Bonding tool with shock absorber

Abstract

The present invention provides a bonding tool with a shock-absorbing device, comprising two springs A and B, both of which have an elastic coefficient of K, connected in series in the vertical direction. A counterweight is connected between springs A and B, and a bonding head is connected below spring B. The bottom of the bonding head can pick up or release a chip, and one or both sides of the bonding head are slidably connected to a bonding track. Preferably, the counterweight is a shock absorber with the same mass and the same height as the counterweight in the free state. The present invention reduces the impact force on the bottom chip when the bonding head picks up or bonds the chip, reduces the rebound of the bonding head, and achieves the purpose of protecting the chip.

Description

Technical Field

[0001] The present application relates to a bonding technology for micro components in the electronics industry. Background Art

[0002] Elastic potential energy is the potential energy that an object possesses due to the interaction of elastic forces between its parts during elastic deformation. For example, compressed gas, a bent bow, a wound spring, and a stretched or compressed spring all possess elastic potential energy.

[0003] Elastic potential energy is the potential mechanical energy stored in the structure of a material or physical system due to work performed to distort its volume or shape. Elastic energy is generated when compression, stretching, or generally any other deformation occurs. The greater the deformation of an elastic object within a certain range, the greater its elastic potential energy, and vice versa. Springs are used in traditional bonding devices.

[0004] When a bonding tool picks up a cut die from a wafer, the rapidly descending bond head can rebound and potentially damage the die surface when it contacts the die. Therefore, measures are needed to mitigate impact contact, such as changing the bonding equipment design to mitigate these issues.

[0005] Application No. 2020114353589 provides a method and tooling for thermocompression bonding of MEMS devices with vibration damping. The method includes: 1) securing a carrier support plate to a tooling base plate; 2) placing a carrier tape on the carrier support plate; 3) placing a carrier pressure plate on the carrier tape; 4) placing a carrier metal leg pressure plate on the carrier pressure plate to reshape the carrier tape's metal legs; 5) removing the reshaped carrier tape; 6) securing a sensor sensitive structure to the tooling base plate; 7) performing ball implantation on the sensor sensitive structure; 8) performing ramming on the gold ball; 9) aligning the reshaped carrier tape with the gold ball with a flat top; and 10) performing thermocompression bonding. This invention involves numerous components and a complex process. Summary of the Invention

[0006] Purpose of the invention:

[0007] Provided is a bonding tool with a shock-absorbing device that has little impact on a chip and has a buffering effect.

[0008] Technical solution:

[0009] Traditional bonding tools typically use a spring-loaded bond head connected to the bottom. The bond head moves back and forth on a vertical track: picking up the chip, moving down, releasing the chip, heating and bonding, moving up, and picking up the chip again, repeating this cycle. The bond head has an attached counterweight (or a partially detachable component, which can be located at the top, middle, or bottom of the bond head).

[0010] The present invention's bonding tool with a damping device replaces the conventional single load spring (with a spring constant of K and a free length of L) with two springs A and B, both with a spring constant of K, connected in series vertically. A counterweight is connected between springs A and B (the sum of the free lengths of springs A and B is the same as the free length of the original load spring). A bond head, minus the counterweight, is connected below spring B. The bond head's lower portion can pick up or release chips (or other microelectronic components).

[0011] One or both sides of the bond head slide onto the bond rail. Assume the weight of the bond head is G (the weight of the chip is very light and can be ignored. The spring is a lightweight spring and its mass is also negligible).

[0012] Preferably, the counterweight is an elastic shock absorber of the same mass and the same height in the free state, i.e., capable of elastic deformation. The shock absorber is a spring or a block of elastic material, preferably a polymer elastic material, and has an elastic coefficient greater than K, so that it has greater elastic potential energy than the spring when subjected to the same tension or compression.

[0013] According to the law of conservation of energy, the sum of the kinetic energy of the bond head (including the counterweight), the gravitational potential energy, and the elastic potential energy of the spring is constant. Assuming the gravitational potential energy of the bond head (including the counterweight) is zero at its lowest position (i.e., when bonding the chip), the sum of the kinetic energy of the bond head (including the counterweight) and the elastic potential energy of the spring is constant.

[0014] When the counterweight is separated from the bond head and moved upward between the two springs, the gravitational potential energy of the bond head (excluding the counterweight) is zero when it is at the lowest position; since the elastic potential energy of the two springs is basically the same, the gravitational potential energy of the counterweight becomes larger, and the kinetic energy of the bond head (excluding the counterweight) will decrease. When the bond head descends to the bottom for bonding, the impact force on the chip will be effectively alleviated, thereby achieving the expected shock absorption effect and providing better protection for the chip.

