CN1380691A - Substrate bonding for ball grid array chip packaging structure - Google Patents

Abstract

A substrate connecting sheet for ball grid array type chip package structure is composed of multiple substrates for package, and features that a special connecting mechanism is used to prevent the thermal deformation of each substrate in high-temp manufacture. The substrate connecting sheet is characterized in that a two-point connecting structure or a one-point connecting structure is adopted to connect each substrate to the supporting rod of the frame instead of a four-point connecting structure adopted in the prior art, namely, each substrate is connected to the supporting rod of the frame only through at most two connecting sheets. In the high temperature treatment process, the heated substrate can expand towards the corners without the connecting pieces, i.e. the thermal stress can be relieved towards the directions, so that the thermal deformation phenomenon of the substrate can not be generated. Since the substrate does not have thermal deformation, the ball grid array subsequently implanted on the back surface of the substrate has high flatness.

Description

Substrate bonding for ball grid array chip packaging structure

The present invention relates to a semiconductor packaging technology, in particular to a substrate strip (substratestrip) suitable for a Ball Grid Array (BGA) chip packaging structure, which includes a plurality of substrates connected by frames (substrate), which is characterized by a special substrate connection structure, which can prevent the thermal deformation of each substrate on it during the high-temperature manufacturing process, so that the solder balls (solder balls) that are subsequently implanted on the back of the substrate have High coplanarity.

Ball Grid Array (BGA) is an advanced semiconductor chip packaging technology, which is characterized in that a substrate is used to place semiconductor chips, and a plurality of arrays arranged in a grid array are placed on the back of the substrate. Solder balls are used to solder and electrically connect the entire package unit to an external printed circuit board through these solder balls.

In the factory manufacturing process, BGA packaging units are generally constructed in batches on a substrate strip; the substrate strip includes multiple substrates connected by frames, each of which is used to make a BGA packaging unit. However, one disadvantage of the existing substrate bonding is that it is subjected to high temperature treatment, such as the curing process (die-bond cure), wire bonding process (wire bonding), molding process of encapsulant ( molding), and the curing process after molding (molding cure), because the temperature in these manufacturing process steps is at least 200? If the temperature is higher than C, thermal deformation of the substrate will easily occur, resulting in poor flatness of the ball grid array subsequently implanted thereon, thereby affecting the soldering effect between the packaging unit and the external printed circuit board. The following is a brief description of the thermal deformation problem in a diagrammatic manner in conjunction with Figures 1A to 1D of the accompanying drawings.

Figure 1A shows a typical BGA package structure. As shown in the figure, this BGA package structure includes: (a) a substrate 11, which has a front surface 11a and a back surface 11b; (b) a semiconductor chip 20, which is placed on the front surface 11a of the substrate 11; and (c) A ball grid array 30 is implanted on the back surface 11 b of the substrate 11 . The semiconductor chip 20 can be electrically coupled to the substrate 10 by using existing wire bonding technology (wirebonding) or flip chip technology (flip chip); The ball grid array 30 is soldered and electrically coupled to an external printed circuit board 40 .

Please refer to FIG. 1B. In the factory manufacturing process, BGA packaging units are generally constructed in batches on a substrate connection 10; the substrate connection 10 includes: (a) a plurality of square substrates 11, wherein Each substrate 11 is used to make a BGA packaging unit; and (b) a frame 12 having a pair of parallel extending support rods 12a, 12b for connecting and supporting the substrates 11 .

In the prior art, each substrate 11 is connected to the support rods 12a, 12b through a four-point connection structure formed by four connecting pieces 13a, 13b, 13c, 13d, and these four connecting pieces 13a, 13b, 13c, 13d are generally set on the four corners of the substrate 11 . In addition, the connecting piece 13a at the upper left corner is generally designed to have a larger width, so that a glue injection channel (not shown) is additionally provided thereon for injecting the glue encapsulation material required in the encapsulation compound manufacturing process.

