An adaptive ball mounting jig suitable for substrate warping

Abstract

The application discloses a self-adaptive ball mounting jig suitable for substrate warping, relates to the technical field of substrate ball mounting, and comprises a correction device which is used for correcting the position of a substrate adsorbed by a vacuum chuck, a flux dipping point device which is used for dipping flux points on pads of the substrate, and a ball mounting device which is used for adsorbing tin balls and implanting the tin balls on the substrate. The flux dipping point device comprises a PIN fixing plate arranged on a three-axis moving device, a gas storage cavity fixedly connected to the middle part of the PIN fixing plate, a flexible layer fixedly connected to the bottom of the gas storage cavity, a plurality of first PINs which are slidably connected to the middle part of the PIN fixing plate, and the upper end of each first PIN is attached to the flexible layer, and a gas cavity which can be filled and discharged is formed between the gas storage cavity and the flexible layer. The ball mounting device is used for adsorbing tin balls and implanting the tin balls on the substrate. According to the application, the independent movement of a single PIN is realized by using the flexible layer and the gas storage cavity structure, and the dynamic adjustment of pressure is used to increase the movement stroke of the PIN.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of substrate ball mounting, and more particularly to a self-adaptive ball mounting jig suitable for substrate warping. BACKGROUND

[0002] With the explosion of AI and high-performance computing (HPC), the demand for large-size BGA packaging has surged, and the demand for solutions for tin ball mounting, as a key link, has also grown. Due to the substrate warping problem (warping degree ≥ 0.6 mm), the one-time yield of large-size BGA packaging ball mounting in the market is zero, and secondary ball mounting (manual or machine) is required. The existing ball mounting method has low one-time yield and efficiency, and high cost, which cannot meet the market demand.

[0003] 1. The existing flux dip point device on the market has the following problems:

[0004] (1) The Pin of the flux dip point device has a short downstroke (0-1 mm). If there is an obstacle (exceeding the downstroke) during the process of the Pin dipping flux, the Pin and the substrate will be extruded, causing deformation or breakage of the PIN, and damage to the substrate.

[0005] (2) The Pin dips flux on the (PCB, ceramic, etc.) substrate or chip (Die), and the pressure of the Pin on the substrate is relatively fixed. The PIN pressure cannot be dynamically adjusted by a large margin according to the on-site debugging situation.

[0006] (3) The whole board Pins (corresponding to the whole (PCB, ceramic, etc.) substrate) or unit Pins (corresponding to a single (PCB, ceramic, etc.) substrate or chip (Die)) of the flux dip point device are lifted synchronously, and cannot be independently floated by a large distance.

[0007] If any of the above problems occurs in the Pin Tool, the Pin Tool is not suitable for dipping flux on any deformed (warping degree ≥ 0.6 mm) whole or single (PCB, ceramic, etc.) substrate or chip (Die).

[0008] 2. The existing ball mounting device on the market has the following problems. During the placement of the tin ball, due to the distance between the ball mounting device and the substrate, the tin ball of the ball mounting device is not accurately positioned during the falling process, and may deviate from the flux or PAD, causing the PAD to lack tin balls or the tin balls to deviate from the PAD.

[0009] 3. The market currently uses an up-down and left-right shaking method to correct the board. If the substrate is a bare DIE, this shaking method may scratch the bare DIE, which is relatively costly.

[0010] Therefore, it is necessary to provide a self-adaptive ball mounting jig suitable for substrate warping to solve the above problems. SUMMARY

[0011] The present application aims at solving the problems mentioned in the background art.

[0012] In order to achieve the above-mentioned purpose, the present application specifically adopts the following technical solutions:

[0013] A self-adaptive ball mounting jig suitable for substrate warping, comprising a correction device, a flux dipping point device and a ball mounting device which are arranged on a machine table and can move through a three-axis moving device.

[0014] The correction device is used for correcting the position of the substrate adsorbed by the vacuum chuck.

