TWI652808B - Multi-chip package ball grid array structure - Google Patents

Abstract

A multi-chip plastic ball array package structure includes: a substrate, a first wafer, a first encapsulant, a stopper, a second wafer, an optical component, and a second encapsulant. The substrate has an upper surface and a lower surface opposite the upper surface. The first wafer is disposed on the lower surface and electrically connected to the substrate. The first gel coats the first wafer. The blocking body is disposed on the lower surface with the first surface and surrounds the first sealing body. The second wafer is disposed on the upper surface and electrically connected to the substrate. The optical element is disposed on the second wafer in a eutectic bonding structure. The second encapsulant encapsulates the second wafer, the optical element, and the eutectic bonding structure. The optical element passes light that coincides with the wavelength range sensed by the second wafer. With the practice of the present invention, the sealing and vacuum effects on the wafer are good.

Description

 Multi-chip plastic spherical array package structure  

The invention relates to a multi-chip plastic ball array (MCPBGA) package structure, in particular to a multi-chip plastic ball array (MCPBGA) package structure capable of improving the reliability of a package structure by fixing a wafer on both sides of a substrate.

Due to the rapid advancement of technology, it has also accelerated the popularity of audio and video multimedia, and the emergence of digital cameras, digital cameras and digital scanners, etc., has made image digitization an inevitable trend. The image sensor is a key component in these digital products. The image sensor can be used to receive optical signals or image signals, and convert the received signals into electrical signals, and then transmit the electrical signals to the circuit board for processing. Analysis, so that digital products can provide functions such as photography, photography, etc.

In order to make digital products meet the needs of light, thin and short, the main image sensors currently used include: charge coupled device image sensor (CCD), complementary metal oxide semiconductor image sensor (CMOS)... Etc., therefore, how to improve the packaging technology of the image sensor, and make the size of the image sensor can be miniaturized, which becomes the key to affect the size of the digital product.

In addition, in addition to the advantages of mass production and low material cost, image sensor packaging technology, because the photosensitive area on the image sensor is quite sensitive, it needs to be protected by proper packaging to avoid dust and moisture. The impact is to ensure the longevity and quality of the digital product, which in turn improves the imaging performance and package reliability of the image sensor.

In view of this, how to improve the sensing sensitivity and simplify the complicated manufacturing process to reduce the cost by structural improvement has become an important issue.

The technical problem to be solved by the present invention is to provide a multi-chip plastic spherical array package structure, which improves the sealing and vacuum effect on the second wafer, reduces the overall package area and avoids warpage of the substrate, and ensures product reliability.

The technical problem solved by the present invention is achieved by the following technical solutions.

The present invention discloses a multi-chip plastic ball array package structure, the multi-chip plastic ball array package structure comprising: a substrate having an upper surface and a lower surface opposite to the upper surface; a first wafer disposed on the lower surface And electrically connected to the substrate; a first encapsulant covering the first wafer; a blocking body having a first surface disposed on the lower surface and surrounding the first encapsulant; and a second wafer disposed on the second substrate The upper surface is electrically connected to the substrate; the optical element is disposed on the second wafer in a eutectic bonding structure; and the second encapsulant covers the second wafer, the optical element, and the eutectic bonding structure.

The technical problem of the present invention can be further realized by the following technical measures.

In the above multi-wafer plastic ball array package structure, the optical element and the second wafer pass through the eutectic bonding structure to form a vacuum region, and the second wafer has a sensing portion located in the vacuum region.

The multi-chip plastic ball array package structure, wherein the first wafer is electrically connected to the substrate through at least one first wire, the first sealing body covers the first wafer and the first wire, and the second chip The substrate is electrically connected to the substrate by at least one second bonding wire, and the second sealing body covers the second wafer, the second bonding wire and the optical component.

The above multi-chip plastic ball array package structure, wherein the periphery of the block is flush with the periphery of the substrate.

In the above multi-chip plastic ball array package structure, the periphery of the second encapsulant is aligned with the periphery of the substrate.