[0015] When the counterweight is replaced with a shock absorber and moved up between the two springs, the gravitational potential energy of the bonding head (excluding the shock absorber) is zero when it is in the lowest position. Since the elastic potential energy of the two springs is basically the same, the gravitational potential energy of the shock absorber becomes larger. The shock absorber is pulled by the upper and lower springs and elastically deforms. Its elastic potential energy is greater than that of springs of the same length. The kinetic energy of the bonding head (excluding the counterweight) will be reduced more. When the bonding head descends to the bottom for bonding, its impact force on the chip will be significantly reduced, thereby achieving an efficient shock absorption effect and better protecting the chip.

[0016] Beneficial effects of the present invention:

[0017] The present invention reduces the impact force on the bottom chip (substrate or lead frame) when the bonding head picks up the chip or bonds the chip, and reduces the rebound force of the bonding head, thereby achieving the purpose of protecting the chip.

[0018] By adjusting the weight or height of the counterweight and the elastic coefficient of the shock absorber, a bonding tool with corresponding vibration reduction effect can be obtained according to design requirements.

[0019] The present invention is suitable for use in the picking up or bonding process of various chips or components in semiconductor manufacturing equipment, has low manufacturing cost, and is easy to use and maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of a traditional bonding tool;

[0021] Figure 2 It is a structural schematic diagram of a bonding tool of the present invention;

[0022] Figure 3 It is a schematic structural diagram of another bonding tool of the present invention;

[0023] Figure 4 4 (1) is a schematic diagram of the vibration process of the bonding head after the counterweight block is moved upward; 4 (2) is a schematic diagram of the vibration process of the bonding head after the shock absorber is used and moved upward, in which the amplitude is reduced and the number of oscillations is reduced.

[0024] In the figure: 1-load spring (1A-spring A; 1B-spring B); 2-bonding head; 3-chip; 4-track; 12-counterweight; 13-shock absorber. DETAILED DESCRIPTION

[0025] Example 1:

[0026] like Figure 1 The conventional bonding tool shown has a bonding head 2 with a connected counterweight 12. One or both sides of the bonding head 2 are slidably connected to the bonding track 4. The bottom of the bonding head 2 can pick up or release the chip 3. The bonding head 2 and the counterweight 12 are connected together or separately.

[0027] When this structure is applied to this application, it is modified, such as Figure 2 As shown, a spring 1 is changed into two springs A [1A] and spring B [1B] connected in series in the vertical direction, both with the same elastic coefficient of K. A counterweight 12 is connected between spring A [1A] and spring B [1B], and a bonding head 2 is connected below spring B [1B].

[0028] Example 2:

[0029] like Figure 3The bonding tool with a shock-absorbing device shown has a bonding head 2, one side or both sides of the bonding head 2 are slidably connected to the bonding track 4, the bottom of the bonding head 2 can pick up or release the chip 3, and the bonding head 2 is connected to the counterweight block 12 together or separately; it also has two springs A [1A] and spring B [1B] with elastic coefficients of K connected in series in the vertical direction, an elastic shock absorber 13 with an elastic coefficient greater than the above-mentioned springs [1A, 1B] is connected between spring A [1A] and spring B [1B], and the bonding head 2 is connected below the spring B [1B].

Claims

1. A bonding tool with a shock-absorbing device, comprising a bonding head (2) and a counterweight block thereof, wherein one or both sides of the bonding head (2) are slidably connected to a bonding track (4), the upper portion of the bonding head (2) is suspended below a load spring having an elastic coefficient of K and a free state length of L, and the lower portion of the bonding head (2) is capable of picking up or releasing a chip (3); characterized in that: The load springs are two springs A (1A) and spring B (1B) connected in series in the vertical direction, both having an elastic coefficient of K, wherein the sum of the free state length of spring A (1A) and the free state length of spring B (1B) is L; a counterweight block separated from the key head (2) is connected between the springs A (1A) and B (1B), and the key head (2) without the counterweight block is connected below the spring B (1B); The counterweight block is an elastic shock absorber (13), and the elastic coefficient of the shock absorber (13) is greater than K.

2. The bonding tool with a shock absorbing device according to claim 1, wherein: The shock absorber (13) is a block of polymer elastic material.

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