FR3099641A1 - Electronic assembly, device and method for automotive lighting - Google Patents

Abstract

The invention provides an electronic assembly comprising an imprint intended to receive the pins of a first electrical box and also intended to receive the pins of a second electrical box, the imprint comprising at least one pad (1). This cushion (1) comprises a main part (2), a secondary part (3) projecting from the main part (2) and at least a first arm (4) also projecting from the main part (2). This first arm (4) is separated from the main part (2) by a first channel (5). The secondary part (3) is intended to receive the pin of a first electrical box and an assembly comprising the secondary part (3) and the first arm (4) is intended to receive a pin of the second electrical box. An automotive lighting device and a method of manufacturing are also included in the invention. Figure for the abstract: Figure 1

Description

Electronic assembly, automobile lighting device and method

This invention is related to the field of automobile lighting devices, and more particularly to the electronics included in these devices.

There are several models of multilayer ceramic capacitors. These capacitors are generally included in boxes. Each box has its own size and its own properties. They are usually installed on printed circuit boards by means of footprints, where the pins of the packages are soldered.

However, each case has its own footprint, and it is not possible to solder a case to the footprint of another case, due to issues regarding assembly issues such as moving components, emergence of the solder ball or a "tombstone defect" known to those skilled in the art.

This poses a problem, because sometimes the shortage of a box or the increase in price is not compensated by the availability of another box: in a given circuit, only the box that corresponds to a particular footprint can be installed. in this location.

This issue has been supported so far, but a workaround is offered.

The invention provides an alternative solution to manage the compatibility of two different housings by an electronic assembly, an automotive lighting device and a method of manufacturing such a lighting device. Preferred embodiments of the invention are described in the dependent claims.

Unless otherwise defined, all terms (including technical and scientific terms) used in this document should be interpreted in accordance with the usages of the profession. It will further be understood that terms in common use should also be construed as is customary in the relevant art and not in an idealized or overly formal sense, except as expressly defined below.

In this text, the term "includes" and its derivatives (such as "comprising", etc.) should not be understood in an exclusive sense, i.e. these terms should not be interpreted as excluding the possibility that what is described and defined may include other elements, steps, etc.

In a first inventive aspect, the invention provides an electronic assembly comprising an imprint intended to receive the pins of a first electrical box and also intended to receive the pins of a second electrical box, the imprint comprising at least one pad, said pellet comprising:

a main part;

a secondary part protruding from the main part, the secondary part being intended to receive a pin of the first electrical box, and

at least a first arm protruding from the main part, separated from the main part by a first channel, so that an assembly comprising the secondary part and the first arm is intended to receive a pin of the second electrical box.

The combination of the abutment and the first arm makes the tampon compatible with packages of two different sizes. A small package is intended to be supported by the abutment of the tampon, which is larger than the arm, then a larger package is supported by the combination of the abutment and the first arm.

Thus, the same footprint can be used for the installation of a small or a large housing, which solves the problem of exclusivity of the one-to-one correspondence between a housing and a footprint.

In certain particular embodiments:

the secondary part exceeds the main part by a first distance; And

the first arm protrudes a second distance from the main part, wherein the second distance is between 95% and 105% of the first distance.

The combination of the secondary part and the first arm aims to be similar to a compact pad to accommodate a larger electrical box, so that the first arm protrudes substantially from the main part by the same distance as the secondary part.

In certain particular embodiments, the main part has a width measured in the direction of the first and second distances, and the first and second distances are between 75% and 125% of the width of the main part.

This projection distance is sufficient for the solder paste to form a suitable and homogeneous film.

In certain particular embodiments, the secondary part and the first arm have different widths, measured in a direction perpendicular to the first and second distances, and the width of the secondary part is at least twice the width of the first arm.

The secondary part is intended to receive a first parcel, and the first arm is an auxiliary element for receiving the second parcel with the secondary part, so that the secondary part is wider than the first arm.

In certain particular embodiments, the first channel has a width, and the width of the first channel is between 0.2 and 0.3 mm.

The channel width is calculated to ensure that when the smaller package is in contact with the secondary part of the pad, the package pins do not touch the first arm or the solder paste that is deposited on the arm, so that the width of the arm is calculated to get enough solder paste to properly solder the larger component.