The above multi-chip plastic spherical array package structure, wherein the thickness of the substrate is greater than or equal to 20% of the maximum thickness of the second encapsulant.

In the above multi-chip plastic ball array package structure, the first surface of the stopper is adhered to the lower surface of the substrate by an adhesive layer.

In the above multi-chip plastic ball array package structure, the thickness of the first encapsulant is less than or equal to the thickness of the stopper plus the adhesive layer.

In the above multi-wafer plastic ball array package structure, the upper edge of the second encapsulant forms an angle between 0 and 60 degrees with a plane extending from the upper edge of the optical element.

The multi-chip plastic ball array package structure further includes at least one passive component electrically connected to the substrate, and the passive component is covered by the second encapsulant.

The present invention is a multi-chip plastic ball array package structure comprising: a substrate, a first wafer, a first encapsulant, a stopper, a second wafer, an optical element, and a second encapsulant. The substrate has an upper surface and a lower surface opposite the upper surface. The first wafer is disposed on the lower surface and electrically connected to the substrate. The first encapsulant encapsulates the first wafer. The blocking body is disposed on the lower surface with its first surface and surrounds the first sealing body. The second wafer is disposed on the upper surface and electrically connected to the substrate. The optical element is disposed on the second wafer in a eutectic bonding structure. The second encapsulant encapsulates the second wafer, the optical element, and the eutectic bonding structure. The optical element passes light that coincides with a wavelength range sensed by the second wafer.

With the implementation of the present invention, at least the following advancements can be achieved:

It does not require complicated manufacturing processes or expensive manufacturing equipment, and the implementation cost is low.

The sealing and vacuum effect on the second wafer is good.

It can solve the disadvantage that the small back of the wafer is large or the adjacent pendulum enlarges the overall package area.

It can avoid warpage of the substrate and ensure product reliability.

The stopper completely covers the first wafer and the first wire to prevent the first sealant from overflowing the welding end.

The upper edge of the second seal body is inclined at a specific range angle θ, which can prevent the second sealant from overflowing to the surface of the optical element to cause contamination.

In order to make the technical content of the present invention known to those skilled in the art and to implement it, and according to the content, the patent scope and the drawings disclosed in the specification, the related objects and advantages of the present invention can be easily understood by those skilled in the art. The detailed features and advantages of the present invention will be described in detail in the embodiments.

100‧‧‧Multi-chip plastic ball array package structure

10‧‧‧Substrate

11‧‧‧ upper surface

12‧‧‧ Lower surface

20‧‧‧First chip

21‧‧‧First line

25‧‧‧ Third chip

27‧‧‧ third line

30‧‧‧First gel

40‧‧ ‧ body

41‧‧‧ first surface

42‧‧‧ second surface

43‧‧‧Adhesive layer

50‧‧‧ welding endpoint

60‧‧‧second chip

61‧‧‧second line

62‧‧‧Sensor

70‧‧‧Optical components

80‧‧‧ Eutectic bonding structure

81‧‧‧vacuum area

90‧‧‧Second seal

95‧‧‧ Passive components

D‧‧‧first thickness

D‧‧‧second thickness

H1‧‧‧ substrate thickness

h2‧‧‧Maximum thickness of the second seal 90

1 is a cross-sectional view showing a multi-chip plastic ball array package structure according to an embodiment of the present invention.

2 is a cross-sectional view showing another multi-wafer plastic ball array package structure according to an embodiment of the present invention.

3 is a cross-sectional view showing a second encapsulant having a tilt angle and defining a thickness of the first encapsulant according to an embodiment of the invention.

4 is a cross-sectional view showing a multi-chip plastic ball array package structure in which a passive component is further disposed on a substrate according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a multi-chip plastic ball array package structure in which two wafers are disposed on a lower surface of a substrate according to an embodiment of the invention.

Please refer to FIG. 1 , which is a multi-chip plastic spherical array package structure 100 of the embodiment, which has a substrate 10 (Base Core), a first wafer 20 , a first sealing body 30 (First Compound), and a blocking body 40 . (Dam Core); second wafer 60; optical element 70; and second sealant 90 (Second Compound).

