JP4065180B2 - Resin sealing mold - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin-sealed mold used for manufacturing a package by resin-sealing chip-shaped electronic components (hereinafter referred to as “chips”) mounted on a printed circuit board.
[0002]
[Prior art]
Conventionally, when manufacturing a package by resin-sealing a chip mounted on a lead frame made of a metal plate, a molten resin is put into a cavity provided in the mold while the lead frame is clamped by the mold. Injected and cured. In this case, there is no gap between the lead frame and the mold by clamping the lead frame. Therefore, it is possible to prevent the resin from leaking onto the lead frame and causing flash.
[0003]
However, in recent years, multilayer printed boards (hereinafter referred to as “substrates”) using a resin plate such as a glass epoxy plate as a base material instead of a lead frame have been widely used. Also in this case, as in the case of the lead frame, the molten resin is injected into the cavity provided in the mold in a state where the substrate is clamped by the mold and is cured. Here, due to the weakness of the substrate, it is necessary to prevent the substrate from being deformed or damaged and the generation of a gap between the mold and the substrate by clamping the substrate with an appropriate clamping pressure.
Further, when the substrate is heated, it is necessary to absorb the warp caused by the difference in thermal expansion coefficient between the glass epoxy plate and the metal and prevent the generation of a gap between the mold and the substrate. For this purpose, the mold is provided with a clamping part that clamps the substrate and a fixed part that does not clamp the substrate (for example, see Patent Document 1).
[0004]
[Patent Document 1]
JP-A-10-284527 (page 5-8, FIGS. 1 to 4)
[0005]
[Problems to be solved by the invention]
However, according to the above conventional technique for preventing the generation of a gap between the mold and the substrate, there are the following problems. This is a problem that due to variations in the density of wiring patterns and external connection pads (hereinafter also referred to as “patterns”) on the substrate, an appropriate clamping pressure on the substrate may not be ensured. In particular, in a package called BGA (Ball Grid Array) which has been widely used in recent years, the area of the densely packed portion of the pattern is small from a rough type to a dense type as the product pattern is diversified. This problem has become prominent because of the diversification from substrates to large substrates. Hereinafter, the problem to be solved by the invention will be described with reference to FIGS.
[0006]
4 (1) and 4 (2) are a plan view and a part of the AA line showing the positional relationship between a substrate and a mold having a large area of a dense pattern area in the conventional case of manufacturing a BGA, respectively. It is sectional drawing. 5 (1) and 5 (2) are a plan view and a portion along the line BB showing the positional relationship between a substrate and a mold having a small area of a dense pattern portion in the conventional case of manufacturing a BGA, respectively. It is sectional drawing.
[0007]
As shown in FIGS. 4 and 5, the substrates B1 and B2 are clamped by the lower mold 51 and the upper mold 52, respectively. On the upper surfaces 53 of the substrates B1 and B2, a wire pad 54 to which a wire to be described later is connected and a wiring pattern 55 drawn from the wire pad 54 are formed, and a chip 56 is mounted. An electrode (not shown) on the chip 56 and the wire pad 54 are electrically connected by a wire 57. External connection pads 59 to which projecting electrodes (not shown) are connected are formed on the lower surfaces 58 of the substrates B1 and B2. The wire pad 54, the wiring pattern 55, and the external connection pad 59 are made of, for example, a copper foil having a thickness of 18 μm or 35 μm. In addition, an insulating film (not shown) called a solder resist is formed on the wiring pattern 55.
The upper mold 52 is provided with a cavity 60 so that the chip 56 and the wire 57 are accommodated, and is provided with a resin flow path 61 that communicates with the cavity 60 and in which a molten resin (not shown) flows.
[0008]
In the substrate B1 shown in FIG. 4, the wiring pattern 55 on the upper surface 53 and the external connection pads 59 on the lower surface 58 are both densely formed. The wiring patterns 55 on the upper surface 53 are concentrated in the dense portion 62, and the dense portion 62 occupies most of the upper surface 53 other than the cavity 60 and the resin flow path 61. Further, the external connection pads 59 are provided over almost the entire lower surface 58, and adopt a so-called entire surface arrangement type configuration.
