CN1173399C - Semiconductor package with glue overflow preventing device - Google Patents

Abstract

A semiconductor package with an overflow glue prevention device comprises a substrate, at least one chip and at least one passive component are adhered to the front surface of the substrate and electrically connected with the substrate, and a plurality of connecting ends are distributed on the back surface of the substrate for electrically connecting the chip and the passive component with an external device; the front surface of the substrate is adhered with an excessive glue prevention device by an elastic adhesive, the heat-conducting metal material is made into a containing space for containing the chip and the passive component, the height of the excessive glue prevention device is higher than the depth of a cavity of a die for coating the chip, the passive component, the excessive glue prevention device and the substrate, and the electrical connection end on the back surface of the substrate is prevented from being polluted during die pressing operation of the die.

Description

Semiconductor package with adhesive overflow prevention device

technical field

The present invention relates to a semiconductor package, in particular to a semiconductor package used as a Multi-Media Card (MMC).

Background technique

Currently used as a semiconductor package for multimedia cards (MMC), in order to meet the thinning requirements of electronic products using MMC, for example, US Patent No. 6,040,622 has disclosed a structure as shown in FIG. 9 . This MMC semiconductor package is that at least one memory chip 11 and at least one passive component 12 are bonded on the front surface 100 of a substrate 10 (for simplicity, only one is shown in the figure), and the two A plurality of electrical connection terminals 102 are formed on the back surface 101 of the substrate 10 for electrically connecting the memory chip 11 and the passive component 12 with external devices. The MMC semiconductor package 1 also has an encapsulant 13 to cover the chip 11, the passive component 12 and the substrate 10, but the back surface 101 of the substrate 10 and the electrical connection end 102 on it are exposed to the encapsulant. 13 while in direct contact with the atmosphere.

The molding operation (Molding Process) of this kind of MMC semiconductor package 1 is to sandwich the substrate 10 with the memory chip 11 and the passive component 12 bonded between the upper mold 140 and the lower mold 141 of the mold 14, as shown in Figure 10 Show. Since the portion of the substrate 10 intended to be covered by the encapsulant 13 is not clamped by the upper mold 140 and the lower mold 141, the encapsulation resin used to form the encapsulant 13 will overflow to the surface of the substrate 10 in order to prevent the molding operation in progress. On the back side 101, causing defects in the appearance of the finished product, or even polluting the exposed electrical connection end 102, a hole 141a must be opened on the lower mold 141, so that the mold can pass through the hole 141a before the molding operation is carried out. The substrate 10 is vacuum-adsorbed on the lower mold 141, so that the back surface 101 of the substrate 10 fits closely on the lower mold 141, so as to prevent the encapsulation resin from entering between the back surface 101 of the substrate 10 and the lower mold 141 during the molding operation. And cause overflow glue (Flash) phenomenon.

However, the use of vacuum adsorption to solve the problem of overflowing glue will make the molding operation unable to use the existing packaging molds, and the cost of the mold with vacuum adsorption function is also higher than the existing molds, and the operation is more complicated. This increases the manufacturing cost. Therefore, how to use the existing packaging molds to reduce the manufacturing cost and simplify the manufacturing process has become a major issue to be solved in the industry. At the same time, since the above-mentioned MMC semiconductor package is covered with more electronic and semiconductor components, the heat generated during its operation is naturally more than that of a single semiconductor chip, so how to improve the heat dissipation efficiency to ensure that the finished product Reliability has also become an urgent issue. In addition, when a semiconductor package is covered with multiple electronic and semiconductor components, it is often susceptible to external electromagnetic interference (Electro Magnetic Interference, EMI) and affects the electronic performance of the semiconductor package. This is also what the industry wants to solve. difficult questions.

Contents of the invention

The object of the present invention is to provide a semiconductor package with a glue overflow prevention device. By using the glue overflow prevention device, the existing packaging mold can be used without vacuum suction mold, and the glue overflow on the back of the substrate can be effectively avoided. .