In certain particular embodiments, the electronic assembly further comprises a second arm projecting from the main part, separated from the secondary part by a second channel, so that an assembly comprising the secondary part, the first arm and the second arm is intended to receive a pin of the second electrical box, and in which the secondary part is located between the first arm and the second arm.

This second arm protrudes from the main part in the same way as the secondary part and the first arm. When the buffer comprises two arms, a more symmetrical arrangement is obtained.

In certain particular embodiments:

the secondary part exceeds the main part by a first distance; And

the second arm protrudes a third distance from the main part, the third distance being between 95% and 105% of the first distance.

The combination of the secondary part and the second arm aims to be similar to a compact pad to accommodate a larger electrical box, so that the second arm protrudes substantially from the main part by the same distance as the secondary part.

In some particular embodiments, the main part has a length measured in the direction of the first and third distances, and the first and third distances are between 75% and 125% of the length of the main part.

This projection distance is sufficient for the solder paste to form a suitable and homogeneous film.

In certain particular embodiments, the secondary part, the first arm and the second arm have different widths, measured in a direction perpendicular to the first and third distances, and the width of the secondary part is at least 5 times the width of the first arm and at least 5 times the width of the second arm.

In this case, the secondary part is intended to receive a first package, and the first and second arms are auxiliary elements for receiving the second package with the secondary part, so that the secondary part is wider than the first arm and that the second arm.

In certain particular embodiments, the second channel has a width, and the width of the second channel is between 0.2 and 0.3 mm.

The channel width is calculated to ensure that when the smaller package is in contact with the abutment of the pad, the package pins do not touch the second arm or the solder paste that is deposited on the second arm, whereas arm width is calculated to get enough solder paste to properly solder the larger component.

In another inventive aspect, the invention provides an automotive lighting device comprising:

an electronic assembly according to the first inventive aspect;

an electrical box assembled in the footprint of the electronic assembly;

a solid state light source.

The term "solid state" refers to light emitted by solid state electroluminescence, which uses semiconductors to convert electricity into light. Compared to incandescent lighting, solid state lighting creates visible light with reduced heat generation and energy dissipation. The generally low mass of a solid-state electronic lighting device provides greater resistance to shock and vibration than brittle glass tubes/bulbs and long, thin filament wires. They also eliminate filament evaporation, which can increase the life of the lighting device. Some examples of these types of lighting include solid-state light-emitting diodes (LEDs), organic light-emitting diodes (OLEDs), or polymer light-emitting diodes (LEDPs) as lighting sources rather than electric filaments, plasma or the gas.

In particular, in one embodiment, the method comprises the following steps:

providing an electronic assembly according to the first inventive aspect;

providing a paste mask in the electronic assembly, the paste mask covering at least a part of the main part, at least a part of the secondary part and at least a part of the first arm

placing an electrical box in contact with the paste mask;

heating the paste mask to obtain an electrical connection between the electrical box and the pad;

adding the electronic assembly to a device with a solid state light source.

The paste mask provides an electrical connection between the housing and the impression. The paste mask cover ensures that the case is connected to the pads of the impression.

The paste mask notably comprises embodiments:

a main part, deposited on the main part of the pad;

a secondary part, deposited on the secondary part of the tampon; And

a part of the first arm, deposited on the first arm;

wherein the main part is separated from the secondary part by a distance between 0.24 mm and 0.26 mm.

The separation between the main part and the secondary part of the paste mask aims to avoid an excessive amount of solder paste on the package during the reflow process.

In particular, the first arm includes an edge line and the first arm portion of the paste mask is separated from the first arm edge line by a distance between 0.018 mm and 0.022 mm.

When a paste is deposited on the first arm, the distance between the paste and the edge line is important to create a proper balance between the component, the cavity and the solder paste due to surface tension.

To complete the description and to allow a better understanding of the invention, a set of drawings is provided. These drawings form an integral part of the description and illustrate one embodiment of the invention, which should not be interpreted as limiting the scope of the invention, but simply as an example of how the invention can be carried out. The drawings include the following figures:

shows a general perspective view of a footprint included in an electronic assembly according to the invention.

shows a glue mask located on the footprint of the previous figure.

and [Fig 4] show examples where different boxes are installed in an electronic assembly according to the invention.

shows a motor vehicle comprising a motor vehicle lighting device according to the invention.