On the other hand, in the substrate B2 shown in FIG. 5, the wiring pattern 55 on the upper surface 53 and the external connection pads 59 on the lower surface 58 are both roughly formed. The wiring patterns 55 on the upper surface 53 are concentrated in the dense portion 63, and the dense portion 63 is located between the wire pad 54 provided corresponding to the four sides of the chip 56 on the upper surface 53 and the outer edge of the substrate B 2. It is provided only in. Further, the external connection pad 59 is provided in the peripheral portion of the lower surface 58 and has a so-called peripheral arrangement type configuration.
[0009]
Here, consider a case where the substrates B1 and B2 are clamped by the same clamping pressure by the lower mold 51 and the upper mold 52, respectively. In the substrate B1, a clamping pressure is applied to the wiring pattern 55 and the external connection pad 59 that are densely formed on the upper surface 53 and the lower surface 58, in other words, to a large area. On the other hand, in the substrate B2, a clamping pressure is applied to the wiring pattern 55 and the external connection pad 59 that are formed roughly on the upper surface 53 and the lower surface 58, in other words, to a small area.
Accordingly, if the clamping pressure is set to be appropriate for the substrate B1, the clamping pressure applied to the substrate B2 becomes excessive. In this case, problems such as deformation and breakage of the substrate B2 and disconnection of the wiring pattern 55 occur. Further, if the clamp pressure is set to be appropriate for the substrate B2, the clamp pressure applied to the substrate B1 becomes too small. In this case, there is a possibility that a gap is generated between the substrate B1 and the upper mold 52, and the molten resin leaks onto the substrate B1 to generate flash.
[0010]
The present invention has been made to solve the above-mentioned problems, and in the case where the areas of dense portions of patterns formed on a plurality of types of substrates are different, ensuring an appropriate clamping pressure on the substrate, It aims at providing the resin sealing metal mold | die which prevents generation | occurrence | production of this.
[0011]
[Means for Solving the Problems]
[0012]
[0013]
In order to solve the technical problem described above, the resin-sealed mold according to the present invention is obtained by resin-sealing a chip-shaped electronic component mounted on a substrate having a pattern while the substrate is sandwiched. A resin-sealed mold used for manufacturing a package, wherein the mold is such that the resin-sealed mold does not overlap a dense portion where patterns on the board are densely placed on the mold surface sandwiching the board. The projection is provided with a projection protruding from the surface by a predetermined projection amount, and the projection is made of another member incorporated in the resin-sealing mold, and the projection amount is substantially equal to the increase in the substrate thickness at the dense portion. It is possible to adjust as follows.
[0014]
According to this, the protrusion amount of the protrusion provided to protrude from the mold surface by the predetermined protrusion amount so as not to overlap the dense portion of the pattern on the substrate is substantially equal to the increase amount of the substrate thickness in the dense portion. Can be adjusted. Therefore, even when the areas of the dense portions are different or the amount of increase in the substrate thickness is different in a plurality of types of substrates, the clamping pressure for the substrates of each model is made uniform.
[0015]
Further, the resin-sealed mold according to the present invention is the above-mentioned resin-sealed mold, wherein the convex portion is retracted from the top of another member using elasticity while the resin-sealed mold is clamped. In this case, the protrusion protrudes from the mold surface by an amount substantially equal to the increase amount.
[0016]
According to this, in a state where the resin-sealed mold is clamped, the convex portion protrudes from the mold surface by an amount substantially equal to the increase amount of the substrate thickness using elasticity. Therefore, in the case of multiple types of substrates, even if the area of the dense part is different or the amount of increase in the substrate thickness is different, without adjusting the protrusion amount according to the increase amount of the substrate thickness of each model, The clamping pressure for the model substrate is made uniform.
