Packaging structure and electronic equipment

Abstract

The utility model provides a packaging structure and electronic equipment. The packaging structure comprises a circuit board, a chip and a height control block. The circuit board is provided with a plurality of bonding pads. The chip is provided with a plurality of solder balls, and the chip is welded with the plurality of pads of the circuit board through the plurality of solder balls. One end of the height control block is connected with one of the circuit board and the chip, and the other end of the height control block abuts against the other one of the circuit board and the chip so as to be supported between the circuit board and the chip. According to the packaging structure, the height of the chip after welding can be controlled, the problem of different welding spot heights caused by the welding spot collapse process of the welding ball of the chip is solved, and the thermal expansion coefficient of the material adopted by the height control block is set to be between the thermal expansion coefficient of the material adopted by the circuit board and the thermal expansion coefficient of the material adopted by the chip, so that the reliability of the packaging structure is improved. A buffering effect can be provided in the warm stamping process, the difference of thermal expansion coefficients on the two sides of the solder ball is small, and therefore the risk that a welding spot cracks in the warm stamping process is reduced, and the creep fatigue resistance reliability of the welding spot is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the surface mount technology field, and particularly relates to a packaging structure and an electronic device. BACKGROUND

[0002] Packaging chips are widely used in electronic devices and are used for imaging in combination with lens assemblies. Due to the limitation of the miniaturization of the packaging itself, the height of the solder balls of the chip is generally small (<0.3 mm), and the solder balls collapse after welding, resulting in a continuous decrease in the height of the solder joints. After the packaging chip is welded to the circuit board, the thermal expansion coefficients of the materials on both sides of the solder balls do not match, and the height of the solder joints is small, the buffer is small, and the solder joints are prone to cracking after rapid temperature change. At the same time, after the solder balls collapse, the heights of the solder joints are not the same, resulting in the inclination of the chip relative to the circuit board. At this time, a calibration process or device needs to be introduced, which requires a large investment in equipment and high product cost. CONTENT OF THE UTILITY MODEL

[0003] The present application provides an improved packaging structure and an electronic device.

[0004] The present application provides a packaging structure, comprising:

[0005] a circuit board provided with a plurality of pads;

[0006] a chip provided with a plurality of solder balls, the chip being welded to the plurality of pads of the circuit board through the plurality of solder balls; and

[0007] a height control block, one end of the height control block being connected to one of the circuit board and the chip, the other end of the height control block abutting against the other one of the circuit board and the chip to support between the circuit board and the chip; wherein the thermal expansion coefficient of the material of the height control block is between the thermal expansion coefficient of the material of the circuit board and the thermal expansion coefficient of the material of the chip.

[0008] Preferably, the height control block is integrally arranged with one of the circuit board and the chip.

[0009] Preferably, one end of the height control block is integrally arranged with the chip, and the other end of the height control block abuts against the circuit board.

[0010] Preferably, one end of the height control block is integrally arranged with the circuit board, and the other end of the height control block abuts against the chip.

[0011] Preferably, the height control block is separately arranged with the chip or the circuit board; wherein the circuit board is provided with a connecting block, one end of the height control block is connected to the connecting block, and the other end of the height control block abuts against the chip.

[0012] Preferably, flatness of the connecting plane or the abutting plane, at which the height-controlling block is connected with at least one of the circuit board and the chip, is set to be no more than 0.08°.

[0013] Preferably, the height of the height-controlling block is between the height of the solder ball and the height of the solder ball after soldering.

[0014] Preferably, the relationship between the height of the height-controlling block and the volume of the solder ball comprises:

[0015] H = V / S;

[0016] V = 4 / 3 * πr 3 ;

[0017] wherein H is used to represent the height of the height-controlling block;

[0018] S is used to represent the cross-sectional area of the height-controlling block;

[0019] V is used to represent the volume of the solder ball;

[0020] r is used to represent the radius of the solder ball.

[0021] Preferably, the number of the height-controlling blocks is at least one, and at least one of the height-controlling blocks is arranged staggered with the solder ball.

[0022] Preferably, when the number of the height-controlling blocks is one, the height-controlling block is located in the middle region of the chip.

[0023] Preferably, when the number of the height-controlling blocks is multiple, the multiple height-controlling blocks are symmetrically and uniformly distributed in the region of the chip projected to the circuit board.

[0024] Preferably, the cross section of the height-controlling block comprises a regular shape surrounded by straight edges, arc edges or both straight edges and arc edges.