Next, as shown in FIG. 1C, a shortcoming of the above-mentioned substrate connection 10 is that when it is subjected to high temperature treatment, such as the solidification process after die bonding, the bonding wire manufacturing process, the molding process of the encapsulant, and the post-moulding process During the curing process, the substrate 11 is prone to deformation. This is because the volume of the substrate 11 will expand in all directions when heated. However, as shown in Figure 1C, since the four corners of the substrate 11 have been respectively provided with connecting pieces 13a, 13b, 13c, 13d, the expansion towards these directions will be hindered, so that the thermal stress will be forced to turn towards The center of the substrate 11 is pushed (the direction of the thermal stress is shown by the arrow in FIG. 1C ), causing the center of the substrate 11 to bulge upwards and cause unnecessary deformation.

Then, as shown in FIG. 1D, the deformed substrate 11 will cause the ball grid array 30 subsequently implanted on its back side 11b to have poor flatness; therefore, the overall packaging unit is coupled to the external printed circuit board 40 When, it will cause some of the solder balls to have poor soldering effect.

The large-size substrates currently used, including substrates of 35'35, 37.5'37.5, 40'40, and 42.5'42.5 (unit: mm), are particularly prone to the above-mentioned thermal deformation phenomenon.

Related patented technologies include, for example, U.S. Patent No. 5,652,185 "MAXIMIZED SUBSTRATE DESIGN FOR GRID ARRAY BASED ASSEMBLIES"; U.S. Patent No. 5,635,671 "MOLD RUNNER REMOVAL FROM A SUBSTRATE-BASED PACKAGE DELECTRONIC DEVICE"; COMPONENT HAVING AN ORGANIC SUBSTRATE"; etc.

US Patent No. 5,652,185 discloses a substrate structure that can reduce the area of the substrate, thereby reducing the consumption of the substrate. The substrate structure disclosed in US Pat. No. 5,635,671 can easily remove the spilled gel packaging material. US Patent No. 5,691,242 discloses a chip packaging method in which a special substrate is used to mount the chip.

However, since the substrates used in the above three U.S. patents are still connected to the support rods of the frame using a four-point connection structure, the above-mentioned thermal deformation phenomenon still exists in its application, which makes the ball grid array on the subsequent implantation Has poor flatness.

In view of the above-mentioned shortcomings of the prior art, the main purpose of the present invention is to provide an improved substrate connection, which can prevent the thermal deformation of each substrate on it during the high-temperature manufacturing process, thereby enabling The ball grid array subsequently implanted on the back of the substrate has high flatness.

According to the above-mentioned purpose, the present invention provides an improved substrate connection.

A substrate connection, comprising:

a) a frame having a pair of parallel extending struts comprising a first strut and a

a second support rod; and

b) at least one base plate, which is placed on the frame and connected by at most two connecting pieces

to the support rods of the frame.

A substrate connection, comprising:

a) a frame having a pair of parallel extending struts comprising a first strut and a

a second support rod; and

b) At least one base plate, which is placed on the frame, and passes through two connecting pieces formed by two

Click Link Frame to link to that frame.

A substrate connection, comprising:

a) a frame having a pair of parallel extending struts comprising a first strut and a

a second support rod; and

b) at least one base plate, which is placed on the pair of support rods and constituted by a connecting piece

Linked to the frame by a point link frame.

The substrate connection of the present invention is characterized in that it adopts a two-point connection structure or a one-point connection structure instead of the four-point connection structure used in the prior art to connect each substrate to the support rod of the frame; that is, only through at most two A connecting piece is used to connect each substrate to the support rods of the frame. During the high-temperature treatment process, the heated substrate can expand toward the corners where the connecting pieces are not arranged, that is, the thermal stress can be relieved in these directions, so that the substrate will not be thermally deformed. Since the substrate does not generate thermal deformation, the ball grid array subsequently implanted on the back of the substrate can have high flatness.

The semiconductor packaging technology of the present invention is suitable for substrate strips of Ball Grid Array (BGA) chip packaging structure, which includes a plurality of substrates connected by frames, and is characterized in that it has a The special substrate connection structure can prevent thermal deformation of each substrate on it during the high-temperature manufacturing process, so that the solder balls (solder balls) that are subsequently implanted on the back of the substrate have high coplanarity.

The essential technical content of the present invention and its embodiments have been disclosed in detail in the drawings attached to this specification by means of diagrams. The contents of these diagrams are briefly described as follows:

Fig. 1A (prior art) is a schematic cross-sectional structure, which shows a typical BGA packaging structure;

Fig. 1B (the prior art) is a top view structural schematic diagram, which shows an existing substrate connection;

FIG. 1C (prior art) shows the expansion state of each substrate in the substrate wafer shown in FIG. 1B when heated;

FIG. 1D (prior art) shows a BGA package structure built on a deformed substrate;

Fig. 2A is a schematic plan view of the structure, which shows the first substrate connection of the present invention.