[0017]
The resin-sealed mold according to the present invention is used when a package is manufactured by resin-sealing chip-shaped electronic components mounted on a substrate having a pattern while the substrate is sandwiched. The resin sealing mold is provided so that the resin sealing mold overlaps at least a dense portion where patterns on the substrate are densely arranged on at least one of the mold surfaces sandwiching the substrate. In addition to including the protruding region, a portion of the dense portion that overlaps the protruding region is common to a plurality of different types of substrates.
[0018]
According to this, the part which is common in the board | substrates of different models among the dense parts is pinched by the convex part. Therefore, even when the areas of the dense portions are different or the amount of increase in the substrate thickness is different in a plurality of types of substrates, the clamping pressure for the substrates of each model is made uniform.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
Hereinafter, a resin-sealed mold according to a first embodiment of the present invention will be described with reference to FIG. FIGS. 1A and 1B are partial cross-sectional views showing a state where the resin-sealed mold according to the present embodiment is applied to a substrate having a large area of dense patterns and a small substrate, respectively. is there.
[0020]
In FIG. 1, the substrates B <b> 1 and B <b> 2 are clamped by the lower mold 1 and the upper mold 2, respectively. On the upper surface 3 of the substrates B1 and B2, a wire pad 4 to which a wire to be described later is connected and a wiring pattern 5 led from there are formed, and a chip 6 is mounted. An electrode (not shown) on the chip 6 and the wire pad 4 are electrically connected by wire bonding using a wire 7. External connection pads 9 to which projecting electrodes (not shown) are connected are formed on the lower surfaces 8 of the substrates B1 and B2. The wire pad 4, the wiring pattern 5, and the external connection pad 9 are made of, for example, a copper foil having a thickness of 18 μm or 35 μm. An insulating film (not shown) called a solder resist is formed on the wiring pattern 5.
The upper mold 2 is provided with a cavity 10 so as to accommodate the chip 6, the wire 7, and the wire pad 4. Further, a resin flow path 11 through which molten resin (not shown) flows is provided in communication with the cavity 10. And molten resin is inject | poured into the cavity 10 via the resin flow path 11 by being pressed by the plunger (all are not shown) in a pot.
[0021]
The substrate B1 shown in FIG. 1 (1) is the same substrate as the substrate B1 shown in FIG. That is, since the wiring pattern 5 on the upper surface 3 and the external connection pads 9 on the lower surface 8 are both densely formed on the substrate B1, the substrate B1 is a substrate having a large area of dense portions of these patterns.
Concave portions 12 and 13 are formed in the lower mold 1 and the upper mold 2 of FIG. The ranges of the recesses 12 and 13 are ranges in which the wiring patterns 5 and the external connection pads 9 are formed, respectively. In other words, the recesses 12 and 13 are provided so as to overlap the densely packed portions of the substrate B1 when viewed in plan. The depths of the recesses 12 and 13 are provided so as to be approximately equal to the increase in the substrate thickness due to the wiring pattern 5 and the external connection pad 9, respectively.
[0022]
On the other hand, the substrate B2 shown in FIG. 1 (2) is the same substrate as the substrate B2 shown in FIG. That is, since the wiring pattern 5 on the upper surface 3 and the external connection pads 9 on the lower surface 8 are both roughly formed on the substrate B2, the substrate B2 is a substrate in which the area of the dense portion of these patterns is small. The substrate B2 has a so-called peripheral arrangement type configuration, and the external connection pads 9 are not formed in the central portion 14 of the lower surface 8.
With respect to the substrate B2 where the area of the densely packed portion of such a pattern is small, the recesses 15 and 16 in the lower mold 1 and the upper mold 2 in FIG. It is formed in this way.
[0023]
Here, the first feature of the resin-sealed mold according to the present embodiment is that the concave portions 12, 13, and the concave portions 12, 13, respectively overlap with the dense portions according to the dense portions of the patterns in the substrates B 1, B 2. 15 and 16 are provided. Second, each recess 12, 13, 15, 16 has a depth that is approximately equal to the amount of increase in substrate thickness at the dense portion.
