JP2000058571A - Mold for resin sealing for semiconductor chip and method therefor using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent reduction in yields due to leakage of resin or destruction of a substrate during sealing operations of a PBGA(plastic ball grid array) or the like. SOLUTION: A mold for sealing is provided with an upper cavity block 10, a lower cavity block 52, upper cavities 53 disposed in the upper cavity block 10, and clamp blocks 12 disposed for each of the upper cavities 53. The upper cavity block 10 and the lower cavity block 52 sandwich semiconductor chips 56 in such a way that each of them is inside each of the upper cavities 53, and the perimeter of a substrate 57 is positioned outside the upper cavities 53. The clamp blocks 12 are provided in the upper cavity block 10 for each of the upper cavities 53 in such a way that they surround the border of the upper cavities 53 which is in contact with the substrate 57. In this way, the substrate 57 can be pressed at every upper cavity 53.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plastic ball grid array package (hereinafter referred to as "P
"BGA package". ) And plastic pins
The present invention relates to a semiconductor chip resin encapsulation mold and a semiconductor chip resin encapsulation method using the same for a single-sided encapsulation type semiconductor device such as a grid array package.

[0002]

2. Description of the Related Art Conventionally, a PBGA package is formed by a mold for encapsulating a semiconductor chip resin (hereinafter referred to as "encapsulation mold") shown in FIG. The sealing mold shown in FIG. 6 includes an upper cavity block 51 and a lower cavity block 52. The upper cavity block 51 has an upper cavity 53 forming a resin sealing area. Also, the lower cavity block 52
Is a fixed cavity block 52A having a lower cavity 54 formed of a relatively large recess, and a lower cavity 54
And a moving cavity block 52B provided therein.

[0003] The moving cavity block 52B is always pushed upward with a predetermined pressing force by a disc spring 55 provided in the lower spring accommodating recess 52Ba. The moving cavity block 52B and the disc spring 55 constitute a pressure relief mechanism (floating mechanism) 60. When the PBGA package is sealed, the substrate 57 is released by the pressure relief mechanism 60.
The substrate wiring (not shown) is protected by absorbing the thickness variation.

[0004] Next, the semiconductor chip resin encapsulation method of the PBGA package in the above-mentioned conventional example (hereinafter referred to as "encapsulation method")
That. ) Will be described.

[0005] First, the sealing mold shown in FIG. 6 is heated. When the temperature of the sealing mold reaches a predetermined temperature, the substrate 57 on which the wire bonding has been performed is placed on the moving cavity block 52B. Subsequently, the upper cavity block 51
The lower cavity block 52 and the lower cavity block 52 are clamped so that the resin does not leak from the periphery of the upper cavity 53 when the sealing resin is injected without breaking the substrate wiring. After the completion of the mold clamping operation, the resin is injected at a predetermined pressure. After the injection is completed, the encapsulation mold is opened after a resin curing reaction time, and the encapsulation process is completed.

[0006]

The substrate used for the PBGA package is a multi-cavity in which a plurality of semiconductor chips are mounted in one frame. For this reason, the encapsulating mold has a plurality of cavities, and the substrate is positioned and then clamped. At this time, the above-described pressure relief mechanism absorbs, for example, about 100 [μm] in the thickness variation of the substrate.

However, because of the unevenness due to the substrate wiring, the pressing force is large on a substrate with a thick substrate wiring, and the pressing force is small on a substrate with a thin substrate wiring. Uniform) occurs. Adjusting the mold clamping pressure to prevent partial destruction of the substrate due to this one-sided contact causes resin leakage, and adjusting the mold clamping pressure to prevent resin leakage will cause partial substrate destruction. Had occurred.

[0008]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an encapsulating mold and an encapsulating method which can prevent the yield from being reduced due to resin leakage or substrate destruction in the encapsulating step of a PBGA package or the like, and can further reduce the size of the package. Is to provide.

[0009]

According to the present invention, there is provided an encapsulating mold comprising a first cavity block, a second cavity block, and a plurality of semiconductor chip resin sealing cavities provided in the first cavity block. , A clamp block. The first cavity block and the second cavity block sandwich a substrate on which a semiconductor chip is partially die-bonded such that the semiconductor chip is located in the cavity and the periphery of the substrate is located outside the cavity. It is. The clamp block is provided in the first cavity block for each cavity so as to surround a peripheral end of the cavity in contact with the substrate, and is independent of the first cavity block and the second cavity block. The substrate can be pressed for each cavity.

Next, a method of using the mold according to the present invention will be described. As described above, an encapsulation mold having a plurality of cavities into which a substrate is used as an insert and a sealing resin is injected, and a movable clamp block that presses the substrate for each cavity is used. Then, the substrate is placed on the second cavity block, and the mold is clamped by the first cavity block and the clamp block so that the cavity forms an enclosed area on the substrate. At this time, the mold clamping pressure is detected for each clamp block, and the clamp block is moved by a predetermined amount when the mold clamping pressure reaches a predetermined pressure. Thereby, the substrate is clamped and resin is injected. Instead of detecting the mold clamping pressure, the position may be detected, or both the pressure and the position may be detected.