Example;

Figure 2B shows the expansion state of each substrate in the substrate bond shown in Figure 2A when heated;

Fig. 3A is a top view structural schematic diagram, which shows the second substrate connection of the present invention.

Example;

FIG. 3B shows the expansion state of each substrate in the substrate bond shown in FIG. 3A when heated;

Fig. 4A is a top view structural schematic diagram, which shows the third substrate connection of the present invention

Example;

Figure 4B shows the expansion state of each substrate in the substrate bond shown in Figure 4A when heated;

Fig. 5A is a schematic top view of the structure, which shows the fourth substrate connection of the present invention.

Example;

FIG. 5B shows the expansion state of each substrate in the substrate bond shown in FIG. 5A when heated;

Figure 6A (the prior art) is a three-dimensional characteristic diagram, which shows the flatness of the ball grid array implanted on the substrate provided by the prior art;

FIG. 6B is a three-dimensional characteristic diagram, which shows the flatness of the ball grid array implanted on the substrate provided by the present invention.

Explanation of schematic symbols

10 Existing substrate connection 11 Substrate

12 Frame 12a 1st support rod

12b The second support rod 13a The first connecting piece

13b The second connecting piece 13c The third connecting piece

13d Fourth link piece 20 Semiconductor chip

30 Ball Grid Array 40 Printed Circuit Board

100 The substrate connection of the first embodiment

110 Substrate 120 Frame

121 The first support rod 122 The second support rod

131 The first connecting piece 132 The second connecting piece

200 Substrate bonding in the second embodiment

210 Substrate 220 Frame

221 The first support rod 222 The second support rod

231 The first connecting piece 232 The second connecting piece

300 Substrate bonding in the third embodiment

310 Substrate 320 Frame

321 First support rod 322 Second support rod

331 The first connecting piece 332 The second connecting piece

400 Substrate bonding in the fourth embodiment

410 Substrate 420 Frame

421 The first support rod 422 The second support rod

431 connecting piece

The following is to cooperate with Figures 2A to 2B, Figures 3A to 3B, Figures 4A to 4B, and Figures 5A to 5B in the accompanying drawings to disclose in detail four different implementations of the substrate connection of the present invention. example.

First Embodiment (Figures 2A to 2B)

The first embodiment of the substrate connection of the present invention is disclosed in detail below in conjunction with FIGS. 2A to 2B of the accompanying drawings.

Please refer to FIG. 2A, the substrate connection 100 of the first embodiment of the present invention includes: (a) a plurality of square substrates 110; and (b) a frame 120, which has a pair of parallel extending support rods 121, 122 , for connecting and supporting the substrates 110 . In this embodiment, each substrate 110 on the substrate connecting piece 100 is only connected to the supporting rods 121, 122 of the frame 120 through a two-point connection structure formed by two connecting pieces 131, 132; wherein the first connecting piece 131 The upper left corner of each substrate 110 is connected to the first support bar 121 , and the second connecting sheet 132 is used to connect the lower left corner of each substrate 110 to the second support bar 122 .

FIG. 2B shows the expansion state of each substrate 110 in the substrate connecting sheet 100 shown in FIG. 2A when heated. Basically, when the substrate 110 is subjected to high temperature processing, its volume expands in all directions. However, as shown in FIG. 2B , since the upper left corner and the lower left corner of the base plate 110 have respectively connected the connecting pieces 131 , 132 , the expansion toward the upper left and lower left will be hindered. However, since the upper right corner and the lower right corner of the substrate 110 are not provided with connecting pieces, the heated substrate 110 can freely expand in these directions (the direction of the thermal stress is shown by the arrow in Fig. 2B), that is, the The thermal stress is released toward these directions, so that the substrate 110 will not be thermally deformed.

Since the substrate 110 does not generate thermal deformation, the ball grid array (not shown) subsequently implanted on the backside thereof can have high flatness.