As a result, in both the substrate B1 where the area of the dense pattern portion is large and the substrate B2 where the area of the dense portion is small, the mold surface of the mold is other than all portions of the pattern in the dense portion and the dense portion in the substrate. The part combined with the part is in contact. In other words, when the substrate B1 and the substrate B2 are clamped, there is no great difference in the area of the clamped portion. Accordingly, an appropriate clamping pressure is ensured for a plurality of types of substrates regardless of the area of the densely packed portion of the pattern, so that the occurrence of flash on the substrate B1, deformation and breakage on the substrate B2, and disconnection of the wiring pattern 5 Etc. are prevented.
[0024]
(Second Embodiment)
Hereinafter, a resin-sealed mold according to the second embodiment of the present invention will be described with reference to FIG. FIGS. 2A and 2B are partial cross-sectional views showing a state in which the resin-sealed mold according to the present embodiment is applied to a substrate having a large area of dense patterns and a small substrate, respectively. is there.
[0025]
As shown in FIG. 2A, in the present embodiment, the recesses 12 and 13 in the first embodiment are not provided for the substrate B1. Instead of these, through-holes 17 are provided in the lower mold 1 and the upper mold 2, respectively, in portions having no pattern, for example, in the vicinity of the outer periphery of the substrate B1 or at the four corners, and each through-hole 17 is movable up and down. Pins 18 are provided. Similarly, with respect to the substrate B2, instead of the recesses 15 and 16 in the first embodiment, the lower mold 1 and the upper mold 2 are provided with through holes 17, respectively, and the through holes 17 can be raised and lowered. A movable pin 18 is provided.
[0026]
Each movable pin 18 is attached to the lower mold 1 and the upper mold 2 via an elastic body (not shown) such as a spring so as to be movable up and down. In addition, each movable pin 18 is provided so as to overlap a portion having no pattern in the substrates B1 and B2 when viewed in plan. 2 (1) and 2 (2), these movable pins 18 operate as follows.
[0027]
First, in a state where the lower mold 1 and the upper mold 2 are opened, each movable pin 18 is pressed by an elastic body such as a spring. Thereby, the tip of each movable pin 18 protrudes from the mold surface by a certain amount.
[0028]
Next, the lower mold 1 and the upper mold 2 are clamped with the substrate B1 or the substrate B2 placed on the lower mold 1. And the movable pin 18 clamps the board | substrate B1 or the board | substrate B2 from the up-down both directions with a predetermined clamp pressure in the part without a pattern.
[0029]
As described above, according to the present embodiment, both the substrate B1 having a large area of the pattern dense portion and the substrate B2 having a small area of the dense portion have the lower mold 1 and the upper portion in the pattern dense portion. In the part which the movable pin 18 contacts with the type | mold 2, it is clamped by the movable pin 18, respectively. Thus, as in the first embodiment, there is no large difference in the area of the clamped portion between the substrates B1 and B2, so that an appropriate clamping pressure is ensured regardless of the area of the densely packed portion of the pattern. Is done. Therefore, the occurrence of flash on the substrate B1, deformation and damage on the substrate B2, and disconnection of the wiring pattern 5 are prevented.
[0030]
In the description of the present embodiment, the movable pin 18 is used. Not limited to this, instead of the movable pin 18, a fixed pin or a block-like member may be adjusted and fixed so as to protrude from the mold surface by an amount substantially equal to the increase amount of the substrate thickness. Here, the increase amount of the substrate thickness can be estimated in advance according to the thickness (for example, 18 μm or 35 μm) of the copper foil forming the wiring pattern 5 and the external connection pad 9. Therefore, the same effect can be obtained by adjusting and fixing a fixing member such as a fixing pin or a block so as to protrude from the mold surface by an amount corresponding to the thickness of the copper foil.