[0025] Preferably, the material of the height-controlling block is the same as or different from the material of one of the circuit board and the chip.

[0026] The application also provides an electronic device comprising the packaging structure as described in any one of the above embodiments.

[0027] The packaging structure and electronic device of the embodiments of the present application. The packaging structure is provided with a height control block, one end of the height control block is connected with one of the circuit board and the chip, the other end of the height control block is in abutment with the other one of the two, so as to support between the circuit board and the chip, so as to control the height of the chip after welding, reduce the included angle between the chip and the circuit board, so as to solve the problem of different solder joint heights caused by the solder ball collapse process of the chip. And the thermal expansion coefficient of the material of the height control block is set between the thermal expansion coefficient of the material of the circuit board and the thermal expansion coefficient of the material of the chip, so as to provide a buffering effect in the temperature shock process, so that the difference of the thermal expansion coefficient on both sides of the solder ball is smaller, thereby reducing the risk of cracking of the solder joint in the temperature shock process, and improving the creep fatigue reliability of the solder joint. Compared with the related art, the investment cost is low and easy to implement.

[0028] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0029] The drawings incorporated into the specification and forming part of the specification, show embodiments consistent with the present application, and together with the specification, serve to explain the principles of the present application.

[0030] Figure 1 The structure schematic diagram of one embodiment of the packaging structure of the present application is shown.

[0031] Figure 2 The structure schematic diagram of the packaging structure after the chip and the circuit board are welded is shown. Figure 1 The structure schematic diagram of the packaging structure after the chip and the circuit board are welded is shown.

[0032] Figure 3 The structure schematic diagram of another embodiment of the packaging structure of the present application is shown.

[0033] Figure 4 The structure schematic diagram of the packaging structure after the chip and the circuit board are welded is shown. Figure 3 The structure schematic diagram of the packaging structure after the chip and the circuit board are welded is shown. DETAILED DESCRIPTION

[0034] The packaging structure and electronic device provided by the embodiments of the present application will be described in detail below with reference to the drawings. In the case of no conflict, the features in each of the following embodiments and implementation manners can be combined with each other at will.

[0035] Figure 1 The structure schematic diagram of one embodiment of the packaging structure 1 of the present application is shown. Figure 2 The structure schematic diagram of the packaging structure 1 after the chip 12 and the circuit board 11 are welded is shown. As Figure 1 The structure schematic diagram of the packaging structure 1 after the chip 12 and the circuit board 11 are welded is shown. As Figure 1 and Figure 2As shown, the packaging structure 1 comprises a circuit board 11, a chip 12 and a height control block 13. The circuit board 11 is provided with a plurality of pads 111. The chip 12 is provided with a plurality of solder balls 121, and the chip 12 is welded to the plurality of pads 111 of the circuit board 11 through the plurality of solder balls 121. The packaging structure 1 of the present application can adopt the CSP packaging technology to package the chip 12 on the circuit board 11. The CSP (Chip Scale Package) packaging refers to the chip level packaging, the latest generation of memory chip packaging technology, the ratio of the chip area to the packaging area is more than 1:1.14, which is close to the ideal case of 1:1. In the present application, it specifically refers to the CSP packaging through the solder balls 121. In the embodiment, the circuit board 11 can be a PCB (Printed Circuit Board) board, and the PCB board can be a printed circuit board. The chip 12 can be a CMOS chip, and the CMOS chip can be a photosensitive element chip used in a camera to cooperate with a lens assembly to form an image.

[0036] In actual packaging, the CMOS chip is welded to the plurality of pads 111 of the PCB board through the plurality of solder balls 121. The materials of the solder balls 121 and the pads 111 can be tin. The plurality of solder balls 121 are welded to the plurality of pads 111 through tin paste. One side of the solder ball 121 is the CMOS chip, which is made of silicon and has a thermal expansion coefficient of about 2-8 PPM / ℃, and the other side is the PCB board, which is made of FR4 board material (resin material, a material specification that can extinguish itself in a burning state) and has a thermal expansion coefficient of about 30-80 PPM / ℃. Due to the mismatch of the thermal expansion coefficients of the two sides of the solder ball 121 and the small height of the solder joint, the solder joint is prone to cracking after rapid temperature change. At the same time, during the welding process, the solder balls 121 collapse due to the sequence of welding of the plurality of solder balls 121, and the solder joint heights of the solder balls 121 after collapse are not the same, which causes the CMOS chip to tilt relative to the PCB board.