[0015] The flux dipping point device is used for dotting flux on the substrate, comprising a PIN fixed plate arranged on the three-axis moving device, a gas storage cavity fixedly connected in the middle of the PIN fixed plate, a flexible layer fixedly connected at the bottom of the gas storage cavity, a plurality of first PINs slidingly connected in the middle of the PIN fixed plate, the upper end of the first PIN abutting the flexible layer, and a gas cavity formed between the gas storage cavity and the flexible layer which can be inflated and deflated.

[0016] The ball mounting device is used for adsorbing and implanting the solder ball on the substrate.

[0017] Further, a gas pressure sensor is fixedly connected in the gas cavity.

[0018] Further, an air inlet and outlet is arranged at the upper end of the gas storage cavity, and a gas inflation and deflation device is connected.

[0019] Further, the correction device comprises a correction panel arranged on the three-axis moving device, and a plurality of positioning plates corresponding to the position of the substrate are fixedly connected at the bottom of the correction panel.

[0020] Each substrate corresponds to two adjacent positioning plates arranged at a right angle, two through holes corresponding to the right angle are arranged on the correction panel, and a third PIN which can move at 45° towards the right angle direction is arranged in the two through holes.

[0021] Further, a third base is fixedly connected at the upper end of the correction panel, and the third base is fixedly connected to the three-axis moving device.

[0022] Further, a transmission plate is slidingly connected inside the third base along the 45° angle direction of the right angle, a top plate is fixedly connected at the bottom of the transmission plate, a hole is arranged on the top plate for plug-in connection of the third PIN, and the third PIN is inserted into the through hole through the hole.

[0023] Further, the upper end of the PIN fixing plate is fixedly connected with a first base, and the first base is fixedly connected with the three-axis moving device.

[0024] Further, the ball planting device comprises a second base fixedly connected with the three-axis moving device and a ball planting panel fixedly connected with the bottom of the second base, the ball planting panel is provided with ball taking holes, the second base is provided with second PINs in the same number as the ball taking holes, the second PINs are inserted into the ball taking holes and push the solder balls out.

[0025] The second base and the ball planting panel are in a sealed state and can be vacuumized, so as to adsorb the solder balls into the ball taking holes by negative pressure.

[0026] Further, the middle part of the second base is provided with a connecting plate which is liftable, the bottom of the connecting plate is fixedly connected with a second floating plate, the bottom of the second floating plate is fixedly connected with a steel sheet, the bottom of the steel sheet is fixedly connected with a mounting plate, and the mounting plate is provided with holes for inserting the second PINs.

[0027] Further, the transmission plate is driven by a driving member, and the driving member is arranged along the 45° direction of the third base.

[0028] Compared with the prior art, the present application has the following beneficial effects:

[0029] 1. The present application realizes the independence of single PIN activity and the dynamic adjustment of pressure by using the flexible layer + air storage cavity structure, so that the PIN activity stroke is increased.

[0030] 2. The correction device of the present application can drive the third PIN to move and push the single substrate to adhere to the positioning plate, so as to realize the righting of the substrate. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a front view schematic diagram of the correction device in the present application.

[0032] Figure 2 It is a front view schematic diagram of the flux dipping point device in the present application.

[0033] Figure 3 It is a front view schematic diagram of the ball planting device in the present application.

[0034] Figure 4 It is a perspective bottom view schematic diagram of the correction device in the present application.

[0035] Figure 5 It is a perspective top view schematic diagram of the correction device in the present application.

[0036] Figure 6 It is a first perspective sectional view schematic diagram of the correction device in the present application.

[0037] Figure 7 It is the second perspective view of the correction device in the application.

[0038] Figure 8 It is the perspective view of the flux dipping device in the application.

[0039] Figure 9 It is the perspective view of the ball planting device in the application.

[0040] Reference signs: 1, first base; 2, gas storage cavity; 3, flexible layer fixing plate; 4, flexible layer; 5, gas cavity; 6, PIN fixing plate; 7, first PIN; 8, air pressure sensor; 9, pinhole; 10, connecting plate; 11, second base; 12, steel sheet; 13, mounting plate; 14, second PIN; 15, ball planting panel; 16, graphite plate; 17, ball taking hole; 18, third base; 19, driving piece; 20, transmission plate; 21, top plate; 22, correction panel; 23, third PIN; 24, through hole; 25, positioning plate; 26, second floating plate; 27, round plate; 28, mounting column; 29, tension spring; 30, transmission block; 31, mounting groove; 32, guide groove. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0042] Please refer to Figures 1 to 9 A self-adaptive ball planting jig suitable for substrate warping includes a correction device, a flux dipping device and a ball planting device arranged on a machine table and capable of moving through a three-axis moving device, that is, the correction device, the flux dipping device and the ball planting device are capable of moving in XYZ directions.