Second Embodiment (Figures 3A to 3B)

The second embodiment of the substrate bonding of the present invention is disclosed in detail below in conjunction with FIGS. 3A to 3B of the accompanying drawings.

Please refer to FIG. 3A, the substrate connecting piece 200 of the second embodiment of the present invention includes: (a) a plurality of square substrates 210; , for connecting and supporting the substrates 210 . In this embodiment, each substrate 210 on the substrate connecting piece 200 is also connected to the support rods 221, 222 of the frame 220 only through the two-point connection structure formed by the two connecting pieces 231, 232; The only difference is that the first connecting piece 231 is disposed at the upper left corner of the substrate 210 , and the second connecting piece 232 is disposed at the lower right corner of the diagonal.

FIG. 3B shows the expansion state of each substrate 210 in the substrate connecting piece 200 shown in FIG. 3A when heated. As shown in the figure, since the upper left corner and the lower right corner of the base plate 210 are connected with the connecting pieces 231 and 232 respectively, the expansion toward the upper left and lower right will be hindered. However, since the upper right corner and the lower left corner of the substrate 210 are not provided with connecting pieces, the heated substrate 210 can expand in these directions (the direction of thermal stress is shown by the arrow in Figure 3B), that is, the thermal stress can be reduced. It is relaxed toward these directions, so that the substrate 210 will not be thermally deformed.

Third Embodiment (Figures 4A to 4B)

The third embodiment of the substrate connection of the present invention is disclosed in detail below in conjunction with FIGS. 4A to 4B of the accompanying drawings.

Please refer to FIG. 4A, the substrate connecting piece 300 of the third embodiment of the present invention includes: (a) a plurality of square substrates 310; , for connecting and supporting the substrates 310 . In this embodiment, each substrate 310 on the substrate connecting piece 300 is also connected to the support rods 321, 322 of the frame 320 only through the two-point connection structure formed by the two connecting pieces 331, 332; The difference between the embodiments is only that the first connecting piece 331 is disposed on the upper left corner of the substrate 310 , and the second connecting piece 332 is disposed on the bottom edge of the substrate 310 .

FIG. 4B shows the expansion state of each substrate 310 in the substrate connecting sheet 300 shown in FIG. 4A when heated. As shown in the figure, since the upper left corner and the bottom edge of the substrate 310 have been connected with the connecting pieces 331 and 332 respectively, the expansion toward the upper left corner and the bottom edge will be hindered. However, since the upper right corner, the lower right corner, and the lower left corner of the substrate 310 are not provided with connecting pieces, the heated substrate 310 can expand in these directions (the direction of thermal stress is shown by the arrow in Fig. 4B). That is, the thermal stress can be relieved in these directions, so that the substrate 310 will not be thermally deformed.

Fourth Embodiment (FIGS. 5A to 5B)

The fourth embodiment of the substrate connection of the present invention is disclosed in detail below in conjunction with FIGS. 5A to 5B of the accompanying drawings.

Please refer to FIG. 5A, the substrate connecting piece 400 of the fourth embodiment of the present invention also includes: (a) a plurality of square substrates 410; and (b) a frame 420, which has a pair of parallel extending support rods 421, 422 for connecting and supporting the substrates 410 .

This fourth embodiment differs from the previous three embodiments in that each substrate 410 on the substrate connecting piece 400 is also connected to the frame 420 through a one-point connection structure formed by a connecting piece 431, and the connecting piece 431 That is, it is disposed at the glue injection corner on the upper left of the substrate 410 . Since the glue injection channel (not shown) of the substrate 410 requires a larger width, the width of the connecting piece 431 must be designed to be greater than the width of the glue injection channel; support.

FIG. 5B shows the expanded state of the substrate 410 in the substrate connecting sheet 400 shown in FIG. 5A when heated. As shown in the figure, since the upper left corner of the substrate 410 has been connected with the connecting piece 431 , the expansion toward the upper left will be hindered. However, since the upper right corner, the lower right corner, and the lower left corner of the substrate 410 are not provided with connecting pieces, the heated substrate 410 can expand toward these directions (the direction of thermal stress is shown by the arrow in Fig. 5B), also That is, the thermal stress can be relieved in these directions, so that the substrate 410 will not be thermally deformed.

