CN115802739A - A mounting structure and method for SOP packaging devices of aerospace electronic products - Google Patents

Abstract

The invention relates to an installation method for SOP packaged 3D-PLUS devices of aerospace electronic products, the method includes the design of electrical equipment auxiliary parts of SOP packaged 3D-PLUS, the bonding of electrical equipment auxiliary parts, device welding, and adhesive reinforcement process methods, It belongs to the technical field of electronic assembly technology. The present invention proposes a process that can realize SOP packaged 3D-PLUS devices, reflow soldering and then reinforcement. By designing suitable electrical accessories, cooperating with specific process flow and bonding and strengthening methods, SOP packaged 3D-PLUS can be realized. The automatic welding of the device can carry out back-end reliability reinforcement, avoiding the interspersed process of welding and adhesive reinforcement during the assembly process of the SOP package 3D-PLUS device, improving the production efficiency of the device from manual welding to automatic welding, and improving the welding efficiency. , Reinforced consistency and reliability.

Description

A mounting structure and method for SOP packaging devices of aerospace electronic products

technical field

The invention relates to an installation structure and method for SOP packaged 3D-PLUS devices of aerospace electronic products. The method includes the design of electrical equipment auxiliary parts of SOP packaged 3D-PLUS, the bonding of electrical equipment auxiliary parts, device welding, and adhesive reinforcement processes The method belongs to the technical field of electronic assembly technology.

Background technique

SOP package 3D-PLUS is the abbreviation of three-dimensional stacked package. It is a chip package developed by the French SOP package 3D-PLUS company in response to the actual needs of the Galileo program and other aerospace, aviation and other fields. Compared with other packages, in Under the premise of the same weight, the capacity can be increased by more than 2000 times, so the packaged device has technical advantages such as high integration and superior electronic performance in practical applications, and is widely used in aerospace products. However, due to the large size of the device body, high center of gravity, and no stress relief bends on the pins, the vibration resistance after assembly on the printed board is weak, and the reinforcement of the device is very important for the entire assembly process.

Many users in the military field still use manual methods for the soldering of SOP packaged 3D-PLUS devices. Before manual soldering of the devices, epoxy glue is sealed between the bottom of the device and the PCB substrate, and then the device and the PCB pad are positioned. Welding, this method can better strengthen the device, but the production efficiency is low, which restricts the increase of production capacity; a small number of users implement automatic reflow soldering for SOP packaged 3D-PLUS devices, but after soldering, the device can only be terminal. Seal reinforcement, compared with bottom filling, the end seal reinforcement method has weaker mechanical resistance, and it is difficult for the product to be used under the severe mechanical conditions of the total root mean square of random vibration of more than 20g. It once happened that an aerospace stand-alone product had a failure problem of SOP packaged 3D-PLUS device in the testing stage of the positive product. Afterwards, after inspection, it was found that the device was reinforced by end sealing. In a large mechanical environment, multiple pins appeared in the solder joint Cracks, resulting in abnormal signals. In the end, the device was manually soldered in the rework stage, and the bottom was filled with epoxy glue for reinforcement, and it was verified that no problems occurred.

Contents of the invention

The technical problem of the present invention is: to overcome the deficiencies of the prior art, in order to realize high-efficiency automatic welding and reliable reinforcement of SOP-packaged 3D-PLUS, and propose an installation method for SOP-packaged 3D-PLUS devices of aerospace electronic products.

Technical solution of the present invention is:

An installation structure for SOP packaging 3D-PLUS devices of aerospace electronic products, including a substrate with PCB pads on the surface of the substrate; electrical accessories, connected to the surface of the PCB substrate, and a PCB between the two rows of pads of the PCB pads The inner side of the pad; the device is located on the side of the electrical auxiliary part away from the substrate. The pins connected to the device are located on both sides of the electrical auxiliary part. The electrical auxiliary part forms a separation area on the PCB substrate that is separated from the area where the pins of the device are located. , There is a reinforcing glue between the bottom of the device and the PCB substrate, and in the separation area.