[0037] To solve the above problems, the packaging structure 1 of the present application connects one end of the height control block 13 to one of the circuit board 11 and the chip 12. The connection here can be understood as a substantial fixed connection, which can be achieved by integral setting, fixed connection or welding, etc. The other end of the height control block 13 abuts against the other one to support between the circuit board 11 and the chip 12. The abutment here can be understood as that the height control block 13 and the chip 12 are not substantially fixedly connected, but represent contact lapping or abutment, and the height control block 13 and the chip 12 have a mutual force.

[0038] In Figure 1In the illustrated embodiment, one end of the height control block 13 is connected to the circuit board 11. The other end of the height control block 13 rests on the bottom of the chip 12. By setting the height control block 13, it assists in soldering the CMOS chip onto the pads 111 of the PCB board, supporting the circuit board 11 and the chip 12, and ensuring that the multiple solder balls 121 maintain a consistent height during the soldering process (e.g., ...). Figure 2 As shown, this allows control over the height of chip 12 after soldering, ensuring that chip 12 and circuit board 11 are set relatively parallel, avoiding the chip 12 tilting to one side relative to circuit board 11, reducing the angle between chip 12 and circuit board 11, and solving the problem of inconsistent solder joint height caused by the collapse of solder joints of solder balls 121 of chip 12.

[0039] Because the materials used in circuit board 11 and chip 12 are different, their coefficients of thermal expansion differ significantly. In this application, the coefficient of thermal expansion of the material used in height control block 13 is set between that of the materials used in circuit board 11 and chip 12. The coefficient of thermal expansion is a physical quantity used to measure the degree of thermal expansion of solid materials; it is the relative change in length or volume of an object per unit length and volume when the temperature increases by 1°C. This setting allows the coefficient of thermal expansion of the material used in height control block 13 to provide a buffering effect during temperature surge, reducing the difference in coefficients of thermal expansion on both sides of solder ball 121, thereby reducing the risk of solder joint cracking during temperature surge and improving the reliability of the solder joint against creep fatigue. Furthermore, compared with related technologies, this packaging structure 1, by incorporating height control block 13, has low investment costs and is easy to implement.

[0040] exist Figure 1 and Figure 2 In the illustrated embodiment, the height control block 13 is separately disposed from the chip 12 or the circuit board 11. In this embodiment, the height control block 13 is separately disposed from the chip 12 and also separately disposed from the circuit board 11. Figure 1 In the illustrated embodiment, the circuit board 11 is provided with a connecting block 112. One end of the height control block 13 is connected to the connecting block 112, and the other end of the height control block 13 abuts against the chip 12 vertically. In this embodiment, the connecting block 112 and the solder pad 111 are located on the same side of the circuit board 11. The connecting block 112 can be a solder paste connecting block, used to connect or solder the height control block 13, so that one end of the height control block 13 is fixed to the circuit board 11. The other end of the height control block 13 is located at the bottom of the chip 12 and abuts against the bottom surface of the chip 12 vertically to support the chip 12. This arrangement ensures that the height of the multiple solder balls 121 remains consistent during the soldering process (e.g., ...). Figure 2As shown, this allows control over the height of the solder ball 121 after it collapses, ensuring that the chip 12 and the circuit board 11 are set relatively parallel to each other, avoiding the chip 12 tilting to one side relative to the circuit board 11, reducing the angle between the chip 12 and the circuit board 11, and solving the problem of inconsistent solder joint height caused by the collapse process of the solder ball 121 of the chip 12.

[0041] Figure 3 The diagram shown is a structural schematic of another embodiment of the packaging structure 1 of this application. Figure 4 As shown Figure 3 The diagram shows the structure of package structure 1 after the chip 12 and circuit board 11 are soldered together. Figures 3 to 4 The illustrated embodiments and Figures 1 to 2 The embodiments shown are similar, the main difference being that... Figure 3 and Figure 4 In the illustrated embodiment, the height control block 13 is integrally formed with either the circuit board 11 or the chip 12. The height control block 13 can be integrally formed with either the circuit board 11 or the chip 12. The integrally formed height control block 13 has a simpler manufacturing process and lower cost. Figure 3 and Figure 4 In the illustrated embodiment, one end of the height control block 13 is integrally formed with the chip 12, and the other end of the height control block 13 abuts against the circuit board 11 vertically. In this embodiment, one end of the height control block 13 is integrally formed with the chip 12, and the side of the height control block 13 that abuts against or is suspended from the circuit board 11 is the abutment surface, overlapping with the surface of the circuit board 11. With this configuration, the bottom of the height control block 13 will collapse onto the circuit board 11 during the soldering process to complete the soldering of the middle side solder ball 121. This process and packaging method are simple and reduce costs. It also reduces costs while improving the height consistency after solder joint collapse.