[0031]
Moreover, you may comprise the movable pin 18 from the material which has flexibility. In this case, the movable pin 18 is clamped from both above and below by being deformed by the flexibility of the movable pin 18 itself while the lower die 1 and the upper die 2 are clamped. To do.
[0032]
(Third embodiment)
Hereinafter, a resin-sealed mold according to a third embodiment of the present invention will be described with reference to FIG. FIGS. 3A and 3B are plan views respectively showing a state in which the resin-sealed mold according to the present embodiment is applied to a substrate having a large area of dense patterns and a small substrate. .
[0033]
The substrate B1 shown in FIG. 3 (1) is the same substrate as the substrate B1 shown in FIG. 4, and has a dense area 19 of a pattern having a large area on the upper surface 3. The dense portion 19 occupies most of the upper surface 3 of the substrate B1 other than the cavity 10 and the resin flow path 11.
On the other hand, the substrate B2 shown in FIG. 3 (2) is the same substrate as the substrate B2 shown in FIG. 5, and has a dense area 20 with a pattern having a small area on the upper surface 3. This dense portion 20 is provided only between the wire pad 4 provided corresponding to the four sides of the chip 6 and the outer edge of the substrate B2 on the upper surface 3 of the substrate B2. The dense portion 20 is included in the dense portion 19 in the substrate B1. Further, the dense portion 20 is a portion common as a portion where patterns are densely arranged not only on the substrate B1 and the substrate B2 but also on other types of substrates as long as the same size substrate is used in which the same size cavity is used. .
[0034]
As shown in FIGS. 3 (1) and 3 (2), the resin-sealed mold according to the present embodiment, that is, the lower mold 1 and the upper mold 2 are clamps common to the substrates B1 and B2. Part 21. The clamp portion 21 is a region that protrudes from the upper surface 3 of the substrate B1 and the substrate B2 by a predetermined protrusion amount, and clamps the vicinity of the cavity 10 and the resin flow path 11, respectively. The clamp part 21 clamps most of the common dense part 20 between the four sides of the chip 6 and the outer edges of a plurality of types of boards including the board B1 and the board B2.
[0035]
As described above, according to the present embodiment, the substrate B1 having the large area of the pattern dense portion and the substrate B2 having the small area of the dense portion are separated by the lower mold 1 and the upper mold 2 in the common dense portion 20. Clamped. Furthermore, substrates of the same size in which cavities of the same size as those of the substrates B1 and B2 are used are clamped at the common dense portion 20. As a result, a plurality of types of substrates having different areas of pattern dense portions are clamped with the same area in the common dense portion 20, thereby ensuring an appropriate clamping pressure. Therefore, the occurrence of flash on the substrate B1 having a large area of dense patterns, deformation and breakage on the substrate B2 having a small area of dense areas, and disconnection of the wiring pattern 5 are prevented.
[0036]
In each of the embodiments so far, the cavity 10 is provided in the upper mold 2. However, the present invention is not limited to this, and a cavity may be provided in the lower mold 1. In addition, the cavity 10 can be provided in both the lower mold 1 and the upper mold 2.
[0037]
In addition, the present invention can be applied not only to a mold having a configuration in which the lower mold 1 and the upper mold 2 are opposed to each other, but also to molds that are opposed to each other such as a mold that is opposed in the horizontal direction.
[0038]
In addition, an electrical connection between an electrode (not shown) on the chip 6 and the wire pad 4 is performed by wire bonding. However, the present invention is not limited to this, and other connection methods such as flip chip bonding can be used.
[0039]
Further, the case where one chip 6 is accommodated in one cavity 10 has been described. However, a plurality of substrates are used, and a plurality of chips arranged in one row or matrix in one large cavity are used. Even when the chip is accommodated, the present invention can be applied. In this case, a concave portion, a movable pin, a fixed member, or a clamp portion may be appropriately provided in the mold around the large cavity.
