regions 6 so as to surround a product region 7. This provision of the convex parts 18 makes it possible to increase an area coming into contact with a resin 13, thereby to enhance an anchor effect. As a result, it is possible to effectively prevent the resin 13 from being peeled off from a dicing tape 15. In a case where the plurality of convex parts 18 are provided as described above, it is unnecessary to make a height of each convex part 18 high. Therefore, such convex part 18 may be formed by using only a resist 20.
In addition to the aforementioned provision in a staggered form, the plurality of convex parts 18 may be provided linearly along the end sides of the element regions 6. Alternatively, the plurality of convex parts 18 may be provided in plural rows (in a lattice form). Still alternatively, the plurality of convex parts 18 may be provided at random. Any of the aforementioned provisions makes it possible to increase a close-contact area and to enhance an anchor effect.
As described above, the wiring board 1 according to the present invention has the configuration that the through hole 17 or the convex part 18 engaged with the resin 13 is provided on the peripheral region 8 surrounding the matrix of the element regions 6, that is, the spacing. Therefore, it is possible to fixedly bond the resin 13 to the wiring board 1 by enhancement in anchor effect and increase in close-contact area. Thus, the wiring board 1 effectively absorbs a stress generated upon performance of dicing, so that the resin 13 can be prevented from being peeled off from the dicing tape 15.
Accordingly, even when the dicing blade 16 is rotated at a high speed or is moved rapidly as compared with a conventional case, it is possible to prevent the resin 13 in the spacing from being peeled off from the dicing tape 15 and to prevent the spacing to be cut or the resin in such spacing from being scattered. Further, it is possible to prevent the resin in a product from becoming chipped and to prevent the dicing blade 16 from being damaged. Moreover, since it is unnecessary to increase a particular step upon fabrication of the wiring board 1, it is possible to improve productivity.
The wiring board 1 according to the present invention is widely utilized for manufacturing a resin-molding type semiconductor device in the following manner. That is, a plurality of semiconductor elements are sealed with a resin collectively, and then the wiring board is divided for each or plural semiconductor element(s) by performance of dicing.
The aforementioned shapes and provisions of the through hole 17 or the convex part 18 may be applied in combination. Further, the through hole 17 and the convex part 18 maybe applied to a base material used like the wiring board 1. Such base material is, for example, a lead frame in which die pad parts and lead parts are provided in plural sets.
Patent Application
20070262462