The electric installation auxiliary part includes two blocking rods and a beam integrally connected between the two blocking rods, and the two blocking rods are located on one side of the pin.

Preferably, the electrical installation auxiliary part is "H" shaped. At this time, the beam is connected to the middle of the two blocking rods.

Optionally, the electric installation accessory is "C" shaped. At this time, the beam is connected to the same end of the two blocking rods.

A method for installing 3D-PLUS devices in SOP packaging for aerospace electronic products, including

Design and produce electrical accessories corresponding to the device;

Complete solder paste printing on PCB pads;

Paste the electrical accessories on the side of the PCB pad printed with solder paste;

Mount the device on the PCB substrate and at the center of the inner side of the PCB pad. The device is located on the side of the electrical auxiliary part away from the PCB substrate. The pins connected to the device are located on both sides of the electrical auxiliary part. The electrical auxiliary part is on the PCB A separation area that is not connected to the area where the two rows of pins are located is formed on the substrate. The electrical accessories are reflow soldered together with the PCB substrate and the device. The epoxy glue on the bottom of the electrical accessories is cured during the high temperature process of reflow soldering. Get PCBA components;

Bottom adhesive reinforcement: inject reinforcement glue on the bottom of the PCBA component and in the separation area and cure it.

Design and produce suitable electrical accessories for different devices.

Specifically, the difference between the height of the electrical assembly auxiliary part and the height from the bottom of the device body to the bottom of the pin is 0.2 mm to 0.3 mm. Ensure that there is a gap between the upper end of the electrical accessories and the bottom of the device, so that when the bottom is glued and reinforced, the reinforcing glue can flow to the bottom of the device, and the reinforcing glue will not overflow the separation area from the gap between the upper end of the electrical accessories and the bottom of the device .

The overall outer width of the electrical accessory is the inner spacing of the PCB pad minus 1.5mm-2mm, and the distance between the two barrier bars of the electrical accessory is 1/4-1/3 of the device width; The overall length of the auxiliary part is the length of the device body minus 1.5mm-2mm; the width of the barrier bar of the electrical auxiliary part is 0.6mm-1mm.

The electric assembly auxiliary parts are pasted on the PCB substrate by epoxy glue.

When using epoxy glue to paste electrical accessories, apply epoxy glue to the beam position of the electrical accessories, and then paste the electrical accessories to the center of the inner side of the PCB pad.

After the device is mounted, the lead offset is less than 10% of the width of the PCB pad.

The material of the electric assembly auxiliary part is consistent with the substrate, which is polyimide.

The reinforcing glue used in the bottom adhesive reinforcement is epoxy glue, the composition of epoxy glue includes ECCOBOND 55/9 and talcum powder filler, the composition of ECCOBOND 55/9 is ECCOBOND55 and Catalyst9, and the mass of ECCOBOND55 is calculated as 100 parts, The mass parts of Catalyst9 is 11.64-12.36 parts, and the mass parts of talcum powder is 50 parts; the preparation method of epoxy glue is: stir and mix ECCOBOND55, Catalyst9 and talcum powder in an "8" shape to obtain epoxy glue.

The bottom adhesive reinforcement method includes: using a glue injection tool to inject epoxy glue to the bottom of the device until the glue overflows, stop dispensing, and cure at room temperature.

Specifically, pour the configured epoxy glue into the 6ml needle tube, install the glue injection hose at the head of the syringe, connect the tail to the glue dispenser, extend the glue head into the bottom of the device, start the glue dispenser until the glue overflows, Stop dispensing, and use the same method to inject and reinforce the other end of the device with epoxy glue.

The curing of the epoxy glue adopts the method of curing at room temperature for 24 hours.

The electrical installation auxiliary parts and the PCB substrate are fixed by epoxy glue, and the composition of the epoxy glue between the electrical installation auxiliary parts and the PCB substrate is the same as that of the reinforcing glue used for bottom adhesive reinforcement.