[0042] In some other embodiments, one end of the height control block 13 is integrally formed with the circuit board 11, and the other end of the height control block 13 abuts against the chip 12 vertically. In this embodiment, one end of the height control block 13 is integrally formed with the circuit board 11, and the side of the height control block 13 that abuts against or is suspended from the chip 12 is the abutting surface, overlapping with the bottom surface of the chip 12. This process and packaging method are simple and reduce costs. It also reduces costs while improving the height consistency after solder joint collapse.

[0043] In some embodiments, the flatness of the connecting plane 131 or the abutting plane 132 of the height-controlling block 13 connected with at least one of the circuit board 11 and the chip 12 is set to be no more than 0.08°. In the present embodiment, the height-controlling block 13 is connected with or abuts against at least one of the circuit board 11 and the chip 12 in a plane, and the flatness of the connecting plane 131 or the abutting plane 132 of the plane connection or the plane abutment is set to be no more than 0.08°. The smaller the flatness is, the better the flatness of the connecting plane 131 or the abutting plane 132 is, so that the height of the chip 12 soldered to the circuit board 11 is kept consistent, and the flatness after soldering of the chip 12 is improved.

[0044] In Figure 1 In the embodiment shown in the figure, the side of the height-controlling block 13 connected with the connecting block 112 of the circuit board 11 is a connecting side, which is the connecting plane 131, and the side of the height-controlling block 13 abutting against or suspended from the chip 12 is an abutting side, which is the abutting plane 132. In the embodiment shown in the figure, the height-controlling block 13 is integrally arranged with the chip 12, and the side of the height-controlling block 13 abutting against the circuit board 11 is an abutting side, which is the abutting plane 132. In order to meet the packaging flatness, the flatness of the connecting plane 131 and the abutting plane 132 is set to be no more than 0.08°, so that the height consistency after collapse of the solder joint is improved, the included angle between the CMOS chip and the PCB board is reduced, the flatness after soldering of the chip is improved, the AA process is cancelled or the AA time is significantly shortened, and the cost is reduced. Figure 3

[0045] In some embodiments, the height of the height-controlling block 13 is between the height of the solder ball 121 and the height of the solder ball 121 after soldering. In the present embodiment, the height of the height-controlling block 13 is set to be between the height of the solder ball 121 and the height of the solder ball 121 after collapse, so that the height of the solder ball after collapse is controlled (reduced), the cyclic shear strain range of the solder joint is reduced, and the time for cracking failure of the solder joint is prolonged.

[0046] In the present embodiment, the solder joint fatigue creep model (Engelmaier-Wild) includes:

[0047]

[0048] wherein Nf(50%) is used to represent the time for half of the given samples to fail; ΔD is used to represent the cyclic shear strain range; εf' is used to represent the fatigue toughness coefficient, the value of which is 0.325; c is used to represent the fatigue toughness index; TSJ is used to represent the average cyclic temperature (the average of the maximum nominal temperature and the minimum nominal temperature); t D is used to represent the time for half of the given samples to fail; ΔD is used to represent the cyclic shear strain range; εf' is used to represent the fatigue toughness coefficient, the value of which is 0.325; c is used to represent the fatigue toughness index; TSJ is used to represent the average cyclic temperature (the average of the maximum nominal temperature and the minimum nominal temperature); t

[0049] ​In the above formula, the cyclic shear strain range ΔD of the leadless CSP package is:

[0050]

[0051] wherein h is used to represent the height of the solder joint after collapse; L D is used to represent the maximum distance from the solder joint to the center point; a is used to represent the thermal expansion coefficient; F is used to represent the experimental correction coefficient, mainly considering the influence of the alloy layer on the solder joint life, and the solder joint of the CSP device is 1.1<F<1.5.

[0052] Therefore, according to the cyclic shear strain range ΔD of the leadless CSP package and the solder joint fatigue creep model, the greater the height h of the solder joint after the CSP packaged CMOS chip is welded, the smaller the shear strain range ΔD, the greater Nf(50%) and the higher the reliability of the packaging structure 1.