The object of the present invention can be achieved through the following measures:

A semiconductor package with a glue overflow prevention device, comprising:

A substrate, which has a front surface and an opposite back surface, on which a plurality of conductive traces are arranged, and a plurality of electrical connection terminals electrically connected to the conductive traces are formed on the back surface;

at least one chip bonded to the front side of the substrate and electrically connected to the conductive trace;

at least one passive component adhered to the front surface of the substrate and electrically connected to the conductive trace;

A glue overflow prevention device, which is glued on the front surface of the substrate, and forms a storage space for storing the chip and passive components therein and a plurality of through holes, and the top of the glue overflow prevention structure is between the front surface of the substrate is slightly higher than the cavity depth of a packaging tool used in the molding operation; and

An encapsulation compound is used to cover the chip, the passive component, the glue overflow prevention device and the substrate, but the encapsulation compound is exposed on the back of the substrate.

The glue overflow preventing device is bonded to the substrate by an elastic adhesive.

The glue overflow prevention device is bonded to the substrate by a thermally conductive adhesive.

The through hole of the overflow prevention device is used for the circulation of the resin compound used to form the encapsulation.

A stepped recess is formed on the edge of the top end of the glue overflow preventing device.

The outer wall of the glue overflow preventing device is close to the side of the substrate.

The outer wall of the glue overflow prevention device is preferably aligned with the side of the substrate.

The top of the glue overflow preventing device exposes the encapsulation glue.

The conductive trace is formed with a grounding trace corresponding to the glue overflow prevention device, so that the glue overflow prevention device and the ground trace are bonded by a conductive adhesive to improve the electrical performance of the semiconductor package. .

Compared with the prior art, the present invention has the following advantages:

In order to achieve the above and other objects of the present invention, the semiconductor package with glue overflow prevention device of the present invention includes: a substrate having a front surface and an opposite back surface, a plurality of conductive traces are arranged on the front surface, and the A plurality of electrical-connection terminals (Electrical-Connection Terminals) are formed on the back side to be electrically coupled with the conductive trace; at least one chip is glued on the front side of the substrate and electrically coupled with the substrate; at least one The passive component is glued on the front surface of the substrate and is electrically coupled with the substrate; a glue overflow prevention device is glued on the front surface of the substrate so that the chip and the passive component are accommodated in a glue overflow preventing device. In the storage space formed by the device, the height between the top surface of the glue overflow prevention device and the front surface of the substrate is slightly higher than an encapsulant used to form the chip, the passive component, the glue overflow prevention device and the substrate The mold cavity depth of the mold; and an encapsulation compound to cover the chip, the passive component, the glue overflow prevention device and the substrate, and expose the top of the glue overflow prevention device.

The invention can effectively avoid glue overflow on the back of the substrate, effectively improve the heat dissipation efficiency of the semiconductor package itself and reduce electromagnetic interference, so that the electrical properties and reliability of the finished product are improved.

Description of drawings

In order to make the characteristics and effects of the present invention more clear, the following are further detailed descriptions with preferred embodiments in conjunction with the accompanying drawings:

1 is a cross-sectional view of a first embodiment of a semiconductor package of the present invention;

2 is a perspective view of the glue overflow prevention device used in the first embodiment of the present invention;

3 is a schematic diagram of the semiconductor package in the first embodiment of the present invention when performing molding operations;

4 is a cross-sectional view of a second embodiment of the semiconductor package of the present invention;

5 is a perspective view of the glue overflow preventing device used in the second embodiment of the present invention;

6 is a cross-sectional view of a third embodiment of the semiconductor package of the present invention;

7 is a perspective view of the glue overflow preventing device used in the third embodiment of the present invention;

8 is a cross-sectional view of a fourth embodiment of a semiconductor package of the present invention;

9 is a cross-sectional view of an existing MMC semiconductor package; and

FIG. 10 is a schematic diagram of a conventional MMC semiconductor package during molding operations.