[0043] Firstly, a tool with adsorbed substrates is placed below the correction device position, the correction device includes a correction panel 22 arranged on a three-axis moving device, and the bottom of the correction panel 22 is fixedly connected with a plurality of positioning plates 25 corresponding to the substrate position;

[0044] Each substrate corresponds to two adjacent positioning plates 25, and the extension lines of the positioning plates 25 perpendicularly form a right angle, two through holes 24 corresponding to the right angle are formed on the correction panel 22, and a third PIN 23 capable of moving by 45° towards the right angle direction is arranged in the two through holes 24, for pushing the adjacent two edges of the substrate to move, so that the other two edges of the substrate are attached to the positioning plates 25.

[0045] The third base 18 is fixedly connected to the upper end of the correction panel 22 and is fixedly connected to the three-axis moving device. The transmission plate 20 is slidably connected to the inside of the third base 18 in a 45° direction, the top plate 21 is fixedly connected to the bottom of the transmission plate 20, the hole for inserting the third PIN 23 is formed in the top plate 21, the third PIN 23 is inserted into the through hole 24 through the hole, that is, the third PIN 23 is fixed through the transmission plate 20 to prevent the third PIN 23 from being pushed out, and in addition, the spring is arranged at the upper end of the third PIN 23 to prevent the third PIN 23 from being hard contacted with the substrate when the correction device is pressed down.

[0046] The transmission plate 20 is driven by the driving member 19, the guide rail is fixedly connected to the upper end of the transmission plate 20 in a 45° direction, the guide rail groove is formed in the bottom of the third base 18, and the guide rail and the guide rail groove are both arranged in a 45° direction, which is to enable the driving member 19 to drive the transmission plate 20 to move in a 45° direction, and in turn to drive the third PIN 23 to push the substrate to the fitting positioning plate 25.

[0047] The driving member 19 is arranged in a 45° direction of the third base 18, including the circular plate 27 fixedly connected to the middle part of the third base 18, the two mounting columns 28 fixedly connected to the third base 18, and the transmission block 30 slidably connected to the circular plate 27 in a 45° reverse direction, the tension spring 29 is fixedly connected between the transmission block 30 and the mounting column 28, the guide groove 32 for the transmission block 30 to slide is formed in the circular plate 27, the mounting groove 31 is formed in the upper end surface of the transmission plate 20, the lower end of the transmission block 30 is fixedly connected in the mounting groove 31, the transmission block 30 is connected to the cylinder (not shown in the figure) on the machine table, the transmission block 30 is moved by the cylinder, and in turn the transmission plate 20 is moved.

[0048] The flux dipping device is used for dipping the flux to the substrate, including the PIN fixed plate 6 arranged on the three-axis moving device, the first base 1 fixedly connected to the upper end of the PIN fixed plate 6, and the first base 1 fixedly connected to the three-axis moving device. The gas storage cavity 2 is fixedly connected to the middle part of the PIN fixed plate 6, the flexible layer fixed plate 3 is fixedly connected to the bottom of the gas storage cavity 2, the flexible layer 4 is clamped and fixed to the bottom of the gas storage cavity 2 by the flexible layer fixed plate 3, the flexible layer fixed plate 3 and the bottom of the gas storage cavity 2 are both provided with the back-shaped groove, the back-shaped groove clamps the outer edge of the flexible layer 4, and then the flexible layer fixed plate 3 is fixed to the gas storage cavity 2 by the screw.

[0049] The flexible layer 4 can be rubber, silica gel or other materials with air-tightness.

