CN108213644B

CN108213644B - Auxiliary device for manually welding components

Info

Publication number: CN108213644B
Application number: CN201810046798.1A
Authority: CN
Inventors: 嵇婷; 庞黎明; 黄鹏; 张伟平; 王中强
Original assignee: Xian institute of Applied Optics
Current assignee: Xian institute of Applied Optics
Priority date: 2018-01-18
Filing date: 2018-01-18
Publication date: 2020-04-28
Anticipated expiration: 2038-01-18
Also published as: CN108213644A

Abstract

The invention provides an auxiliary device for manually welding components, which consists of a pressing assembly and a clamping assembly; the pressing assembly comprises a height adjusting hand wheel, a pressing screw rod, a bearing outer ring fixing pressing plate and a pressing seat; the clamping assembly comprises a supporting plate, a metal bracket, a clamping adjusting hand wheel, a clamping screw and a screw fixing block; the compressing assembly can compress the components without causing displacement or rotation of the compressed components, so that relative isolation can be achieved; the clamping assembly supports the components through an L-shaped structure at the lower end of the metal support, and can adjust the position of the metal support, expand outwards and contract inwards to achieve the effect of clamping the components.

Description

Auxiliary device for manually welding components

Technical Field

The invention relates to the technical field of welding, in particular to an auxiliary device for manually welding a packaged component with pins at the periphery and a pad-free center.

Background

With the development of circuit board integration and miniaturization, small-package devices are widely used in circuit boards, and leadless package devices represented by LCCC packages are widely used in military products due to the features of miniaturization, high density and high reliability, as shown in fig. 1.

According to related researches, in the process of temperature change, the solder in the gap between the LCCC packaging device and the printed board can be increased by properly increasing the soldering height of the LCCC packaging device, the stress on a soldering point is reduced, and the reliability of the soldering point is improved, wherein the soldering height is shown in figure 2. For example, for high reliability products, CCGA package devices or BGA devices with high lead solder balls are generally selected, and solder joint reliability is improved by increasing solder joint height.

Due to the characteristics of small batch and multiple varieties of scientific research products, at present, a considerable number of units such as military institute still adopt manual welding of circuit boards. When a component, such as an LCCC component, is packaged by manually welding a pin center without a pad around the pin center, the welding height needs to be improved in order to improve the reliability of the welding point.

Generally, manual soldering increases the height of the solder by placing a polyimide pad on the bottom of the device before soldering. The gasket at the bottom of the device needs to ensure that the height of the gasket around the device is consistent, the alignment and welding between the device and the bonding pad are not affected, the device is easy to take out after welding, and it is difficult to achieve the conditions, and the welding technical requirements for operators are high, even the welding is difficult to achieve.

Disclosure of Invention

The invention provides an auxiliary device for manually welding components and parts, aiming at solving the problem of improving the welding height in the prior art during manual welding.

The technical scheme of the invention is as follows:

the auxiliary device for manually welding the components is characterized in that: the clamping device consists of a pressing component and a clamping component;

the pressing assembly comprises a height adjusting hand wheel, a pressing screw rod, a bearing outer ring fixing pressing plate and a pressing seat; the height adjusting hand wheel is fixed at one end of the compression screw rod, the other end of the compression screw rod is sleeved in the bearing and is fixedly connected with the inner ring of the bearing, the bearing is arranged in the compression seat, and the bearing outer ring fixing pressure plate is fixedly connected with the compression seat to fix the bearing outer ring in the compression seat;

the clamping assembly comprises a supporting plate, a metal bracket, a clamping adjusting hand wheel, a clamping screw and a screw fixing block; the center of the supporting plate is provided with an axial threaded through hole which is used for being matched and installed with the compression screw; a plurality of wedge-shaped grooves are uniformly distributed on the peripheral side wall of the supporting plate, and unthreaded holes are formed in the bottom of the wedge-shaped grooves along the radial direction of the supporting plate; threaded holes are formed around the wedge-shaped groove on the side wall of the supporting plate and are used for being fixedly connected with the screw fixing block; the center of the screw rod fixing block is provided with a unthreaded hole, and connecting holes are formed in the periphery of the screw rod fixing block and are used for being fixedly connected with the side wall of the supporting plate; two ends of the clamping screw rod are polished rods, the middle of the clamping screw rod is a screw rod, one end of the clamping screw rod is arranged in a unthreaded hole at the radial bottom of the wedge-shaped groove along the supporting plate, and the other end of the clamping screw rod penetrates through the wedge-shaped groove and the unthreaded hole at the center of the screw rod fixing block and is fixedly connected with the clamping adjusting hand wheel; the upper end of the metal support is provided with a wedge-shaped block matched with the wedge-shaped groove, the wedge-shaped block is provided with a threaded hole, the lower end of the metal support is of an L-shaped structure, and the thickness of the horizontal part at the bottom of the L-shaped structure is the height of the device pad; the wedge-shaped block threaded hole is matched with a screw rod in the middle of the clamping screw rod, and when the screw rod rotates, the metal support can axially move along the clamping screw rod.