Detailed ways

FIG. 1 is a cross-sectional view of a first embodiment of a semiconductor package of the present invention. The semiconductor package 2 of the first embodiment includes a substrate 20 having a front surface 200 and an opposite back surface 201 on which a plurality of conductive traces 202 are formed and on the back surface 201 a plurality of conductive traces 202 are formed. The electrical connection end 203, and the conductive trace 202 is electrically connected with the electrical connection end 203 through conductive vias (Conductive Vias) or interconnecting circuits (Interconnecting Wires). Since the arrangement of the conductive through hole or the connection circuit is a prior art, it will not be illustrated and described in detail here. As for the material of the substrate 20, the existing polyimide resin (Polyimide Resin), polybutadiene (BT) resin, epoxy resin glass (FR4) or ceramic (Ceramic) materials are applicable.

The preset position on the front surface 200 of the substrate 20 is for bonding a chip 21 and a passive component 22 , but it should be noted that the number of chips and passive components can be increased as required. After the chip 21 is bonded, a plurality of existing gold wires 23 are electrically connected to the conductive traces 202 on the substrate 20. Bonding) technology is electrically connected to the conductive trace 202 . The passive component 22 can also form an electrical connection with the conductive trace 202 on the substrate 20 in the aforementioned electrical connection manner. Since the conductive trace 202 is electrically connected to the electrical connection terminal 203 on the back surface 201 of the substrate 20, the chip 21 and the passive component 22 can be electrically connected to external devices (External Devices) through the electrical connection terminal 203.

After the bonding of the substrate 20, the chip 21 and the passive component 22 is completed, it is a default to bond a glue overflow prevention device 24 to the front surface 200 of the substrate 20 by means of an existing thermally conductive and elastic adhesive 25. position. The glue overflow preventing device 24 is in the shape of a hollow rectangular frame, as shown in FIG. The chip 21 and the passive component 22 are just accommodated in the storage space 240 without touching the glue overflow prevention device 24; at the same time, in order to maximize the area of the front surface 200 of the substrate 20 located in the storage space 240 In order to accommodate more chips and passive components with larger numbers or sizes, the outer wall 241 of the glue overflow prevention device 24 should be aligned with the side 204 of the substrate 20 .

The semiconductor package 2 also includes an encapsulant 26 to cover the chip 21 and the passive component 22 to be airtightly isolated from the outside world, and at the same time partially cover the substrate 20 and the glue overflow prevention device 24, so that the substrate The encapsulant 26 is exposed from the back side 201 of the 20 and the top 242 of the overflow preventing device 24 . The back surface 201 of the substrate 20 is not covered by the encapsulant 26 , but the electrical connection end 203 is exposed to the atmosphere, so as to form a good electrical connection relationship with external devices.

As shown in FIG. 3 , the encapsulation compound 26 is formed in an encapsulation mold 27 . The packaging mold 27 is existing and is divided into an upper mold 270 and a lower mold 271. A mold cavity 270a is provided on the upper mold 270 for the chip 21 on the substrate 20, the passive component 22 and the glue overflow prevention device 24. It is accommodated in the mold cavity 270a. After the upper mold 270 is clamped onto the lower mold 271, the peripheral part 20a (that is, the part outside the mold cavity 270a) that is connected to the substrate 20 but not covered by the encapsulant 26 is the upper mold 270 and the lower mold. 271, so that the substrate 20 is positioned in the mold cavity 270a of the packaging mold 27. Since the height H from the top 242 of the glue overflow preventing device 24 to the front surface 200 of the substrate 20 is set slightly higher than the depth h of the mold cavity 270a, the top 242 of the glue overflow preventing device 24 is positioned between the upper mold 270 and the lower mold 271 After the mold is closed, it will be pressed against the top wall 270b of the mold cavity 270a, so that the pressure of the mold clamping is transmitted to the substrate 20 through the glue overflow prevention device 24, and the back surface 201 of the substrate 20 is pressed tightly against the lower mold 271 Therefore, there is no gap between the substrate 20 and the lower mold 271, so that the resin compound used to form the encapsulant 26 will not overflow on the back surface 201 of the substrate 20 when the molding operation is carried out, so that the substrate shown in FIG. 1 After the packaging process of the semiconductor package 2 is completed, the back surface 201 of the substrate 20 must have a good appearance, and the electrical connection terminal 203 on it will not be polluted by resin compounds, and can produce good electrical connection with external devices . Therefore, the molding of the encapsulant 26 can be carried out with the existing encapsulation mold by using the glue overflow preventing device 24 , without the need of a mold with vacuum suction function, so the encapsulation process can be simplified as well as the manufacturing cost can be reduced.