[0050] A needle hole 9 is formed in the middle of the PIN fixing plate 6, and a plurality of first PINs 7 are slidably connected in the needle hole 9. Under the action of no external force, the upper end of the first PIN 7 is attached to the flexible layer 4, and the air cavity 5 that can be inflated and deflated is formed between the gas storage cavity 2 and the flexible layer 4. The gas pressure sensor 8 is fixedly connected in the air cavity 5, which can monitor the internal gas pressure of the gas storage cavity 2 in real time and send signals to the machine. The machine can adjust the internal gas pressure in real time according to the signal, ensure that the pressure value is within the set range, and open the gas inlet and outlet in the upper end of the gas storage cavity 2. The charging and discharging device is connected, and the PIN / Pad point feedback such as pressure distribution signal can also be obtained. The linkage control system adjusts the charging and discharging rate to optimize the buffering performance.

[0051] The purpose of the flexible layer 4 is to leave a moving space after the first PIN 7 is stressed, to ensure the depression and rebound of the first PIN 7, and to make the elasticity of the flexible layer 4 absorb the impact force on the top of the first PIN 7 by inflation, so as to avoid the damage of the substrate caused by the rigid contact of the first PIN 7 with the substrate. The effective extension length of the first PIN 7 is automatically adjusted according to the real-time warping deformation of the substrate during the crimping process, so as to ensure that each first PIN 7 realizes stable and reliable contact with the Pad point.

[0052] The ball planting device is used for adsorbing and planting tin balls on a substrate. The ball planting device comprises a second base 11 fixedly connected to a three-axis moving device and a ball planting panel 15 fixedly connected to the bottom of the second base 11. The ball planting panel 15 is provided with ball taking holes 17, and the second base 11 is provided with second PINs 14 which are the same in number as the ball taking holes 17 and are arranged in a lifting manner. The second PINs 14 are used for inserting into the ball taking holes 17 to push the tin balls out to the flux of the substrate.

[0053] The ball planting panel 15 can be made of aluminum plate material, or graphite material, or aluminum plate plus graphite plate 16. The graphite plate 16 is fixedly connected to the lower end of the ball planting panel 15. The kinetic energy of the tin ball leaving the ball planting panel hole diameter is increased by using the ball planting panel and the graphite plate, the contact area of the tin ball and the flux is increased, and the flux is more easily adhered to the tin ball.

[0054] The second base 11 and the ball planting panel 15 are in a sealed state, and a vacuum can be generated by a vacuum generator. In a continuous air extraction state, the tin ball is adsorbed into the ball taking hole 17 by negative pressure. The second base 11 is provided with a connecting plate 10 arranged in a lifting manner in the middle. The lifting of the connecting plate 10 can be controlled by a gas cylinder. The gas cylinder is fixed to the corresponding machine position (not shown in the figure). The second base 11 is provided with a second floating plate 26 fixedly connected to the bottom of the connecting plate 10. The second floating plate 26 is fixedly connected to a steel sheet 12 at the bottom. The steel sheet 12 is fixedly connected to a mounting plate 13 at the bottom. The mounting plate 13 is provided with holes for inserting the second PIN 14. After the second PIN 14 is inserted into the hole, the mounting plate 13 is fixed to the steel sheet 12 to complete the installation of the second PIN 14.

[0055] Working principle: First, the substrate fixture adsorbed by the vacuum chuck is placed below the calibration device. The calibration device, flux application device, and ball placement device can all move in three axes. They are carried out in sequence according to the process. First, calibration is performed. The calibration device is controlled to move down to a certain distance, which is close to the substrate adsorbed by the vacuum chuck. Then, the machine cylinder is controlled to drive the transmission block 30 to move, which in turn drives the transmission plate 20 to move, so that the third PIN 23 pushes the substrate to the position where it is in contact with the positioning plate 25.

[0056] Then, control the flux dispensing device to move down to pick up the flux. After the dispensing is complete, move it horizontally above the substrate fixture that is adsorbed by the vacuum suction cup. Then, control the flux dispensing device to move down to apply the flux.

[0057] Finally, the ball-planting device is moved down, and the solder balls are placed uniformly in the solder ball box. The solder ball box is installed on the vibrating plate, which causes the solder balls to vibrate and jump. Then, by drawing negative pressure in the second base 11 and the ball-planting panel 15, the solder balls are adsorbed into the ball-retrieving hole 17. Then, the ball-planting device is moved above the fixture, and the connecting plate 10 is moved down by controlling the machine cylinder. This causes the second PIN 14 to push the solder balls in the ball-retrieving hole 17 onto the flux, completing the ball-planting of the substrate on the fixture.