Further preferred scheme, the auxiliary device of manual welding components and parts, its characterized in that: four wedge-shaped grooves are arranged on the peripheral side wall of the supporting plate in the clamping assembly at equal intervals of 90 degrees.

Further preferred scheme, the auxiliary device of manual welding components and parts, its characterized in that: the thickness of the horizontal part at the bottom of the L-shaped structure is the height of the device pad, and the height of the device pad is 0.15-0.2 mm.

Advantageous effects

The beneficial effects of the invention are shown in the following aspects:

(I) simplify manual operation, effectively compress tightly

Conventional manual die bonding typically involves placing the device on the circuit board pads with tweezers, pressing down on the aligned device with a small hoe or other pointed tool, and then securing the device. The difficulty of operation of this kind of mode is great, aligns device and pad and needs slowly to adjust, and the external force that the soldering iron was applyed when fixing after the alignment spot welding lets the chip position change again easily, and the dynamics of pressing down the chip can influence the area of contact of side pin and printed board moreover, and then influences the tin consumption of welding height and pin.

The device can simplify the alignment and welding steps, reduces manual operation, and can realize the uniform compression of the chip force and the adjustment of the force by self-locking the whole device through four support pins stretching into the bottom of the chip and the pressing device at the top of the chip, and the thickness of the four pins of the control device can control the gap between the pins of the device and the bonding pad (the lifting height of the device), so that the tin eating amount of the pins can be well controlled.

(II) ensuring the levelness of the device and quantitatively controlling the welding height

The bottoms of the four pins are positioned on the same base plane, the thickness of the pins is consistent, the pins are clamped up and down by rotating the pressing device, and the problem of device installation inclination caused by different tin amounts of each bonding pad of a circuit board and each welding end pool of a device in the traditional manual welding is solved. Meanwhile, the thickness of the bottom of the prefabricated L-shaped metal support is fixed, so that the welding height of the device can be controlled quantitatively, and the reliability of welding spots is improved.

(III) increasing heat dissipation

The surface mounting component is generally small and light and thin, the temperature conduction is fast due to the small size, the temperature of the internal chip is easily overhigh, and the four pins of the device extend into the bottom of the chip, so that the heat conduction way is effectively increased, and the heat dissipation of the chip is increased.

(IV) peripheral devices are not affected

The density of the elements arranged on the circuit board is high, the device is a physical device, and the contact part of the device and the circuit board is only provided with four thin pins, so that the occupied space is small, and the surrounding devices cannot be influenced.

(V) extensive applicability

The welding end device is suitable for components with welding ends on four sides and no welding pads at the bottom, and the components with the welding ends on two sides only need to be used by two of the brackets according to actual conditions.

Drawings

Fig. 1 is an external view of an LCCC device. (a) Front view, (b) side view.

Fig. 2 is a schematic diagram of the soldering height of the component, and X is the soldering height. (a) Front view, (b) enlarged view.

Fig. 3 is a schematic structural view of the manual welding assistance device.

Fig. 4 is a schematic view of the pressing assembly and the clamping assembly of fig. 3. (a) A pressing component drawing, and (b) a clamping component drawing.

Fig. 5 is a view of the hold down assembly.

Fig. 6 is a view showing the structure of the height adjusting hand wheel.

Fig. 7 is a view showing the structure of the pressing screw.

Fig. 8 is a view showing a structure of a bearing outer ring fixed pressure plate.

Fig. 9 is a view showing a structure of a bearing retainer.

Figure 10 is a view of the clamp assembly.

Fig. 11 is a view showing the structure of the support plate.

Fig. 12 is a view showing the structure of a metal holder.

Figure 13 is a view of the clamp adjustment handwheel.

Fig. 14 is a view showing a structure of a clamping screw.

Fig. 15 is a clamp screw anchor block diagram.

FIG. 1 shows a hold-down assembly; 2. a clamping assembly; 1-1, a height adjusting hand wheel; 1-2, pressing a screw rod; 1-3 bearings; 1-4 bearing outer ring fixing pressure plate; 1-5 compressing seats; 2-1, a support plate; 2-2, a metal bracket; 2-3 clamping the adjusting hand wheel; 2-4 clamping the screw; and 2-5 screw fixing blocks.

Detailed Description

The invention is described below with reference to specific examples:

the invention discloses an auxiliary device for manually welding a packaged component with pins at the periphery and a pad-free center, which is shown in figure 3. The device consists of a pressing component and a clamping component, and is shown in figure 4.

The pressing assembly consists of a height adjusting hand wheel, a pressing screw rod, a bearing outer ring fixing pressing plate and a pressing seat, the general structure of the pressing assembly is shown in figure 5, and the height adjusting hand wheel, the pressing screw rod, the bearing outer ring fixing pressing plate and the pressing seat are respectively shown in figures 6, 7, 8 and 9. The lower end of the screw rod penetrates through the bearing inner ring (rotating part), the bearing outer ring is fastened with the pressing seat through the pressing plate, and the pressing plate and the pressing seat are fixed through screws. The bearing is installed to ensure that when the hand wheel is rotated to adjust the height of the pressing seat, the displacement or rotation of the pressed component cannot be caused, and relative separation can be achieved.