[0053] Therefore, in the present application, the height of the height control block 13 should not be too high or too low. If the height of the height control block 13 is too high, the solder balls 121 of the chip 12 and the pads 111 of the circuit board 11 may not be welded or the welding may not be completely fused, which is easy to produce a virtual welding defect that looks like a pillow, that is, a CSP package solder joint pillow effect. If the height of the height control block 13 is too low, it cannot support the chip 12 and the circuit board 11. In the present embodiment, since the height of the solder ball 121 is a known parameter, the height of the solder ball 121 after welding or collapse can be a proportional height before welding (for example, at least 50%), which is also a known parameter, so that the height of the height control block 13 can be determined. By setting the height of the height control block 13 appropriately, the height of the solder ball after collapse can be controlled (reduced), the cyclic shear strain range of the solder joint is reduced, the time for the solder joint to crack and fail is prolonged, and the reliability of the packaging structure 1 is improved.

[0054] In actual application, some solder balls 121 of the chip 12 are small, which may cause the problem that the solder balls 121 and the pads 111 on the circuit board 11 cannot be connected, that is, the pillow effect is poor. Therefore, in order to improve the strength of the solder joint and ensure that the solder joint does not produce a pillow effect, there is a certain correlation between the total tin amount of the solder joint and the height of the height control block 13.

[0055] In some embodiments, the relationship between the height of the height control block 13 and the volume of the solder ball 121 includes:

[0056] H=V / S;

[0057] V=4 / 3*πr 3 ;

[0058] Wherein, H is used to represent the height of the height control block 13; S is used to represent the cross-sectional area of the height control block 13; V is used to represent the volume of the solder ball 121; and r is used to represent the radius of the solder ball 121.

[0059] The height of the height control block 13 of the embodiment can be set according to the volume of the solder ball 121, the height after the solder ball collapses can be controlled (reduced), the range of the cyclic shear strain of the solder joint is reduced, the time for the solder joint to crack and fail is prolonged, and the pillow effect after soldering is avoided. Meanwhile, under the same area of the height control block 13, a higher height control block 13 can be selected to increase the height of the solder joint, thereby improving the reliability of the packaging structure 1.

[0060] Alternatively, the height of the height control block 13 that meets the reliability requirement can be deduced from the solder joint fatigue creep model. The radius of the solder ball 121 can be calculated from the relationship between the height of the height control block 13 and the volume of the solder ball 121. The solder ball 121 with a larger radius is provided with the CMOS chip. Alternatively, the solder ball with a larger radius can be added by tin steel screen printing.

[0061] In combination with the solder joint fatigue creep model, the height of the solder joint of the solder ball 121 can be deduced, and the amount of tin of the solder ball 121 can be deduced from the relationship between the height of the solder joint of the solder ball 121 and the tin of the solder ball 121. The appropriate amount of tin can be provided with the solder ball 121 or added by tin printing. On the basis of increasing the height of the solder joint to improve the reliability, the pillow effect after soldering can also be avoided.

[0062] In some embodiments, the number of the height control block 13 is at least one, and the at least one height control block 13 is arranged staggered with the solder ball 121. The number of the height control block 13 can be set to one or more than one, and arranged staggered with the solder ball 121. In some embodiments, when the number of the height control block 13 is one, the height control block 13 is located in the middle region of the chip 12. When the number of the height control block 13 is set to one, the height control block 13 is arranged at the center of the chip 12 to ensure that the chip 12 and the circuit board 11 are parallel, thereby avoiding tilting. In other embodiments, when the number of the height control block 13 is multiple, the multiple height control blocks 13 are symmetrically and uniformly distributed in the region where the chip 12 is projected onto the circuit board 11. When the number of the height control block 13 is multiple, the height control blocks 13 are uniformly and symmetrically arranged in the projection region of the chip 12 projected onto the circuit board 11, and are arranged away from the solder ball 121. Alternatively, when the number of the height control block 13 is set to two, the two height control blocks 13 are symmetrically arranged at the bottom of the chip 12. When the number of the height control block 13 is set to three, the three height control blocks 13 are arranged in a triangular shape at the bottom of the chip 12. When the number of the height control block 13 is set to four, the four height control blocks 13 are arranged at the four corners of the chip 12. In this way, the flatness of the chip 12 and the circuit board 11 after soldering is ensured, thereby avoiding tilting.

[0063] In some embodiments, the cross section of the height control block 13 comprises a regular shape surrounded by straight edges, arc edges or both. In some embodiments, the shape of the height control block 13 can be one of a cuboid, a cylinder, a truncated cone, but not limited to these. Figures 1 to 4 In the illustrated embodiment, the shape of the height control block 13 is a cuboid, and the cross section of the height control block 13 is adapted to the area of the connecting block 112. The height control block 13 selected in this embodiment has a regular shape, simple structure and low cost.