[0058] The aforementioned machine tool cylinders are not a single cylinder, but rather cylinders corresponding to their respective positions, in order to achieve the effects described in this invention. Furthermore, the aforementioned 45° direction refers to the direction of the 45° angle formed by the extensions of the two positioning plates 25, or a direction parallel to that angle.

[0059] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the content of the present invention's specification shall also be included within the scope of protection of the present invention.

Claims

1. An adaptive ball-mounting fixture suitable for substrate warping, characterized in that: It includes a correction device, a flux application device, and a ball placement device, all of which are mounted on the machine base and can be moved by a three-axis moving device; A calibration device is used to calibrate the position of the substrate adsorbed by the vacuum suction cup; A flux application device for applying flux onto a substrate includes a PIN fixing plate mounted on a three-axis moving device. A gas storage cavity is fixedly connected to the middle of the PIN fixing plate, and a flexible layer is fixedly connected to the bottom of the gas storage cavity. A plurality of first PINs are slidably connected to the middle of the PIN fixing plate, and the upper ends of the first PINs are attached to the flexible layer. An inflatable and deflated gas cavity is formed between the gas storage cavity and the flexible layer. A solder ball mounting device is used to adsorb solder balls and implant them onto a substrate.

2. The adaptive ball-mounting fixture for substrate warping according to claim 1, characterized in that: A pressure sensor is fixedly connected to the air cavity.

3. The adaptive ball-mounting fixture for substrate warping according to claim 1, characterized in that: The upper end of the gas storage cavity is provided with an air inlet and outlet, which are connected to a gas filling and releasing device.

4. The adaptive ball-mounting fixture for substrate warping according to claim 1, characterized in that: The calibration device includes a calibration panel mounted on a three-axis moving device, and a plurality of positioning plates corresponding to the positions of the substrate are fixedly connected to the bottom of the calibration panel. Each substrate corresponds to two adjacent positioning plates arranged at right angles. Two through holes are opened on the correction panel at positions corresponding to the right angles, and a third PIN that can move 45° in the right-angle direction is provided in the two through holes.

5. The adaptive ball-mounting fixture for substrate warping according to claim 4, characterized in that: The upper end of the calibration panel is fixedly connected to a third base, which is fixedly connected to the three-axis moving device.

6. The adaptive ball-mounting fixture for substrate warping according to claim 5, characterized in that: The third base has a transmission plate that slides along a 45° right angle inside. The bottom of the transmission plate is fixedly connected to a top plate. The top plate has a hole for inserting the third PIN. The third PIN passes through the hole and is inserted into the through hole.

7. The adaptive ball-mounting fixture for substrate warping according to claim 1, characterized in that: The upper end of the PIN fixing plate is fixedly connected to a first base, and the first base is fixedly connected to a three-axis moving device.

8. The adaptive ball-mounting fixture for substrate warping according to claim 1, characterized in that: The ball-planting device includes a second base fixedly connected to a three-axis moving device and a ball-planting panel fixedly connected to the bottom of the second base. The ball-planting panel has ball-removing holes. The second base is provided with a number of second pins equal to the number of ball-removing holes. The second pins are inserted into the ball-removing holes and push out the solder balls. The second base and the ball-planting panel are sealed together and can be vacuumed to draw the solder balls into the ball-receiving hole under negative pressure.

9. The adaptive ball-mounting fixture for substrate warping according to claim 8, characterized in that: The second base has a connecting plate that can be raised and lowered in the middle. A second floating plate is fixedly connected to the bottom of the connecting plate. A steel sheet is fixedly connected to the bottom of the second floating plate. An installation plate is fixedly connected to the bottom of the steel sheet. The installation plate has a hole for inserting a second PIN.

10. The adaptive ball-mounting fixture for substrate warping according to claim 6, characterized in that: The transmission plate is driven by a driving component, which is positioned at a 45° angle along the third base.

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