In addition, the glue overflow prevention device 24 must have a plurality of through holes 243, so that during the molding operation, the molten resin compound can flow into the storage space 240 of the glue overflow prevention device 24 from the through holes 243 to cover the chip 21. And the passive component 22; at the same time, the resin compound flows through the through hole 243, and after the molding operation is completed, the combination between the overflow prevention device 24 and the cured molding compound 26 can be improved.

In order to improve the heat dissipation efficiency of the semiconductor package 2, the glue overflow prevention device 24 is made of a metal material with good thermal conductivity, such as copper, aluminum, copper alloy, aluminum alloy or other metal materials with good thermal conductivity, etc., and because of the The top 242 of the glue overflow prevention device 24 is directly exposed to the atmosphere, so after the heat is transferred to the glue overflow prevention device 24, it has to be directly dissipated from the top 242 to the atmosphere.

As shown in FIG. 4 , it is a cross-sectional view of a semiconductor package according to a second embodiment of the present invention. The structure of the semiconductor package 3 of the second embodiment is substantially the same as that of the first embodiment, the difference is that the glue overflow prevention device 34 is a rectangular box-shaped structure, as shown in FIG. 5 . The glue overflow prevention device 34 has a rectangular ring body 344 and a sheet body 345 connected to one end of the rectangular ring body 344, and a receiving space 340 is defined by the rectangular ring body 344 and the sheet body 345 for storing chip 31 and passive components 32 . A plurality of protrusions 342 are formed on the sheet 345, so that the height from the top 342a of the protrusions 342 to the front surface 300 of the substrate 30 is slightly higher than that used to form the chip 31, the passive component 32 and the overflow. The mold cavity depth of the mold (not shown) of the encapsulant 36 of the glue preventing device 34, so that the top 342a of the protrusion 342 will be pressed against the top wall of the mold cavity during the molding operation, so as to avoid the overflow of the resin compound On the back surface 301 of the substrate 30 where the chip 31 and the passive component 32 are attached. At the same time, the rectangular ring body 344 also defines a plurality of through holes 344b for the molten resin compound to flow through the through holes 344b and enter the receiving space 340 . In addition, the conductive traces 302 on the front surface 300 of the substrate 30 are formed with ground traces 302a (GroundTraces) at the place corresponding to the bottom 344a of the rectangular ring body 344, so that the glue overflow preventing device 34 can be glued with a conductive adhesive. After the glue 35 is bonded to the substrate 30, the glue overflow prevention device 34 is electrically connected to the ground trace 302a, so that the electrical performance of the semiconductor package 3 can be improved. Furthermore, the glue overflow prevention device 34 covers the chip 31 and the passive component 32, so when the chip 31 operates at high frequency, the shielding of the glue overflow prevention device 34 can be used to reduce the impact of the outside world. The influence of electromagnetic interference (EMI) on the operation of the chip 31 further improves the electrical properties of the semiconductor package 3 .