As shown in FIG. 1, the substrate 10, which may be a plastic substrate, has an upper surface 11 and a lower surface 12 opposite to the upper surface 11, and the substrate 10 may also have at least one set of electrical traces combined with at least one pass. Plastic circuit board (Through Hole).

As shown in FIG. 1, the first wafer 20 is disposed on the lower surface 12 of the substrate 10, and can be electrically connected to the substrate 10 through at least one first bonding wire 21 (first bonding wire), and the first wafer 20 is disposed on the lower surface. The way of 12 can be fixed or adhered.

The first wafer 20 can be a system wafer, for example, a digital signal processor (DSP) or an infrared signal processing chip (IR Signal Processor), and the thickness of the first wafer 20 can be greater than 100 micrometers. In this embodiment, the thickness of the first wafer 20 is selected to be in the range of 200 μm plus or minus 10%.

On the other hand, the first bonding wires 21 electrically connecting the first wafer 20 and the substrate 10 may use gold wires, copper wires, conductive alloy wires or other metal wires which are excellent in conductivity and are not easily oxidized or chemically acted upon.

As also shown in FIG. 1, the first sealant 30 (First Compound) can completely surround and cover the first wafer 20. The material of the first colloid 30 may be selected from a liquid compound or a thermosetting sealant, and the first sealant 30 has a thickness that can completely cover and cover the first wafer 20, thereby achieving protection. The efficacy of the first wafer 20.

As further shown in FIG. 1, the body 40 has a first surface 41 and a second surface 42 opposite the first surface 41. The blocking body 40 is disposed on the lower surface 12 of the substrate 10 through the first surface 41, and the blocking body 40 directly surrounds the first sealing body 30. A plurality of soldering end points 50 electrically connected to the substrate 10 are disposed on the second surface 42 of the blocking body 40. The soldering end points 50 may be solder balls or solder pads.

As shown in FIG. 1 to FIG. 3, the periphery of the stopper 40 may be flush with the periphery of the substrate 10, and the first surface 41 of the stopper 40 may be adhered to the lower surface 12 of the substrate 10 through the adhesive layer 43 by The adhesive layer 43 can be used to protect the circuitry or through holes (not shown) of the lower surface 12 of the substrate 10.

As shown in FIG. 3, in the present embodiment, the first sealant 30 has a first thickness d that is less than or equal to the thickness of the stopper 40 and the second thickness D formed by the thickness of the adhesive layer 43, so that the stopper 40 can be prevented. The first gel 30 overflows to the second surface 42 of the block 40, which in turn causes contamination of the solder end 50 or the solder pads, affecting its normal function.

Still referring to FIG. 1 , the second wafer 60 is, for example, an image sensor chip disposed on the upper surface 11 of the substrate 10 , and the second wafer 60 passes through the second wire. 61 is electrically connected to the substrate 10.

In addition, the second wafer 60 further has a sensing portion 62, and the second wafer 60 is fixed on the upper surface 11 of the substrate 10 on a side opposite to the sensing portion 62. Thus, the sensing portion 62 can receive the sensing medium and working normally.

The second wire 61 electrically connected to the second wafer 60 and the substrate 10 may be a gold wire, a copper wire, a conductive alloy wire or other metal wire which is excellent in conductivity and is not susceptible to oxidation or chemical action.

Since the size of the second wafer 60 (the contact area of the second wafer 60 and the substrate 10) is generally larger than the size of the first wafer 20 (the contact area of the first wafer 20 and the substrate 10), and the second wafer 60 must be sensed by the sensing portion 62 The image signal is as described above, and the second wafer 60 and the first wafer 20 are respectively fixed on the upper surface 11 and the lower surface 12 of the substrate 10, thereby avoiding the disadvantage that the adjacent pendulum enlargement width increases the overall package area or The problem that the wafer generated by the second wafer 60 is superposed on the first wafer 20 has a small back.