In summary, the present application at least includes the following beneficial technical effects:

The present invention proposes an installation method for SOP-packaged 3D-PLUS devices of aerospace electronic products, by designing suitable electrical assembly auxiliary parts for different SOP-packaged 3D-PLUS devices, and presetting before device electrical assembly, it can realize SOP packaged 3D-PLUS devices are highly reliable and reinforced after automatic welding, reducing the interludes of welding and adhesive reinforcement during the assembly process of SOP packaged 3D-PLUS devices, improving the production efficiency of devices from manual welding to automatic welding, and improving welding at the same time , Reinforced consistency and reliability, it can be used reliably under severe mechanical conditions with a total root mean square of random vibration above 20g.

Description of drawings

Fig. 1 is the schematic diagram of the mounting structure of the SOP package 3D-PLUS device in the embodiment of the present application;

FIG. 2 is a schematic structural view of an electrical accessory in an embodiment of the present application;

FIG. 3 is a schematic structural view of the electrical installation auxiliary part bonded to the PCB substrate in the embodiment of the present application.

Explanation of reference signs: 1. The overall width of the electrical auxiliary parts, 2. The height of the electrical auxiliary parts, 3. The inner distance of the electrical auxiliary parts, 4. The width of the barrier bar of the electrical auxiliary parts, 5. The length of the electrical auxiliary parts;

6. Substrate; 61. PCB pad; 62. Inside the PCB pad

7. Electrical accessories; 71. Barrier rod; 72. Beam;

8. Device; 81. Pin;

Wherein, the distance between the barrier rods of the electrical installation auxiliary parts is the inner spacing of the electrical installation auxiliary parts.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment the application is described in further detail:

In this embodiment, the device is a SOP packaged 3D-PLUS device.

The embodiment of the present application discloses a mounting structure and method for SOP packaging 3D-PLUS devices 8 of aerospace electronic products. Referring to FIGS. 6. The electrical installation auxiliary part 7 and the device 8 on the surface. The device 8 is located on the side of the electrical installation auxiliary part 7 away from the substrate 6. The pins 81 connected to the device 8 are located on both sides of the electrical installation auxiliary part 7. The electrical installation auxiliary part 7 is on the PCB A separation area is formed on the substrate 6 to separate from the area where the pins 81 of the device 8 are located, and a reinforcing glue is provided between the bottom of the device 8 and the PCB substrate 6 and in the separation area. The inner side 62 of the PCB pad is between the two rows of pads of the PCB pad 61 .

Referring to FIG. 3 , the electrical installation auxiliary component 7 includes two blocking rods 71 and a beam 72 integrally connected between the two blocking rods 71 , and the two blocking rods 71 are located on one side of the pin 81 . Preferably, the beam 72 is connected to the middle of the two blocking rods 71, so that the electrical installation auxiliary part 7 is in an "H" shape.

The installation method includes the following steps:

(1) For different SOP packaged 3D-PLUS devices 8, it is necessary to design and produce suitable electrical assembly accessories 7.

The design principle of the electrical installation auxiliary part 7: the material of the electrical installation auxiliary part 7 is consistent with the PCB substrate, which is polyimide; the electrical installation auxiliary part 7 is "H" shaped; The height difference from the bottom of the main body to the bottom of pin 81 is controlled within 0.2 mm to 0.3 mm to ensure that there is a gap between the upper end of the electrical accessory 7 and the bottom of the device 8; Remove 1.5mm-2mm, the inner spacing of the electrical installation auxiliary part 7 is 1/4-1/3 of the width of the device 8 body; the overall length of the electrical installation auxiliary part 7 is the length of the device 8 body minus 1.5mm-2mm; The barrier bar 71 of the auxiliary part 7 has a width of 0.6mm-1mm.

(2) Use a screen printing machine to print solder paste on the PCB pad 61 , and then paste the electrical assembly accessory 7 in step (1) on the center of the inner side 62 of the PCB pad with epoxy glue.

The epoxy glue used is ECCOBOND 55/9, and the ratio is ECCOBOND55:Catalyst9=100×(1±3%):12×(1±3%) (weight ratio).

The preparation method of the epoxy adhesive is: stir and mix ECCOBOND55 and Catalyst9 "8" shape to obtain an epoxy adhesive. After the epoxy adhesive is prepared, place it for 1 hour and use it within 2 hours.