By controlling the pressure or position on the clamp block for each cavity, the mold clamping pressure is uniform across all cavities to accommodate different substrate thicknesses for each cavity. Therefore, resin leakage at the time of encapsulation is prevented and one-side contact does not occur,
With no breakage of the substrate, the minimum amount of mold clamping pressure required for each cavity or the amount of pressing by position control,
Resin injection can be performed.

[0012]

FIG. 1 is a schematic sectional view showing a first embodiment of an encapsulating mold according to the present invention. FIG. 2 is an exploded perspective view showing a part of the sealing mold of FIG. Hereinafter, description will be made based on this drawing. However, the same parts as those in FIG.

The encapsulating mold of the present embodiment includes an upper cavity block 10, a lower cavity block 52, a plurality of upper cavities 53 provided in the upper cavity block 10 for sealing a semiconductor chip resin, and each upper cavity 53. And a plurality of clamp blocks 12 provided at the same position.
Upper cavity block 10 and lower cavity block 5
Reference numeral 2 denotes a substrate for sandwiching a substrate 57 to which a semiconductor chip 56 is partly die-bonded such that the semiconductor chip 56 is located in the upper cavity 53 and the periphery of the substrate 57 is located outside the upper cavity 53. The clamp block 12 is provided in the upper cavity block 10 for each of the upper cavities 53 so as to surround a peripheral end of the upper cavity 53 in contact with the substrate 57, and is provided independently of the upper cavity block 10 and the lower cavity block 52. The substrate 57 can be pressed for each upper cavity 53. That is, the clamp block 12 can slide up and down inside the upper cavity block 10. Note that only one upper cavity 53 and one clamp block 12 are shown for convenience.

In addition, a pressurizing mechanism (only the pressing member 14A is shown) for controlling the pressing force on the substrate 57 is provided for each clamp block 12 in the sealing mold of the present embodiment. The pressing mechanism includes a pressing force source (not shown), a pressing member 14 for transmitting the pressing force generated from the pressure generating source to the clamp block 12, and a pressure sensor (not shown) for detecting the pressing force on the substrate 57. ), And a controller (not shown) for controlling a pressing force source so that the pressing force detected by the pressure sensor becomes a predetermined value. Therefore, the mold clamping pressure can be adjusted for each upper cavity 53 by the pressurizing mechanism.

The source of the pressing force is, for example, a servomotor, a hydraulic device or the like. The pressure sensor is, for example, a load cell provided in a pressurizing mechanism. A position sensor may be used instead of the pressure sensor. The controller is, for example, a microcomputer.

Next, the operation of the sealing mold shown in FIG. 1 will be described.

For example, when enclosing a six-substrate PBGA board, the pushing force of the pressure relief mechanism 60 by the disc spring 55 of the lower cavity 54 is approximately 80 to 100 kg / cm ² . By combining a plurality of disc springs 55,
Adjust so that the required spring force is obtained. At this time, even if the clamping force by the upper cavity block 10 and the lower cavity block 52 is set to 100 kg / cm ² or more, the plate relief spring 55
Only a certain pressure due to This disc spring 5
It is desirable that the set value of 5 be a pressure that does not damage the substrate 57. In this state, the clamp block 12 is lowered for each of the upper cavities 53 and pushed down until the pressure reaches about 100 to 150 [kg / cm ² ] at which the substrate 57 does not break. As described above, after the clamp is completed in a state where the resin does not leak in each of the upper cavities 53, the resin is injected.

FIG. 3 is a schematic sectional view showing a second embodiment of the encapsulating mold according to the present invention. Hereinafter, description will be made based on this drawing. However, the same parts as those in FIG.

The mold of the present embodiment is provided with a clamp block relief 52Bb for releasing the substrate 57 deformed by the pressing of the clamp block 12. The clamp block relief 52Bb is provided at a position of the moving cavity block 52B constituting the lower cavity block 20 facing the clamp block 12. This allows
The stroke of the clamp block 12 can be maximized. After the resin injection is completed, the clamp block 12 is further moved by the thickness of the substrate 57 (in this case, 0.1 mm).
36 [mm]), the substrate 57 can be cut into individual pieces.

FIG. 4 is a schematic sectional view showing a third embodiment of the encapsulating mold according to the present invention. Hereinafter, description will be made based on this drawing. However, the same parts as those in FIG.

In the mold of the present embodiment, a part of the cavity 32 provided in the upper cavity block 30 is constituted by the clamp block 12. For more information,
The side surface (the surface perpendicular to the substrate 57) of the cavity 32 is constituted by the clamp block 12. This allows
It is possible to manufacture a PBGA package in which the ridgeline of the resin outer periphery is vertical. Therefore, according to the sealing mold of the present embodiment, it is possible to minimize the resin sealing area.

FIG. 5 is a schematic sectional view showing a sealing method using the sealing mold of FIG. 3 in the order of steps. Hereinafter, description will be made based on this drawing.