In order to be able to afford the second wafer 60 and the first wafer 20, and no warpage in the package fabrication process causes the multi-wafer plastic ball array package structure 100 to be abnormal or failed, the substrate 10 is designed to have a specific thickness h1. . The maximum thickness h2 of the second encapsulant 90 refers to the vertical distance from the upper edge of the second encapsulant 90 to the upper surface 11 of the substrate 10 where the optical element 70 meets. Therefore, the thickness h1 of the substrate 10 is based on 20% or more of the maximum thickness h2 of the second encapsulant 90. In the present embodiment, the substrate 10 of 0.3 mm or more may be selected, or the substrate 10 having a thickness of between 30% and 80% of the thickness of the second encapsulant 90 may be selected.

The first wafer 20 or the second wafer 60 may be a complementary CMOS chip, which has a mature manufacturing process, a large amount of use, and a relatively low cost.

Referring to FIG. 1 again, the optical element 70 (Filter) is fixed on the second wafer 60 by the Eutectic Joining Ring 80 and does not shield the sensing portion 62 of the second wafer 60.

The optical component 70 can provide light through a particular range of wavelengths, filtering out other optical signals, eliminating stray light interference, and ensuring image sensing functionality of the second wafer 60. The particular wavelength range is consistent with the wavelength range of light that the second wafer 60 can sense.

As such, the optical element 70 and the second wafer 60 are surrounded by a eutectic bonding structure 80 to form a vacuum region 81, while the sensing portion 62 of the second wafer 60 is located within the vacuum region 81 and is unobstructed.

The eutectic bonding structure 80 may be selected as a solder ring having a vacuum sealing effect or a eutectic bonding structure 80 formed of other metal materials or alloy materials.

The eutectic bonding structure 80 formed of a metal material or an alloy material has a vacuum sealing effect superior to that of an organic sealing material used in the industry, and can prevent moisture from entering the vacuum region 81 and maintaining the vacuum region 81. In an effective vacuum state.

Referring again to FIG. 1, the second encapsulant 90 covers the periphery of the second wafer 60, the optical element 70, and the eutectic bonding structure 80.

The periphery of the second encapsulant 90 may be flush with the periphery of the substrate 10, and the material of the second encapsulant 90 may be selected from a liquid compound or a thermosetting sealant, and the present invention does not limit.

Referring to FIG. 1 to FIG. 3, the upper edge of the second encapsulant 90 may be inclined at a specific range of angle θ, and the height is decreased from the junction of the second encapsulant 90 and the upper edge of the optical element 70 toward the edge. The upper edge of the second encapsulant 90 forms an angle θ with the plane extending from the upper edge of the optical element 70, and the second encapsulant 90 can be controlled to prevent the second encapsulant 90 from creeping onto the optical component 70 to affect the second wafer 60. Sensing function, wherein the angle θ can be selected to be between 0-60 degrees.

Next, referring to FIG. 4, the upper surface 11 of the substrate 10 of the multi-chip plastic ball array package structure may further be provided with more than one passive component 95. In addition to being electrically connected to the substrate 10, the passive component 95 is simultaneously Covered and protected by the second sealant 90. Further, passive component 95 can be a capacitor, resistor, or other passive electronic component.

As shown in FIG. 5, a plurality of wafers may be disposed on the lower surface 12 of the substrate 10 of the multi-chip plastic ball array package structure 100 as needed for application. In this embodiment, the first wafer 20 and the third wafer 25 disposed on the first wafer 20 are disposed on the lower surface of the substrate 10, and the first wafer 20 is electrically connected to the substrate 10 and the third wafer by the first bonding wires 21 25 is electrically connected to the substrate 10 by a third wire 27 .

The total thickness of the first wafer 20 and the third wafer 25 or the first thickness d of the first encapsulant 30 is set to be less than or equal to the thickness of the stopper 40 plus the thickness of the adhesive layer 43 to form a second thickness. D.