When using epoxy glue to paste the electrical installation auxiliary part 7, apply an appropriate amount of epoxy glue to the position of the crossbeam 72 of the "H" shaped electrical installation auxiliary part 7, and then paste the electrical installation auxiliary part 7 to the inner side of the PCB pad 62. Central location. After the pasting is completed, lightly press the electrical installation auxiliary part 7 to ensure that the electrical installation auxiliary part 7 and the substrate 6 are in a bonded state, and the epoxy glue does not overflow to the position of the PCB pad 61.

(3) Mount the SOP-packaged 3D-PLUS device 8 using a placement machine or a rework workstation. After the device 8 is mounted, the offset of the pin 81 is less than 10% of the pad width. The electrical assembly auxiliary part 7 is reflow soldered together with the device 8, and the SOP package 3D-PLUS device 8 and the PCB substrate 6 are welded together. At the same time, the epoxy glue on the bottom of the electrical assembly auxiliary part 7 is cured during the high temperature process of reflow soldering. , get PCBA.

(4) Carry out bottom adhesive reinforcement to the SOP package 3D-PLUS device 8 on the PCBA.

The epoxy glue used for bottom adhesive reinforcement is ECCOBOND 55/9+talcum powder, and the ratio is ECCOBOND55: Catalyst9: talc powder = 100×(1±3%): 12×(1±3%): 50× (1±3%) (weight ratio).

The preparation method of epoxy glue is: configure epoxy glue and use electronic balance, according to ECCOBOND55: Catalyst9: talcum powder = 100×(1±3%): 12×(1±3%): 50×(1±3%) (weight ratio) to take the material, and in the container, ECCOBOND55, Catalyst9 and talcum powder are stirred and mixed uniformly in the shape of "8" with a small wooden stick to obtain an epoxy adhesive.

The reinforcement method is as follows: pour the prepared epoxy adhesive into the 6ml needle tube, install the glue injection hose at the head of the syringe, connect the tail to the glue dispenser, extend the glue dispenser head into the bottom of the device 8, start the glue dispenser until the glue liquid Overflow (glue fills the gap between the bottom of the device 8 and the substrate 6, and overflows from the open end of the separation area, and does not overflow from the gap between the device 8 and the top of the electrical auxiliary part 7), stop dispensing, and use the same method, the other end of the device 8 is injected and reinforced with epoxy glue, and the bottom of the device 8 is bonded and reinforced.

The epoxy glue is cured by curing at room temperature for 24 hours.

The final PCBA board assembly was subjected to environmental tests according to ECSS-Q-ST-70-08C. After the test and assessment, the metallographic examination of the solder joints showed that no cracks were found, and the test results showed that the standard qualification criteria were met.

Example 1

A method for installing a SOP-packaged 3D-PLUS device 8 used in aerospace electronic products. The SOP-packaged 3D-PLUS device 8 is a SOP64 package. The length of the device 8 body is 28mm, and the width of the body is 10.95mm. The bottom distance is 1.25mm, and the inner spacing of the device 8 pads is 6.5mm. The steps of this method include:

(1) Design and produce electrical auxiliary parts 7 for 3D-PLUS devices 8 packaged in SOP64. The material of electrical auxiliary parts 7 is polyimide; electrical auxiliary parts 7 are "H" shaped; electrical auxiliary parts 7 The height is 1.05mm, and the height difference from the body of the device 8 to the bottom of the pin 81 of the device 8 is 0.2mm; the overall outer width of the electrical installation auxiliary part 7 is 5mm, and the difference in distance from the inner side of the device 8 is 1.5mm; the electrical installation auxiliary part The inner spacing of 7 is 3mm, which is more than 1/4 of the width of the device 8 body; the overall length of the electrical auxiliary part 7 is 26mm, which is 2mm less than the length of the device 8 body; the 4-pin width of the electrical auxiliary part 7H" shape is 1mm.

(2) Use a screen printing machine to complete solder paste printing on the PCB pad 61, and then paste the electrical assembly accessory 7 in step (1) on the central area of the pad of the 3D-PLUS device 8 with epoxy glue.