[0064] In some embodiments, the material of the height control block 13 is the same as or different from that of one of the circuit board 11 and the chip 12. Figure 1 In the illustrated embodiment, the height control block 13 is fixed to the circuit board 11 through the connecting block 112, and the material of the height control block 13 can be brass or brass plated with tin. After soldering, one side of the split height control block 13 is overlapped with the bottom of the flat chip 12, and the other side is connected to the surface of the flat circuit board 11, which can be selected as bright copper with good flatness. Figure 3 In the illustrated embodiment, the height control block 13 is integrally arranged with the chip 12, and the material of the height control block 13 is silicon or other material with a thermal expansion coefficient between that of silicon of the chip 12 and FR4 board material of the circuit board 11. The side of the height control block 13 that is suspended can be overlapped with the surface of the flat circuit board 11, which can be selected as bright copper or FR4 with good flatness. In this way, the material of the height control block 13 can be flexibly selected according to the actual material and integration mode of the chip 12 and the circuit board 11, which has strong flexibility and adaptability and low cost.

[0065] The application also provides an electronic device comprising the packaging structure 1 as shown in the above Figures 1 to 4 embodiments. The electronic device can be a video camera or a still camera, but not limited to these. By arranging the height control block 13 as described above, the electronic device can not only control the height of the chip 12 after soldering, but also avoid the inclination of one side of the chip 12 relative to the circuit board 11, reduce the included angle between the chip 12 and the circuit board 11, and solve the problem of uneven height of the solder joint caused by the collapse of the solder ball 121 of the chip 12 during the solder joint collapsing process. In addition, the height control block 13 can provide a buffering effect during the thermal shock process, so that the difference in thermal expansion coefficient between the two sides of the solder ball 121 is small, thereby reducing the risk of cracking of the solder joint during the thermal shock process, improving the creep fatigue reliability of the solder joint, and having low cost.

[0066] It should be understood that the application is not limited to the precise construction which has been described above and illustrated in the accompanying drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the application is limited only by the claims that follow.

Claims

1. A packaging structure, characterized in that, include: The circuit board has multiple solder pads; A chip having multiple solder balls is soldered to multiple pads on a circuit board via the solder balls; and A height control block, one end of which is connected to one of the circuit board and the chip, and the other end of which abuts against the other to support the circuit board and the chip; wherein the coefficient of thermal expansion of the material used for the height control block is between that of the material used for the circuit board and the material used for the chip.

2. The packaging structure according to claim 1, characterized in that, The height control block is integrally formed with either the circuit board or the chip.

3. The packaging structure according to claim 2, characterized in that, One end of the height control block is integrally formed with the chip, and the other end of the height control block abuts against the circuit board vertically; or One end of the height control block is integrally formed with the circuit board, and the other end of the height control block abuts against the chip vertically.

4. The packaging structure according to claim 1, characterized in that, The height control block is separately disposed from the chip or the circuit board; wherein, the circuit board is provided with a connecting block, one end of the height control block is connected to the connecting block, and the other end of the height control block abuts against the chip vertically.

5. The packaging structure according to claim 1, characterized in that, The flatness of the connection plane or abutting plane of the height control block that connects to at least one of the circuit board and the chip is set to be no greater than 0.08°.

6. The packaging structure according to claim 1, characterized in that, The height of the height control block is between the height of the solder ball and the height of the solder ball after welding.

7. The packaging structure according to claim 1 or 6, characterized in that, The relationship between the height of the height control block and the volume of the solder ball includes: H = V / S; V＝4 / 3*πr 3 ； Wherein, H represents the height of the height control block; S represents the cross-sectional area of ​​the height control block; V is used to represent the volume of the solder ball; r is used to represent the radius of the solder ball.

8. The packaging structure according to claim 1, characterized in that, The number of height control blocks is at least one, and at least one height control block is staggered from the solder ball; wherein... When there is only one height control block, the height control block is located in the central region of the chip; or When there are multiple height control blocks, the multiple height control blocks are symmetrically and evenly distributed in the area where the chip is projected onto the circuit board.

9. The packaging structure according to claim 1, characterized in that, The cross-section of the height control block includes a regular shape formed by straight edges, curved edges, or both straight and curved edges; and / or The material of the height control block may be the same as or different from the material of either the circuit board or the chip.

10. An electronic device, characterized in that, include: The packaging structure as described in any one of claims 1 to 9.

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