The clamping assembly consists of a supporting plate, a metal bracket, a clamping adjusting hand wheel, a clamping screw rod and a screw rod fixing block, and is shown in figure 10.

The structure of the supporting plate is shown in fig. 11, the geometric center is provided with a threaded through hole, and the supporting plate is matched with a screw rod of the pressing component for installation. Wedge-shaped grooves are distributed on the periphery of the supporting plate at intervals of 90 degrees, and the wedge-shaped grooves are provided with a unthreaded hole along the radial bottom of the supporting plate and used for fixedly clamping the end of the screw rod. Four threaded holes are distributed in the supporting plate on the outer side of each wedge-shaped groove and used for fixing the screw fixing block.

4 metal support, interval 90 evenly distributed in backup pad a week for bed hedgehopping, press from both sides tight by the welding components and parts, metal support structure is as shown in figure 12. The upper end of the metal bracket is wedge-shaped, and the wedge-shaped block is matched with the wedge-shaped groove on the pressing disc. The wedge-shaped block is provided with a threaded hole, and the clamping screw penetrates through the threaded hole. The lower end of the metal support is L-shaped, the thickness of the horizontal part at the bottom is the height of the device pad, and the height is 0.15-0.2 mm.

The schematic diagrams of the clamping adjusting hand wheel, the clamping screw rod and the rod fixing block are respectively shown in figures 13, 14 and 15, one end of the clamping screw rod is fixed at the bottom hole of the wedge-shaped groove, the other end of the clamping screw rod penetrates through a threaded hole of the wedge-shaped block of the metal support and a central hole of the screw rod fixing block to be connected with the clamping adjusting hand wheel, the screw rod fixing block is assembled with the supporting plate through a screw, the position of the metal support can be adjusted by rotating the hand wheel, the metal support can be expanded and.

Specifically, when manual welding is carried out, the following steps are adopted:

1. solder bump treatment for circuit board pads and chip bonding terminals

The temperature control electric soldering iron head is wiped clean in advance, and the temperature of the electric soldering iron is set to be about 260 ℃.

1.1 solder pad tin

And cleaning the corresponding bonding pad of the device on the printed board by using the cotton ball stained with alcohol.

And (3) coating a proper amount of soldering tin on the soldering iron head, carrying out tin-soaking treatment on the device bonding pad on the printed board, wherein a thin layer of tin material is required for the bonding pad after tin-soaking.

1.2 chip solder terminal tin

And coating a layer of soldering flux on the soldering end of the chip.

And carrying out tin soaking treatment on the welding end of the chip by using an electric iron.

For a device with gold plated on the surface of the pin, a temperature control tin pot is adopted to remove gold from the electrode of the device before welding, and then tin is plated.

2. Use auxiliary device to accomplish component welding

2.1 preheating of Circuit boards

The heating stage temperature was set at 215 ℃, and the printed board was placed on the heating stage whose temperature had risen to the set temperature.

2.2 clamping, pressing devices using devices

By using the device, the clamping adjusting hand wheel 2-3 is rotated according to the size of the component to enable the metal support 2-2 to expand outwards or contract to a size slightly larger than the component, the support extends into the bottom of the component from the top points of the four sides of the component, the clamping adjusting hand wheel 2-3 is continuously rotated until the metal support clamps the component, and the height adjusting hand wheel 1-1 is rotated to enable the pressing seat 1-5 to press the top of the component.

2.3 fixing devices and devices

And placing the component connected with the auxiliary device into the circuit board, aligning the welding pads of the component on the circuit board, and spot-welding two welding ends on the diagonal line of the component so as to fix the device and the component.

2.4 welding devices

Each bonding terminal of the device is bonded separately.

2.5 extraction device

When the welding spot of the welding end of the device is checked to meet the requirement, the height adjusting hand wheel 1-1 is rotated to enable the pressing seat 1-5 to be away from the top of the device, the clamping adjusting hand wheel 2-3 is rotated to enable the metal support 2-2 to be drawn out from the bottom of the device, and at the moment, the whole device can be taken down.

Claims

1. The utility model provides an auxiliary device of manual welding components and parts which characterized in that: the clamping device consists of a pressing component and a clamping component;

2. An auxiliary device for manually welding components and parts according to claim 1, wherein: four wedge-shaped grooves are arranged on the peripheral side wall of the supporting plate in the clamping assembly at equal intervals of 90 degrees.

3. An auxiliary device for manually welding components and parts according to claim 1, wherein: the thickness of the horizontal part at the bottom of the L-shaped structure is the height of the device pad, and the height of the device pad is 0.15-0.2 mm.