[0040]
The substrate is a multilayer printed board using a resin plate as a base material. The present invention is not limited to this and can be applied to a silicon substrate, a ceramic base substrate, and the like.
[0041]
Further, the present invention is not limited to the above-described embodiment, and can be adopted by arbitrarily combining, changing, and selecting as necessary within a range not departing from the gist of the present invention. It is.
[0042]
【The invention's effect】
According to the present invention, even if the area of the dense portion of the pattern is different in a plurality of types of substrates due to the predetermined concave portion, convex portion, or protruding region provided on the mold surface of the resin-sealed mold, Regardless of the size of the area, the pressure at which the substrates of each model are clamped, that is, the clamping pressure is made uniform. Therefore, it is possible to prevent the occurrence of burrs on a substrate having a large area of dense patterns, deformation and breakage of the substrate on a substrate having a small area of dense areas, and disconnection of a wiring pattern. As a result, the present invention has an excellent practical effect that it can provide a resin-sealed mold that secures an appropriate clamping pressure against the substrate and prevents the occurrence of defects.
[Brief description of the drawings]
FIGS. 1 (1) and 1 (2) show a resin-sealed mold according to a first embodiment of the present invention, which is applied to a substrate having a large area of dense patterns and a substrate having a small area. It is a fragmentary sectional view showing a state, respectively.
2 (1) and 2 (2), the resin-sealed mold according to the second embodiment of the present invention is applied to a substrate with a large area of pattern dense portions and a small substrate. It is a fragmentary sectional view showing a state, respectively.
FIGS. 3 (1) and 3 (2) show a case where a resin-sealed mold according to a third embodiment of the present invention is applied to a substrate with a large area of pattern dense portions and a small substrate. It is a top view which shows a state, respectively.
FIGS. 4 (1) and 4 (2) are a plan view and its A-, respectively, showing a positional relationship between a substrate and a mold having a large area of pattern dense portions in a conventional case of manufacturing a BGA. It is a fragmentary sectional view in the A line.
FIGS. 5 (1) and 5 (2) are a plan view showing a positional relationship between a substrate having a small pattern dense area and a mold, respectively, in the conventional case of manufacturing a BGA, and FIG. It is a fragmentary sectional view in the B line.
[Explanation of symbols]
1 Lower mold 2 Upper mold 3 Top surface 4 Wire pad 5 Wiring pattern (pattern)
6 Chip (electronic component)
7 Wire 8 Lower surface 9 External connection pad (pattern)
DESCRIPTION OF SYMBOLS 10 Cavity 11 Resin flow path 12, 13, 15, 16 Concave part 14 Center part 17 Through-hole 18 Movable pin (convex part)
19, 20 Dense part 21 Clamp part (protrusion area)
B1, B2 substrate

Claims (3)

A resin-sealed mold used for manufacturing a package by resin-sealing chip-shaped electronic components mounted on a substrate having a pattern in a state where the substrate is sandwiched,
On the mold surface where the resin-sealed mold sandwiches the substrate, a convex portion provided by projecting a predetermined amount of projection from the mold surface so as not to overlap the dense portion where the pattern on the substrate is dense With
The convex portion is made of another member incorporated in the resin sealing mold, and the protruding amount can be adjusted to be substantially equal to the increase amount of the substrate thickness in the dense portion. Mold. In the resin-sealed mold according to claim 1 ,
The convex portion protrudes from the mold surface by an amount substantially equal to the increased amount by retreating the top of the separate member using elasticity in a state where the resin-sealed mold is clamped. A resin-sealed mold characterized by A resin-sealed mold used for manufacturing a package by resin-sealing chip-shaped electronic components mounted on a substrate having a pattern in a state where the substrate is sandwiched,
The resin-sealed mold includes a protruding region provided on at least one mold surface of the mold surfaces sandwiching the substrate so as to overlap at least a dense portion where the pattern on the substrate is dense,
A portion of the dense portion that overlaps the protruding region is common to a plurality of different types of substrates.

Images