In summary, the multi-chip plastic ball array package structure 100 has the feature that the first wafer 20 having a smaller area and the second wafer 60 having a larger area are placed on both sides of the substrate 10, and the first wafer 20 is blocked. Surrounded by the body 40; only the optical element 70 through which the infrared light can pass is fixed to the outer line sensing wafer 60 and exposed to the sensing portion 62 by a vacuum-sealed eutectic bonding structure 80; the second encapsulant 90 is completely covered The second bonding wire 61 is wrapped around the edge of the second wafer 60 and the optical component 70. The first sealing body 30 completely covers the first wafer 20 and the first bonding wire 21; the upper edge of the second sealing body 90 has a specific range. The inclination of the included angle θ, that is, the angle θ of 0-60 degrees with the optical element 70, prevents the glue from overflowing to the optical element 70; the thickness of the substrate 10 is selected to be greater than 0.3 mm, and can withstand the first wafer 20 and the second wafer 60. The weight of the two wafers, and no warpage is generated in the manufacturing process; and the first encapsulant 30 completely covers the first wafer 20 and the first bonding wire 21, and the thickness thereof is not greater than the blocking body 40 plus the adhesive layer 43 thickness, so it does not require complicated manufacturing process or The manufacturing cost of the manufacturing equipment is low; the sealing and vacuum effect of the second wafer 60 is good; the reliability of the wafer stacking due to the small area of the backing area is reduced, or the reliability of the adjacent pendulum is increased. The substrate 10 can be prevented from being warped to ensure product reliability; the blocking body 40 completely covers the first wafer 20 and the first bonding wire 21 to prevent the first sealing body 30 from overflowing the welding end 50 or the welding pad; And the inclination of the upper edge of the second seal body 90 at a specific range angle θ can avoid the advantage that the second sealant 90 overflows to the surface of the optical element 70 to produce pollution and improve the effect.

In the above embodiments, the first wafer 20 and the second wafer 60 may be respectively fixed on the lower surface 12 and the upper surface 11 of the substrate 10 by die bond epoxy.

The above-described embodiments are intended to be illustrative of the present invention, and are intended to be understood by those skilled in the art, and the invention is not limited by the scope of the invention. The equivalent modifications or modifications made by the spirit of the spirit should still be included in the scope of the patent application.

Claims (9)

A multi-chip plastic ball array package structure comprising: a substrate having an upper surface and a lower surface opposite to the upper surface; a first wafer disposed on the lower surface and electrically connected to the substrate; the first encapsulant The second wafer is disposed on the lower surface and surrounds the first encapsulant; the second wafer is disposed on the upper surface and electrically connected to the substrate; An element disposed on the second wafer in a eutectic bonding structure; and a second encapsulant covering the second wafer, the optical element, and the eutectic bonding structure; wherein the optical element and the second wafer The eutectic bonding structure is passed between to form a vacuum region, and the second wafer has a sensing portion located in the vacuum region. The multi-chip plastic ball array package structure according to claim 1, wherein the first wafer is electrically connected to the substrate through at least one first wire, the first sealing body covering the first wafer and the first wire. The second wafer is electrically connected to the substrate through at least one second wire, and the second sealing body covers the second wafer, the second wire and the optical component. The multi-chip plastic ball array package structure according to claim 1, wherein a periphery of the stopper is flush with a periphery of the substrate. The multi-chip plastic ball array package structure according to claim 1, wherein a periphery of the second encapsulant is aligned with a periphery of the substrate. The multi-chip plastic ball array package structure according to claim 1, wherein the substrate has a thickness greater than or equal to 20% of a maximum thickness of the second encapsulant. The multi-chip plastic ball array package structure according to claim 1, wherein the first surface of the stopper is adhered to the lower surface of the substrate by an adhesive layer. The multi-chip plastic ball array package structure according to claim 6, wherein the first The thickness of a gel is less than or equal to the thickness of the body plus the adhesive layer. The multi-chip plastic ball array package structure according to claim 1, wherein an upper edge of the second encapsulant and an upper surface of the optical element extend at an angle of between 0 and 60 degrees. The multi-chip plastic ball array package structure of claim 1, further comprising at least one passive component electrically connected to the substrate, and the passive component is covered by the second encapsulant.