In these figures, the following reference numbers have been used:

1 cushion

2 Buffer main body

3 Seal secondary body

4 First arm of the insert

5 First channel of the pad

6 Second arm of the pad

7 Second pad channel

8 First arm border line

9 electrical box

10 Paste mask

12 Main part of paste mask

13 Paste mask abutment

14 Dough Mask Arm Part

30 Lighthouse

31 LEDs

100 Motor vehicle

The exemplary embodiments are described in sufficient detail to enable those of ordinary skill in the art to design and implement the systems and processes described herein. It is important to understand that embodiments may be provided in many alternative forms and should not be construed as being limited to the examples presented herein.

Accordingly, although an embodiment may be modified in various ways and take various alternative forms, specific embodiments thereof are shown in the drawings and described in detail below by way of example. There is no intention to be limited to the particular forms disclosed. Rather, all modifications, equivalents and alternatives falling within the scope of the appended claims should be included.

shows a general perspective view of a footprint comprised in an electronic assembly according to the invention, which is suitable for installation in an automotive headlight.

This footprint includes two 1 stamps, and each 1 stamp includes

a main body 2;

a secondary body 3 protruding from the main body 2;

a first arm 4 protruding from the main body 2; And

a second arm 6 which protrudes from the main body 2.

The main body 2 serves as a common support for the secondary body 3 and for the two first and second arms 4, 6.

The first arm 4 is separated from the secondary body 3 by a first channel 5 and the second arm 6 is in turn separated from the secondary body 3 by a second channel 7. The secondary body 3 is placed between the first arm 4 and the second arm 6.

Therefore, this buffer 1 is a single arrangement which may be suitable for receiving different boxes of different sizes. Until now, each pillow was a solid element that could only accept a pin that matched the size of the pillow. With this invention, the same pad 1 can be used to receive the pin of a small case, which will fit the secondary body 3 or the pin of a larger case, which will fit the assembly comprising the body secondary 3 and the first and second arms 4, 6.

As can be seen in this figure, the secondary body 3 protrudes from the main body 2 by the same distance as the first and second arms 4, 6. In this case, this distance is substantially approximately 0.6 mm, whereas the main body 2 is also 0.6 mm long. These lengths are measured in the direction of the projection of the main body 2.

This invention can be advantageously used with packages comprising multilayer ceramic capacitors, such as 1206 and 1210.

The channels 5, 7 have a width of at least 0.2 mm, the width of a channel is the distance between the secondary body 3 and the corresponding arm 4, 6, being therefore measured in a direction which is perpendicular to the lengths which were mentioned above.

The channel width is calculated to ensure that when the smaller package is installed on the abutment of the pad, the package pins do not touch any of the arms or the solder paste that is deposited on the arms.

The first and second arms 4, 6 are between 0.25 and 0.30 mm. The width of the arm is calculated to get enough solder paste to properly solder the largest case.

shows a bonding mask 10 located on the imprint 1 of the previous figure. This paste mask 10 includes:

a main part 12, deposited on the main body 2

a secondary part 13, deposited on the secondary body 3; And

a first arm part 14, placed on the first arm 4.

This paste mask 10 is intended to undergo a reflow process when a packaging is installed on the impression of . Therefore, the choice of the margins between the different parts of the mask 10 and between a part of the mask and the edge of the parts of the stamp is important to obtain a good welding behavior and to avoid certain problems which could arise if incorrect decisions are made.

In this case, the main part 12 is separated from the secondary part 13 by a distance of between 0.24 mm and 0.26 mm. This distance ensures that during the reflow process no excessive amount of solder paste accumulates near the end of the capacitor so that it does not reach the top of the capacitor by capillary action.

As can also be seen in this figure, the first arm 4 comprises an edge line 8 and the first part of the arm 14 is separated from the edge line 8 of the first arm 4 by a distance of between 0.018 mm and 0.022 mm . This distance ensures a good balance between the capacitor, the footprint and the solder paste during the reflow process, so that this part of the paste mask stays on the corresponding arm.

shows an electrical box 9 comprising a capacitor installed in the previous footprint. In this case, a small casing has been chosen, so that the two arms 4, 6 of the cavity do not receive the casing. The secondary body (hidden under the packaging 9) acts as a reception buffer.