As shown in FIG. 6 , it is a cross-sectional view of a semiconductor package according to a third embodiment of the present invention. The structure of the semiconductor package 4 of the third embodiment is substantially the same as that described in the second embodiment, the difference is that no protrusion is formed on the sheet 445 of the glue overflow preventing device 44, as shown in FIG. 7, that is, the top surface 445a of the sheet body 445 must be completely exposed to the encapsulant 46 after the encapsulant 46 is cured and directly in contact with the atmosphere. Therefore, the height between the top surface 445a of the sheet 445 and the front surface 400 of the substrate 40 must be set slightly higher than the cavity depth of the packaging mold (not shown) forming the packaging compound 46, so that the glue overflow prevention device 44, there is no gap between the back side 401 of the bonded substrate 40 and the lower mold (not shown) of the package mold where the molten resin compound will flow, so as to avoid the formation of excess glue on the back side 401 of the substrate 40. Similarly, the rectangular ring body 444 is also formed with a plurality of through holes 444b through which the molten resin compound flows.

As shown in FIG. 8 , it is a cross-sectional view of a semiconductor package according to a fourth embodiment of the present invention. The structure of the semiconductor package 5 of the fourth embodiment is substantially the same as that described in the third embodiment, the difference is that a stepped recess 542a is formed on the side edge of the sheet 545 of the glue overflow preventing device 54, so as to The formation of the stepped concave portion 542 a prevents the melted resin compound from overflowing on the sheet body 545 .

It should be noted that the above are only specific embodiments of the present invention, and any other equivalent changes or modifications made without departing from the spirit and technology of the present invention shall still be included within the protection scope of the claims of this patent application.

Claims (9)

1. A semiconductor package with a glue overflow preventing device, comprising: A substrate, which has a front surface and an opposite back surface, a plurality of conductive traces are arranged on the front surface, and a plurality of electrical connection terminals electrically connected to the conductive traces are formed on the back surface; at least one chip bonded to the front side of the substrate and electrically connected to the conductive trace; at least one passive component adhered to the front side of the substrate and electrically connected to the conductive trace; and An encapsulant used to cover the chip, passive components, glue overflow prevention device and substrate, but the encapsulant is exposed on the back of the substrate; Its characteristics are: A glue overflow prevention device, which is glued on the front surface of the substrate, and forms a storage space for storing the chip and passive components and a plurality of through holes, and the top of the glue overflow prevention device is between the front surface of the substrate The height is slightly higher than the cavity depth of a package mold used in the molding operation. 2 . The semiconductor package with a glue overflow prevention device as claimed in claim 1 , wherein the glue overflow prevention device is bonded to the substrate by an elastic adhesive. 3 . 3 . The semiconductor package with a glue overflow prevention device as claimed in claim 1 , wherein the glue overflow prevention device is bonded to the substrate by a thermally conductive adhesive. 4 . 4. The semiconductor package with a glue overflow preventing device as claimed in claim 1, wherein the ring body of the glue overflow preventing device has a plurality of through holes for forming the resin compound of the encapsulating glue circulation. 5 . The semiconductor package with a glue overflow prevention device as claimed in claim 1 , wherein a stepped concave portion is formed on a top edge of the glue overflow prevention device. 6 . 6 . The semiconductor package with an adhesive overflow preventing device as claimed in claim 1 , wherein an outer wall of the adhesive overflow preventing device is close to a side of the substrate. 6 . 7 . The semiconductor package with a glue overflow prevention device as claimed in claim 1 , wherein the outer sidewall of the glue overflow prevention device is aligned with the side of the substrate. 8 . 8 . The semiconductor package with a glue overflow prevention device as claimed in claim 1 , wherein the encapsulant is exposed from the top of the glue overflow prevention device. 9. The semiconductor package with a glue overflow prevention device as claimed in claim 1, wherein, the conductive trace is formed with a ground trace corresponding to the glue overflow prevention device, and the glue overflow prevention device is connected with the glue overflow prevention device. The ground trace is bonded by a conductive adhesive.

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