Actual test results (Figures 6A to 6B)

Actual test results show that the present invention can greatly reduce the degree of deformation of the substrate after being subjected to high temperature treatment, so that the ball grid array subsequently implanted on the back of the substrate has high flatness. The table below shows an example of the actual test data (the values in the table represent the distance between the solder ball and the reference plane). Comparing the data in this table, it can be seen that the flatness of the ball grid array obtained by adopting the present invention is better than that of the prior art. Min Max x σ C _pk existing technology 2.05 4.91 3.17 0.82 1.05 Sample 1 of the present invention 1.67 3.77 2.26 0.59 1.95 Sample 2 of the present invention 1.56 2.48 1.95 0.25 5.11 Sample 3 of the present invention 1.98 3.33 2.61 0.44 2.38

In addition, the characteristic diagram in Fig. 6A shows the flatness of the ball grid array placed on the substrate provided by the prior art; and Fig. 6B shows the flatness of the ball grid array placed on the substrate provided by the present invention. flatness. Comparing Fig. 6B with Fig. 6A, it can be seen that the flatness of the ball grid array obtained by adopting the present invention is better than that of the prior art. The present invention is thus more progressive than the prior art.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the scope of the substantive technical content of the present invention. The essential technical content of the present invention is broadly defined in the claims. Any technical entity or method accomplished by others, if it is exactly the same as that defined in the claims, or if it is an equivalent change, will be deemed to be covered by the claims.

Claims (16)

1. base plate connection sheet is characterized in that this base plate connection sheet comprises:

A) framework, it has the support bar that pair of parallel is extended, and comprises one first support bar and one second support bar; And

B) at least one substrate, it is placed on this framework, and by be linked to the support bar of this framework to the too many by two link piece.

2. base plate connection sheet as claimed in claim 1, wherein this substrate is in order to construction one sphere grid several-group type chip packaging unit.

3. base plate connection sheet as claimed in claim 1, wherein this substrate only is linked on this framework by two link piece.

4. base plate connection sheet as claimed in claim 3, wherein these two link piece are disposed on two adjacent corners of this substrate, and are linked to first support bar and second support bar of this framework respectively.

5. base plate connection sheet as claimed in claim 3, wherein these two link piece are disposed at respectively on two relative corners of a diagonal of this substrate, and are linked to first support bar and second support bar of this framework respectively.

6. base plate connection sheet as claimed in claim 3, wherein these two link piece one of them be disposed on the corner of this substrate, and be linked to first support bar of this framework; Another link piece then is disposed on the side of this substrate, and is linked to second support bar of this framework.

7. base plate connection sheet as claimed in claim 1, wherein this substrate only is linked on this framework by a link piece.

8. base plate connection sheet as claimed in claim 7, wherein this link piece is disposed on the injecting glue corner of this substrate.

9. base plate connection sheet is characterized in that this base plate connection sheet comprises:

A) framework, it has the support bar that pair of parallel is extended, and comprises one first support bar and one second support bar; And

B) at least one substrate, it is placed on this framework, and is linked on this framework by two 2 binding frameworks that link piece constituted.

10. base plate connection sheet as claimed in claim 9, wherein this substrate is in order to construction one sphere grid several-group type chip packaging unit.

11. base plate connection sheet as claimed in claim 9, wherein these two link piece are disposed at respectively on two adjacent corners of this substrate, and are linked to first support bar and second support bar of this framework respectively.

12. base plate connection sheet as claimed in claim 9, wherein these two link piece are disposed at respectively on two relative corners of a diagonal of this substrate, and are linked to first support bar and second support bar of this framework respectively.

13. base plate connection sheet as claimed in claim 9, wherein these two link piece one of them be disposed on the corner of this substrate, and be linked to first support bar of this framework; Another link piece then is disposed on the side of this substrate, and is linked to second support bar of this framework.

14. a base plate connection sheet is characterized in that this base plate connection sheet comprises:

A) framework, it has the support bar that pair of parallel is extended, and comprises one first support bar and one second support bar; And

B) at least one substrate, it is placed in this on the support bar, and is linked on this framework by a framework that a bit links that link piece constituted.

15. base plate connection sheet as claimed in claim 14, wherein this substrate is in order to construction one sphere grid several-group type chip packaging unit.

16. base plate connection sheet as claimed in claim 14, wherein this link piece is disposed on the injecting glue corner of this substrate.

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