First, the substrate 57 is positioned on the moving cavity block 52B (FIG. 5A), and the upper cavity block 10 and the lower cavity block 20 are clamped (FIG. 5B). Since the lower cavity 54 is provided with a pressure relief mechanism 60 using a disc spring 55, the substrate 57 is clamped by the spring force of the disc spring 55 in the state of FIG. At this time, the mold clamping pressure due to the spring force is
7 is not destroyed. In this state, since no resin is injected, there may be a gap.

When the clamp block 12 is pressurized while monitoring the pressure from the state shown in FIG. 5B and the substrate 57 is deformed, the pressurization of the clamp block 12 is stopped (FIG. 5C). In this state, the resin is injected. When resin injection is completed, open the mold and take out the product.

The operation of the clamp block 12 for deforming the substrate 57 can be performed by position control, or by using both position and pressure. Further, after the resin injection is completed, the clamp block 1 is used until the substrate 57 is broken.
By pressing 2, the cutting step at the resin ridge line can be performed at the same time.

In addition to those described in the above embodiments, the present invention can be widely applied to the encapsulating step and the cutting step of a single-sided sealed package using a plastic substrate. According to the present invention, encapsulation with less resin leakage and less substrate damage is possible, and it is possible to make the outer dimensions of the package smaller than when using a conventional encapsulation die.

[0027]

According to the sealing mold and the sealing method according to the present invention, the first cavity block and the second cavity block are provided by providing the clamp block for each cavity so as to surround the peripheral end of the cavity in contact with the substrate. Since the substrate can be pressed for each cavity independently of the cavity block, problems such as resin leakage or substrate wiring destruction due to variations in substrate thickness can be prevented, thereby improving the yield. it can.

According to the enclosing mold according to the second aspect or the enclosing method according to the fourth aspect, the substrate is more reliably pressed by providing the clamp block relief for releasing the substrate deformed by the pressing of the clamp block. Therefore, it is possible to more reliably prevent resin leakage due to variations in the thickness of the substrate.

According to the third aspect of the present invention, since a part of the cavity is constituted by the clamp block, it is possible to realize cutting at a resin ridge line which can reduce the size of a product.

According to the enclosing method of the fifth aspect, the substrate cutting step which has been conventionally required can be omitted by cutting the substrate by the clamp block.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a first embodiment of a semiconductor chip resin sealing mold according to the present invention.

FIG. 2 is an exploded perspective view showing a part of the semiconductor chip resin sealing mold of FIG. 1;

FIG. 3 is a schematic sectional view showing a second embodiment of a semiconductor chip resin sealing mold according to the present invention.

FIG. 4 is a schematic sectional view showing a third embodiment of a semiconductor chip resin sealing mold according to the present invention.

FIG. 5 is a schematic cross-sectional view showing a method for sealing a semiconductor chip resin using the encapsulating mold shown in FIG. 3, and the process proceeds in the order of FIGS. 5 [1] to [3].

FIG. 6 is a schematic cross-sectional view showing a conventional semiconductor chip resin sealing mold.

[Explanation of symbols]

10, 30 Upper cavity block (first cavity block) 12 Clamp block 14A Pressing member of pressure mechanism 30, 52 Lower cavity block (second cavity block) 32, 53 Upper cavity (cavity for sealing semiconductor chip resin) 54 Lower cavity 57 Substrate 56 Semiconductor chip 52Bb Clamp block escape

Claims (6)

[Claims] 1. A first cavity block, a second cavity block, and a plurality of cavities provided in the first cavity block for sealing a semiconductor chip resin, wherein the first cavity block and the second cavity are provided. The block is for holding a substrate on which a semiconductor chip is partially die-bonded so that the semiconductor chip is located in the cavity and the periphery of the substrate is located outside the cavity. In the mold, provided in the first cavity block for each of the cavities so as to surround a peripheral end of the cavity in contact with the substrate, and each of the cavities is independent of the first and second cavity blocks. A clamp block capable of pressing the substrate for each cavity. The semiconductor chip resin sealing die according to symptoms. 2. The semiconductor chip resin sealing mold according to claim 1, further comprising a clamp block relief for releasing a substrate deformed by the pressing of the clamp block. 3. The semiconductor chip resin sealing mold according to claim 1, wherein a part of said cavity is constituted by said clamp block. 4. A semiconductor chip resin sealing method using a semiconductor chip resin sealing mold according to claim 1, 2 or 3, wherein the first cavity block and the second cavity block comprise a substrate. A semiconductor chip resin sealing method, wherein a mold is preliminarily clamped by sandwiching the mold, and then the mold is clamped by pressing the substrate for each of the cavities by the clamp block. 5. A semiconductor chip resin sealing method using the semiconductor chip resin sealing mold according to claim 2, wherein the substrate is sandwiched between the first cavity block and the second cavity block. A semiconductor mold resin sealing method, wherein the mold is preliminarily clamped, the mold is clamped by pressing the substrate for each cavity by the clamp block, and the substrate is deformed by the clamp block. . 6. A semiconductor chip resin sealing method using a semiconductor chip resin sealing mold according to claim 2, wherein the substrate is sandwiched between the first cavity block and the second cavity block. Preliminarily, clamping is performed by pressing the substrate for each of the cavities by the clamp block, and the substrate is further cut by the clamp block. .