When pasting the electrical accessories 7, just apply an appropriate amount of epoxy glue on the beam 72 of the "H" shaped electrical accessories 7, and then paste the electrical accessories 7 to the center of the PCB pad. After the pasting is completed, lightly press the electrical assembly auxiliary part 7 to ensure that the electrical installation auxiliary part 7 and the substrate 6 are in a bonded state, and the epoxy glue does not overflow to the PCB pad position.

The composition of the epoxy glue used includes ECCOBOND 55/9, the composition of ECCOBOND 55/9 is ECCOBOND55 and Catalyst9, and the mass part of ECCOBOND55 is 100 parts, and the mass part of Catalyst9 is 12 parts; the preparation method of epoxy glue is: Stir and mix ECCOBOND55 and Catalyst9 in the shape of "8" to obtain epoxy glue. After the epoxy glue is prepared, it will be used in about 1.5 hours.

(3) Mount the SOP64 package 3D-PLUS device 8 with a placement machine. After the device 8 is mounted, the offset of the pin 81 is less than 10% of the width of the pad; Flow soldering, the epoxy glue at the bottom of the electrical assembly auxiliary part 7 is cured in a high temperature process to obtain a PCBA.

(4) After the soldering is completed, inject epoxy glue at the bottom of the SOP64 packaged 3D-PLUS device 8 . Insert the dispensing head into the bottom of the device 8, start the dispensing machine until the glue overflows, stop dispensing, and use the same method to inject epoxy glue into the other end of the device 8 to complete the bonding and reinforcement of the bottom of the device 8. The curing of the epoxy glue adopts the method of curing at room temperature for 24 hours.

The composition of epoxy glue includes ECCOBOND 55/9 and talcum powder, and the composition of ECCOBOND 55/9 is ECCOBOND55 and Catalyst9, and the mass number of ECCOBOND55 is 100 parts, the mass number of Catalyst9 is 12 parts, and the mass number of talcum powder is 50 parts; the preparation method of epoxy glue is: stir and mix ECCOBOND55, Catalyst9 and talcum powder in an "8" shape to obtain epoxy glue.

The epoxy glue is filled with a small wooden stick and put into a 6ml needle tube. The injection hose is installed at the head of the syringe, and the tail is connected to the dispenser.

Finally, the obtained PCBA board assembly was subjected to an environmental test according to ECSS-Q-ST-70-08C. After the test assessment, the metallographic examination of the solder joints showed that no cracks were found, and the test results showed that the standard qualification criteria were met.

The implementation principle of the present application is: the present invention can realize automatic welding of SOP packaged 3D-PLUS devices 8 by designing suitable electrical assembly auxiliary parts 7 for different SOP packaged 3D-PLUS devices 8, and presetting before the device 8 is installed. Reinforce with high reliability, reduce the interludes of soldering and adhesive reinforcement during the assembly process of the SOP packaged 3D-PLUS device 8, improve the production efficiency of the device 8 from manual welding to automatic welding, and improve the consistency of welding and reinforcement and reliability. This installation method can meet the more stringent environmental requirements of the product and ensure the reliability of the product.

Although the present invention is disclosed above with preferred embodiments, it is not intended to limit the present invention, and any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The protection scope of the invention shall be defined by the claims of the present invention.

Claims (10)

1. A mounting structure for an SOP (silicon on insulator) packaged 3D-PLUS (three-dimensional-planar) device of an aerospace electronic product is characterized in that: comprises that

The PCB comprises a PCB substrate (6), wherein a PCB pad (61) is arranged on the surface of the substrate (6), and the inner side (62) of the PCB pad is arranged between two rows of pads of the PCB pad (61);

the electric fitting auxiliary part (7) is connected to the surface of the PCB substrate (6) and is positioned at the center of the inner side (62) of the PCB bonding pad;

the device (8) is located one side, deviating from the substrate (6), of the electric fitting auxiliary part (7), the pins (81) connected with the device (8) are located on two sides of the electric fitting auxiliary part (7), the electric fitting auxiliary part (7) forms a separation area separated from the area where the pins (81) are located on the PCB substrate (6), and reinforcing glue is arranged between the device (8) and the PCB substrate (6) and in the separation area.