Once the case 9 is placed on the cavity, a reflow process is performed, so that the solder paste melts and serves as a conductive seal between the case 9 and the cavity.

shows another housing 9 which has been installed in the same footprint. Housing 9 is wider than the housing in [Fig 3], so in this case the housing is installed in the entire pad, including the first and second arms (which are covered by housing 9).

shows an automotive headlamp 30 installed in a vehicle 100. This headlamp 30 consists of an electronic assembly which in turn comprises a footprint according to what has been shown in the previous figures. This lighting device 30 also includes a group of LEDs 31.

Claims (14)

Electronic assembly comprising a footprint intended to receive pins from a first electrical box and also intended to receive pins from a second electrical box, the footprint comprising at least one stud (1), the stud (1) comprising:

• a main part (2);
• a secondary part (3) protruding from the main part (2), the secondary part being intended to receive a pin of the first electrical box, and
• at least a first arm (4) protruding from the main part (2), separated from the main part (2) by a first channel (5), so that an assembly comprising the secondary part (3) and the first arm (4) is intended to receive a pin of the second electrical box.

Electronic assembly according to claim 1, in which:

• the secondary part (3) protrudes a first distance from the main part (2); And
• the first arm (4) protrudes a second distance from the main part (2), wherein the second distance is between 95% and 105% of the first distance.

An electronic assembly according to claim 2, wherein the main part has a length measured in the direction of the first and second distances, and the first and second distances are between 75% and 125% of the length of the main part (2). An electronic assembly according to claim 3, wherein the abutment (3) and the first arm (4) have different widths, measured in a direction perpendicular to the first and second distances, and the width of the abutment is at least twice the width of the first arm. Electronic assembly according to claim 4, wherein the first channel (5) has a width, and the width of the first channel is between 0.2 and 0.3 mm. Electronic assembly according to any one of the preceding claims, further comprising a second arm (6) projecting from the main part (2), separated from the secondary part (3) by a second channel (7), so that an assembly comprising the secondary part, the first arm and the second arm is intended to receive a pin of the second electrical box, and in which the secondary part (3) is located between the first arm (4) and the second arm (6) . Electronic assembly according to claim 6, in which:

• the secondary part (3) protrudes a first distance from the main part (2); And
• the second arm (6) protrudes a third distance from the main part (2), wherein the third distance is between 95% and 105% of the first distance.

An electronic assembly according to claim 7, wherein the main part has a length measured in the direction of the first and third distances, and the first and third distances are between 75% and 125% of the length of the main part (2). An electronic assembly according to claim 8, wherein the abutment, the first arm and the second arm have different widths, measured in a direction perpendicular to the first and third distances, and the width of the abutment is at least 5 times the width of the first arm and at least 5 times the width of the second arm. Electronic assembly according to claim 9, wherein the second channel (7) has a width, and the width of the second channel is between 0.2 and 0.3 mm. Motor vehicle lighting device (30) comprising

• an electronic assembly according to one of the preceding claims;
• an electrical box (9) assembled in the footprint of the electronic assembly (1); And
• a solid-state light source (31).

A method of manufacturing an automobile lighting device according to claim 11, comprising the following steps

• providing an electronic assembly according to one of claims 1 to 10;
• providing a paste mask (10) in the electronic assembly, the paste mask (10) covering at least a part of the main part (2), at least a part of the secondary part (3) and at least a part of the first arm (4)
• placing an electrical box (9) in contact with the paste mask (10);
• heating the paste mask (10) to obtain an electrical connection between the electrical box (9) and the pad;
• adding the electronic assembly (1) to a device with a solid state light source (31).

A method according to claim 12, wherein the paste mask (10) comprises

• a main part (12), deposited on the main part (2) of the pad;
• a secondary part (13), deposited on the secondary part (3) of the pad; And
• a first arm part (14), deposited on the first arm (14);
• wherein the main part (12) is separated from the secondary part (13) by a distance between 0.24 mm and 0.26 mm.

A method according to claim 13, wherein the first arm (4) includes an edge line (8) and the first arm portion (14) of the paste mask (10) is separated from the edge line (8) of the first arm (4) with a distance between 0.018 mm and 0.022 mm.