2. A mounting structure for an aerospace electronics SOP packaged 3D-PLUS device (8) according to claim 1, wherein: the electric fitting auxiliary part (7) comprises two blocking rods (71) and a cross beam (72) integrally connected between the two blocking rods (71), and the two blocking rods (71) are located on one side of a pin (81).

3. A mounting structure for an aerospace electronics SOP packaged 3D-PLUS device (8) according to claim 2, wherein: the cross beam (72) is connected to the middle parts of the two blocking rods (71).

4. A mounting method for an aerospace electronics SOP packaged 3D-PLUS device (8) according to any one of claims 1-3, characterised in that: comprises that

Completing printing of solder paste on the PCB pad (61);

pasting the electric fitting auxiliary part (7) on the central position of the inner side (62) of the PCB pad;

the method comprises the following steps that a device (8) is attached to a PCB (printed circuit board) bonding pad (61), the device (8) is located on one side, away from a PCB substrate (6), of an electric auxiliary component (7), pins (81) connected with the device (8) are located on two sides of the electric auxiliary component (7), the electric auxiliary component (7) forms a separation area separated from an area where the pins (81) are located on the PCB substrate (6), and the electric auxiliary component (7) is subjected to reflow soldering together with the PCB substrate (6) and the device (8) to obtain a PCBA assembly;

gluing and reinforcing the bottom: and injecting reinforcing glue between the bottom of the device (8) of the PCBA assembly and the PCB substrate (6) and in the separation area and curing.

5. A mounting method for an aerospace electronics SOP packaged 3D-PLUS device (8) according to claim 4, characterized in that: the electric fitting auxiliary part (7) is adhered to the PCB substrate (6) through epoxy glue; after the device (8) is mounted, the pins (81) are deviated by less than 10% of the width of the PCB pad (61).

6. A mounting method for an aerospace electronics SOP packaged 3D-PLUS device (8) according to claim 4, characterised in that: the difference between the height of the electric fitting auxiliary part (7) and the height from the bottom of the device (8) body to the bottom of the pin (81) is 0.2-0.3 mm.

7. A mounting method for an aerospace electronics SOP packaged 3D-PLUS device (8) according to claim 4, characterized in that: the overall outer width of the electric fitting auxiliary part (7) is the distance between the inner sides (62) of the PCB pads minus 1.5mm-2mm, and the distance between two barrier rods (71) of the electric fitting auxiliary part (7) is 1/4-1/3 of the width of the device (8); the overall length of the electric fitting auxiliary part (7) is the length of the device (8) body minus 1.5mm-2mm; the width of the blocking rod (71) of the electric auxiliary part (7) is 0.6mm-1mm.

8. A mounting method for an aerospace electronics SOP packaged 3D-PLUS device (8) according to claim 7, characterised in that: the bottom adhesive reinforcement adopts epoxy glue, the epoxy glue comprises ECCOCOND 55/9 and talcum powder filler, the ECCOCOND 55/9 comprises ECCOCOND 55 and Catalyst9, the mass of the ECCOCOND 55 is 100 parts, the mass of the Catalyst9 is 11.64-12.36 parts, and the mass of the talcum powder is 50 parts;

the preparation method of the epoxy adhesive comprises the following steps: and stirring and mixing ECCOCOND 55, catalyst9 and talcum powder uniformly to obtain the epoxy adhesive.

9. A mounting method for an aerospace electronics SOP packaged 3D-PLUS device (8) according to claim 1, characterised in that: the bottom gluing and reinforcing method comprises the following steps: and injecting the epoxy glue to the bottom of the device (8) by using a glue injection tool until the glue fills the separation area between the device (8) and the PCB substrate (6), stopping dispensing and curing at room temperature.

10. A mounting method for an aerospace electronics SOP packaged 3D-PLUS device (8) according to claim 1, characterised in that: the electric fitting auxiliary part (7) and the PCB substrate (6) are fixed through epoxy glue.

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